Derivatives of imidazo(4,5-d)pyridazine, their preparation and their therapeutic application

Abstract

The present invention relates to a compound of formula (I) wherein R1 represents H, (C1-C6)alkyl-; hydroxy-(C1-C6)alkyl-; NH2-(C1-C6)alkyl-; NH-(C1-C6)alkyl-(C1-C6)alkyl-; N((C1-C6)alkyl)2-(C1-C6)alkyl-; (C2-C6)alkenyl-; (C2-C6)alkynyl-; phenyl(C1-C6)alkyl-; (C3-C10)cycloalkyl(C1-C6)alkyl-; (C3-C10)membered heterocycloalkyl(C1-C6)alkyl-; (C5-C10)membered heteroaryl(C1-C6)alkyl-; (C3-C10)membered heterocycloalkyl- NH-(C1-C16)alkyl-; and (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl-; R2 represents a halogen atom, a (C1-C6)alkyl- group or other well defined groups; and R3 represents a deuterium atom; H, (C1-C6)alkyl-; (C2-C6)alkenyl-; (C2-C6)alkynyl-; (C1-C6)alkylthio-; -OR6; -NR7R8; (C3-C10)membered heterocycloalkyl-; (C5-C10)membered heteroaryl-; -(C6-C10)membered aryl; and (C3-C10)cycloalkyl-. The present invention further relates to intermediates of these compounds, processes for their preparation, a medicament and a pharmaceutical composition comprising them, and their therapeutic uses, in particular as TLR7 and / or TLR8 agonists, as well as their use in a vaccine.

Description

[0001] DERIVATIVES OF IMIDAZO[4,5-d]PYRID AZINE, THEIR PREPARATION AND THEIR THERAPEUTIC APPLICATION

[0002] The present disclosure relates to novel imidazo[4,5-d]pyridazine compounds, processes for their preparation, novel intermediates, as well as their therapeutic uses thereof, for instance as Toll-like receptor 7 agonists and / or Toll-like receptor 8 agonists.

[0003] Background of the invention

[0004] The innate immune system contains several families of germline-encoded pattern recognition receptors (PRRs), including Toll-like receptors (TLRs). These receptors recognize microbial components termed pathogen-associated molecular patterns (PAMPs) which are highly conserved molecular structures on a wide range of pathogens such as viruses, fungi, bacteria, and parasites.

[0005] It is well known that TLRs are promising targets for the development of new and effective therapeutic agents. More particularly, TLR7 and TLR8 are both located within endo-lysosomes and play an important role in the immune response during viral infection by their ability to recognize single stranded RNA PAMPs, as well as synthetic small molecules. Their stimulation leads to intracellular signaling and downstream activation of genes coding, among others for co- stimulatory molecules, pro-inflammatory cytokines and type I interferons.

[0006] Various small molecules agonists of TLR7 (commonly named TLR7 agonists) and / or agonists of TLR8 (commonly named TLR8 agonists) have already been described, for example Imiquimod (R-837), Resiquimod (R-848), and Gardiquimod.

[0007] For example, Resiquimod can act simultaneously as TLR7 agonist and TLR8 agonist. Some other synthetic small molecules like Imiquimod activates preferentially TLR7.

[0008] The activation of TLR such as TLR7 and / or TLR8, by an agonist can induce secretion of type I interferons such as IFNa and IFNP, Tumor necrosis factor (TNFa) and interleukins such as IL6, IL12, which are important actors in the initiation of innate and adaptative immunity. The secretion of these cytokines, associated with the expression of costimulatory molecules, are known to induce the maturation of dendritic cells, monocytes and macrophages, facilitating the presentation of antigen and the stimulation of the adaptive immune response.

[0009] TLR7 agonists and / or TLR8 agonists have already been reported as adjuvants for vaccines and for the treatment of infections and diseases, for example to treat cancer of the skin and bladder, of renal cell carcinoma, autoimmune diseases, inflammatory diseases, allergic diseases.

[0010] However, there is still a need to provide novel compounds which are useful as TLR7 agonists and / or TLR8 agonists.

[0011] The objective of the present disclosure is thus to provide novel compounds which act as agonists of TLR7 and / or TLR8 agonists. 2 Summary of the disclosure The present disclosure relates to a compound of formula (I) or a 5 pharmaceutically acceptable salt thereof: wherein: R1 represents: - a hydrogen atom, or 10 - a group selected from: a) - a (C1-C6)alkyl- group; - a hydroxy-(C1-C6)alkyl- group; 15 - a NH2-(C1-C6)alkyl- group; - a NH-(C1-C6)alkyl-(C1-C6)alkyl- group;- a N((C1-C6)alkyl)2-(C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; 20 b) - a phenyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b1) - a (C1-C6)alkoxy- group; 25 b2) - a hydroxyl group; b3) a -C(O)-H group; and b4) - a (C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b4.1) - a hydroxyl group; and 30 b4.2) - a -NR4R5group wherein R4and R5, being independently from each other selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, a 35 (C1-C6)alkoxy(C1-C6)alkyl- group, or a (C1-C6)alkoxy(C1-C6)alkoxy(C1-C6)alkyl- group; b4.2.4) - a (C1-C6)alkyl-S(O2)- group; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group; b4.2.7) - a (C1-C16)alkyl-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30; b4.2.9) - a (C3-C10)cycloalkyl- group being unsubstituted or substituted by at least one substituent selected from: - a hydroxyl group; and - a (C1-C6)alkyl- group; or b4.2.10) - a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(O)- and -SO2-; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.13) - a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.14) - a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, said (C3-C10)membered heterocycloalkyl- group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from -NH2and a NH2-(C1-C6)alkyl- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; and e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heteroaryl being unsubstituted or substituted by at least one substituent selected from: - a (C1-C6)alkyl- group; - a NH2-(C1-C6)alkyl- group and - a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur; g) - a (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur; R2represents a halogen atom, or a group selected from: - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C1-C6)alkylthio- group; - a (C1-C6)alkylthio(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O)- group; - a (C1-C6)alkyl-S(O2)- group; - a (C1-C6)alkyl-S(O)-(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O2)-(C1-C6)alkyl- group; - a (C1-C6)alkoxy- group; - a (C1-C6)alkoxy(C1-C6)alkyl- group; - a (C1-C6)haloalkoxy(C1-C6)alkyl- group; - a (C3-C5)cycloalkyl-O-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group; - a ((C1-C6)alkyl)2-N-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH- group; and - a ((C1-C6)alkyl)2N- group; R3 represents: - a deuterium atom; - a hydrogen atom or a group selected from: a) - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; and -a (C1-C6)alkylthio- group; b) - a -OR6group wherein R6is selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C3-C10)cycloalkyl- group; - a phenyl group; - a phenyl(C1-C6)alkyl- group; and - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(=O)- and -S(=O)2-; c) - a -NR7R8group wherein R7and R8being, independently from each other, selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; - a (C1-C6)alkyl- group unsubstituted or substituted by - a (C5-C10)membered heteroaryl group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; or - a phenyl group being unsubstituted or substituted by at least one substituent selected from: - a cyano group and - a NR9R10-(C1-C6)alkyl- group wherein: R9and R10being, independently from each other, selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30, or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C3-C10)membered heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; or R7and R8form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from: - a phenyl group and - a hydroxy(C1-C6)alkyl-phenyl- group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; e) - a (C5-C10)membered heteroaryl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group; f) - a -(C6-C10)membered aryl group; and g) - a (C3-C10)cycloalkyl- group. The disclosure further relates to processes for the preparation of the compounds of formula (I) in accordance with the present disclosure. Thus, according to one specific embodiment, the disclosure relates to a first process for the preparation of the compounds of formula (I) or a pharmaceutically acceptable salt thereof in accordance with the present disclosure, as illustrated by scheme 1 below (also named SynMethod 1 in the present disclosure) and as detailed below. According to another specific embodiment, the disclosure relates to a second process for the preparation of the compounds of formula (I) or a pharmaceutically acceptable salt thereof in accordance with the present disclosure, as illustrated by scheme 2 below (also named SynMethod 2, SynMethod 2a and SynMethod 2b in the present disclosure) and as detailed below. According to another specific embodiment, the disclosure relates to a third process for the preparation of the compounds of formula (I) or a pharmaceutically acceptable salt thereof in accordance with the present disclosure, as illustrated by scheme 3 below (also named SynMethod 3 in the present disclosure) and as detailed below. According to another specific embodiment, the disclosure relates to a fourth process for the preparation of the compounds of formula (I) or a pharmaceutically acceptable salt thereof in accordance with the present disclosure, as illustrated by scheme 4 below (also named SynMethod 4, SynMethod 4a and SynMethod 4b in the present disclosure) and as detailed below. The disclosure also relates to intermediate compounds or a pharmaceutically acceptable salt thereof of formulae: wherein - R1, R1a, R2,R3a, HAL and G1are as defined in the present disclosure. The present disclosure further concerns specific intermediate compounds or a pharmaceutically acceptable salt thereof selected from:

[0012] in which: - compounds (H) and (J) or a pharmaceutically acceptable salt thereof belong to formula (VIIa) as defined in the present disclosure; - compounds (Ia) and (K) or a pharmaceutically acceptable salt thereof belong to formula (VIIIa) as defined in the present disclosure; - compounds (L) and (N) or a pharmaceutically acceptable salt thereof belong to formula (VIII) as defined in the present disclosure and - compounds (M) and (R) or a pharmaceutically acceptable salt thereof belong to formula (IX) as defined in the present disclosure. The compounds of formula (I) may comprise one or more asymmetric carbon atoms. They may thus exist in the form of enantiomers, preferably pure enantiomers, or diastereoisomers and mixture thereof. The compounds of formula (I) may be present as well under tautomer forms. Indeed, it is to be understood that the present disclosure encompasses all isomers of formulae (I), (Ia), (VIIa), (VIII), (VIIIa), (IX) and (X) and their pharmaceutically acceptable derivatives, including all geometric, tautomeric and optical forms, and mixtures thereof (e.g. racemic or non-racemic mixtures). It is to be understood that in the present disclosure isomers can be restricted to geometric, optical and tautomeric isomers. The compounds of formulae (I), (Ia), (VIIa), (VIII), (VIIIa), (IX) and (X), may exist in the form of bases, acids, zwitterion or of addition salts with acids or bases, in particular pharmaceutically acceptable salts. Such addition salts, bases, acids and zwitterion form part of the disclosure. Hence, the disclosure relates, inter alia, to the compounds of formulae (I), (Ia), (VIIa), (VIII), (VIIIa), (IX) and (X), or to pharmaceutically acceptable salts thereof. These salts may be prepared with pharmaceutically acceptable acids or bases, although the salts of other acids or bases useful, for example, for purifying or isolating the compounds of formulae (I), (Ia), (VIIa), (VIII), (VIIIa), (IX) and (X), also form part of the disclosure. Among suitable salts which form part of the disclosure, the following may be cited: hydrochloride and trifluoroacetate. Another subject-matter of the instant disclosure is a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for use as a medicine. Another subject-matter of the instant disclosure is a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for use in therapy, especially as a TLR7 agonist and / or as a TLR8 agonist. Another subject-matter of the instant disclosure is a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for use in the prevention and / or treatment of a disease or a disorder associated with TLR7 and / or TLR8 activity such a cell-proliferative disease, a cancer, a chronic myelogenous, a hairy cell leukemia, a dermatological disease such as a skin lesion or a skin cancer (for example an external genital and perianal warts / condyloma acuminate, a genital herpes, an actinic keratosis, a basal cell carcinoma, a cutaneous T-cell lymphoma), an autoimmune disease, an inflammatory disease, a respiratory disease, a sepsis, an allergy (for example an allergic rhinitis or an respiratory allergy), an asthma, a graft rejection, a graft-versus-host disease, an immunodeficiency. Another subject-matter of the instant disclosure is a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for use in the prevention and / or treatment of a cancer. Another subject-matter of the instant disclosure is a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for use in a vaccine. For example, a compound of formula (I) in accordance with the disclosure can be used as a vaccine adjuvant or the vaccine can be a self-adjuvanting vaccine. Another subject-matter of the instant disclosure is a method of treating a disease or a disorder associated with TLR7 and / or TLR7 / 8 activity such as a cell-proliferative disease, a cancer, a chronic myelogenous, a hairy cell leukemia, a dermatological disease such as a skin lesion or a skin cancer (for example an external genital and perianal warts / condyloma acuminate, a genital herpes, an actinic keratosis, a basal cell carcinoma, a cutaneous T-cell lymphoma), an autoimmune disease, an inflammatory disease, a respiratory disease, a sepsis, an allergy (for example an allergic rhinitis or an respiratory allergy), an asthma, a graft rejection, a graft-versus-host disease, an immunodeficiency, which comprises administering to a subject in need thereof, for instance a human, a therapeutically effective amount of a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof. The present disclosure also relates, in another aspect, to a method of preventing and / or treating a disease or a disorder associated with TLR7 and / or TLR7 / 8 activity such as a cell-proliferative disease, a cancer, a chronic myelogenous, a hairy cell leukemia, a dermatological disease such as a skin lesion or a skin cancer (for example an external genital and perianal warts / condyloma acuminate, a genital herpes, an actinic keratosis, a basal cell carcinoma, a cutaneous T-cell lymphoma), an autoimmune disease, an inflammatory disease, a respiratory disease, a sepsis, an allergy (for example an allergic rhinitis or an respiratory allergy), an asthma, a graft rejection, a graft-versus-host disease, an immunodeficiency, in a patient in need thereof, for instance a human, which comprises immunizing said patient with a vaccine comprising a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof. The present disclosure also relates, in another aspect, to an adjuvant for vaccines. The present disclosure further relates to the use of a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, for the manufacture of a vaccine and / or of a medicament for preventing and / or treating a disease or a disorder associated with TLR7 and / or TLR7 / 8 activity such as a cell-proliferative disease, a cancer, a chronic myelogenous, a hairy cell leukemia, a dermatological disease such as a skin lesion or a skin cancer (for example an external genital and perianal warts / condyloma acuminate, a genital herpes, an actinic keratosis, a basal cell carcinoma, a cutaneous T-cell lymphoma), an autoimmune disease, an inflammatory disease, a respiratory disease, a sepsis, an allergy (for example an allergic rhinitis or an respiratory allergy), an asthma, a graft rejection, a graft-versus-host disease, an immunodeficiency. Another subject-matter of the instant disclosure is a medicament comprising as active principle an effective dose of a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof. Another subject-matter of the instant disclosure is a pharmaceutical composition comprising as active principle an effective dose of a compound of formula (I) in accordance with the disclosure selected from the above and below lists, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. Definitions In the context of the present disclosure, the terms below have the following definitions unless otherwise mentioned throughout the instant specification: - a “halogen atom”: a fluorine, a chlorine, a bromine or an iodine atom, and for example a fluorine and a chlorine atom; - a “hydroxyl group”: a “-OH” group; - an “oxo group”: a “=O” group; - a “cyano group”: a “-C≡N” group; - a “(Cx-Cy)alkyl” group: a linear or branched saturated hydrocarbon-based aliphatic group comprising from x to y carbon atoms, for example from 1 to 6 carbon atoms, or from 1 to 16 carbon atoms. By way of examples, mention may be made of, but not limited to: methyl, ethyl, propyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, octyl, nonyl, decyl groups, and the like; - a “(Cx-Cy)alkenyl” group: a linear or branched hydrocarbon-based aliphatic group comprising at least one unsaturation (double bond) and comprising, from x to y carbon atoms (x being an integer of at least 2), for example from 2 to 6 carbon atoms. By way of examples, mention may be made of, but not limited to: ethenyl, propenyl, butenyl, pentenyl, hexenyl groups, and the like; - a “(Cx-Cy)alkynyl” goup: a linear or branched hydrocarbon-based aliphatic group comprising at least one triple bond and comprising from x to y carbon atoms (x being an integer of at least 2) for example from 2 to 6 carbon atoms. By way of examples, mention may be made of, but not limited to: ethynyl, propynyl, butynyl, pentynyl, hexynyl groups, and the like; - a “(Cx-Cy)alkoxy” group: an -O-alkyl group where the alkyl group is as previously defined. For example, a (C1-C6)alkoxy group. By way of examples, mention may be made of, (but not limited to: methoxy, ethoxy, propoxy, isopropoxy, linear, secondary or tertiary butoxy, isobutoxy, pentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy groups, and the like; -a “(Cx-Cy)haloalkoxy” group: an -O-alkyl group where the alkyl group is as previously defined and is further substituted by at least one halogen atom as previously defined. For example, a (C1-C6)haloalkoxy group. By way of examples, mention may be made of but not limited to: chloromethoxy, fluoromethoxy, dichloromethoxy, 2-fluoropropoxy groups, and the like; - a “(Cx-Cy)alkythio” group: an -S-alkyl group where the alkyl group is as previously defined. For example, a (C1-C6)alkylthio group. By way of examples, mention may be made of but not limited to: methylthio, ethylthio, propylthio, isopropylthio, linear, secondary or tertiary butylthio, isobutylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio groups, and the like; - a “(C3-C10)cycloalkyl” group or a “(C3-C5)cycloalkyl”” group: a cyclic alkyl group comprising, unless otherwise mentioned, from 3 to 10 carbon atoms (noted “(C3- C10)cycloalkyl group”) or from 3 to 5 carbon atoms (noted “(C3-C5)cycloalkyl group”), saturated or partially unsaturated and unsubstituted or substituted. By way of examples, mention may be made of, but not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl groups and the like; - a “(C3-C10)heterocycloalkyl” group: a monocyclic alkyl group comprising, unless otherwise mentioned, from 3 to 10 carbon atoms (noted “a (C3-C10) membered heterocycloalkyl group”) and comprising 1 to 4 heteroatoms selected from oxygen, nitrogen, sulfur , -S(O)-, and -SO2- (in other terms, one heteroatom replaces one carbon atom). Such heterocycloalkyl group may be saturated or partially saturated and unsubstituted or substituted. By way of examples of heterocycloalkyl groups, mention may be made of, but not limited to: piperazine, morpholino, pyrrolidine, tetrahydropyrane, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, tetrahydrofurane, azetidine, oxetane, thietane, 2H-pyrrole, 1H-, 2H- or 3H-pyrroline, tetrahydrothiophene, oxadiazole and for example 1,3,4-oxadiazole or 1,3,5-oxadioazole, thiadiazole and for example 1,3,4-thiadiazole, isoxazoline, 2- or 3-pyrazoline, pyrroline, pyrazolidine, imidazoline, imidazolidine, thiazolidine, isooxazoline, isoxazolidine, dioxalane, oxathiazole, oxathiadiazole, dioxazole groups and the like; - a “(C5-C10)heteroaryl” group means: a cyclic aromatic group comprising from 5 to 10 carbon atoms and comprising from 1 and 4 heteroatoms selected from nitrogen, oxygen and sulfur (noted “a (C5-C10) membered heteroaryl group”) (in other terms, one heteroatom replaces one carbon atom). Such heteroaryl group may be unsubstituted or substituted. By way of examples of 5 to 10-membered heteroaryl groups, mention may be made of, but not limited to: pyridine, furan, pyrrole, thiophene, pyrazole, oxazole, isoxazole, triazole, tetrazole, oxadiazole, furazan, thiazole, isothiazole, thiadiazole, imidazole, pyrimidine, pyridazine, triazine groups and the like; - a “(C6-C10)aryl” group: a cyclic aromatic group comprising from 6 to 10 carbon atoms (noted “a (C6-C10) membered aryl group”). Such aryl group may be unsubstituted or substituted. By way of examples of 6 to 10-membered aryl groups, mention may be made of, but not limited to: phenyl, naphthyl groups, and the like; - a “deuterium atom” (D or2H) is a stable, non-radioactive isotope of hydrogen and has an atomic weight of 2.0144; - a “hydroxyl protecting group” means: Ethers, Silyl Ethers, Esters, carbonates, carbamates etc, such as Acetyl (Ac), Benzoyl (Bz), Benzyl (Bn), β-methoxyethoxymethyl ether (MEM), dimethoxytrityl, [bis-(4-methoxyphenyl)phenylmethyl] (DMT), methoxymethyl ether (MOM), methoxytrityl [(4-methoxyphenyl)diphenylmethyl] (MMT), p- methoxybenzyl ether (PMB), p-methoxyphenyl ether (PMP), methylthiomethyl ether, pivaloyl (Piv), tetrahydropyranyl (THP), tetrahydrofuran (THF), trityl (triphenylmethyl, Tr), silyl ether (for instance trimethylsilyl (TMS), tert-butyldimethylsilyl (TBDMS), tri-iso- propylsilyloxymethyl (TOM), and triisopropylsilyl (TIPS) ethers), methyl ethers, ethoxyethyl ethers (EE), for instance acetyl (Ac), benzyl (Bn), β-methoxyethoxymethyl ether (MEM), dimethoxytrityl, [bis-(4-methoxyphenyl)phenylmethyl] (DMT), p- methoxybenzyl ether (PMB), tetrahydropyranyl (THP), trityl (triphenylmethyl, Tr), trimethylsilyl (TMS), and tert-butyldimethylsilyl (TBDMS).(see the manual Greene’s protective groups in organic synthesis », P.G.M. WUTS and T.W. GREENE, fourth edition, 1807 Wiley 207, Wiley Interscience); - an “amino protecting group” means: carbamates, amides, alkyls, enamines, imides, imines, etc , such as carbobenzyloxy (Cbz) group, p-methoxybenzyl carbonyl (Moz or MeOZ) group, tert-butyloxycarbonyl (BOC) group, 9-fluorenylmethyloxycarbonyl (Fmoc) group, acetyl (Ac) group, benzoyl (Bz) group, benzyl (Bn) group, carbamate group, p- methoxyphenyl (PMP) group, tosyl (Ts) group, p-methoxybenzyl (PMB), 3,4- dimethoxybenzyl (DMPM), Troc (trichloroethyl chloroformate) group, other sulfonamides, for instance carbobenzyloxy (Cbz) group, tert-butyloxycarbonyl (BOC) group, 9- fluorenylmethyloxycarbonyl (Fmoc) group, acetyl (Ac) group, benzoyl (Bz) group, p- methoxybenzyl (PMB), 3,4-dimethoxybenzyl (DMPM), Troc (trichloroethyl chloroformate) group. (see the manual Greene’s protective groups in organic synthesis », P.G.M. WUTS and T.W. GREENE, fourth edition, 1807 Wiley 207, Wiley Interscience;. - a “carboxylic acid protecting group” means : Esters, silyl esters, amides, hydrazides, etc such as methyl esters, benzyl esters, tert-Butyl esters, esters of 2,6-disubstituted phenols (e.g. 2,6-dimethylphenol, 2,6-diisopropylphenol, 2,6-di-tert-butylphenol), silyl esters, orthoesters, oxazoline, for instance, methyl esters and benzyl esters. (see the manual Greene’s protective groups in organic synthesis », P.G.M. WUTS and T.W. GREENE, fourth edition, 1807 Wiley 207, Wiley Interscience); - an “aldehyde protecting group” or a ketone protecting group (also named carbonyl protecting groups) means: acetals and ketals, dithio acetals and ketals, substituted hydrazones, oximes, etc, such as acetals and ketals, acylals and dithianes. (see the manual Greene’s protective groups in organic synthesis », P.G.M. WUTS and T.W. GREENE, fourth edition, 1807 Wiley 207, Wiley Interscience); - A “zwitterion” means: a globally neutral molecule with a positive and a negative electrical charge and having an acid group and a basic group; - “room temperature” (also named rt) in the present disclosure means a temperature ranging from 18°C to 30°C, for example from 18°C to 25°C;. - “TLR”: the terms "Toll-like receptor" and "TLR" refer to any member of a family of highly-conserved mammalian proteins which recognize pathogen-associated molecular patterns and act as key signaling elements in innate immunity. TLR polypeptides share a characteristic structure that includes an extracellular domain that has leucine-rich repeats, a transmembrane domain, and an intracellular domain that is involved in TLR signaling; - “TLR7”: the terms "Toll-like receptor 7" and "TLR7" refer to nucleic acids or polypeptides sharing at least 70%; at least 80%, at least 90%, at least 95%, at least 96%, at least 97%), at least 98%, at least 99%, or more sequence identity to a publicly-available TLR7 sequence, e.g., GenBank accession number AAZ99026 for human TLR7 polypeptide, or GenBank accession number AAK62676 for murine TLR7 polypeptide; - “TLR8”: the terms "Toll-like receptor 8" and "TLR8" refer to nucleic acids or polypeptides sharing at least 70%; at least 80%, at least 90%, at least 95%, at least 96%, at least 97%), at least 98%, at least 99%, or more sequence identity to a publicly-available TLR7 sequence, e.g., GenBank accession number AAZ95441 for human TLR8 polypeptide, or GenBank accession number AAK62677 for murine TLR8 polypeptide;. - “TLR agonist”: it is a substance that binds, directly or indirectly, to a TLR (e.g., TLR7 and / or TLR8) to induce TLR signaling. Any detectable difference in TLR signaling can indicate that an agonist stimulates or activates a TLR. Signaling differences can be manifested, for example, as changes in the expression of target genes, in the phosphorylation of signal transduction components, in the intracellular localization of downstream elements such as NF-kB, in the association of certain components (such as IRAK) with other proteins or intracellular structures, or in the biochemical activity of components such as kinases (such as MAPK); - “Immune response”: An "immunological response" or "immune response" to an antigen or composition, as used herein, refers to the development in a subject of a humoral and / or cellular immune response to the antigen or composition; Immune responses include innate and adaptive immune responses. Innate immune responses are fast-acting responses that provide a first line of defense for the immune system. In contrast, adaptive immunity uses selection and clonal expansion of immune cells having somatically rearranged receptor genes (e.g., T- and B-cell receptors) that recognize antigens from a given pathogen or disorder (e.g., a tumor), thereby providing specificity and immunological memory. Innate immune responses, among their many effects, lead to a rapid burst of inflammatory cytokines and activation of antigen-presenting cells (APCs) such as macrophages and dendritic cells. To distinguish pathogens from self-components, the innate immune system uses a variety of relatively invariable receptors that detect signatures from pathogens, known as pathogen-associated molecular patterns, or PAMPs. The mechanism behind this potentiation of the immune responses has been reported to involve pattern- recognition receptors (PRRs), which are differentially expressed on a variety of immune cells, including neutrophils, monocytes, macrophages, dendritic cells, natural killer cells, B cells and some nonimmune cells such as epithelial and endothelial cells. Engagement of PRRs leads to the activation of some of these cells and their secretion of cytokines and chemokines, as well as maturation and migration of other cells. In tandem, this creates an inflammatory environment that leads to the establishment of the adaptive immune response. PRRs include nonphagocytic receptors, such as Toll-like receptors (TLRs) and nucleotide- binding oligomerization domain (NOD) proteins, and receptors that induce phagocytosis, such as scavenger receptors, mannose receptors and β-glucan receptors. Dendritic cells are recognized as some of the most important cell types for initiating the priming of naive CD4+helper T (TH) cells and for inducing CD8+T cell differentiation into killer cells. TLR signaling has been reported to play an important role in determining the quality of these helper T cell responses, for instance, with the nature of the TLR signal determining the specific type of TH response that is observed (e.g., TH1 versus TH2 response). A combination of antibody (humoral) and cellular immunity are produced as part of a TH1 -type response, whereas a TH2-type response is predominantly an antibody response. - A "humoral immune response" refers to an immune response mediated by antibody molecules, while a "cellular immune response" refers to an immune response mediated by T- lymphocytes and / or other white blood cells. One important aspect of cellular immunity involves an antigen-specific response by cytolytic T-cells ("CTLs"). CTLs have specificity for peptide antigens that are presented in association with proteins encoded by the major histocompatibility complex (MHC) and expressed on the surfaces of cells. CTLs help induce and promote the destruction of intracellular microbes, or the lysis of cells infected with such microbes. Another aspect of cellular immunity involves an antigen-specific response by helper T-cells. Helper T-cells act to help stimulate the function, and focus the activity of, nonspecific effector cells against cells displaying peptide antigens in association with MHC molecules on their surface. A "cellular immune response" also refers to the production of cytokines, chemokines and other such molecules produced by activated T-cells and / or other white blood cells, including those derived from CD4+and CD8+T-cells. - An “immune response” associated with TLR7 and / or TLR8 is an immune response which involves activation of TLR7 and / or TLR8 receptors. Activation of TLR7 and / or TLR8 receptors may be determined in vitro using methods such as those described in the Examples. - “Induce”: "Induce" and variations thereof refer to any measurable increase in cellular activity. For example, induction of an immune response may include, for example, an increase in the production of a cytokine, activation, proliferation, or maturation of a population of immune cells, and / or other indicator of increased immune function. " Detailed description of the present disclosure The disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R1represents: - a hydrogen atom, or - a group selected from: a) - a (C1-C6)alkyl- group; - a hydroxy-(C1-C6)alkyl- group; - a NH2-(C1-C6)alkyl- group; - a NH-(C1-C6)alkyl-(C1-C6)alkyl- group;- a N((C1-C6)alkyl)2-(C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; b) - a phenyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b1) - a (C1-C6)alkoxy- group; b2) - a hydroxyl group; b3) a -C(O)-H group; and b4) - a (C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b4.1) - a hydroxyl group; and b4.2) - a -NR4R5group wherein R4and R5, being independently from each other selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, a (C1-C6)alkoxy(C1-C6)alkyl- group, or a (C1-C6)alkoxy(C1-C6)alkoxy(C1-C6)alkyl- group; b4.2.4) - a (C1-C6)alkyl-S(O2)- group; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group; b4.2.7) - a (C1-C16)alkyl-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30; b4.2.9) - a (C3-C10)cycloalkyl- group being unsubstituted or substituted by at least one substituent selected from: - a hydroxyl group; and - a (C1-C6)alkyl- group; or b4.2.10) - a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(O)- and -SO2-; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.13) - a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.14) - a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group; or R4 and R5 form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, said (C3-C10)membered heterocycloalkyl- group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from -NH2and a NH2-(C1-C6)alkyl- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; and e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heteroaryl being unsubstituted or substituted by at least one substituent selected from: - a (C1-C6)alkyl- group; - a NH2-(C1-C6)alkyl- group and - a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur; g) - a (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur; R2 represents a halogen atom, or a group selected from: - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C1-C6)alkylthio- group; - a (C1-C6)alkylthio(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O)- group; - a (C1-C6)alkyl-S(O2)- group; - a (C1-C6)alkyl-S(O)-(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O2)-(C1-C6)alkyl- group; - a (C1-C6)alkoxy- group; - a (C1-C6)alkoxy(C1-C6)alkyl- group; - a (C1-C6)haloalkoxy(C1-C6)alkyl- group; - a (C3-C5)cycloalkyl-O-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group; - a ((C1-C6)alkyl)2-N-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH- group; and - a ((C1-C6)alkyl)2N- group; R3represents: - a deuterium atom; - a hydrogen atom or a group selected from: a) - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; and -a (C1-C6)alkylthio- group; b) - a -OR6group wherein R6is selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C3-C10)cycloalkyl- group; - a phenyl group; - a phenyl(C1-C6)alkyl- group; and - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(=O)- and -S(=O)2-; c) - a -NR7R8group wherein R7and R8being, independently from each other, selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; - a (C1-C6)alkyl- group unsubstituted or substituted by - a (C5-C10)membered heteroaryl group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; or - a phenyl group being unsubstituted or substituted by at least one substituent selected from: - a cyano group and - a NR9R10-(C1-C6)alkyl- group wherein: R9and R10being, independently from each other, selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30, or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C3-C10)membered heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; or R7and R8form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from: - a phenyl group and - a hydroxy(C1-C6)alkyl-phenyl- group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; e) - a (C5-C10)membered heteroaryl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group; f) - a -(C6-C10)membered aryl group; and g) - a (C3-C10)cycloalkyl- group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R1represents - a hydrogen atom or - a group selected from: a) - a (C1-C6)alkyl- group; - a hydroxy-(C1-C6)alkyl- group or - a NH2-(C1-C6)alkyl- group; b) - a phenyl(C1-C6)alkyl- group being unsubstituted or substituted by one substituent, selected from: b1) - a (C1-C6)-alkoxy- group; b3) - a -C(O)-H group and b4) - a (C1-C6)alkyl- group substituted by at least one substituent selected from: b4.1) - a hydroxyl group; b4.2) - a -NR4R5group wherein R4and R5, being independently from each other, selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, a (C1C6)alkoxy(C1-C6)alkyl- group, or a (C1-C6)alkoxy(C1-C6)alkoxy(C1- C6)alkyl- group; b4.2.4) - a (C1-C6)alkyl-S(O2)- group; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group; b4.2.7) - a (C1-C16)alkyl-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30; b4.2.9) - a (C3-C10)cycloalkyl- group being unsubstituted or substituted by at least one a (C1-C6)alkyl group or a hydroxyl group; b4.2.10) - a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen and -SO2-; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.13) - a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.14) - a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3C10)membered heterocycloalkyl- group comprising one to two heteroatoms selected from oxygen and nitrogen; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group being unsubstituted or substituted by one substituent selected from -NH2, and a NH2-(C1-C6)alkyl- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group, unsubstituted comprising one to two nitrogen heteroatoms; e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group comprising one nitrogen heteroatom, said heteroaryl being unsubstituted or substituted by at least one substituent selected from: - a NH2-(C1-C6)alkyl- group and - a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one heteroatom selected from oxygen, nitrogen, S(O), SO2and sulfur; g) - a (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one heteroatom selected from oxygen, nitrogen, S(O), SO2and sulfur. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R1represents: - a hydrogen atom or - a group selected from: a) - a methyl group; - a C(OH)(CH3)2-CH2- group, a C(CH3)(CH2OH)2-CH2- group, a CH(CH2OH)2-CH2- group; - a NH2-(CH2)4- group, a NH2-(CH2)5- group or a NH2-(CH2)6- group; b) - a phenylmethyl group (that is to say a benzyl group), the phenyl group being unsubstituted or substituted by at least one substituent selected from: b1) - a methoxy group, such as a methoxy group in para position of the phenyl group; b3) - a -C(O)-H group, such as -C(O)-H in para position of the phenyl group; b4) - a methyl group substituted by at least one substituent selected from: b4.1) - a hydroxyl group; b4.2) - a -NR4R5group wherein R4and R5being, independently from each other, selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a methyl group, an isopropyl group, a pentyl group, a hexyl group, a nonyl group, a decyl group; b4.2.3) - a CH3-O-(CH2)2- group, a CH3-O-((CH2)2-O)11-(CH2)2- group, a CH3-O-((CH2)2-O)7-(CH2)2- group, a CH3-O-((CH2)2-O)5-(CH2)2- group, a CH3-O-((CH2)2-O)3-(CH2)2- group, a CH3-O-((CH2)2-O)2-(CH2)2- group or a CH3-O-(CH2)2-O-(CH2)2- group; b4.2.4) - a CH3-S(O2)- group; b4.2.5) - a CH3-CH2-NH-C(O)- group; b4.2.6) - a CH3-C(O)- group, a CH3-CH2-C(O)- group, a CH3-(CH2)5- C(O)- group, a CH3-(CH2)9-C(O)- group or a CH3-(CH2)3-C(O)- group; b4.2.7) - a CH3-CH2-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]2-C(O)- group or a CH3-O-(CH2)2-C(O)- group; b4.2.9) - a cyclopropyl group or a cyclobutyl group, said cyclopropyl or cyclobutyl group being unsubstituted or substituted by at least one substituent selected from a hydroxyl group or a methyl group; b4.2.10) - a tetrahydropyranyl group or a thietane dioxide group; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a CH3-O-phenyl-CH2-O-C(O)- group; b4.2.13) - a CH3-C(O)-NH-phenyl-CH2-O-C(O)- group; b4.2.14) - a C(CH3)3-O-C(O)-CH2- group or a C(CH3)3-O-C(O)- (CH2)2- group; or R4and R5form together with the nitrogen atom to which they are attached a piperazinyl group, a morpholino group or a pyrrolidinyl group; c) - a cyclohexyl-CH2- group being unsubstituted or substituted by at least one substituent selected from a -NH2group and a NH2-CH2- group; d) - a piperazinyl-(CH2)2- group, a piperidinyl-CH2- group or a piperidinyl-(CH2)2- group; and e) - a pyridyl-CH2- group being unsubstituted or substituted by at least one substituent selected from a NH2-CH2- group and a cyano group; f) - a tetrahydropyranyl-NH-(CH2)4- group, a tetrahydropyranyl-NH-(CH2)6- group, a dioxothietanyl-NH-(CH2)4- group, or a dioxothietanyl-NH-(CH2)6- group; g) - a tetrahydropyranyl-N(C(O)-CH3)-(CH2)4- group, a tetrahydropyranyl-N(C(O)-CH3)- (CH2)6- group, a dioxothietanyl-N(C(O)-CH3)-(CH2)4- group, or a dioxothietanyl-N(C(O)- CH3)-(CH2)6- group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R2represents a group selected from: - a (C1-C6)alkyl- group; - a (C1-C6)alkylthio- group; - a (C1-C6)alkyl-S(O)- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH- group; and - a (C1-C6)alkoxy(C1-C6)alkyl- group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R2represents a group selected from : - a methyl group, an ethyl group, a n-propyl group, a n-butyl group; - a CH3-(CH2)2-S- group; - a CH3-(CH2)2-S(O)- group; - a CH3-S-(CH2)2- group; - a CH3-CH2-O-CH2- group; - a CH3-O-(CH2)2- group; - a CH3-CH2-NH-CH2- group; and - a CH3-(CH2)2-NH- group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R2represents a (C1-C6)alkyl group, for instance a butyl group, such as an n-butyl group, a methyl group, or a propyl group such as a n-propyl group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R3represents: - a hydrogen atom or - a group selected from: a) - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C1-C6)alkylthio- group; b) - a -OR6group wherein R6is selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; - a (C2-C6)alkenyl group; - a (C3-C10)cycloalkyl group; - a phenyl group; - a phenyl(C1-C6alkyl)- group; and - a (C3-C10)membered heterocycloalkyl- group comprising one heteroatom selected from oxygen, sulfur, -S(O)- and -SO2-; c) - a -NR7R8group wherein R7and R8, being independently from each other, selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; - a (C1-C6)alkyl- group unsubstituted or substituted by: - a (C5-C10)membered heteroaryl- group comprising one oxygen atom; or - a phenyl group being unsubstituted or substituted by at least one substituent selected from: - a cyano group and - a NR9R10-(C1-C6)alkyl- group wherein R9and R10being, independently from each other, selected from: - a hydrogen atom; - a -(C1-C6)alkyl group or - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to two heteroatoms selected from oxygen, and nitrogen, said (C3-C10)membered heterocycloalkyl- group being substituted by at least one (C1- C6)alkyl- group, for instance one to three (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group; or R7and R8form together with the nitrogen atom to which they are attached a (C3C10)membered heterocycloalkyl- group comprising one nitrogen heteroatom, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent, for instance one to three substituents, such as one substituent selected from: - a phenyl group and - a hydroxy(C1-C6)alkyl-phenyl- group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one heteroatom selected from oxygen and nitrogen; e) - a (C5-C10)membered heteroaryl- group comprising one to two heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to three a (C1-C6)alkyl- groups, such as one (C1- C6)alkyl- group; f) - a (C6-C10)membered aryl- group and g) - a (C3-C10)cycloalkyl- group. Among the compounds of formula (I) or a pharmaceutically acceptable salt thereof that are subject matter of the disclosure, a group of compounds is composed of the compounds for which R3represents: - a hydrogen atom or - a group selected from: a) - an isopropyl group, an isobutyl group, an isopentyl group; - a C-(CH3)(=CH2)- group, a (CH3)2C=CH- group, a (CH3)2CH-CH=CH- group; - an isopropylthio- group; b) - a -OR6group wherein R6represents: - a hydrogen atom; - a methyl group, an ethyl group, an isopropyl group, a n-propyl group, a n-butyl group, a sec-butyl group; - a CH3-O-(CH2)2- group; - a propenyl group; - a cyclopentyl group; - a phenyl group unsubstituted, a phenyl-CH2- group; - a tetrahydropyranyl group, a thiolane group, a thiolane oxide group, a thiolane dioxide group or a tetrahydrofuranyl group; c) a -NR7R8group wherein R7and R8, being independently from each other, selected from: - a hydrogen atom; - a CH3-O-(CH2)2- group; - a methyl group, an isopropyl group; - a furanyl-(CH2)3- group; - a phenyl-(CH2)- group, said phenyl group being unsubstituted or substituted by at least one substituent, for instance one to five substituents, such as one substituent selected from: - a cyano group and - a NR9R10-CH2- group wherein R9and R10, being independently from each other, selected from: - a hydrogen atom; - a methyl group or - a CH3-O-(CH2)2- group; or R9and R10 together form with the nitrogen atom to which they are attached a morpholino group or a piperazinyl group, said morpholino group or piperazinyl group being unsubstituted or substituted by at least one methyl group, or R7and R8form together with the nitrogen atom to which they are attached, a pyrrolidinyl group, said pyrrolidinyl group being unsubstituted or substituted by at least one substituent, for instance one to three substituents, such as one substituent selected from : - a phenyl group or - a OH-CH2-phenyl- group, for example a OH-CH2- group is in para position of the phenyl group; d) - a tetrahydrofuranyl group, a dihydropyrrolyl group or a dihydrofuranyl group; e) - a thienyl group, a furanyl group, a pyrrolyl group, a pyrazolyl group, said thienyl group, furanyl group, pyrrolyl group or pyrazolyl group being unsubstituted or substituted by at least one methyl group, for instance one to three methyl groups, such as one methyl group; f) - a phenyl group; g) - a cyclopentenyl group, a cyclopentyl group, a cyclohexenyl group and a cyclohexyl group. All these sub-groups taken alone or in combination are part of the present disclosure. According to a particular embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof, provided that at least one of R1, and R3 is other than a hydrogen atom. According to another particular embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof, provided that R1and R3are simultaneously other than a hydrogen atom. According to another embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R1represents a group selected from: a) - a (C1-C6)alkyl group, for instance a methyl group; - a NH2-(C1-C6)alkyl- group, for instance a NH2-(CH2)4- group, a NH2-(CH2)5- group, a NH2-(CH2)6- group; b) - a phenyl(C1-C6)alkyl- group, for instance a benzyl group, the phenyl group being unsubstituted or substituted by at least one substituent, for instance one to five substituents, such as one substituent, selected from: b1) - a (C1-C6)alkoxy group, for instance a methoxy group, such as a methoxy group in para position of the phenyl group; b3) - -C(O)-H, such as -C(O)-H in para position of the phenyl group and b4) - a (C1-C6)alkyl group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, said alkyl group being itself unsubstituted or substituted by at least one substituent, for instance one substituent, selected from: b4.1) - a hydroxyl group; b4.2) - a -NR4R5group, R4and R5being independently from each other: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group, for instance an isopropyl group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance n being 6 or 8; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group, for instance a CH3-CH2-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group, for instance CH3- C(O)-; b4.2.7) - a (C1-C16)alkyl-O-C(O)- group, for instance a CH3-CH2-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30, for instance n being 1; b4.2.9) - a (C3-C10)cycloalkyl- group, for instance a cyclobutyl group, said cycloalkyl group being unsubstituted or substituted by at least one substituent, for instance one to five substituents, such as one (C1-C6)alkyl group, for instance a methyl group; b4.2.10) - a (C3-C10) membered heterocycloalkyl- group comprising from one heteroatom which is -SO2-, for instance a thietane dioxide group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group, for instance a CH3-O-para-phenyl-CH2-O-C(O)- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, said (C3-C10)membered heterocycloalkyl- group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance R4and R5form together with the nitrogen atom to which they are attached a piperazinyl; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group, for instance a cyclohexyl-CH2- group, said cycloalkyl being unsubstituted or substituted by at least one substituent, for instance one to five substituents, such as one substituent selected from NH2, and a NH2-(C1- C6)alkyl- group, for instance a NH2-CH2- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group, for instance a piperazinyl-(CH2)2- group or a piperidinyl-(CH2)2- group, said heterocycloalkyl group comprising 1 to 2 nitrogen heteroatoms, for instance a piperazinyl group or a piperidinyl group; e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group, for instance a pyridyl- CH2- group, said heteroaryl comprising one nitrogen heteroatom, for instance a pyridyl group, said heteroaryl being unsubstituted or substituted by at least one substituent, for instance one to three substituents, such as one substituent, which is a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms, for instance one heteroatom, selected from oxygen, nitrogen, S(O), SO2and sulfur, for instance a dioxothietanyl-NH- (CH2)4- group and g) - a (C3-C10)membered heterocycloalkyl- N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms, for instance one heteroatom, selected from oxygen, nitrogen, S(O), SO2and sulfur, for instance a tetrahydropyranyl-N(C(O)-(CH3))-(CH2)4- group, a tetrahydropyranyl-N(C(O)-(CH3))- (CH2)6- group, a dioxothietanyl-N(C(O)-(CH3))-(CH2)4- group or a dioxothietanyl-N(C(O)- (CH3))-(CH2)6- group; R2represents a group selected from: - a (C1-C6)alkyl group, for instance a n-butyl group or a n-propyl group; - a (C1-C6)alkoxy(C1-C6)alkyl- group, for instance CH3CH2-O-CH2- group and - a (C1-C6)alkyl-S(O)- group, for instance a CH3CH2CH2-S(O)- group; R3represents a group selected from: a) - a (C1-C6)alkyl- group, for instance an isopropyl group, an isobutyl group, or an isopentyl group; - a (C2-C6)alkenyl- group, for instance a propenyl group such as C(CH3)(=CH2)- , a butenyl group such as (CH3)2C=CH-, or a pentenyl group such as (CH3)2CH-CH=CH-; - a (C1-C6)alkylthio- group, for instance an isopropylthio- group; b) - a -OR6group, R6being : - a (C1-C6)alkyl- group, for instance a methyl group, an isopropyl group, a n-propyl group, a n-butyl group, or a sec-butyl group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance CH3-O-(CH2)2-; - a (C2-C6)alkenyl- group, for instance a propenyl group such as -CH2- CH=CH2; - a (C3-C10)cycloalkyl group, for instance a cyclopentyl group; - a phenyl group; - a phenyl(C1-C6)alkyl)- group, for instance a benzyl grou; or - a (C3-C10)membered heterocycloalkyl- group comprising one heteroatom selected from oxygen, sulfur, -S(O)- and -SO2-, for instance a tetrahydropyranyl group, a thiolane dioxide group, a thiolane group, a thiolane oxide group, and a tetrahydrofuranyl group; c) - a -NR7R8group, R7and R8being independently from each other selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance CH3-O-(CH2)2-; - a (C1-C6)alkyl group, for instance a methyl group, or an isopropyl group, said (C1-C6)alkyl group being unsubstituted or substituted by a phenyl group (to form for instance a benzyl group), said phenyl group being unsubstituted or substituted by at least one NH2- (C1-C6)alkyl-, for instance one to five NH2-(C1-C6)alkyl-, such as one NH2-(C1-C6)alkyl-, such as NH2-CH2-: or R7and R8form together with the nitrogen atom to which they are attached a (C3-C10) membered heterocycloalkyl- group comprising one nitrogen heteroatom, for instance a pyrrolidinyl group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one oxygen heteroatom, for instance a tetrahydrofuranyl group or a dihydrofuranyl group; e) - a (C5-C10)membered heteroaryl- group comprising one to two heteroatoms selected from oxygen, nitrogen, and sulfur, for instance a thienyl group, a furanyl group, or a pyrrolyl group, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to three (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group, for instance a methyl group and g) - a (C3-C10)cycloalkyl group, for instance a cyclopentenyl group, a cyclopentyl group, a cyclohexenyl group or a cyclohexyl group. According to another embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R1represents a hydrogen atom or a group selected from: a) - a (C1-C6)alkyl- group, for instance a methyl group; - a hydroxy-(C1-C6)alkyl- group, for instance a C(OH)(CH3)2-CH2- group a C(CH3)(CH2OH)2-CH2- group or a CH(CH2OH)2-CH2- group; b) - a phenyl(C1-C6)alkyl- group, for instance a benzyl group, the phenyl group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to five (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, said alkyl group which can substitute said phenyl group being itself unsubstituted or substituted by at least one -NR4R5group, for instance one -NR4R5group, R4and R5being independently from each other: - b4.2.1) a hydrogen atom; - b4.2.2) a (C1-C16)alkyl- group, for instance a methyl group, a hexyl group or a decyl group; - b4.2.3) a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance n being 1, 2 , 3, 4, or 12; - b4.2.4) a (C1-C6)alkyl-S(O2)- group, for instance a CH3-S(O2)- group; - b4.2.6) a (C1-C16)alkyl-C(O)- group for instance a CH3-CH2C(O)- group; - b4.2.9) a (C3-C10)cycloalkyl- group, for instance a cyclopropyl group or a cyclobutyl group, said cycloalkyl group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to five (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group, for instance one methyl group or by at least one hydroxyl group; - b4.2.10) a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(O)- and -SO2, for instance a thietane dioxide group; - b4.2.11) - a phenyl-C(O)- group; - b4.2.13) a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group, for instance a CH3-C(O)-NH-phenyl-CH2-O-C(O)- group; - b4.2.14) a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group for instance a C(CH3)3-O-C(O)-CH2- group or a C(CH3)3-O-C(O)-(CH2)2- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, for instance one to two heteroatoms selected from nitrogen and oxygen, said (C3-C10)membered heterocycloalkyl- group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O- (CH2)2]n- group with n being an integer from 1 to 30, for instance R4and R5form together with the nitrogen atom to which they are attached a pyrrolidinyl group or a morpholino group; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group, for instance a cyclohexyl-CH2- group, said cycloalkyl being unsubstituted or substituted by at least one NH2group, for instance one to five NH2groups, such as one NH2group; e) - a (C5-C10) membered heteroaryl(C1-C6)alkyl- group, for instance a pyridyl-CH2- group, said heteroaryl comprising one nitrogen heteroatom, for instance a pyridyl group, said heteroaryl being unsubstituted or substituted by at least one NH2-(C1- C6)alkyl-group, for instance NH2-CH2-, for instance one to three NH2-(C1-C6)alkyl-group, for instance one to three NH2-CH2-, such as one NH2-(C1-C6)alkyl-group, for instance one NH2-CH2- and f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms, for instance one heteroatom, selected from oxygen, nitrogen, S(O), SO2 and sulfur, for instance a tetrahydropyranyl-NH-(CH2)4- group, a tetrahydropyranyl-NH-(CH2)6- group, or a dioxothietanyl-NH-(CH2)6- group; R2represents a group selected from: -a (C1-C6)alkyl- group, for instance a methyl group, a n-butyl group; - a (C1-C6)alkylthio- group, for instance a CH3CH2CH2S- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group, for instance a CH3CH2-NH-CH2- group; - a (C1-C6)alkyl-NH- group for instance a CH3CH2CH2-NH- group; R3 represents a group selected from: a) - a (C1-C6)alkyl- group, for instance a isopentyl group; - a (C2-C6)alkenyl- group, for instance a (CH3)2-CH-CH=CH- group; - a (C1-C6)alkylthio- group, for instance an isopropylthio- group b) - a -OR6group, R6being a (C1-C6)alkyl- group, for instance an isopropyl group and c) - a -NR7R8group, R7and R8being independently from each other selected from a hydrogen atom; a (C1- C6)alkyl- group, for instance a methyl group, or an isopropyl group; a (C1-C6)alkyl- group substituted by a phenyl group, for instance a benzyl group, said phenyl group being unsubstituted or substituted by at least one NR9R10-(C1-C6)alkyl- group, for instance one to five NR9R10-(C1-C6)alkyl- groups, such as one NR9R10-(C1-C6)alkyl- group, for instance NR9R10-CH2- group, R9and R10being independently from each other a (C1-C6)alkyl- group, for instance a methyl group, or a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance a CH3-O-(CH2)2- group, or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10) membered heterocycloalkyl group comprising one to two heteroatoms selected from oxygen and nitrogen, for instance a morpholino group or R7and R8form together with the nitrogen atom to which they are attached a (C3-C10) membered heterocycloalkyl- group comprising one nitrogen heteroatom, for instance a pyrrolidinyl group, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent, for instance one to three substituents, such as one substituent selected from a phenyl group, and a hydroxy(C1-C6)alkyl-phenyl- group, for instance a OH-CH2-phenyl group such as a para OH-CH2-phenyl group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur for instance a dihydropyrrolyl group or a pyrrolidinyl group or e) - a (C5-C10)membered heteroaryl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one a (C1-C6)alkyl- group, for instance a pyrrolyl group. According to another embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt: wherein: R1represents a group selected from: a) - a (C1-C6)alkyl- group, for instance a methyl group; - a hydroxy-(C1-C6)alkyl- group, for instance a C(OH)(CH3)2-CH2- group, CH(CH2OH)2-CH2- group or a C(CH2OH)2(CH3)-CH2- group; b) - a phenyl(C1-C6)alkyl- group, for instance a benzyl group, the phenyl group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to five (C1-C6)alkyl- groups, such as one (C1-C6)alkyl group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, said alkyl group being itself unsubstituted or substituted by at least one substituent, for instance one substituent, selected from: b4.1) - a hydroxyl group; b4.2) - a -NR4R5group, R4and R5being independently from each other: b4.2.1) - a hydrogen atom; b4.2.6) - a (C1-C16)alkyl-C(O)- group, for instance a CH3- C(O)- group; b4.2.9) - a (C3-C10)cycloalkyl group, for instance a cyclopropyl group or a cyclobutyl group, said cycloalkyl group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to five (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group, for instance a methyl group; or R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, for instance a nitrogen atom; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group, for instance a cyclohexyl-CH2- group, said cycloalkyl being unsubstituted or substituted by at least one substituent, for instance one to five substituents, such as one substituent selected from NH2, and a NH2-(C1- C6)alkyl- group, for instance a NH2-CH2- grou; and e) - a (C5-C10) membered heteroaryl(C1-C6)alkyl- group, for instance a pyridyl- CH2- group, said heteroaryl comprising one nitrogen heteroatom, for instance a pyridyl group, said heteroaryl being unsubstituted or substituted by at least one NH2-(C1-C6)alkyl- group, for instance one to three NH2-(C1-C6)alkyl-groups, such as one NH2-(C1-C6)alkyl- group, for instance a NH2-CH2- group; R2represents a group selected from: - a (C1-C6)alkyl- group, for instance a n-butyl group; - a (C1-C6)alkoxy(C1-C6)alkyl- group, for instance a CH3CH2-O-CH2- group; - a (C1-C6)alkylthio- group, for instance a CH3CH2CH2-S- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group, for instance a CH3CH2-NH-CH2- group; - a (C1-C6)alkyl-NH- group, for instance a CH3CH2CH2-NH- group; R3represents a group selected from: b) - a -OR6group, R6being a (C1-C6)alkyl- group, for instance an isopropyl group and c) - a -NR7R8group, R7and R8being independently from each other selected from a (C1-C6)alkyl- group, for instance a methyl group; and a (C1-C6)alkyl- group substituted by a phenyl group, for instance a benzyl group, said phenyl group being unsubstituted or substituted by at least one NR9R10-(C1-C6)alkyl- group, for instance one to five NR9R10-(C1-C6)alkyl- groups, such as one NR9R10-(C1-C6)alkyl- group, for instance a NR9R10-CH2- group, R9and R10being independently from each other a (C1-C6)alkyl group, for instance a methyl group or a CH3- [O-(CH2)2]n- with n being an integer from 1 to 30, for instance a –(CH2)2-OCH3group or d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur for instance a dihydropyrrolyl group. According to another embodiment, the disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt: wherein: R1 represents: - a hydrogen atom, or - a group selected from: a) - a (C1-C6)alkyl- group for instance a methyl group; b) - a phenyl(C1-C6)alkyl- group, for instance a phenylmethyl- group (that is to say a benzyl group) being unsubstituted or substituted by at least one substituent selected from: b1) - a (C1-C6)alkoxy- group, for instance a methoxy group; and b4) - a (C1-C6)alkyl- group, for instance a methyl group, being unsubstituted or substituted by at least one: b4.2) - -NR4R5group wherein R4and R5, being independently from each other selected from: b4.2.1) - a hydrogen atom; and b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, for instance n is 12; and c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group, for instance a cyclohexylmethyl- group, being unsubstituted or substituted by at least one -NH2group; R2 represents a group selected from: - a (C1-C6)alkyl- group for instance a methyl group or a n-butyl group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group, for instance a CH3CH2-NH-CH2- group; and - a (C1-C6)alkyl-NH- group, for instance a CH3CH2CH2-NH- group; R3represents: - a hydrogen atom or a group selected from: b) - a -OR6group wherein R6is selected from: - a hydrogen atom; and - a (C1-C6)alkyl- group, for instance an isopropyl group; c) - a -NR7R8group wherein R7and R8being, independently from each other, selected from: - a hydrogen atom; - a (C1-C6)alkyl- group, for instance a methyl group or an isopropyl group, unsubstituted or substituted by - a phenyl group being unsubstituted or substituted by at least one: - a NR9R10-(C1-C6)alkyl- group wherein: R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, for instance a piperazinyl group, said (C3-C10)membered heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, for instance a methyl group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, for instance a dihydropyrrolyl group or a pyrrolidinyl group; and e) - a (C5-C10)membered heteroaryl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, for instance a pyrazolyl group or a pyrrolyl group, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance a methyl group. In the present disclosure, the symbol on the bond denotes a covalentattachment site. When R1represents a (C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or an hexyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group. When R1represents a hydroxy-(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a hydroxymethyl group, a dihydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a dihydroxybutyl group, a trihydoxybutyl group, a hydroxypentyl group, a dihydroxypentyl group, a hydroxyhexyl group, for instance a hydroxybutyl group such as C(OH)(CH3)2-CH2-, a dihydroxybutyl group such as CH(CH2OH)2-CH2-, or a dihydroxypentyl group such as C(CH3)(CH2OH)2-CH2-. In other terms, at least one hydroxyl group replaces a hydrogen atom belonging to the alkyl moiety. When R1represents a NH2-(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a NH2-methyl- group, a NH2-ethyl- group, a NH2-propyl- group, a NH2-butyl- group, a NH2-pentyl- group or a NH2-hexyl- group, for instance a NH2- butyl- group such as NH2-(CH2)4-, a NH2-pentyl- group such as NH2-(CH2)5-, or a NH2- hexyl- group such as NH2-(CH2)6-. When R1represents a NH-(C1-C6)alkyl)-(C1-C6)alkyl- group, examples of suitable R1 groups that may be mentioned include a NH(CH3)-CH2- group, a NH(C2H5)- CH2- group, a NH(CH3)-(CH2)3- group or a NH(C3H7)-(CH2)6- group. When R1represents a N((C1-C6)alkyl)2-(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a N(CH3)2-CH2- group, a N(CH3)(C2H5)- CH2- group, a N(C3H7)(CH3)-(CH2)3- group or a NH(C4H9)-(CH2)6- group. When R1represents a (C2-C6)alkenyl- group, examples of suitable R1groups that may be mentioned include an ethenyl (or vinyl) group, a propenyl group, a butenyl group, a pentenyl group, or a hexenyl group, for instance a vinyl group or a propenyl group. When R1represents a (C2-C6)alkynyl- group, examples of suitable R1groups that may be mentioned include an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, or a hexynyl group, for instance an ethynyl group or a propynyl group. When R1represents a phenyl(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a benzyl group, a phenylpropyl group, a phenylbutyl group, a phenylpentyl group, or a phenylhexyl group, for instance a benzyl group. When R1represents a phenyl(C1-C6)alkyl- group, that the phenyl group is substituted by a (C1-C6)alkyl group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, and that said (C1-C6)alkyl group is itself substituted by a -NR4R5group, examples of suitable (C3-C10)membered heterocycloalkyl groups for R4and R5groups that may be mentioned include: piperazine, morpholino, pyrrolidine, tetrahydropyrane, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, tetrahydrofurane, azetidine, oxetane, thietane, 2H-pyrrole, 1H-, 2H- or 3H-pyrroline, tetrahydrothiophene, oxadiazole, 1,3,4-oxadiazole, 1,3,5-oxadioazole, thiadiazole, 1,3,4-thiadiazole, isoxazoline, 2- or 3-pyrazoline, pyrroline, pyrazolidine, imidazoline, imidazolidine, thiazolidine, isooxazoline, isoxazolidine, dioxalane, oxathiazole, oxathiadiazole, and dioxazole groups, for instance tetrahydropyrane or thietane dioxide such as When R1represents a phenyl(C1-C6)alkyl- group, that the phenyl group is substituted by a (C1-C6)alkyl group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, and that said (C1-C6)alkyl group is itself substituted by a -NR4R5group, examples of suitable unsubstituted or substituted (C3- C10)cycloalkyl groups for R4and R5groups that may be mentioned include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, or a cyclohexenyl group, for instance a cyclopropyl group or a cyclobutyl group, such as When R1represents a phenyl(C1-C6)alkyl- group, that the phenyl group is substituted by a (C1-C6)alkyl group, for instance a methyl group, such as a methyl group in para and / or meta position(s) of the phenyl group, and that said (C1-C6)alkyl group is itself substituted by a -NR4R5group wherein R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group, examples of suitable -NR4R5 group that may be mentioned include an unsubstituted or substituted (C3- C10)membered heterocycloalkyl- group, for instance an unsubstituted or substituted piperazinyl group, an unsubstituted or substituted morpholino group or an unsubstituted or substituted pyrrolidinyl group, such as When R1represents an unsubstituted or substituted (C5-C10) membered heteroaryl(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a pyridyl-CH2- group, a pyridyl-(CH2)2- group, a pyridyl-(CH2)3- group, a pyridyl- (CH2)4- group, a pyridyl-(CH2)5- group, a pyridyl-(CH2)6- group, a pyridyl-(C(CH3)2)- group, for instance a pyridyl-CH2- group in which the pyridyl group is unsubstituted or substituted and is for example as follows: When R1represents a (C3-C10) membered heterocycloalkyl(C1-C6)alkyl- group, examples of suitable R1groups that may be mentioned include a piperazinyl(C1-C6)alkyl- group, a piperidinyl(C1-C6)alkyl- group, a morpholino(C1-C6)alkyl- group, a tetrahydofuran (C1-C6)alkyl- group, or a tetrahydropyran(C1-C6)alkyl- group, for instance a piperazinyl- (CH2)2- group, a piperazinyl-CH2- group, a piperazinyl-(CH2)3- group, a piperazinyl-(CH2)4- group, a piperidinyl-(CH2)- group or a piperidinyl-(CH2)2- group, such as When R1represents an unsubstituted or substituted (C3-C10)cycloalkyl(C1- C6)alkyl- group, examples of suitable R1groups that may be mentioned include a cyclopropyl(C1-C6)alkyl- group, a cyclopropenyl(C1-C6)alkyl- group, a cyclobutyl(C1- C6)alkyl- group, a cyclobutenyl(C1-C6)alkyl- group, a cyclopentyl(C1-C6)alkyl- group, a cyclopentenyl(C1-C6)alkyl- group, a cyclohexyl(C1-C6)alkyl- group, a cyclooctyl(C1- C6)alkyl- group, a cyclononyl(C1-C6)alkyl- group, or a cyclodecyl(C1-C6)alkyl- group, for instance a cyclohexyl-CH2- group in which the cyclohexyl group is unsubstituted or substituted , such as: When R1represents a (C3-C10) membered heterocycloalkyl-NH-(C1-C16)alkyl- group, examples of suitable R1groups that may be mentioned include a dioxothietanyl-NH- (C1-C16)alkyl- group, a piperazinyl-NH-(C1-C16)alkyl- group, a piperidinyl-NH-(C1- C16)alkyl- group, a morpholino-NH-(C1-C16)alkyl- group, a tetrahydofuranyl-NH-(C1- C16)alkyl- group, or a tetrahydropyranyl-NH-(C1-C16)alkyl- group, for instance a tetrahydropyranyl-NH-(CH2)4- group, a tetrahydropyranyl-NH-(CH2)6- group, a dioxothietanyl-NH-(CH2)4- group, a dioxothietanyl-NH-(CH2)6- group such as , and . When R1represents a (C3-C10) membered heterocycloalkyl-N(C(O)-(C1- C6)alkyl)-(C1-C16)alkyl- group, examples of suitable R1groups that may be mentioned include a dioxothietanyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, a piperazinyl-N(C(O)- (C1-C6)alkyl)-(C1-C16)alkyl- group, a piperidinyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, a morpholino-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, a tetrahydofuranyl- N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, or a tetrahydropyranyl-N(C(O)-(C1-C6)alkyl)- (C1-C16)alkyl- group, for instance a tetrahydropyranyl-N(C(O)CH3)-(CH2)4- group, a tetrahydropyranyl-N(C(O)CH3)-(CH2)6- group, a dioxothietanyl-N(C(O)CH3)-(CH2)4- group, a dioxothietanyl-N(C(O)CH3)-(CH2)6- group such as When R2represents a (C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include : a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group, for instance a methyl group, an ethyl group, a propyl group such as a n-propyl group, a butyl group such as a n-butyl group. When R2represents a (C2-C6)alkenyl- group, examples of suitable R2groups that may be mentioned include an ethenyl (or vinyl) group, a propenyl group, a butenyl group, a pentenyl group, or a hexenyl group, for instance a vinyl group or a propenyl group. When R2represents a (C2-C6)alkynyl- group, examples of suitable R2groups that may be mentioned include an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, or a hexynyl group, for instance an ethynyl group or a propynyl group. When R2represents a (C1-C6)alkylthio- group, examples of suitable R2groups that may be mentioned include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group or a hexylthio group, for instance a propylthio group such as CH3-(CH2)2-S-. When R2represents a (C1-C6)alkylthio(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a methythiomethyl group, a methylthioethyl group, an ethylthiopropyl group, a butylthioethyl group, a pentylthiohexyl group, for instance CH3- S-(CH2)2-. When R2represents a (C1-C6)alkyl-S(O)- group, examples of suitable R2groups that may be mentioned include a methyl-S(O)- group, an ethyl-S(O)- group, a propyl-S(O)- group, a butyl-S(O)- group, a pentyl-S(O)- group, a hexyl-S(O)- group, for instance a methyl-S(O)- group, an ethyl-S(O)- group or a propyl-S(O)- group. When R2represents a (C1-C6)alkyl-SO2- group, examples of suitable R2groups that may be mentioned include a methyl-SO2- group, an ethyl-SO2- group, a propyl-SO2- group, a butyl-SO2- group, a pentyl-SO2- group, a hexyl-SO2- group, for instance a methyl- SO2- group or an ethyl-SO2- group. When R2represents a (C1-C6)alkyl-S(O)-(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a methyl-S(O)-methyl group, an ethyl- S(O)-propyl group, or a pentyl-S(O)-hexyl group When R2represents a (C1-C6)alkyl-SO2-(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a methyl-SO2-methyl- group, an ethyl- SO2-propyl- group, a hexyl-SO2-butyl- group. When R2represents a (C1-C6)alkoxy- group, examples of suitable R2groups that may be mentioned include a methoxy group, an ethoxy group, a propoxy group such as a n- propoxy group or an isopropoxy group, a butoxy group such as a n-butoxy group, a sec- butoxy group, a tertio-butoxy or an isobutoxy group, a pentyloxy group such as a n- pentyloxy group, an isopentyloxy group or a tertio-pentyloxy group, or a hexyloxy group such as a n-hexyloxy group, an isohexyloxy group or a tertio-hexyloxy group. When R2represents a (C1-C6)alkoxy(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a methoxymethyl group, a methoxyethyl group, an ethoxypropyl group, a butoxyethyl group, such as CH3-CH2-O-CH2- or CH3-O-(CH2)2-. When R2represents a (C1-C6)haloalkoxy(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a trifluoromethoxymethyl group, or a difluoromethoxyethyl group, When R2represents a (C3-C5)cycloalkyl-O-(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a cyclopropyl-O-methyl group, a cyclopropyl-O-ethyl group, cyclopropyl-O-hexyl group, a cyclopropenyl-O-ethyl group, a cyclobutyl-O-methyl group, a cyclobutyl-O-propyl group, a cyclobutenyl-O-butyl group, a cyclopentyl-O-methyl group, a cyclopentyl-O-ethyl group or a cyclopentenyl-O-ethyl group, such as a cyclobutyl-O-methyl group or a cyclopentyl-O-ethyl group. When R2represents a (C1-C6)alkyl-NH- group, examples of suitable R2groups that may be mentioned include a methyl-NH- group, an ethyl-NH- group, a propyl-NH- group, a butyl-NH- group, a pentyl-NH- group or a hexyl- NH- group such as CH3NH-, CH3CH2NH-, or CH3CH2CH2NH-. When R2represents a ((C1-C6)alkyl)2-N- group, examples of suitable R2groups that may be mentioned include a (CH3)2-N- group, a (C2H5)2-N- group, a (CH3)(C2H5)N- group or a (C3H7)2-N- group. When R2represents a (C1-C6)alkyl-NH-(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a CH3-NH-CH2- group, a CH3-CH2-NH- CH2- group a CH3-NH-C2H5- group, or a C3H7-NH-CH2- group. When R2represents a ((C1-C6)alkyl)2-N-(C1-C6)alkyl- group, examples of suitable R2groups that may be mentioned include a (CH3)2-N-CH2- group, a (CH3)(C2H5)N- CH2- group or a (CH3)(C2H5)N-C3H7- group. When R3represents a (C1-C6)alkyl- group, examples of suitable R3groups that may be mentioned include : a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group, for instance a propyl group, a butyl group, and a pentyl group such as an isopropyl group, an isobutyl group, or an isopentyl group. When R3represents a (C2-C6)alkenyl- group, examples of suitable R3groups that may be mentioned include : an ethenyl (or vinyl) group, a propenyl group, a butenyl group, a pentenyl group, or a hexenyl group, for instance a propenyl group such as C(CH3)(=CH2)- , a butenyl group such as (CH3)2C=CH-, or a pentenyl group such as (CH3)2CH-CH=CH-. When R3represents a (C2-C6)alkynyl- group, examples of suitable R3groups that may be mentioned include : an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, or a hexynyl group, for instance an ethynyl group or a propynyl group. When R3represents a (C1-C6)alkylthio- group, examples of suitable R3groups that may be mentioned include : a methylthio- group, an ethylthio- group, a propylthio- group, a butylthio- group, a pentylthio- group or a hexylthio group, for instance a propylthio- group such as an isopropylthio- group. When R3represents a -OR6group and that R6is a (C1-C6)alkyl- group, examples of suitable R6groups that may be mentioned include: a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group, an ethyl group, an isopropyl group, a n-propyl group, a n-butyl group, or a sec-butyl group. When R3represents a -OR6group and that R6is a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, examples of suitable R6groups that may be mentioned include: CH3-O-(CH2)2-, CH3-[O-(CH2)2]2-, CH3-[O-(CH2)2]3-, CH3-[O-(CH2)2]4-, CH3-[O- (CH2)2]5-, CH3-[O-(CH2)2]6-, CH3-[O-(CH2)2]7-, CH3-[O-(CH2)2]8-, CH3-[O-(CH2)2]9,CH3- [O-(CH2)2]10-, CH3-[O-(CH2)2]11-, CH3-[O-(CH2)2]12-, CH3-[O-(CH2)2]13-, CH3-[O- (CH2)2]14-, CH3-[O-(CH2)2]15-, CH3-[O-(CH2)2]16-, CH3-[O-(CH2)2]17-, CH3-[O-(CH2)2]18-, CH3-[O-(CH2)2]19-, CH3-[O-(CH2)2]20-, CH3-[O-(CH2)2]21-, CH3-[O-(CH2)2]22-, CH3-[O- (CH2)2]23-, CH3-[O-(CH2)2]24-, CH3-[O-(CH2)2]25-, CH3-[O-(CH2)2]26-, CH3-[O-(CH2)2]27-, CH3-[O-(CH2)2]28-, CH3-[O-(CH2)2]29-, CH3-[O-(CH2)2]30-, such as CH3-[O-(CH2)2]24- and CH3-O-(CH2)2-. When R3represents a -OR6group and that R6is a (C2-C6)alkenyl- group, examples of suitable R6groups that may be mentioned include an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a hexenyl group, for instance a propenyl group such as CH=CH-CH2-. When R3represents a -OR6group and that R6is a (C2-C6)alkynyl- group, examples of suitable R6groups that may be mentioned include: an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, or a hexynyl group, for instance an ethynyl group or a propynyl group. When R3represents a -OR6group and that R6is a (C3-C10)cycloalkyl- group, examples of suitable R6groups that may be mentioned include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, or a cyclohexenyl group, for instance a cyclopentyl group. When R3represents a -OR6group and that R6is a phenyl((C1-C6)alkyl)- group, examples of suitable R6groups that may be mentioned include a benzyl group (that is to say a phenylmethyl group), a phenylpropyl group, a phenylbutyl group, a phenylpentyl group, or a phenylhexyl group, for instance a benzyl group. When R3represents a -OR6group and that R6is a (C3-C10) membered heterocycloalkyl group, examples of suitable R6 groups that may be mentioned include piperazine, morpholino, pyrrolidine, tetrahydropyrane, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, tetrahydrofurane, azetidine, oxetane, thietane, 2H-pyrrole, 1H-, 2H- or 3H-pyrroline, tetrahydrothiophene, oxadiazole, 1,3,4- oxadiazole, 1,3,5-oxadioazole, thiadiazole, 1,3,4-thiadiazole, isoxazoline, 2- or 3- pyrazoline, pyrroline, pyrazolidine, imidazoline, imidazolidine, thiazolidine, isooxazoline, isoxazolidine, dioxalane, oxathiazole, oxathiadiazole, and dioxazole groups, for instance piperazine, morpholino, pyrrolidine, tetrahydropyrane, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, and tetrahydrofurane groups, such as tetrahydropyrane group, a thiolane dioxide group, a thiolane group, a thiolane oxide group, and a tetrahydrofuranyl group, for example When R3represents a -NR7R8group and that R7and R8form together with the nitrogen to which they are attached an unsubstituted or substituted 3-10 membered heterocycloalkyl group, examples of suitable -NR7R8groups that may be mentioned include an unsubstituted or substituted piperazine, morpholino, or pyrrolidine, for instance an unsubstituted or substituted pyrrolidinyl group, such as When R3represents a -NR7R8group and that R7and / or R8represents a 5-10 membered heteroaryl(C1-C6)alkyl- group, examples of suitable R7and / or R8groups that may be mentioned include pyridine(C1-C6)alkyl- group, furan(C1-C6)alkyl- group, pyrrole(C1- C6)alkyl- group, thiophene(C1-C6)alkyl- group, pyrazole(C1-C6)alkyl- group, oxazole(C1- C6)alkyl- group, isoxazole(C1-C6)alkyl- group, triazole(C1-C6)alkyl- group, tetrazole(C1- C6)alkyl- group, oxadiazole(C1-C6)alkyl- group, furazan(C1-C6)alkyl- group, thiazole(C1- C6)alkyl- group, isothiazole(C1-C6)alkyl- group, thiadiazole(C1-C6)alkyl- group, imidazole(C1-C6)alkyl- group, pyrimidine(C1-C6)alkyl- group, pyridazine(C1-C6)alkyl- group, and triazine(C1-C6)alkyl- group, for instance a furanyl-CH2- group, a furanyl-(CH2)2- group, a furanyl-(CH2)3- group, a furanyl-(CH2)4- group, a furanyl-(CH2)5- group, a furanyl- (CH2)6- group such as . When R3represents a -NR7R8group, that R7and / or R8represents a phenyl(C1- C6)alkyl- group, for instance a benzyl group, and that said phenyl group is substituted by at least one substituent, such as one NR9R10-(C1-C6)alkyl- group, examples of suitable NR9R10- (C1-C6)alkyl- groups that may be mentioned include: . For R3, when R9and R10together form with the nitrogen atom to which they are attached an unsubstituted or substituted (C3-C10) membered heterocycloalkyl- group, examples of suitable NR9R10groups that may be mentioned include: piperazine, morpholino, pyrrolidine, tetrahydropyrane, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, tetrahydrofurane, azetidine, oxetane, thietane, 2H-pyrrole, 1H-, 2H- or 3H-pyrroline, tetrahydrothiophene, oxadiazole, 1,3,4-oxadiazole, 1,3,5-oxadioazole, thiadiazole, 1,3,4-thiadiazole, isoxazoline, 2- or 3-pyrazoline, pyrroline, pyrazolidine, imidazoline, imidazolidine, thiazolidine, isooxazoline, isoxazolidine, dioxalane, oxathiazole, oxathiadiazole, and dioxazole groups, for instance a morpholino group or a piperazinyl group, such as and . When R3represents a (C3-C10) membered heterocycloalkyl- group, examples of suitable 3-10 membered heterocycloalkyl groups that may be mentioned include piperazine, morpholino, pyrrolidine, tetrahydropyrane, dihydropyrrole, thietane dioxide, piperidine, thiolane, thiolane oxide, thiolane dioxide, dihydrofurane, tetrahydrofurane, azetidine, oxetane, thietane, 2H-pyrrole, 1H-, 2H- or 3H-pyrroline, tetrahydrothiophene, oxadiazole, 1,3,4-oxadiazole, 1,3,5-oxadioazole, thiadiazole, 1,3,4-thiadiazole, isoxazoline, 2- or 3- pyrazoline, pyrroline, pyrazolidine, imidazoline, imidazolidine, thiazolidine, isooxazoline, isoxazolidine, dioxalane, oxathiazole, oxathiadiazole, and dioxazole groups, for instance a tetrahydrofuranyl group, a dihydropyrrolyl group or a dihydrofuranyl group, such as When R3represents a (C3-C10)cycloalkyl- group, examples of suitable (C3- C10)cycloalkyl groups that may be mentioned include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, or a cyclohexenyl group, for instance a cyclopentenyl group, a cyclopentyl group, a cyclohexenyl group or a cyclohexyl group, such as When R3 represents an unsubstituted or substituted (C5-C10) membered heteroaryl- group, examples of suitable groups that may be mentioned include pyridine, furan, pyrrole, thiophene, pyrazole, oxazole, isoxazole, triazole, tetrazole, oxadiazole, furazan, thiazole, isothiazole, thiadiazole, imidazole, pyrimidine, pyridazine, and triazine groups, for instance a thienyl group, a furanyl group, a pyrrolyl group or a pyrazolyl group, such as , When R3 represents a (C6-C10)aryl- group, examples of suitable (C6-C10)aryl- groups that may be mentioned include naphthyl group and phenyl group. According to another embodiment, R3represents: In the meaning of the present disclosure, examples of suitable CH3-[O-(CH2)2]n- groups with n being an integer from 1 to 30, that may be mentioned include: CH3-O-(CH2)2- , CH3-[O-(CH2)2]2-, CH3-[O-(CH2)2]3-, CH3-[O-(CH2)2]4-, CH3-[O-(CH2)2]5-, CH3-[O- (CH2)2]6-, CH3-[O-(CH2)2]7-, CH3-[O-(CH2)2]8-, CH3-[O-(CH2)2]9,CH3-[O-(CH2)2]10-, CH3- [O-(CH2)2]11-, CH3-[O-(CH2)2]12-, CH3-[O-(CH2)2]13-, CH3-[O-(CH2)2]14-, CH3-[O- (CH2)2]15-, CH3-[O-(CH2)2]16-, CH3-[O-(CH2)2]17-, CH3-[O-(CH2)2]18-, CH3-[O-(CH2)2]19-, CH3-[O-(CH2)2]20-, CH3-[O-(CH2)2]21-, CH3-[O-(CH2)2]22-, CH3-[O-(CH2)2]23-, CH3-[O- (CH2)2]24-, CH3-[O-(CH2)2]25-, CH3-[O-(CH2)2]26-, CH3-[O-(CH2)2]27-, CH3-[O-(CH2)2]28-, CH3-[O-(CH2)2]29-, CH3-[O-(CH2)2]30-, such as CH3-[O-(CH2)2]24- and CH3-O-(CH2)2.Among the compounds of formula (I) that are subject matter of the present disclosure, mention may be made for instance of the following compounds: (1) 2-butyl-7-isopropoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (2) 2-butyl-N7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4,7-diamine; (3) 2-butyl-7-(isopropylthio)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (4) 2-butyl-1-(4-methoxybenzyl)-7-(2-methoxyethoxy)-1H-imidazo[4,5- d]pyridazin-4-amine; (5) 2-butyl-1-(4-methoxybenzyl)-7-propoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (6) 7-(allyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (7) 7-(sec-butoxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (8) 7-butoxy-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (9) 2-butyl-7-(cyclopentyloxy)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d] pyridazin-4-amine; (10) 2-butyl-1-(4-methoxybenzyl)-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (11) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-3-yl)-1H- imidazo[4,5d] pyridazin-4-amine; (12) (E)-2-butyl-1-(4-methoxybenzyl)-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (13) 2-butyl-7-isopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (14) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (15) 2-butyl-7-(cyclopent-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (16) 2-butyl-7-cyclopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (17) 2-butyl-1-(4-methoxybenzyl)-7-(prop-1-en-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (18) 2-butyl-7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (19) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride; (20) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate; (21) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d] pyridazin-4-amine; (22) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (23) 1-(((1S,3R)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (and enantiomer); (24) 1-(4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)-2- methylpropan-2-ol; (25) Trans 1-(4-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (26) 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (27) 6-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)nicotinonitrile; (28) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5d]pyridazin-1- yl)methyl)benzyl)acetamide; (29) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)undecanamide; (30) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)pentanamide; (31) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-(2-methoxyethoxy)propanamide; (32) 1-(((1S,3S)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-]pyridazin-4-amine (and enantiomer); (33) 1-(3-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (34) 4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzaldehyde; (35) (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)phenyl)methanol; (36) 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (37) 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (38) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide; (39) 2-butyl-7-isopropoxy-1-(4-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine; (40) 2-butyl-7-isopropoxy-1-(4-(piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (41) 2-butyl-N7,N7,1-trimethyl-1H-imidazo[4,5-d]pyridazin-4,7-diamine; (42) 2-butyl-1-methyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5-d]pyridazin-4- amine; (43) 2-butyl-N7-(4-((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H- imidazo[4,5-d]pyridazin-4,7-diamine; (44) 2-butyl-N7,1-dimethyl-N7-(4-(morpholinomethyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (45) 4-(((4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)(methyl)amino)methyl)benzonitrile; (46) N7-(4-(aminomethyl)benzyl)-2-butyl-N7,1-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (47) 2-butyl-N7-(4-(((2-methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1- dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (48) 2-butyl-7-ethoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (49) 2-butyl-1-(4-methoxybenzyl)-N7-(2-methoxyethyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (50) 2-butyl-7-methoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (51) 2-butyl-7-cyclohexyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (52) 7-(benzyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (53) 2-butyl-1-(4-methoxybenzyl)-N7-methyl-1H-imidazo[4,5-d]pyridazine- 4,7-diamine; (54) (S)-2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (55) 2-butyl-7-(furan-2-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazine- 4-amine; (56) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (57) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydro-2H-pyran-4-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (58) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrothiophen-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (59) 2-butyl-1-(4-methoxybenzyl)-7-(tetrahydrofuran-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (60) 2-butyl-1-(4-methoxybenzyl)-7-(2-methylprop-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (61) 2-butyl-7-isobutyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (62) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (63) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (64) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (65) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer A; (66) 2-butyl-7-(cyclohex-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (67) 2-butyl-7-(furan-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (68) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1,1-dioxide; (69) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer B; (70) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-2-yl)-1H- imidazo[4,5-d]pyridazin-4-amine hydrochloride; (71) 2-butyl-1-(4-methoxybenzyl)-N7,N7-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (72) 2-butyl-1-(4-methoxybenzyl)-7-phenoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (73) 2-butyl-7-(2,5-dihydrofuran-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (74) 2-butyl-7-isopropoxy-1-(pyridin-3-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (75) 2-butyl-7-isopropoxy-1-(pyridin-2-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (76) 2-butyl-7-isopropoxy-1-(pyridin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (77) 1-(5-aminopentyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (78) 2-butyl-7-isopropoxy-1-(2-(piperidin-4-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (79) 2-butyl-7-isopropoxy-1-(2-(piperazin-1-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (80) 1-benzyl-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride; (81) 2-butyl-1-(cyclohexylmethyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride; (82) 2-butyl-7-isopropoxy-1-(4-(((tetrahydro-2H-pyran-4- yl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride; (83) 2-butyl-7-isopropoxy-1-(4-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride; (84) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)heptanamide; (85) (4-(1-(4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)pyrrolidin-3-yl)phenyl)methanol hydrochloride; (86) 2-butyl-7-isopropoxy-1-methyl-1H-imidazo[4,5-d]pyridazin-4-amine; (87) N7-(4-(aminomethyl)benzyl)-2-butyl-1-methyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (88) 2-butyl-N7-isopropyl-1-methyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (89) 2-butyl-1-methyl-7-(3-phenylpyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (90) N7-benzyl-2-butyl-N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7- diamine; (91) 2-butyl-1-methyl-N7-(4-((4-methylpiperazin-1-yl)methyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (92) 2-butyl-1-(4-methoxybenzyl)-7-phenyl-1H-imidazo[4,5-d]pyridazin-4- amine; (93) 4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7-ol; (94) 2-butyl-N7-(3-(furan-2-yl)propyl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (95) 2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (96) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrazol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (97) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrazol-4-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (98) 2-butyl-N7-isopropyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (99) 2-butyl-7-(isopropylthio)-1H-imidazo[4,5-d]pyridazin-4-amine; (100) (1R,3R)-3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)cyclobutan-1-ol dihydrochloride salt; (101) 2-butyl-7-isopropoxy-1-(4-(pyrrolidin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (102) 2-butyl-7-isopropoxy-1-(4-(morpholinomethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (103) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)propionamide; (104) 2-butyl-7-isopropoxy-1-(4-(((2-methoxyethyl)amino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (105) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[ 4,5-d]pyridazin-7-amine; (106) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)benzamide; (107) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-methoxypropanamide; (108) 2-butyl-7-isopropoxy-1-(4-(((2-(2- methoxyethoxy)ethyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (109) 2-butyl-1-(4-((hexylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (110) 2-butyl-1-(4-((decylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (111) ethyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)carbamate; (112) 4-methoxybenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (113) 1-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-ethylurea; (114) 4-acetamidobenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (115) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)methanesulfonamide; (116) 2-butyl-1-(4-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (117) tert-butyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)glycinate; (118) 2-butyl-7-isopropoxy-1-(4-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (119) tert-butyl 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)propanoate; (120) 1-(4-(5,8,11-trioxa-2-azadodecyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (121) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[4,5- d]pyridazin-7-amine; (122) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl] methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2-trifluoroacetate; (123) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethox y]ethylamino]methyl]phenyl]methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2- trifluoroacetate; (124) 2-butyl-7-isopropoxy-1-(3-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (125) 2-butyl-1-(3-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (126) 2-butyl-1-(3-((cyclobutylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (127) 2-butyl-1-(3-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (128) 2-butyl-7-isopropoxy-1-(3-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (129) 3-((3-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (130) 2-butyl-7-isopropoxy-1-(3-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (131) 2-butyl-7-isopropoxy-1-(3-(piperazin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (132) (E)-1-(4-(aminomethyl)benzyl)-2-butyl-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (133) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopentyl-1H-imidazo[4,5- d]pyridazin-4-amine; (134) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (135) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (137) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-((E)-3- methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine (138) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopentyl- 1H-imidazo[4,5-d]pyridazin-4-amine; (139) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-((E)-3-methylbut-1- en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (140) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-isopentyl-1H- imidazo[4,5-d]pyridazin-4-amine; (141) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (142) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-(pyrrolidin- 1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (143) 3-[(4-aminocyclohexyl)methyl]-2-butyl-4-pyrrolidin-1-yl-imidazo[4,5- d]pyridazin-7-amine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (145) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-pyrrolidin-3-yl- imidazo[4,5-d]pyridazin-4-amine; (146) 3-(6-aminohexyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7- amine dihydrochloride salt; (147) 2-butyl-4-isopropoxy-3-[6-(tetrahydropyran-4- ylamino)hexyl]imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (148) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-tetrahydropyran-4-yl-acetamide; (149) 3-(4-aminobutyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (150) 2-butyl-4-isopropoxy-3-[4-(tetrahydropyran-4- ylamino)butyl]imidazo[4,5-d]pyridazin-7-amine hydrochloride salt; (151) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-tetrahydropyran-4-yl-acetamide; (152) 2-butyl-3-[4-[(1,1-dioxothietan-3-yl)amino]butyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (153) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-(1,1-dioxothietan-3-yl)acetamide; (154) 2-butyl-3-[6-[(1,1-dioxothietan-3-yl)amino]hexyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (155) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-(1,1-dioxothietan-3-yl)acetamide hydrochloride salt; (156) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3-yl)methyl]- 2-methyl-propane-1,3-diol hydrochloride salt; (157) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)methyl]propane-1,3-diol hydrochloride salt; (158) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-propyl-1H-imidazo[4,5- d]pyridazin-4-amine; (159) 1-(4-(aminomethyl)benzyl)-2-(ethoxymethyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (160) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-methyl-1H-imidazo[4,5- d]pyridazin-4-amine; (161) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfanyl- imidazo[4,5-d]pyridazin-7-amine; (162) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfinyl- imidazo[4,5-d]pyridazin-7-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine; (165) 2-butyl-7-isopropoxy-1-(piperidin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; or a pharmaceutically acceptable salt thereof. Among the preceding listed compounds, the following compounds which are of interest may for example be cited: (1) 2-butyl-7-isopropoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (2) 2-butyl-N7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4,7-diamine; (3) 2-butyl-7-(isopropylthio)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (4) 2-butyl-1-(4-methoxybenzyl)-7-(2-methoxyethoxy)-1H-imidazo[4,5- d]pyridazin-4-amine; (5) 2-butyl-1-(4-methoxybenzyl)-7-propoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (6) 7-(allyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (7) 7-(sec-butoxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (8) 7-butoxy-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (9) 2-butyl-7-(cyclopentyloxy)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d] pyridazin-4-amine; (10) 2-butyl-1-(4-methoxybenzyl)-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (11) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-3-yl)-1H- imidazo[4,5d] pyridazin-4-amine; (12) (E)-2-butyl-1-(4-methoxybenzyl)-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (13) 2-butyl-7-isopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (14) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (15) 2-butyl-7-(cyclopent-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (16) 2-butyl-7-cyclopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (17) 2-butyl-1-(4-methoxybenzyl)-7-(prop-1-en-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (18) 2-butyl-7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (19) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride; (20) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate; (25) Trans 1-(4-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (26) 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (27) 6-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)nicotinonitrile; (28) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5d]pyridazin-1- yl)methyl)benzyl)acetamide; (29) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)undecanamide; (30) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)pentanamide; (31) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-(2-methoxyethoxy)propanamide; (34) 4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzaldehyde; (35) (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)phenyl)methanol; (37) 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (48) 2-butyl-7-ethoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (49) 2-butyl-1-(4-methoxybenzyl)-N7-(2-methoxyethyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (50) 2-butyl-7-methoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (51) 2-butyl-7-cyclohexyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (52) 7-(benzyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (53) 2-butyl-1-(4-methoxybenzyl)-N7-methyl-1H-imidazo[4,5-d]pyridazine- 4,7-diamine; (54) (S)-2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (55) 2-butyl-7-(furan-2-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazine-4-amine; (56) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (57) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydro-2H-pyran-4-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (58) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrothiophen-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (59) 2-butyl-1-(4-methoxybenzyl)-7-(tetrahydrofuran-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (60) 2-butyl-1-(4-methoxybenzyl)-7-(2-methylprop-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (61) 2-butyl-7-isobutyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (62) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (63) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (64) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (65) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer A; (66) 2-butyl-7-(cyclohex-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (67) 2-butyl-7-(furan-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (68) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1,1-dioxide; (69) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer B; (70) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-2-yl)-1H- imidazo[4,5-d]pyridazin-4-amine hydrochloride; (71) 2-butyl-1-(4-methoxybenzyl)-N7,N7-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (72) 2-butyl-1-(4-methoxybenzyl)-7-phenoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (73) 2-butyl-7-(2,5-dihydrofuran-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (75) 2-butyl-7-isopropoxy-1-(pyridin-2-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (76) 2-butyl-7-isopropoxy-1-(pyridin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (77) 1-(5-aminopentyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (78) 2-butyl-7-isopropoxy-1-(2-(piperidin-4-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (79) 2-butyl-7-isopropoxy-1-(2-(piperazin-1-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (80) 1-benzyl-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride; (81) 2-butyl-1-(cyclohexylmethyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride; (87) N7-(4-(aminomethyl)benzyl)-2-butyl-1-methyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (92) 2-butyl-1-(4-methoxybenzyl)-7-phenyl-1H-imidazo[4,5-d]pyridazin-4- amine; (94) 2-butyl-N7-(3-(furan-2-yl)propyl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (97) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrazol-4-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (105) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[ 4,5-d]pyridazin-7-amine; (107) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-methoxypropanamide; (111) ethyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)carbamate; (112) 4-methoxybenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (113) 1-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-ethylurea; (122) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl] methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2-trifluoroacetate; (128) 2-butyl-7-isopropoxy-1-(3-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (131) 2-butyl-7-isopropoxy-1-(3-(piperazin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (134) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (137) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-((E)-3- methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (138) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopentyl- 1H-imidazo[4,5-d]pyridazin-4-amine; (139) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-((E)-3-methylbut-1- en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (140) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-isopentyl-1H- imidazo[4,5-d]pyridazin-4-amine; (142) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-(pyrrolidin- 1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (143) 3-[(4-aminocyclohexyl)methyl]-2-butyl-4-pyrrolidin-1-yl-imidazo[4,5- d]pyridazin-7-amine; (146) 3-(6-aminohexyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7- amine dihydrochloride salt; (148) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-tetrahydropyran-4-yl-acetamide; (149) 3-(4-aminobutyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (151) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-tetrahydropyran-4-yl-acetamide; (152) 2-butyl-3-[4-[(1,1-dioxothietan-3-yl)amino]butyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (153) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-(1,1-dioxothietan-3-yl)acetamide; (155) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-(1,1-dioxothietan-3-yl)acetamide hydrochloride salt; (158) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-propyl-1H-imidazo[4,5- d]pyridazin-4-amine; (159) 1-(4-(aminomethyl)benzyl)-2-(ethoxymethyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (162) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfinyl- imidazo[4,5-d]pyridazin-7-amine; (165) 2-butyl-7-isopropoxy-1-(piperidin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; or a pharmaceutically acceptable salt thereof. Among the preceding listed compounds, the following compounds which are of interest may for example be cited: (21) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d] pyridazin-4-amine; (22) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (23) 1-(((1S,3R)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (and enantiomer); (24) 1-(4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)-2- methylpropan-2-ol; (32) 1-(((1S,3S)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-]pyridazin-4-amine (and enantiomer); (33) 1-(3-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (36) 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (38) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide; (39) 2-butyl-7-isopropoxy-1-(4-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine; (40) 2-butyl-7-isopropoxy-1-(4-(piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine ; (41) 2-butyl-N7,N7,1-trimethyl-1H-imidazo[4,5-d]pyridazin-4,7-diamine; (42) 2-butyl-1-methyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5-d]pyridazin-4- amine; (43) 2-butyl-N7-(4-((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H- imidazo[4,5-d]pyridazin-4,7-diamine; (44) 2-butyl-N7,1-dimethyl-N7-(4-(morpholinomethyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine ; (45) 4-(((4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)(methyl)amino)methyl)benzonitrile; (46) N7-(4-(aminomethyl)benzyl)-2-butyl-N7,1-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (47) 2-butyl-N7-(4-(((2-methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1- dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine ; (74) 2-butyl-7-isopropoxy-1-(pyridin-3-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (82) 2-butyl-7-isopropoxy-1-(4-(((tetrahydro-2H-pyran-4- yl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride salt; (83) 2-butyl-7-isopropoxy-1-(4-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (84) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)heptanamide; (85) (4-(1-(4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)pyrrolidin-3-yl)phenyl)methanol hydrochloride salt; (86) 2-butyl-7-isopropoxy-1-methyl-1H-imidazo[4,5-d]pyridazin-4-amine; (88) 2-butyl-N7-isopropyl-1-methyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (89) 2-butyl-1-methyl-7-(3-phenylpyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (90) N7-benzyl-2-butyl-N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7- diamine; (91) 2-butyl-1-methyl-N7-(4-((4-methylpiperazin-1-yl)methyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (95) 2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (98) 2-butyl-N7-isopropyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; and (99) 2-butyl-7-(isopropylthio)-1H-imidazo[4,5-d]pyridazin-4-amine; (100) (1R,3R)-3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)cyclobutan-1-ol dihydrochloride salt; (101) 2-butyl-7-isopropoxy-1-(4-(pyrrolidin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (102) 2-butyl-7-isopropoxy-1-(4-(morpholinomethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (103) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)propionamide; (104) 2-butyl-7-isopropoxy-1-(4-(((2-methoxyethyl)amino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (106) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)benzamide; (108) 2-butyl-7-isopropoxy-1-(4-(((2-(2- methoxyethoxy)ethyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (109) 2-butyl-1-(4-((hexylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (110) 2-butyl-1-(4-((decylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (114) 4-acetamidobenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (115) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)methanesulfonamide; (116) 2-butyl-1-(4-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (117) tert-butyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)glycinate; (118) 2-butyl-7-isopropoxy-1-(4-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (119) tert-butyl 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)propanoate; (120) 1-(4-(5,8,11-trioxa-2-azadodecyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (121) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[4,5- d]pyridazin-7-amine; (123) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethox y]ethylamino]methyl]phenyl]methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2- trifluoroacetate; (124) 2-butyl-7-isopropoxy-1-(3-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (125) 2-butyl-1-(3-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (126) 2-butyl-1-(3-((cyclobutylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (127) 2-butyl-1-(3-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (129) 3-((3-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (130) 2-butyl-7-isopropoxy-1-(3-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (132) (E)-1-(4-(aminomethyl)benzyl)-2-butyl-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (133) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopentyl-1H-imidazo[4,5- d]pyridazin-4-amine; (135) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (141) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (145) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-pyrrolidin-3-yl- imidazo[4,5-d]pyridazin-4-amine; (147) 2-butyl-4-isopropoxy-3-[6-(tetrahydropyran-4- ylamino)hexyl]imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (150) 2-butyl-4-isopropoxy-3-[4-(tetrahydropyran-4- ylamino)butyl]imidazo[4,5-d]pyridazin-7-amine hydrochloride salt; (154) 2-butyl-3-[6-[(1,1-dioxothietan-3-yl)amino]hexyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (156) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3-yl)methyl]- 2-methyl-propane-1,3-diol hydrochloride salt; (157) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)methyl]propane-1,3-diol hydrochloride salt; (160) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-methyl-1H-imidazo[4,5- d]pyridazin-4-amine; (161) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfanyl- imidazo[4,5-d]pyridazin-7-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine ora pharmaceutically acceptable salt thereof. Among the preceding listed compounds, the following compounds which are of interest may for example be cited: (19) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (20) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate; (21) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine; (22) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (23) 1-(((1S,3R)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (and enantiomer); (24) 1-(4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)-2- methylpropan-2-ol; (25) Trans 1-(4-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo [4,5-d]pyridazin-4-amine; (26) 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (28) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5d]pyridazin-1- yl)methyl)benzyl)acetamide; (33) 1-(3-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (35) (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)phenyl)methanol; (36) 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (39) 2-butyl-7-isopropoxy-1-(4-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine; (40) 2-butyl-7-isopropoxy-1-(4-(piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (43) 2-butyl-N7-(4-((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (47) 2-butyl-N7-(4-(((2-methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1- dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (156) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3-yl)methyl]- 2-methyl-propane-1,3-diol hydrochloride salt; (157) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)methyl]propane-1,3-diol hydrochloride salt; (159) 1-(4-(aminomethyl)benzyl)-2-(ethoxymethyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (161) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfanyl- imidazo[4,5-d]pyridazin-7-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine or a pharmaceutically acceptable salt thereof. Among the preceding listed compounds, the following compounds which are of interest may for example be cited: (91) 2-butyl-1-methyl-N7-(4-((4-methylpiperazin-1-yl)methyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (93) 4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7-ol; (95) 2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (96) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrazol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (97) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrazol-4-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (98) 2-butyl-N7-isopropyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (123) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethox y]ethylamino]methyl]phenyl]methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2- trifluoroacetate; (141) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (145) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-pyrrolidin-3-yl- imidazo[4,5-d]pyridazin-4-amine; (160) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-methyl-1H-imidazo[4,5- d]pyridazin-4-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine or a pharmaceutically acceptable salt thereof. In accordance with the present disclosure, the compounds of the formula (I) can be prepared for example by the following processes, corresponding to schemes 1 (SynMethod 1), 2 (including SynMethods 2, 2a, and 2b), 3 (SynMethod 3) and 4 (SynMethod 4). These processes form also part of the present disclosure and are detailed below. The compounds of the formula (I) and other related compounds having different substituents are synthesized using techniques and materials described below or otherwise known by the skilled person in the art. In addition, solvents, temperatures and other reaction conditions presented below may vary as deemed appropriate to the skilled person in the art. General below methods for the preparation of compounds of the disclosure are optionally modified by the use of appropriate reagents and conditions for the introduction of the various moieties found in the formula (I) as described below.

[0013] SCHEME 1: Preparation of compounds of the formula (I) – General process (SynMethod 1) According to SCHEME 1, a process in accordance with the present disclosure comprises at least the following steps: (iB) providing a compound of formula (II), (iiB) cyclization of the compound of formula (II) provided in step (iB) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in the present disclosure in order to obtain a compound of formula wherein R2is as defined in in the present disclosure; (iiiB) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (iiB) in order to obtain a compound of formula (IV), wherein R2is as defined in the present disclosure; (ivB) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iiiB) in order to obtain a compound of formula (V), wherein R is a (C1-C4)alkyl- group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in the present disclosure; (vB) optionally reacting the compound of formula (V) obtained from step (ivB) with R1-X wherein R1is as defined in the present disclosure, and X represents a halogen atom, for instance chlorine, iodine or bromine atom in order to obtain a compound of formula (Vb), wherein R is a (C1-C4)alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R1and R2are as defined in the present disclosure; (viB) cyclization of the compound of formula (Vb) obtained from step (vB) or the compound of formula (V) (in which R1is a hydrogen atom) obtained from step (ivB) in order to obtain a compound of formula (VIb), wherein R1and R2are as defined in the present disclosure; (viiB) dihalogenation of the compound of formula (VIb) obtained from step (viB) in order to obtain a compound of formula (VIIa), wherein R1and R2are as defined in the present disclosure and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (viiiB) nucleophilic aromatic substitution of the compound of formula (VIIa) obtained from step (viiB) in order to obtain a compound of formula (VIIIa), (VIIIa) wherein R1and R2are as defined in the present disclosure and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom; (ixB) substitution and / or coupling of the compound of formula (VIIIa) obtained from step (viiiB) in order to obtain a compound of formula (Ia), wherein R1and R2are as defined in the present disclosure, and R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group; (xB) when R3ais other than R3as defined in the present disclosure, then reacting the compound of formula (Ia) obtained from step (ixB) with any suitable reagents and in any suitable conditions in order to obtain a compound of formula (I) as defined in the present disclosure. Said route allows to prepare, for example the following compounds of formula (I) in accordance with the present disclosure: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 86, 92, 93, 94, 95, 96, 97, 98 and 99.

[0014] SCHEME 2: Preparation of compounds of the formula (I) – General process (SynMethods 2, 2a and 2b) comprises at least the following steps: (i) providing a compound of formula (II), (ii) cyclization of the compound of formula (II) provided in step (i) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in the present disclosure or is a hydrogen atom in order to obtain a compound of formula (III), wherein R2is as defined in the present disclosure or is a hydrogen atom; (iii) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (ii) in order to obtain a compound of formula (IV), wherein R2is as defined in the present disclosure or is a hydrogen atom; (iv) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iii) in order to obtain a compound of formula (V), wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in the present disclosure or is a hydrogen atom; (v) cyclization of the compound of formula (V) obtained from step (iv) in order to obtain a compound of formula ( wherein R2is as defined in the present disclosure or is a hydrogen atom; (vi) dihalogenation of the compound of formula (VI) obtained from step (v) in order to obtain a compound of formula (VII), wherein R2is as defined in the present disclosure or is a hydrogen atom and HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (vii) nucleophilic aromatic substitution of the compound of formula (VII) obtained from step (vi) with a compound of formula (AA) wherein the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, in order to obtain a compound of formula (VIII), a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom, and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group; (viii) substitution and / or coupling reaction of the compound of formula (VIII) obtained from step (vii) in order to obtain a compound of formula (IX), represents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group and the two G1 represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group; then either (ixAlpha, also named ixα) reacting the compound of formula (IX) obtained from step (viii) with R1a-X wherein R1ais R1as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate in order to obtain a compound of formula (X), represents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1ais as defined above in this step (ixAlpha); or (ixBeta, also named ixβ) reacting the compound of formula (IX) obtained from step (viii) with an epoxide of formula in which R’ and R’’ are independently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group in order to obtain a compound of formula (X), wherein R2is as defined in the present disclosure or is a hydrogen atom, R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1ais as defined above in the step (ixAlpha); and either (x) deprotecting the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (I) as defined in the present disclosure; and when R2is a hydrogen atom in compound of formula (X), before deprotection, the hydrogen was transformed to R2as defined in formula (I) through chemistry modification, such as metalation, followed for example either by reaction with alkyldisulfide, or dimethylformamide, or N-Bromosuccinimide, which was further submitted to other chemistry reaction, if necessary, such as oxidation, or reduction amination or nucleophilic substitution, to give requisite R2; or (x) deprotecting the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (XI) wherein R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in the present disclosure and R1bis R1aas defined in the present disclosure or R1awith a function such as an amino group, an alcohol, and an aldehyde; and then (xi) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (XI) obtained from this step (x) in order to obtain a compound of formula (I) as defined in the present disclosure; or (Gamma, also named γ) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (XII) wherein R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in the present disclosure, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1 are a methoxy group, and R1b is a derivative of R1a as defined in the present disclosure through reductive amination, reduction, substitution, and / or oxydation; and then (x) deprotecting the compound of formula (XII) obtained from step (Gamma) in order to obtain a compound of formula (I) as defined in the present disclosure. As shown in scheme 2, three options are available from compounds of formula (X). The first option is called in the present disclosure SynMethod 2. It comprises only step (x) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. The second option is called in the present disclosure SynMethod 2a. It comprises step (x) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (XI) as defined in the present disclosure and then step (xi) from a compound of formula (XI) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. The third option is called in the present disclosure SynMethod 2b. It comprises step (Gamma) (also named step γ) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (XII) as defined in the present disclosure and then step (x) from a compound of formula (XII) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. Said route SynMethod 2 allows to prepare for example the following compounds of formula (I) in accordance with the present disclosure: 19, 20, 21, 22, 23, 24, 25, 27, 32, 33, 34, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83 and 165. Said route SynMethod 2a allows to prepare for example the following compounds of formula (I) in accordance with the present disclosure: 38, 39, 40, 84, 103, 104, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 119, 148, 151, 153 and 155. Said route SynMethod 2b allows to prepare for example the following compounds of formula (I) in accordance with the present disclosure: 26, 28, 29, 30, 31, 35, 36, 37, 100 to 102, 105, 120 to 131, 146, 147, 149, 150, 152, 154, and 156 to 160

[0015] SCHEME 3: Preparation of compounds of the formula (I) – General process (SynMethod 3) According to SCHEME 3, a process in accordance with the present disclosure comprises at least the following steps: (iA) providing a compound of formula (II) (iiA) cyclization of the compound of formula (II) provided in step (iA) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in the present disclosure in order to obtain a compound of formula ( wherein R2is as defined in the present disclosure; (iiiA) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (iiA) in order to obtain a compound of formula (IV), wherein R2is as defined in the present disclosure; (ivA) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iiiA) in order to obtain a compound of formula (V), wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in the present disclosure; (vA) cyclization of the compound of formula (V) obtained from step (ivA) in order to obtain a compound of formula (VI), wherein R2is as defined in the present disclosure; (viA) dihalogenation of the compound of formula (VI) obtained from step (vA) in order to obtain a compound of formula (VII); wherein R2is as defined in the present disclosure, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (viiA) optionally reacting the compound of formula (VII) obtained from step (viA) with R1-X wherein R1is as defined in the present disclosure, and X represents a halogen atom for instance a chlorine atom, an iodine atom or a bromine atom in order to obtain a compound of formula (VIIa) wherein R1and R2are as defined in the present disclosure, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (viiiA) nucleophilic aromatic substitution of the compound of formula (VIIa) obtained from step (viiA) or of the compound of formula (VII) (in which R1is a hydrogen atom) obtained from step (viA) in order to obtain a compound of formula (VIIIa), (VIIIa) wherein R1 and R2 are as defined in the present disclosure, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom; (ixA) substitution and / or coupling of the compound of formula (VIIIa) obtained from step (viiiA) in order to obtain a compound of formula (Ia), wherein R3arepresents R 3 as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and R1and R2are as defined in the present disclosure; (xA) when R3ais other than R3as defined in the present disclosure, then reacting the compound of formula (Ia) obtained from step (ixA) with any suitable reagents and in any suitable conditions in order to obtain a compound of formula (I) as defined in the present disclosure. Said route SynMethod 3 allows to prepare for example the following compounds of formula (I) in accordance with the present disclosure: 41, 42, 43, 44, 45, 46, 47, 85, 87, 88, 89, 90 and 91.

[0016] SCHEME 4: Preparation of compounds of the formula (I) – General process (SynMethod 4) According to SCHEME 4, a process in accordance with the present disclosure comprises at least the following steps: (i) providing a compound of formula (II), (ii) cyclization of the compound of formula (II) provided in step (i) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in the present disclosure in order to obtain a compound of formula (III), wherein R2is as defined in the present disclosure; (iii) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (ii) in order to obtain a compound of formula (IV), wherein R2is as defined in the present disclosure; (iv) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iii) in order to obtain a compound of formula (V), wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in the present disclosure; (v) cyclization of the compound of formula (V) obtained from step (iv) in order to obtain a compound of formula ( wherein R2is as defined in the present disclosure; (vi) dihalogenation of the compound of formula (VI) obtained from step (v) in order to obtain a compound of formula (VII), wherein R2is as defined in the present disclosure and HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; then either (viialpha, also named viiα) reacting the compound of formula (VII) obtained from step (vi) with R1a-X wherein R1ais R1as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate in order to obtain a compound of formula (VIIIaa), (VIIIaa)wherein R2is as defined in the present disclosure, HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms, and R1ais as defined above in this step (viialpha); or (viiBeta, also named viiβ) reacting the compound of formula (VII) obtained from step (vi) with an epoxide of formula in which R’ and R’’ are independently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group in order to obtain a compound of formula (VIIIaa), (VIIIaa) wherein R2is as defined in the present disclosure, HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms, and R1ais as defined above in the step (viialpha); (viiiAA) nucleophilic aromatic substitution of the compound of formula (VIIIaa) obtained from step (viialpha) or step (viibeta) with a compound of formula (AA) wherein the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, in order to obtain wherein R2is as defined in the present disclosure, HAL is a halogen atom for instance a chlorine atom, a fluorine atom, a iodine atom or a bromine atom, for example a chlorine atom, R1ais as defined above in the step (viialpha), and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group ; (ixAA) substitution and / or coupling reaction of the compound of formula (IXaa) obtained from step (viiiAA) in order to obtain a compound of formula (X),

[0017] wherein R2is as defined in the present disclosure, R1ais as defined above in the step (viialpha), R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group ; and either (x) deprotecting the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formula (I) as defined in the present disclosure; or (x) deprotecting the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formula wherein R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in the present disclosure and R1bis R1a or R1a with a function such as an amino group, an alcohol, and an aldehyde; and then (xi) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (XI) obtained from this step (x) in order to obtain a compound of formula (I) as defined in the present disclosure; or (Gamma, also named γ) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formula (XII)

[0018] wherein R3arepresents R3as defined in the present disclosure comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in the present disclosure, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1bis a derivative of R1athrough reductive amination, reduction, substitution, and / or oxidation; and then (x) deprotecting the compound of formula (XII) obtained from step (Gamma) in order to obtain a compound of formula (I) as defined in the present disclosure. As shown in scheme 4, three options are available from compounds of formula (X). The first option is called in the present disclosure SynMethod 4. It comprises only step (x) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. The second option is called in the present disclosure SynMethod 4a. It comprises step (x) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (XI) as defined in the present disclosure and then step (xi) from a compound of formula (XI) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. The third option is called in the present disclosure SynMethod 4b. It comprises step (Gamma) (also named step γ) from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (XII) as defined in the present disclosure and then step (x) from a compound of formula (XII) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure. Said route SynMethod 4 allows to prepare for example the following compounds of formula (I) in accordance with the present disclosure: 132 to 135, 137 to 145. Concerning steps (i), (iA) and (iB) (not shown in the schemes 1, 2, 3 and 4): The compound of formula (II) is a commercially available compound, for example from Fisher or Merck-Sigma company or can be prepared by any method well known by the skilled person. Concerning steps (ii), (iiA) and (iiB) (respectively schemes 2 (or 4), 3 and 1): The cyclization steps (ii), (iiA) and (iiB) of a compound (II) as defined in the present disclosure allow to obtain a compound of formula (III) as defined in the present disclosure. For instance, the cyclization steps (ii), (iiA) and (iiB) of the compound (II) can be carried out by using as a reagent R2-C(OCH3)3 wherein R2 is as defined in the present disclosure (steps (ii), (iiA) and (iiB)) or is a hydrogen atom (step (ii)) and further in the presence of a solvent such as xylene, acetonitrile, dioxane, toluene or mixtures thereof, for example a mixture of xylene and acetonitrile, under heat that is to say at a temperature ranging from 25°C to 200°C, for example from 85°C to 150°C. The cyclization steps (ii), (iiA) and (iiB) of the compound (II) can also be carried out by using as a reagent R2-COCl wherein R2is as defined in the present disclosure (steps (ii), (iiA) and (iiB)) or is a hydrogen atom (step (ii)) in ethyl acetate (EtOAc) at room temperature and then treatment with sodium hydride (NaH) in dimethylformamide (DMF), followed by heating at reflux. Concerning steps (iii), (iiiA) and (iiiB) (respectively schemes 2 (or 4), 3 and 1): The hydrolysis steps (iii), (iiiA) and (iiiB) of nitrile groups present on a compound of formula (III) as defined in the present disclosure allow to obtain a compound of formula (IV) as defined in the present disclosure. For instance, the hydrolysis steps (iii), (iiiA) and (iiiB) of nitrile groups of the compound of formula (III) can be carried out in the presence of an acid such as sulfuric acid, hydrochloric acid or mixtures thereof, in the presence of water (water reflux) or in the presence of water and other organic solvent, such as dioxane, for example in the presence of sulfuric acid in water, under heat that is to say at a temperature ranging from 25°C to 150°C for example at 100°C. The hydrolysis steps (iii), (iiiA) and (iiiB) of nitrile groups of the compound of formula (III) can also be carried out in refluxing sodium hydroxide followed by acidification with hydrochloric acid. Concerning steps (iv), (ivA) and (ivB) (respectively schemes 2 (or 4), 3 and 1): The esterification steps (iv), (ivA) and (ivB) of carboxylic acid functions present on the compound of formula (IV) as defined in the present disclosure allow to obtain a compound of formula (V) as defined in the present disclosure. For instance, the esterification steps (iv), (ivA) and (ivB) of carboxylic acid functions present on the compound of formula (IV) can be carried out in the presence of a chlorinating agent such as thionyl chloride (SOCl2), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), oxalyl chloride or mixtures thereof, for example SOCl2, and in the presence of a primary alcohol R-OH in which R is a C1-C4alkyl group (for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group), such as methanol, ethanol, propanol, or butanol, for example methanol, for instance in SOCl2and methanol, at a temperature ranging from 25°C to 100°C, for example at 60°C. The esterification steps (iv), (ivA) and (ivB) of carboxylic acid functions present on the compound of formula (IV) can also be carried out in the presence of H2SO4, H2O, MeOH (methanol) at 100°C. Concerning step (vB) (scheme 1): The step (vB) from a compound of formula (V) as defined in the present disclosure allows to obtain a compound of formula (Vb) as defined in the present disclosure. The step (vB) is an optional step which can be carried out if a compound of formula (Vb) in which R1is as defined in the present disclosure (that is to say R1not only a hydrogen atom), is needed. In other terms, a compound of formula (V) (corresponding to R1is a hydrogen atom): - can be directly submitted to step (viB) in order to provide a compound of formula (VIb) in which R1and R2are as defined in the present disclosure, or - can be submitted to step (vB) in order to provide a compound of formula (Vb) in which R1and R2are as defined in the present disclosure and then the thus obtained compound of formula (Vb) is submitted to step (viB) in order to provide a compound of formula (VIb) in which R1and R2are as defined in the present disclosure. Depending on the wished compound, the skilled person will choose the more appropriate step to be conducted. For instance, the step (vB) can be carried out in the presence of R1-X wherein R1and X are as defined in the present disclosure, and further in the presence of a base such as potassium carbonate, cesium carbonate, or sodium hydride, for example in potassium carbonate, in a solvent such as dimethylformamide, acetone, acetonitrile, 1,4-dioxane, tetrahydrofuran (THF), or mixtures thereof, for example in dimethylformamide, such as in the presence of potassium carbonate and dimethylformamide from 0°C to 150°C, for example from 25°C to 130°C. Concerning steps (v), (vA) and (viB) (respectively schemes 2 (or 4), 3 and 1): The cyclization steps (v), (vA) and (viB) from respectively a compound of formula (V), (V) or (Vb) as defined in the present disclosure allow respectively to obtain a compound of formula (VI), (VI) and (VIb) as defined in the present disclosure. For instance, the cyclization steps (v), (vA) and (viB) can be carried out in the presence of a reagent such as hydrazine hydrate, in the presence of a solvent such as methanol, ethanol or mixtures thereof, for example methanol, such as in the presence of hydrazine, water and methanol, under heat that is to say at a temperature ranging from 25°C to 150°C, for example from 60°C to 85°C. Concerning steps (vi), (viA) and (viiB) (respectively schemes 2 (or 4), 3 and 1): The dihalogenation steps (vi), (viA) and (viiB) from respectively a compound of formula (VI), (VI) or (VIb) as defined in the present disclosure allow respectively to obtain a compound of formula (VII), (VII) and (VIIa) as defined in the present disclosure. For instance, the dihalogenation steps (vi), (viA) and (viiB) can be carried out in the presence of a reagent such as phosphorus oxychloride (POCl3), phosphorus pentachloride (PCl5), or mixtures thereof, for example POCl3,in the presence of a solvent such as N,N- dimethylaniline, such as in the presence of phosphorus oxychloride and N,N- dimethylaniline, under heat that is to say at a temperature ranging from 80°C to 160°C, for example from 100°C to 110°C. The dihalogenation steps (vi), (viA) and (viiB) can also be carried out in the presence of a mixture of phosphorus oxychloride and phosphorus pentachloride at reflux temperature. Concerning step (vii) (scheme 2): The step (vii) from a compound of formula (VII) as defined in the present disclosure allows to obtain a compound of formula (VIII) as defined in the present disclosure. The step (vii) is a nucleophilic aromatic substitution which for instance can be carried out in the presence of a solvent such as butanol, isoamyl alcohol, isopropanol or mixtures thereof, for example butanol, in the presence of a base such as N,N- diisopropylethylamine (DIEA), triethylamine (TEA), 1,8-Diazabicyclo[5.4.0]undec-7-ene DBU, for example N,N-diisopropylethylamine, such as in the presence of N,N- diisopropylethylamine and butanol, under heat that is to say at a temperature ranging from 80°C to 200°C, for example from 120°C to 130°C, or also in the presence of N-methyl-- pyrrolidone, at 130°C or in the presence of TEA, dimethylacetamide from room temperature to 50°C, and in the presence of a compound of formula (AA), wherein G1represents a hydrogen atom or a methoxy group. Advantageously, to increase the speed of the reaction, the two G1radicals in formula (AA) are each a methoxy group. Concerning step (viiA) (scheme 3): The step (viiA) from a compound of formula (VII) as defined in the present disclosure allows to obtain a compound of formula (VIIa) as defined in the present disclosure. The step (viiA) is an optional step which can be carried out if a compound of formula (VIIa) in which R1is as defined in the present disclosure (that is to say R1not only a hydrogen atom), is needed. In other terms, a compound of formula (VII) (corresponding to R1is a hydrogen atom): - can be directly submitted to step (ViiiA) in order to provide a compound of formula (VIIIa) in which R1, R2and HAL are as defined in the present disclosure, or - can be submitted to step (viiA) in order to provide a compound of formula (VIIa) in which R1, R2and HAL are as defined in the present disclosure and then the thus obtained compound of formula (VIIa) is submitted to step (viiiA) in order to provide a compound of formula (VIIIa) in which R1, R2and HAL are as defined in the present disclosure. Depending on the wished compound, the skilled person will choose the more appropriate step to be conducted. The step (viiA) can be carried out in the presence of R1-X wherein R1and X are as defined in the present disclosure, such as in the presence of methyl iodide (MeI), in acetone and K2CO3, at room temperature (25°C), or in the presence of R1-X as defined in the present disclosure, in Cs2CO3, 1,4-Dioxane, from room temperature (25°C) to 120°C. Concerning step (viialpha, also named viiα) and step (viibeta, also named viiβ) (scheme 4): The step (viialpha) or the step (viibeta) from a compound of formula (VII) as defined in the present disclosure allow to obtain a compound of formula (VIIIaa) as defined in the present disclosure. The step (viialpha) can be carried out in the presence of R1a-X wherein R1ais R1as defined in the present disclosure, comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate The step (viibeta) can be carried out in the presence of an epoxide of formula in which R’ and R’’ are independently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group. Concerning step (viiiAA) (scheme 4): The step (viiiAA) from a compound of formula (VIIIaa) as defined in the present disclosure allows to obtain a compound of formula (IXaa) as defined in the present disclosure. The step (viiiAA) is a nucleophilic aromatic substitution which for instance can be carried out in the presence of a solvent such as butanol, isoamyl alcohol, isopropanol or mixtures thereof, for example butanol, in the presence of a base such as N,N- diisopropylethylamine (DIEA), triethylamine (TEA), 1,8-Diazabicyclo[5.4.0]undec-7-ene DBU, for example N,N-diisopropylethylamine, such as in the presence of N,N- diisopropylethylamine and butanol, under heat that is to say at a temperature ranging from 80°C to 200°C, for example from 120°C to 130°C, or also in the presence of N-methyl-- pyrrolidone, at 130°C or in the presence of TEA, dimethylacetamide from room temperature to 50°C, and in the presence of a compound of formula (AA), wherein G1represents a hydrogen atom or a methoxy group. Advantageously, to increase the speed of the reaction, the two G1radicals in formula (AA) are each a methoxy group. Concerning steps (viiiA) and (viiiB) (respectively schemes 3 and 1) : In scheme 1, the step (viiiB) is applied to a compound of formula (VIIa) as defined in the present disclosure to obtain a compound of formula (VIIIa) as defined in the present disclosure. In scheme 3, depending on the wished compound, the step (viiiA) can be applied either to a compound of formula (VIIa) in which HAL, R1 and R2 are as defined in the present disclosure, obtained from step (viiA) as defined in the present disclosure or to a compound of formula (VII) in which HAL and R2are as defined in the present disclosure ,obtained from step (viA) as defined in the present disclosure in order to obtain a compound of formula (VIIIa) as defined in the present disclosure. For instance, the nucleophilic aromatic substitution steps (viiiA) and (ViiiB) can be carried out in the presence of a base such as ammonia (NH3), for example in the presence of water, alcohol, dioxane, or mixtures thereof, such as in the presence of ammonia and water, under heat that is to say at a temperature ranging from 25°C to 200°C, for example at 150°C. Concerning step (viii) (scheme 2): The step (viii) from a compound of formula (VIII) as defined in the present disclosure allows to obtain a compound of formula (IX) as defined in the present disclosure. For instance, the step (viii) can be carried out in the presence of a reagent such as alcoholates, for example sodium propan-2-olate (iPrONa), for example sodium propan-2- olate, in a solvent such as isopropanol, for example in sodium propan-2olate / isopropanol, under heat that is to say at a temperature ranging from 50°C to 200°C, for example from 150°C to 170°C. Concerning step (ixAA) (scheme 4): The step (ixAA) from a compound of formula (IXaa) as defined in the present disclosure allows to obtain a compound of formula (X) as defined in the present disclosure. For instance, the step (ixAA) can be carried out in the presence of a reagent such as alcoholates, for example sodium propan-2-olate (iPrONa), for example sodium propan-2- olate, in a solvent such as isopropanol, for example in sodium propan-2olate / isopropanol, under heat that is to say at a temperature ranging from 50°C to 200°C, for example from 150°C to 170°C. Concerning steps (ixA) and (ixB) (respectively schemes 3 and 1): The substitution and / or coupling steps (ixA) and (ixB) from a compound of formula (VIIIa) as defined in the present disclosure allow to obtain a compound of formula (Ia) as defined in the present disclosure. The substitution and / or coupling steps (ixA) and (ixB) can be any appropriate chemical reaction which involves the dehalogenating of the molecule for instance as an alkylation, a nucleophilic aromatic substitution, and / or a coupling such as Suzuki coupling, for example a reaction with the presence of R3a-Y wherein R3arepresents R3as defined in the formula (I) according to the present disclosure or is a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, a aldehyde and ketone protecting group, and Y represents, hydroxyl, amine, boronic acid. Concerning steps (xA) and (xB) : (respectively schemes 3 and 1): The steps (xA) and (xB) from a compound of formula (Ia) as defined in the present disclosure allow to obtain a compound of formula (I) as defined in the present disclosure. It is to be understood that if in compound of formula (Ia) obtained from respectively step (ixA) and steps (ixB), R3ais R3then it is not necessary to perform respectively step (xA) or step (xB). Thus, the compounds of formula (Ia) in which R3ais other than R3as defined in the present disclosure, can be reacted with any suitable reagents and in any suitable conditions in order to obtain a compound of formula (I) as defined in the present disclosure. For example, these steps can be selected from reduction steps, deprotection steps, hydrolysis steps, oxidation steps, and combinations thereof, being understood that these steps can be carried out only once or several times, if needed. All these steps are well known by the skilled person. Concerning step (ixAlpha, also named ixα) and step (ixBeta, also named ixβ) (scheme 2): The step (ixAlpha) or the step (ixBeta) from a compound of formula (IX) as defined in the present disclosure allow to obtain a compound of formula (X) as defined in the present disclosure. The step (ixAlpha) can be carried out in the presence of R1a-X wherein R1ais R1as defined in the present disclosure, comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate The step (ixBeta) can be carried out in the presence of an epoxide of formula in which R’ and R’’ are independently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group. Concerning step (Gamma, also named γ) (scheme 2, SynMethod 2b or scheme 4, SynMethod 4b): The step (Gamma) from a compound of formula (X) as defined in the present disclosure allow to obtain a compound of formula (XII) as defined in the present disclosure. The step (Gamma) can be a reduction, a reductive amination, a nucleophilic substitution, and / or an oxidation. Concerning step (x) (scheme 2 or scheme 4): The deprotection step (x) can be carried out in order to deprotect the amino group linked to the pyridazine part of the imidazopyridazine ring and optionally, if applicable, the protected group corresponding to R1aand / or R3a. In other terms, the step (x) can be conducted either from a compound of formula (X) as defined in the present disclosure or from a compound of formula (XII) as defined in the present disclosure to obtain a compound of formula (I) as defined in the present disclosure, or can be conducted from a compound of formula (X) as defined in the present disclosure to obtain a compound of formula (XI) as defined in the present disclosure. For instance, the step (x) can be carried out in the presence of an acid such as trifluoroacetic acid (TFA), hydrochloric acid, or mixtures thereof, for example TFA, in the presence of a solvent such as dichloromethane (DCM), dioxane, tetradydrofuran (THF), or mixtures thereof, for example DCM, for example in TFA and DCM. Concerning step (xi) (scheme 2, SynMethod 2a or scheme 4, SynMethod 4a): The step (xi) from a compound of formula (XI) as defined in the present disclosure allow to obtain a compound of formula (I) as defined in the present disclosure. The step (xi) can be a reduction, a reductive amination, a nucleophilic substitution, and / or an oxidation. The specific compounds of formula (I) as defined in the present disclosure are indicated in Table 1 (number, chemical name and formula) and are further detailed hereafter. In Table 2, NMR, Retention time and liquid chromatography / mass spectra are also indicated. The1H NMR of Table 2 is1H NMR Spectra (400 MHz, δ in ppm, DMSO-d6) as defined in the Experimental part. The liquid chromatography / mass spectra (LC / MS) of Table 2 were obtained according to one of the seven methods described in the Experimental part. The Retention time (RT) of Table 2 is defined in minutes. Table 1: po mb 144 145 146 Table 2

[0019] Among the intermediate compounds of formulae (VIIa), (VIII), (VIIIa) and (IX) or a pharmaceutically acceptable salt thereof, that are subject matter of the present disclosure, mention may be made for instance of the following compounds as shown in Table 3 below: Table 3:

[0020] In Table 4 below,1H NMR, Retention time and liquid chromatography / mass spectra are also indicated. The1H NMR of Table 4 is1H NMR Spectra (400 MHz, δ in ppm, DMSO-d6) as defined in the Experimental part. The liquid chromatography / mass spectra (LC / MS) of Table 4 were obtained according to one of the seven methods described in the Experimental part. The Retention time (RT) of Table 4 is defined in minutes. Table 4:

[0021] The examples which follow describe the preparation of some compounds in accordance with the disclosure. The numbers of the compounds exemplified below match those given in the Tables 1 and 3 above. All reactions are performed under inert atmosphere, unless otherwise stated. In the following examples, when the source of the starting products is not specified, it should be understood that said products are known compounds. EXAMPLES In the Preparations and in the Examples, the following abbreviations are used: ACN, MeCN or CH3CN: acetonitrile CDCl3: deuterated chloroform DCM: dichloromethane DIPEA: diisopropylethylamine DMF: N,N-dimethylformamide DMSO: dimethylsulfoxide EDCI: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide Et2O: diethyl ether EtOAc: ethyl acetate EtOH: ethanol HBTU: (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HOBt: hydroxybenzotriazole iPrOH: isopropanol mCPBA : meta-Chloroperoxybenzoic acid MeOH: methanol Me-THF: methyl tetrahydrofuran MgSO4: magnesium sulfate MS: mass spectrometry MTBE: methyl ter-butyl ether NaCl: sodium chloride NBS: N-bromosuccinimide nBuLi: n-Butyllithium rt: room temperature RT: Retention Time NMR: nuclear magnetic resonance NMP: N-methyl-2-pyrrolidone TEA: triethylamine TFA: trifluoroacetic acid THF: tetrahydrofuran Ti(iPrO)4: Titanium (IV) isopropoxide TLC: thin-layer chromatography TMS: tetramethyl silane h or hr(s): hour(s) MATERIALS AND METHODS The progress of the synthetic reactions is monitored by TLC. The plates are made of glass and are coated with Merck 60 F254 silica gel. After elution, the plates are observed under ultraviolet light at 254 nm. The microwave reactions were performed using a Biotage Initiator 8 EXP microwave machine. The products were purified, when necessary, on a Biotage Isolera chromatograph or a Spot 2 chromatograph from Merck. The columns used are Merck 15-40 μm silica columns (2.5 g to 800 g). ANALYSES Mass Spectrometry (MS): Method A: The spectra were acquired on a Waters UPLC-SQD. Ionization: electrospray in positive and / or negative mode (ES+ / -) - Column: ACQUITY CORTECS C18+ - 1.6 µm - 2.1 x 50 mm - Solvents: A: H2O (0.1 % formic acid) B: CH3CN (0.1 % formic acid) - Column temperature: 40 °C - Flow rate: 1 mL / min - Gradient (3 min): from 2 to 100 % B in 2.0 min; 2.6 min: 100 % B; 2.7 min: 2 % B Method A has been used for compounds: 2, 9, 35, 65, 69, 86, 87 and 91. Method B: The spectra were acquired on a Waters UPLC-SQD. Ionization: electrospray in positive and / or negative mode (ES+ / -) - Column: ACQUITY CORTECS C18+ - 1.6 µm - 2.1 x 50 mm - Solvents: A: H2O (0.1 % TFA) B: CH3CN (0.1 % TFA) - Column temperature: 40 °C - Flow rate: 1 mL / min - Gradient (10 min): 1 min 2 % B, from 2 to 100 % B in 6.5 min ; 1.7 min : 100 % B; from 100 % B to 2 % B in 0.1 min; 1.7 min : 2% B Method B has been used for compounds: 68. Method N: The spectra were acquired on a Waters UPLC-SQD2: Ionization: electrospray in positive and / or negative mode (ES+ / -). - Column ACQUITY CSH C18 - 1.7 µm - 2.1 x 50 mm - Solvents: A: H2O (0.1 % formic acid) B: CH3CN (0.1 % formic acid) - Column temperature: 60 °C - Flow rate: 1 mL / min - Gradient (2.5 min): from 3 to 100 % B in 2.1 min; 2.45 min: 100 % B; 2.50 min: 3 % of B Method N has been used for compounds: 1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 88, 89, 90, 92, 93, 94, 95, 96, 97, 101, 102, 103, 104, 105, 107 to 117, 120, 121, 124 to 135, 137 to 146, 149, 150, 152 to 161, 163 to 165; intermediates: (IA), (IB), (J), (K), (L), (M) and (N). Method N1: The spectra were acquired on a Waters UPLC-SQD2: Ionization: electrospray in positive and / or negative mode (ES+ / -). - Column ACQUITY CSH C18 - 1.7 µm - 2.1 x 50 mm - Solvents: A: H2O (0.1 % formic acid) B: CH3CN (0.1 % formic acid) - Column temperature: 60 °C - Flow rate: 1 mL / min - Gradient (10 min): from 3 to 100 % B in 8.6 min; 9.6 min: 100 % B ; 9.8 min: 3 % B Method N1 has been used for compound: 106. Method O: The spectra were acquired on a WATERS QUATTRO PREMIER Ionization: electrospray in positive and / or negative (ES+ / -) - Column: ACQUITY MSS T3 - 1.8 µm - 2.1 x 50 mm - Solvents: A: H2O (0.1 % formic acid) B: CH3CN (0.1 % formic acid) - Column temperature: 55 °C - Flow rate: 0.9 ml / min - Gradient (3.7 min): de 5 to 100 % of B in 3 min; 3.1 min: 5 % of B Method O has been used for compounds: 80, 81, 82, 83, 84, 100, 118, 119, 147 and intermediate (O). Method P: The spectra were acquired on a Waters XeVo - QTof Ionization: electrospray in positive (ES+). - Column ACQUITY BEH C18 - 1.7 µm - 2.1 x 100 mm - Solvents: A: H2O (0.1 % formic acid) B: CH3CN (0.1 % formic acid) - Column temperature: 45 °C - Flow rate: 0.6 mL / min - Gradient (5.3 min): 0.3 min 5% B; from 5 to 100 % B in 3.7 min; 0.6 min: 100 % B; 0.7 min: 5 % B Method P has been used for compounds: 16, 42 and 85. Method M: The spectra were acquired on an Agilent 1200 & 6110B Ionization: electrospray in positive (ES+). - Kinetex C1850*2.1mm, 5 µm - Solvents: A: H2O+0.037 % (v / v) TFA B: ACN+0.018 % (v / v) TFA - Column temperature: 40 °C - Flow rate: 1 mL / min - Gradient (5 min): from 5 to 95 % B in 3 min; 1 min: 95 % B; 1.50 min: 5 % B Method M has been used for intermediates: (A), (B) and (E) and for compounds: 122, 123, 148, 151 and 162. Method Z: The spectra were acquired on a Waters Acquity UPLC system with PDA detector Ionization: electrospray in positive and / or negative mode (ES+ / -) - Acquity BEH C18 column (50 mm x 2.1 mm) 1.7 µm - Solvents: A: H2O (0.05 % formic acid) B: CH3CN (0.05 % formic acid) - Column temperature: 35 °C - Flow rate: 0.6 mL / min - Gradient (4 min): 0.4 min: 3 % B; from 3 to 98 % B in 1.6 min; 1.5 min: 98 % B; 0.50 min: 3 % B Method Z has been used for intermediates: (F), (G) and (H).1H Nuclear magnetic resonance (NMR) The1H NMR spectra were recorded on a Brüker Avance and / or Varian G spectrometer (300 MHz, 400 MHz, 500 MHz or 600 MHz) in deuterated DMSO. The chemical shifts are expressed in units (ppm) using tetramethyl silane (TMS) as internal reference. For the interpretation of the spectra, the following abbreviations were used: s = singlet, d = doublet, t = triplet, q = quartet, quint = quintet, sext = sextet, dd = doubled doublet, ddd = doublet of doubled doublets, m = multiplet, ax. = axial, equat. = equatorial. PREPARATION All the following compounds were synthesized according to the protocols described below. Preparation of intermediate (E): Preparation 1: Intermediate (A) 2-butyl-1H-imidazole-4,5-dicarbonitrile A suspension of (Z)-2,3-diaminobut-2-enenitrile (45.0 g, 416 mmol, 1.00 eq) and 1,1,1- trimethoxypentane (67.5 g, 416 mmol, 1.00 eq) in MeCN (90.0 mL) was stirred in an oil bath and it was kept at 85 °C for 6 hrs. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure. The whole of this compound was dissolved in xylene (90.0 mL), and the resulting solution was stirred in an oil bath kept at 150 °C for 8 hrs. The mixture was concentrated to give a residue, which was filtered, and washed with methylbenzene. Then the filter cake was dried to give the expected product. The product was used in the next step without any purification. Intermediate (A) (63.0 g, 87% Yield)1H NMR (400 MHz, δ in ppm, CDCl3): 2.82 (t, J = 7.6 Hz, 15.2 Hz ,2H), 1.72-1.80 (m, 2H), 1.36-1.45 (m, 2H), 0.93-0.97 (m, 3H) MS Method M: RT=1.019 min, m / z 175.1 (M+H)+Preparation 2: Intermediate (B) 2-butyl-1H-imidazole-4,5-dicarboxylic acid (A)(B)A solution of compound (A) (63.0 g, 362 mmol, 1.00 eq) in H2SO4(284 mL) and H2O (126 mL) was stirred at 100 °C for 8 hrs. By TLC one major new spot with lower polarity was observed. The pH of the solution was adjusted to 9-10 using 10% sodium hydroxide solution. The mixture was filtered, and the filter cake was concentrated to give the expected product which was used into the next step without further purification. Intermediate (B) (76.5 g, 99.7% yield) was obtained as a black brown solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 2.59 (t, J = 7.6 Hz, 2H), 1.57-1.63 (m, 2H), 1.19- 1.28 (m, 2H), 1.27-1.33 (m, 2H), 0.86 (t, J = 7.2 Hz, 14.8 Hz ,2H). MS Method M: RT=1.163 min, m / z 213.1 (M+H)+. Preparation 3: Intermediate (C) dimethyl 2-butyl-1H-imidazole-4,5-dicarboxylate To a mixture of compound (B) (76.5 g, 361 mmol, 1.00 eq) in MeOH (230 mL) was added SOCl2(214 g, 1.80 mol, 131 mL, 5.00 eq) slowly and degassed and purged with N2for 3 times, and then the mixture was stirred at 40-45 °C for 12 hrs under N2atmosphere. The mixture was cooled and then poured slowly to chilled water (500 mL). It was neutralized by the addition of 10 % sodium hydroxide solution. Then the mixture was extracted with EtOAc (3 x 500 mL). The combined organic layers were washed with brine (1.00 L), dried over Na2SO4, filtered and concentrated under reduced pressure to give a residue. The crude product was used into the next step without further purification. Intermediate (C) (81.0 g, 93.5% yield) was obtained as a black brown solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 3.87 (s, 6H), 2.77 (t, J = 8.0 Hz, 2H), 1.68-1.76 (m, 2H), 1.30-1.40 (m, 2H), 0.90 (t, J = 7.6 Hz, 3H). Preparation 4: Intermediate (D) 2-butyl-5,6-dihydro-1H-imidazo[4,5-d]pyridazine-4,7- dione A mixture of compound (C) (81.0 g, 337 mmol, 1.00 eq), NH2NH2.H2O (51.7 g, 1.01 mol, 50.2 mL, 98.0 % purity, 3.00 eq) in MeOH (243 mL) was degassed and purged with N2 for 3 times, and then the mixture was stirred at 60 °C for 1 hour under N2 atmosphere. The reaction mixture was filtered and washed with methanol. This material was suspended in water (1.00 L), heated to 85 °C, and then rendered acidic by addition of conc. HCl (100 mL). After stirring for 12 hours at 85 °C, the mixture was cooled and the white product filtered with suction and washed with water. The crude product was used into the next step without further purification. Intermediate (D) (49.5 g, 70.5% yield) was obtained as an off-white solid. Preparation 5: Intermediate (E) 2-butyl-4,7-dichloro-1H-imidazo[4,5-d]pyridazine To a cooled solution of compound (D) (49.5 g, 238 mmol, 1.00 eq) in POCl3(248 mL) was added N,N-dimethyl aniline (50.0 mL) and the reaction mixture was stirred at 110 °C for 90 mins. The reaction mixture was concentrated under reduced pressure to give a residue. The residue was poured into cold water (2.00 L) and adjusted pH to 7 with solid sodium bicarbonate and extracted with EtOAc (2 x 1 L). The combined organic layers were washed with brine (500 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to give a residue. The residue in MTBE (200 mL) was stirred for 2 hrs. The suspension was filtered, and the filter cake was collected. Intermediate (E) (54.5 g, 92.0 % yield) was obtained as a yellow solid.1H NMR (400 MHz, δ in ppm, CDCl3): 3.18 (t, J = 7.6 Hz, 2H), 1.90-1.97 (m, 2H), 1.40- 1.49 (m, 1H), 0.92 (t, J = 7.2 Hz, 3H). MS Method M: RT= 2.161 min, m / z 245.0 (M+H)+. Preparation of intermediate (H): Preparation 6: Intermediate (F) dimethyl 2-butyl-1-[(4-methoxyphenyl)methyl]imidazole- 4,5-dicarboxylate To a solution of intermediate (C) (300 g, 1.25 mol) in DMF (3.5 L), was added K2CO3(260 g, 1.88 mol) and stirred at rt for 1 h, then was added 4-Methoxybenzyl chloride (244.6 g, 1.56 mol) and stirred at rt for 16 h. The reaction mixture was poured into water (5 L), extracted with EtOAc (2 x 3 L), the combined organic layer was dried over anhydrous sodium sulphate, filtered and concentrated under vacuum to afford intermediate (F) (450 g, crude) as a pale-yellow color oil which was taken to next step as such.1H NMR (400 MHz, δ in ppm, CDCl3): 6.95 (d, J = 8.8 Hz, 2H) 6.84 (d, J = 8.6 Hz, 2H) 5.31 (s, 2H) 3.91 (s, 3H) 3.81 (s, 3H) 3.78 (s, 3H) 2.68 - 2.64 (t, 2H) 1.36 – 1.63 (m, 2H) 1.37 – 1.31 (m, 2H) 0.89-0.84 (t, 3H). MS: Method Z, TR= 1.97 min, m / z 361.1 (M+H)+Preparation 7: Intermediate (G) 2-butyl-3-[(4-methoxyphenyl)methyl]-5,6- dihydroimidazo[4,5-d]pyridazine-4,7-dione. To a solution of intermediate (F) (450 g, 1.25 mol) in methanol (1.3 L) was added NH2NH2.H2O (175.2 g, 3.49.8 mol) and heated to 75oC for 5 h. The reaction mixture was cooled to room temperature, diluted with Et2O (1 L) and the precipitated solid was filtered and dried to afford intermediate (G) (250 g, 61.7 % yield) as off-white color solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 7.17 (d, J = 8.8 Hz, 2H) 6.89 (d, J = 8.4 Hz, 2H) 6.87 - 6.64 (bs, 2H) 5.68 (s, 2H) 3.72 (s, 3H) 2.69 - 2.65 (t, 2H) 1.59 – 1.54 (m, 2H) 1.32 – 1.23 (m, 2H) 0.83-0.8 (t, 3H). MS: Method Z, RT= 1.59 min m / z 329.1 (M+H)+. Preparation 8: Intermediate (H) 2-butyl-4,7-dichloro-3-[(4- methoxyphenyl)methyl]imidazo[4,5-d]pyridazine. To a cooled solution of intermediate (G) (70 g, 213.4 mmol) in POCl3 (620 mL, 8.8 Vol) was added N, N-dimethyl aniline (140 mL, 2 Vol) and the reaction mixture was stirred at 110 °C for 4 h. The reaction mixture was cooled to room temperature, poured into cold water (5 L) and adjusted pH to 7 with solid Na2CO3and extracted with EtOAc (2 x 3 L). The combined organic layer was dried over anhydrous sodium sulphate, filtered and concentrated under vacuum. The crude product was triturated with Et2O (200 mL) for 2h, filtered and dried to afford intermediate (H) (38 g, 48.5 % yield) as pale-yellow color solid.1H NMR (400 MHz, δ in ppm, CDCl3): 6.92 – 6.85 (m, 4H) 5.68 (s, 2H) 3.79 (s, 3H) 2.91- 2.87 (t, 2H) 1.82 – 1.78 (m, 2H) 1.44 – 1.38 (m, 2H) 0.93-0.89 (t, 3H) MS: Method Z, m / z 365.3 (M+H)+Preparation 9: Intermediate (IA) 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine and Intermediate (IB) 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride Intermediate (IA) 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine A mixture of intermediate (H) (5 g, 13.7 mmol) and ammonia solution (10 mL, 35 %) were introduced into a microwave vial. The suspension was heated at 150 °C during 6 hours under microwave. The resulting mixture was filtered and washed with water to give 5 g of crude product, which was purified by crystallization in EtOH to afford intermediate (IA) (2.15 g, 45 % yield) as white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 1.32 (m, 2 H) ; 1.64 (m, 2 H) ; 2.83 (m, 2 H) ; 3.72 (s, 3 H) ; 5.65 (s, 2 H) ; 6.71 (s broad, 2 H) ; 6.91 (d, J=8.9 Hz, 2 H) ; 6.96 (d, J=8.9 Hz, 2 H) MS method N: RT (min) : 1.22; [M+H]+346; ES-[MH-+HCO2H]-: m / z 390 Intermediate (IB) 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride A mixture of intermediate (H) (5 g, 13.7 mmol) and ammonia solution (25 mL, 35 %) were introduced into an autoclave. The suspension was heated at 150°C during 6h under interne pressure of 25 bars and then kept overnight without heating. The resulting precipitates were filtered and the filter cake was dissolved in HCl Dioxane (200 mL, 4N), which was concentrated under reduced pressure to 1 / 10thvolume. The new precipitates were filtered, washed with EtOAc, and dried overnight at 30°C under vacuum to intermediate (IB) (3.65 g, 54% yield), which was used directly to the following steps.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.83 (t, J=7 Hz, 3 H), 1.32 (sxt, J=7 Hz, 2 H), 1.63 (quin, J=8 Hz, 2 H), 2.90 (t, J=8 Hz, 2 H), 3.73 (s, 3 H), 5.75 (s, 2 H), 6.92 (d, J=9 Hz, 2 H), 7.07 (d, J=9 Hz, 2 H), 8.97 (br s, 2 H), 15.13 (br s, 1 H) MS method N: RT (min) : 1.22; [M+H]+346; ES-[MH-+HCO2H]-: m / z 390 Preparation 10: Intermediate (J) 2-butyl-4,7-dichloro-1-methyl-1H-imidazo[4,5- d]pyridazine (E)(J)To a solution of intermediate (E) (4.9 g, 20 mmol) in acetone (200 mL) was added potassium carbonate (8.29 g, 60 mmol). The suspension was stirred 30 min at rt. Then it was added methyl iodide (1.9 mL, 30 mmol) and the mixture was stirred 18 hours at rt. The reaction mixture was filtered, washed with acetone (2 x 20 mL) and DCM (2 x 20 mL). The filtrate was concentrated under reduced pressure to give 6.75 g of a yellow solid. The solid was dissolved in EtOAc (250 mL) and washed with water (150 mL) and brine (150 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 5.1 g of yellow solid. The product was purified by a silica gel column chromatography on a Merck cartridge (300 g 15-40 µm silica) using as eluent a mixture DCM / MeOH / CH3CN (96 / 2 / 2) to afford the expected product (J) (3.64 g, 70 % yield) as a yellow solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.95 (t, J=7.4 Hz, 3 H) ; 1.43 (m, 2 H) ; 1.79 (m, 2 H) ; 3.00 (m, 2 H) ; 4.04 (s, 3 H) MS method N: RT (min): 1.32; [M+H]+259 Preparation 11: Intermediate (K) 2-butyl-7-chloro-1-methyl-1H-imidazo[4,5-d]pyridazin- 4-amine (J)(K)A mixture of intermediate (J) (3.64 g, 14 mmol) and ammonia solution (100 mL, 35%) were introduced into an autoclave and heated 6 hours at 150°C under 35 bars. The solid was dissolved into 100 mL of MeOH and concentrated under vacuum to give 4.16 g of crude product. The product was poured into water (100 mL) and stirred 1h at rt. The suspension was filtered, washed with water and dried to afford expected product (K) (1.44 g, 43 % yield) as a beige solid.^1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.93 (t, J=7.4 Hz, 3 H) ; 1.41 (m, 2 H) ; 1.74 (m, 2 H) ; 2.90 (m, 2 H) ; 3.95 (s, 3 H) ; 6.63 (s broad, 2 H) MS method N: RT (min): 0.84; [M+H]+240 Preparation 12: Intermediate (L) 2-butyl-7-chloro-N,N-bis(2,4-dimethoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine To a solution of intermediate (E) (15 g, 61.20 mmol) in n-butanol (150 mL) was added DIPEA (107 mL, 612.63 mmol) and bis(2,4-dimethoxybenzyl)amine (7 g, 22.1 mmol). The reaction mixture was refluxed during 1 hour. A further 5 g (15.8 mmol) of bis(2,4- dimethoxybenzyl)amine were added and the heating was continued for 1 hour. This operation was repeated twice again (2 x 5 g, 31.5 mmol). The resulting mixture was heated overnight. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure to remove most of n-butanol. The residue was diluted with DCM (500 mL), then washed with H2O (250 mL), brine (200 mL), dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 38.8 g of crude product. The residue was purified by chromatography on a Merck cartridge (800 g of 15-40 μm silica) using as eluent DCM / Acetone 96 / 4 to 90 / 10 to give compound (L) (12 g, 37 % yield) as a pale-yellow solid.1H NMR (400MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.4 Hz, 3 H) ; 1.28 (m, 2 H) ; 1.68 (m, 2 H) ; 2.82 (t, J=7.6 Hz, 2 H) ; 3.72 (s, 12 H) ; 5.07 (s broad, 4 H) ; 6.39 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.54 (d, J=2.4 Hz, 2 H) ; 6.95 (d, J=8.4 Hz, 2 H) ; 13.35 (s broad, 1 H) MS method N: RT (min): 1.59; [M+H]+526 Preparation 13: Intermediate (M) 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-4-amine. To a suspension of intermediate (L) (4 g, 7.60 mmol) in dioxane (30 mL) was added sodium isopropoxide (3.74 g, 45.62 mmol) and 2-propanol (30 mL, 1.05 mol). The mixture was heated at 170 °C under 18 bars for 7 hours. The reaction mixture was cooled and filtered, and the cake was washed with EtOAc (100 mL). The filtrate was concentrated under reduced pressure. The crude product was dissolved with EtOAc (150 mL) then washed with H2O (2 x 75 mL), brine (75 mL), dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 4.37 g of product. The residue was purified by chromatography on a Merck cartridge (200 g of 15-40 μm silica) with an EtOAc / Heptane (55 / 45) elution. Compound (M) (2.11 g, 50 % yield) was obtained as a white solid.1H NMR (400MHz, δ in ppm , DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 1.26 (m, 2 H) ; 1.37 (d, J=6.2 Hz, 6 H) ; 1.66 (m, 2 H) ; 2.77 (t, J=7.6 Hz, 2 H) ; 3.70 (s, 6 H) ; 3.71 (s, 6 H) ; 5.00 (s broad, 4 H) ; 5.41 (sept, J=6.2 Hz, 1 H) ; 6.38 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.94 (d, J=8.4 Hz, 2 H) ; 13.01 (s broad, 1 H) MS method N: RT (min): 1.58; [M+H]+550 Preparation 14: Intermediate (N) 2-butyl-7-chloro-N,N-bis(4-methoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine To a solution of intermediate (E) (1.6 g, 6.53 mmol) in n-butanol (8 mL), in a microwave vial, was added DIPEA (3.42 mL, 19.58 mmol) and bis(4-methoxybenzyl)amine (1.68 g, 6.53 mmol). The resulting mixture was stirred 5 mins at rt, and then heated at 150°c during 6 h under microwave. After cooling to room temperature, the reaction mixture was filtered. And the filtrate was concentrated under vacuum to give 3.75g of crude product, which was purified by chromatography on a Merck cartridge (150 g of 15-40 μm silica) using as eluent Heptane / EtOAc 90 / 10 to 20 / 80 to give compound (N) (1.25 g, 41 % yield) as a pale-yellow solid.1H NMR (400MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7 Hz, 3 H), 1.31 (sxt, J=7 Hz, 2 H), 1.72 (quin, J=8 Hz, 2 H), 2.86 (t, J=7 Hz, 2 H), 3.72 (s, 6 H), 5.08 (br s, 4 H), 6.86 (d, J=9 Hz, 4 H), 7.19 (d, J=9 Hz, 4 H), 13.45 (br s, 1 H) MS method N: RT (min): 1.78; [M+H]+466 Preparation 15: Intermediate (R) 2-butyl-N,N-bis,4-methoxybenzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine. To a solution of isopropanol (11 mL), was added under stirring, sodium (418.6 mg, 18.03 mmol), the mixture was heated at 70°C until the end of hydrogen bubbling. The hot sodium isopropoxide solution was added quickly into a microwave vial containing 2-butyl-7-chloro- N,N-bis(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine, intermediate (N) (1.2 g, 2.58 mmol) in dioxane (8 mL). The mixture was heated at 170°C under 5 bars for 6 hours and kept overnight. The reaction mixture was filtered and washed with EtOAc to give 1.94 g of crude product. The crude product was dissolved with EtOAc (100 mL) under stirring to give a suspension, which was filtered and washed with EtOAc. The filtrate was concentrated under reduced pressure to give 1.63 g of crude material which was purified by chromatography on a Merck cartridge (150 g of 15-40 μm silica) with eluant EtOAc / Heptane 20 / 80 to 80 / 20. Compound (R) (0.76 g, 60 % yield) was obtained as a white solid.1H NMR (400MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7 Hz, 3 H), 1.30 (sxt, J=7 Hz, 2 H), 1.39 (d, J=6 Hz, 6 H), 1.71 (quin, J=7 Hz, 2 H), 2.82 (t, J=7 Hz, 2 H), 3.71 (s, 6 H), 4.98 (s, 4 H), 5.44 (spt, J=6 Hz, 1 H), 6.84 (d, J=9 Hz, 4 H), 7.16 (d, J=8 Hz, 4 H), 13.11 (s, 1 H) MS method O: RT (min): 2.79; [M+H]+490 EXAMPLES Example (1): Preparation of Compound 1: 2-butyl-7-isopropoxy-1-(4-methoxybenzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine To a suspension of potassium hydroxide (250 mg, 3.79 mmol) in anhydrous CH3CN (2 mL) was added 2-propanol (500 µL, 6.50 mmol). The mixture was stirred 5 min at rt. Then, 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine hydrochloride, intermediate (IB) (200 mg, 0.52 mmol), was added. The mixture was heated 2 hours at 150°C under microwave. The mixture was cooled, filtered, then washed with 2-propanol and ethyl acetate. The filtrate was concentrated under reduced pressure to give 836 mg of crude product. The residue was dissolved in EtOAc (100 mL), washed with H2O, brine, dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 242 mg of crude material which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with a 99 / 1 to 95 / 5 EtOAc / EtOH elution. Example (1) (27 mg, 14 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.85 (t, J=7.4 Hz, 3 H) ; 1.25 (d, J=6.2 Hz, 6 H) ; 1.33 (m, 2 H) ; 1.63 (m, 2 H) ; 2.81 (m, 2 H) ; 3.71 (s, 3 H) ; 5.36 (sept, J=6.2 Hz, 1 H) ; 5.51 (s, 2 H) ; 5.91 (s, 2 H) ; 6.90 (d, J=8.8 Hz, 2 H) ; 7.06 (d, J=8.8 Hz, 2 H) MS method N: RT (min): 1.2; [M+H]+370. The following compounds may be made by analogy to Example 1: 48, 50, 52, 54, 56, 57, 58, 65, 68, 69, 72 and 86. Example (2): Preparation of Compound 2: 2-butyl-N7-isopropyl-1-(4-methoxybenzyl)- 1H-imidazo[4,5-d]pyridazine-4,7-diamine To a solution of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine, intermediate (IA), (200 mg, 0.58 mol) in 1,4-Dioxane (10 mL) was added isopropyl amine (1.8 mL, 20.85 mmol). The reaction mixture was heated 3 h at 230°C under microwave. The mixture was concentrated under reduced pressure to give 208 mg of crude product, which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with a DCM / MeOH / NH4OH elution 98 / 2 / 0.5 to 90 / 10 / 0.5. Example (2) (8 mg, 4 % yield) was obtained as a white amorphous solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.87 (t, J=7.4 Hz, 3 H) ; 1.03 (d, J=6.3 Hz, 6 H) ; 1.36 (m, 2 H) ; 1.67 (m, 2 H) ; 2.87 (m, 2 H) ; 3.71 (s, 3 H) ; 4.00 (m, 1 H) ; 4.79 (d, J=6.5 Hz, 1 H) ; 5.59 (s, 2 H) ; 6.10 (s, 2 H) ; 6.90 (d, J=8.9 Hz, 2 H) ; 7.00 (d, J=8.9 Hz, 2 H) MS method A: RT (min): 0.82; [M+H]+369. The following compounds may be made by analogy to Example 2: 49, 53, 71, 94, 98. Example (3): Preparation of Compound 3: 2-butyl-7-(isopropylthio)-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine

[0022] To a suspension of potassium hydroxide (150 mg, 2.27 mmol) in acetonitrile (2 mL), was added 2-propanethiol (400 µl, 4.18 mmol). The mixture was stirring 5 min at rt then, 2- butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (180 mg, 0.52 mmol) was added. The reaction mixture was heated 2 h at 150°C under microwave. The mixture was filtered, washed with EtOAc. The filtrate was concentrated under reduced pressure to give 695 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with a 80 / 20 to 50 / 50, DCM / DCM-MeOH (90 / 10) elution. Example (3) (26 mg, 13 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.81 (t, J=7.4 Hz, 3 H) ; 1.22 (d, J=6.8 Hz, 6 H) ; 1.29 (m, 2 H) ; 1.60 (m, 2 H) ; 2.74 (m, 2 H) ; 3.71 (s, 3 H) ; 5.85 (sept, J=6.8 Hz, 1 H) ; 5.74 (s, 2 H) ; 6.46 (s, 2 H) ; 6.90 (m, 4 H) MS method N: RT (min): 1.23; [M+H]+386 The following compounds may be made by analogy to Example 3: 99. Example (4): Preparation of Compound 4: 2-butyl-1-(4-methoxybenzyl)-7-(2- methoxyethoxy)-1H-imidazo[4,5-d]pyridazin-4-amine To a suspension of potassium hydroxide (90 mg, 1.36 mmol), in anhydrous acetonitrile (4 mL) was added 2-methoxyethanol (460.71 µL, 5.78 mmol). The mixture was stirred 5 min at rt, then 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (200 mg, 0.58 mmol), was added. The reaction mixture was heated 2 h at 170°C under microwave. The mixture was filtered, washed with 2-propanol and EtOAc. The filtrate was concentrated under reduced pressure and the residue was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with a 100 / 0 to 0 / 100 DCM / DCM-MeOH (95-5) elution. Example (4) (46 mg, 21 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.4 Hz, 3 H) ; 1.33 (m, 2 H) ; 1.63 (m, 2 H) ; 2.82 (m, 2 H) ; 3.25 (s, 3 H) ; 3.65 (m, 2 H) ; 3.71 (s, 3 H) ; 4.50 (m, 2 H) ; 5.52 (s, 2 H) ; 5.98 (s, 2 H) ; 6.89 (d, J=8.7 Hz, 2 H) ; 7.13 (d, J=8.7 Hz, 2 H) MS method N: RT (min): 1.13; [M+H]+386 Example (5): Preparation of Compound 5: 2-butyl-1-(4-methoxybenzyl)-7-propoxy- 1H-imidazo[4,5-d]pyridazin-4-amine Sodium (43 mg, 1.87 mmol) was added to 1-propanol (3 mL, 39.73 mmol) and the mixture was stirred until the end of hydrogen bubbling. The sodium propoxide solution was added to a mixture of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride, intermediate (IB), (200 mg, 0.52 mmol) and triethylamine (150 µL, 1.07 mmol), in a microwave reactor, and the reaction mixture was heated 2 h at 150°C under microwave. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was dissolved in EtOAc, washed with water and brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give 147 mg of crude product, which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with a 90 / 10 to 80 / 20 DCM / DCM-MeOH-MeCN (80-10-10) elution. Example (5) (73 mg, 38 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 0.89 (t, J=7.4 Hz, 3 H) ; 1.32 (m, 2 H) ; 1.61 (m, 2 H) ; 1.70 (m, 2 H) ; 2.79 (m, 2 H) ; 3.71 (s, 3 H) ; 4.32 (t, J=6.4 Hz, 2 H) ; 5.54 (s, 2 H) ; 5.97 (s, 2 H) ; 6.90 (d, J=8.8 Hz, 2 H) ; 7.06 (d, J=8.8 Hz, 2 H) MS method N: RT (min): 1.2; [M+H]+370 Example (6): Preparation of Compound 6: 7-(allyloxy)-2-butyl-1-(4-methoxybenzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine Sodium (43 mg, 1.87 mmol) was added to allyl alcohol (3 mL, 43.47 mmol) and the mixture was stirred at rt until the end of hydrogen bubbling. The sodium allyl oxide solution was added to 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (200 mg, 0.58 mmol), in a microwave reactor, and the reaction mixture was heated 2 h at 150°C under microwave. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was dissolved with EtOAc, washed with water and brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give 496 mg of crude product, which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with a 80 / 20 to 0 / 100 DCM / DCM-MeOH (90-10) elution. Example (6) (43 mg, 20 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 1.32 (m, 2 H) ; 1.61 (m, 2 H) ; 2.80 (m, 2 H) ; 3.71 (s, 3 H) ; 4.93 (td, J=1.6 & 5.21 Hz, 2 H) ; 5.19 (qd, J=1.6 &10.5 Hz, 1 H) ; 5.30 (qd, J=1.6 & 17.3 Hz, 1 H) ; 5.54 (s, 2 H) ; 6.00 (s, 2 H) ; 6.06 (m, 1 H) ; 6.89 (d, J=8.9 Hz, 2 H) ; 7.07 (d, J=8.9 Hz, 2 H) MS method N: RT (min): 1.17; [M+H]+368 Example (7): Preparation of Compound 7: 7-(sec-butoxy)-2-butyl-1-(4-methoxybenzyl)- 1H-midazo[4,5-d]pyridazin-4-amine Sodium (43 mg, 1.87 mmol) was added to 2-butanol (3 mL, 32.46 mmol) and the mixture was stirred at rt until the end of hydrogen bubbling. The sodium 2-butoxide solution was added to a mixture of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride, intermediate (IB) (200 mg, 0.52 mmol) and triethylamine (150 µL, 1.07 mmol) in a microwave reactor and the reaction mixture was heated 2h at 150°C under microwave. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was dissolved with EtOAc, washed with water and brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give 165 mg of crude product, which was purified on a Gilson GX271 system, by using a CSH 50x250mm, 5µm column (WatersTM) operating at 150ml / min and at room temperature. The following A / B gradient was used: t = 0 min: 18% of solution B, t = 5min: 18% of solution B, t = 25min: 38% of solution B, with A: water / formic acid 0.1% (v / v) and B: acetonitrile / formic acid 0.1% (v / v). Example (7) (82 mg, 41 % yield) was obtained as a white amorphous solid.^^1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.81 (t, J=7.4 Hz, 3 H) ; 0.85 (t, J=7.4 Hz, 3 H) ; 1.22 (d, J=6.2 Hz, 3 H) ; 1.33 (m, 2 H) ; 1.55 to 1.67 (m, 4 H) ; 2.79 (m, 2 H) ; 3.71 (s, 3 H) ; 5.23 (m, 1 H) ; 5.50 (d, J=16.2 Hz, 1 H) ; 5.55 (d, J=16.2 Hz, 1 H) ; 5.97 (s, 2 H) ; 6.78 (d, J=8.9 Hz, 2 H) ; 7.03 (d, J=8.9 Hz, 2 H) MS method N: RT (min): 1.28; [M+H]+384 Example (8): Preparation of Compound 8: 7-butoxy-2-butyl-1-(4-methoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine Sodium (86 mg, 3.74 mmol) was added to 1-Butanol (3 mL, 32.46 mmol) and the mixture was stirred at rt until the end of hydrogen bubbling. The sodium butoxide solution was added to a mixture of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine hydrochloride, intermediate (IB), (200 mg, 0.52 mmol) and Triethylamine (150 µL, 1.07 mmol) in a microwave reactor and the reaction mixture was heated 2 h at 150°C under microwave. The mixture was concentrated under reduced pressure and the residue was dissolved with EtOAc, washed with water and brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give 156 mg of crude product, which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with a 90 / 10 to 80 / 20 DCM / DCM80-MeOH10-MeCN10 elution. Example (8) (59 mg, 29 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 0.85 (t, J=7.4 Hz, 3 H) ; 1.31 (m, 4 H) ; 1.63 (m, 4 H) ; 2.80 (m, 2 H) ; 3.71 (s, 3 H) ; 4.36 (t, J=6.5 Hz, 2 H) ; 5.53 (s, 2 H) ; 5.96 (s, 2 H) ; 6.90 (d, J=8.8 Hz, 2 H) ; 7.03 (d, J=8.8 Hz, 2 H) MS method N: RT (min): 1.25; [M+H]+384 ; ES- : [M-H+HCO2H]-: m / z 428 Example (9): Preparation of Compound 9: 2-butyl-7-(cyclopentyloxy)-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine. A mixture of cyclopentanol (1.5 mL, 16.34 mmol) and sodium (93.11 mg, 4.05 mmol) was stirred at 80°C for 1h. Then, a solution of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (0.2 g, 58 mmol) in 1,4-Dioxane (4 mL) was added and the mixture was heated at 170°C under microwave for 6h. The reaction mixture was concentrated under reduced pressure to afford 310 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15- 40 μm silica) with DCM / MeOH (95 / 5) elution, to afford 63 mg (26.5 %, yield) of Example (9) as a white solid.1H NMR (400MHz, δ in ppm, DMSO-d6)^: 0.83 (t, J=7.40 Hz, 3 H) 1.32 (sxt, J=7.60, 2 H) 1.45 - 1.76 (m, 8 H) 1.78 - 1.94 (m, 2 H) 2.78 (t, J=7.60 Hz, 2 H) 3.70 (s, 3 H) 5.42 - 5.57 (m, 3 H) 5.92 (s, 2 H) 6.89 (d, J=8.78 Hz, 2 H) 7.01 (d, J=8.78 Hz, 2 H) MS method A: RT (min): 0.96; [M+H]+396 Example (10): Preparation of Compound 10: 2-butyl-1-(4-methoxybenzyl)-7- (pyrrolidin-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine. A mixture of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine, intermediate (IA) (0.2 g, 0.58 mmol) in pyrrolidine (2 mL, 23.72 mmol) and water (1 mL) was stirred at 160 °C under microwave for 4 h. The reaction mixture was concentrated under reduced pressure to afford 347 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with DCM / MeOH (90 / 10) elution, to afford 20 mg (9.1 %, yield) of Example (10) as a white foam.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.83 (t, J=7.5 Hz, 3 H) ; 1.31 (m, 2 H) ; 1.63 (m, 2 H) ; 1.82 (m, 4 H) ; 2.70 (m, 2 H) ; 3.15 (m, 4 H) ; 3.71 (s, 3 H) ; 5.62 (s, 2 H) ; 6.11 (s, 2 H) ; 6.88 (d, J=8.9 Hz, 2 H) ; 6.96 (d, J=8.9 Hz, 2 H) MS method N: RT (min): 1.26; [M+H]+381 Example^(11): Preparation of Compound 11: 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl- 1H-pyrrol-3-yl)-1H-imidazo[4,5d] pyridazin-4-amine In a microwave vial was added a solution of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H- imidazo[4,5-d] pyridazin-4-amine, intermediate (IA), (250 mg, 0.72 mmol) in 1,4-Dioxane (5 mL), followed by addition of Pd(dppf)Cl2.DCM (88.55 mg, 0.11 mmol), 1-Methyl-3- (4,4,5,5-tetramethyl-1,3,2-dioxa borolan-2-yl)-1H pyrrole (224.55 mg, 1.08 mmol) and finally 2M aqueous solution of Cs2CO3(1.45 mL, 2.89 mmol). The mixture was heated at 135°C for 60 min under microwave. The solvent was evaporated under reduced pressure, and the residue was dissolved in DCM and washed with a saturated aqueous solution of NaHCO3. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure. The crude material was purified by silica gel chromatography using as eluent a mixture CHCl3 / iPrOH (90 / 10) to give 18.3 mg (6.5%, yield) of Example^(11) as a creamy solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.83 (t, J=7.4 Hz, 3 H) ; 1.31 (m, 2 H) ; 1.63 (m, 2 H) ; 2.71 (m, 2 H) ; 3.60 (s, 3 H) ; 3.68 (m, 3 H) ; 5.32 (s, 2 H) ; 6.08 (dd, J=1.9 & 2.5 Hz, 1 H) ; 6.28 (s, 2 H) ; 6.68 (d, J=8.9 Hz, 2 H) ; 6.72 (m, 2 H) ; 6.81 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 1.18; [M+H]+391 The following compounds may be made by analogy to Example 11: 55, 62, 63, 64, 67, 70, 92, 93, 95, 96 and 97. Example (12 A): Preparation of Compound 12: (E)-2-butyl-1-(4-methoxybenzyl)-7-(3- methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine and Example (12 B): Preparation of Compound 13: 2-butyl-7-isopentyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: Example (12 A): ^ Preparation of Compound 12: (E)-2-butyl-1-(4- methoxybenzyl)-7-(3-methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine In a microwave vial was added 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine, intermediate (IA), (500 mg, 1.45 mmol) in 1,4-Dioxane (10 mL), followed by addition of Pd(dppf)Cl2.DCM (177.10 mg, 0.22 mmol), (E)-4,4,5,5- tetramethyl-2-(3-methylbut-1-en-1-yl)-1,3,2-dioxaborolane (567 mg, 2.89 mmol) and finally a 2M aqueous solution of Cs2CO3(2.89 mL, 5.78 mmol). The mixture was heated at 120 °C for 1h 30 min under microwave. The solvent was evaporated under reduced pressure and the residue was diluted with DCM, and washed with a saturated aqueous solution of NaHCO3. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure. The crude material was purified by silica gel chromatography using as eluent a mixture DCM / NH3in MeOH (2N) (97 / 3) to give 70 mg (12.7 %, yield) as a beige solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.86 (t, J=7.5 Hz, 3 H) ; 0.92 (d, J=6.8 Hz, 6 H) ; 1.35 (m, 2 H) ; 1.68 (m, 2 H) ; 2.34 (m, 1H) ; 2.87 (m, 2 H) ; 3.70 (s, 3 H) ; 5.55 (s, 2 H) ; 6.37 (s, 2 H) ; 6.44 (dd, J=5.9 & 15.5 Hz, 1 H) ; 6.51(d, J=15.5 Hz, 1 H) ; 6.86 (d, J=9.1 Hz, 2 H) ; 6.90 (d, J=9.1 Hz, 2 H) MS method N: RT (min): 1.33; [M+H]+380 Step 2 : Example (12B) Preparation of Compound 13: 2-butyl-7-isopentyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of (E)-2-butyl-1-(4-methoxybenzyl)-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine Example (12A) (40 mg, 0.11 mmol) in MeOH (7 mL) was added Pd / C 10% (23 mg). The mixture was kept under Hydrogen atmosphere (4 bars) at 30°C for 1h 30 min. The mixture was filtered through a 0.2 µm filter membrane and the filtrate was evaporated under reduced pressure to give 28 mg (67 %, yield) of Example (12B) as a cream solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.79 (d, J=6.6 Hz, 6 H) ; 0.85 (t, J=7.4 Hz, 3 H) ; 1.29 to 1.40 (m, 4 H) ; 1.48 (m, 1 H) ; 1.68 (m, 2 H) ; 2.74 to 2.84 (m, 4 H) ; 3.70 (s, 3 H) ; 5.52 (s, 2 H) ; 6.20 (s, 2 H); 6.79 (d, J=8.7 Hz, 2 H) ; 6.91 (d, J=8.7 Hz, 2 H) MS method N: RT (min): 1.41; [M+H]+ 382 The following compounds may be made by analogy to Example 12:51, 59, 60, 61, 66 and 73. Example^(13): Preparation of Compound 14: 2-butyl-1-(4-methoxybenzyl)-7-(1H- pyrrol-3-yl)-1H-imidazo[4,5-d]pyridazin-4-amine In a microwave vial was added a solution of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (150 mg, 0.43 mmol) in 1,4-Dioxane (3 mL), followed by addition of Pd(dppf)Cl2.DCM (53.13 mg, 0.065 mmol), 3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole (167.47 mg 0.87 mmol) and finally 2M aqueous solution of Cs2CO3(867.48 µL, 1.73 mmol). The mixture was heated at 110°C for 60 min under microwave and at 130 °C for 45 min. Then the solvent was evaporated under reduced pressure, and the residue was dissolved in DCM and washed with a saturated aqueous solution of NaHCO3. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure. The crude material was purified by silica gel chromatography using as eluent a mixture 97 / 3 DCM / NH3in MeOH (2N) to give 41.24 mg (25.5 %, yield) of Example^(13) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.82 (t, J=7.5 Hz, 3 H) ; 1.29 (m, 2 H) ; 1.61 (m, 2 H) ; 2.69 (m, 2 H) ; 3.68 (s, 3 H) ; 5.31 (s, 2 H) ; 6.16 (dt, J=1.8 & 2.5 Hz, 1 H) ; 6.26 (s, 2H) ; 6.69 (d, J=9.0 Hz, 2 H) ; 6.80 (m, 3 H) ; 6.85 (td, J=1.8 & 2.5 Hz, 1 H) ; 11.00 (s, 1 H) MS method N: RT (min): 1.15; [M+H]+ 377 ; ES- : [M-H+HCO2H]- : m / z 421 Example^(14A): Preparation of Compound 15: ^2-butyl-7-(cyclopent-1-en-1-yl)-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride and Example^(14B): Preparation of Compound 16: 2-butyl-7-cyclopentyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1:^Example^(14A): Preparation of Compound 15: 2-butyl-7-(cyclopent-1-en-1-yl)- 1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride In a microwave vial was added a solution of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H- imidazo[4,5-d]pyridazin-4-amine, intermediate (IA), (250 mg, 0.72 mmol) in a mixture of Me-THF / DMF (8 / 2, 4 mL), followed by addition of Pd(dppf)Cl2.DCM (88.55 mg, 0.11 mmol), cyclopent-1-en-1-ylboronic acid (121.38 mg, 1.08 mmol) and finally 2M aqueous solution of Cs2CO3(1.45 mL, 2.89 mmol). The mixture was heated at 100 °C for 2h under microwave. It was then diluted with Me-THF and washed with H2O and with a saturated aqueous solution of NaCl. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure. The crude material was purified by silica gel chromatography using as eluent a mixture DCM / MeOH 98 / 2. The first fractions containing expected compound, was evaporated to dryness and then dissolved in Et2O, and at 0°C was added a solution 2M of HCl in Et2O. The resulting solid was filtered and dried under vacuum to give 37 mg (12.4 %, yield) of Example (14A). A second fraction containing expected compound was evaporated to dryness to give 70 mg of as free base and engaged in the next step as it.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.86 (t, J=7.5 Hz, 3 H) ; 1.36 (m, 2 H) ; 1.70 (m, 2 H) ; 1.80 (m, 2 H) ; 2.31 (m, 2 H) ; 2.47 (m, 2 H) ; 2.91 (m, 2 H) ; 3.71 (s, 3 H) ; 5.51 (s, 2 H) ; 6.00 (m, 1 H) ; 6.81 (d, J=8.9 Hz, 2 H) ; 6.89 (d, J=8.9 Hz, 2 H) ; 8.82 (m broad, 2 H) ; 14.60 (s broad, 1 H) MS method N: RT (min): 1.27; [M+H]+378 Step 2: Example^(14B): Preparation of Compound 16: 2-butyl-7-cyclopentyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of 2-butyl-7-(cyclopent-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine (70 mg, 0.19 mmol), from Step 1, in MeOH (6 mL) was added platinum (IV) oxide hydrate (13 mg). The mixture was kept under Hydrogen atmosphere (2 bars) at 25 °C for 1 h 50 min. The mixture was filtered through a 0.2 µm filter membrane and the filtrate was evaporated under reduced pressure. The obtained crude material was purified by silica gel chromatography using as eluent a mixture DCM / MeOH (98 / 2) to give 46 mg (63.8 %, yield) of Example^(14B) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.5 Hz, 3 H) ; 1.35 (m, 2 H) ; 1.52 (m, 2 H) ; 1.61 to 1.83 (m, 8 H) ; 2.88 (m, 2 H) ; 3.45 (m, 1 H) ; 3.72 (s, 3 H) ; 5.66 (s, 2 H) ; 6.92 (s, 4 H) ; 8.15 (m, 2 H) MS method P: RT (min): 2.36; [M+H]+ 380 Example^(15A): ^ Preparation of Compound 17: 2-butyl-1-(4-methoxybenzyl)-7-(prop-1- en-2-yl)-1H-imidazo[4,5-d]pyridazin-4-amine and Example^(15B): Preparation of Compound 18: 2-butyl-7-isopropyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: Example^(15A):^ Preparation of Compound 17: 2-butyl-1-(4-methoxybenzyl)-7- (prop-1-en-2-yl)-1H-imidazo[4,5-d]pyridazin-4-amine To a suspension of 2-butyl-7-chloro-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine, intermediate (IA), (200 mg, 0.58 mmol) in 1,4-Dioxane (6 mL) was added Pd(dppf)Cl2.DCM (47.3 mg, 0.58 mmol), 4,4,5,5-Tetramethyl-2-(prop-1-en-2-yl)- 1,3,2-dioxaborolane (228.85 µL, 1.16 mmol) and finally a 2M aqueous solution of Cs2CO3(809.64 µl, 1.62 mmol). The mixture was heated at reflux for 6 h, then diluted with EtOAc and washed with H2O. The organic layer was separated and washed with an aqueous saturated solution of NaCl solution. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure. The crude material was purified by silica gel chromatography using as eluent a mixture DCM / MeOH (97 / 3) to give 88 mg as a creamy foam. The obtained product was triturated with Et2O, filtered and dried to give 71.2 mg (35 %, yield) of Example^(15A).1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7.5 Hz, 3 H) ; 1.35 (m, 2 H) ; 1.69 (m, 2 H) ; 1.83 (s broad, 3 H) ; 2.82 (m, 2 H) ; 3.69 (s, 3 H) ; 4.94 (s broad, 1 H) ; 5.36 (s broad, 1 H) ; 5.48 (s, 2 H) ; 6.42 (s, 2 H) ; 6.72 (d, J=8.9 Hz, 2 H) ; 6.86 (d, J=8.9 Hz, 2 H) MS method N: RT (min): 1.22; [M+H]+352 Step 2: Example^(15B) Preparation of Compound 18: 2-butyl-7-isopropyl-1-(4- methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of 2-butyl-1-(4-methoxybenzyl)-7-(prop-1-en-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine (55 mg, 0.16 mmol), Example^(15A), in MeOH (6 mL) was added platinum (IV) oxide hydrate (7 mg). The mixture was kept under Hydrogen atmosphere (2 bars) at 25 °C for 2 h. Then platinum (IV) oxide hydrate (7 mg) was added and the mixture was kept under Hydrogen atmosphere (2 bars) at 25°C for 4 h 30 min. The mixture was filtered through a 0.2 µm filter membrane and the filtrate was evaporated under reduced pressure to give 65 mg of crude product, which was purified by silica gel chromatography using as eluent a mixture CHCl3 / iPrOH (94 / 6) to give 25 mg (44.2 %, yield) of Example^(15B), as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.5 Hz, 3 H) ; 1.11 (d, J=6.7 Hz, 6 H) ; 1.35 (m, 2 H) ; 1.68 (m, 2 H) ; 2.83 (m, 2 H) ; 3.26 (sept, J= 6.7 Hz, 1 H) ; 3.70 (s, 3 H) ; 5.53 (s, 2 H) ; 6.19 (s, 2 H) ; 6.82 (d, J=9.0 Hz, 2 H) ; 6.91 (d, J=9.0 Hz, 2 H) MS method N RT (min): 1.23; [M+H]+354 The following compound may be made by analogy to Example 15: 159. Example^(16A): Preparation of Compound 19: 1-(((1r,4r)-4- (aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine dihydrochloride Step 1:^tert-butyl (4-(4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)methyl)carbamate To a suspension of 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine, intermediate (M) (1 g, 1.82 mmol) in Me-THF (20 mL) was added Cs2CO3 (1.78 g, 5.46 mmol). The mixture was^stirred^at rt 30 min. Then tert-butyl n-([(1r,4r)- 4(bromomethyl)cyclohexyl]methyl)carbamate (879 mg, 2.73 mmol) in Me-THF (12 mL) was added. The mixture was stirred 5 min at^rt then refluxing for 24 hours. After, the reaction mixture was diluted with EtOAc (150 mL), washed with water and brine, concentrated under reduced pressure to give 1.73 g of crude product, which was purified by chromatography on a Merck cartridge (70 g of 15-40^μm^silica) with a 0 / 100 to 50 / 50^EtOAc / Heptane elution. Expected product (1.03 g, 73% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.75 (m.2 H); 0.83 (t. J=7 Hz.3 H); 1.08 (m.2 H); 1.24 to 1.40 (m.18 H); 1.48 (d. J=12 Hz.2 H); 1.58 to 1.81 (m.5 H); 2.73 (t. J=6 Hz.2 H); 2.77 (t. J=7 Hz.2 H); 3.66 to 3.76 (m.12 H); 4.10 (d. J=6 Hz.2 H); 5.00 (s broad.4 H); 5.37 (spt. J=6 Hz.1 H); 6.39 (dd. J=2 & 8 Hz.2 H); 6.52 (d. J=2 Hz.2 H); 6.78 (t. J=6 Hz. 1 H); 6,96 (d, J=8 Hz, 2 H) MS method N: RT (min): 1.87; [M+H]+775 Step 2: Example^(16A): Preparation of Compound 19: 1-(((1r,4r)-4- (aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine dihydrochloride To a solution of tert-butyl (4-((4-(bis(4-methoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)methyl)carbamate of Step 1 (1.03 g, 1.33 mmol) in DCM (6 mL) was added 2,2,2-trifluoroacetic acid (6 mL, 77.9 mmol) and 1,3- dimethoxybenzene (522 µL, 3.99 mmol). The mixture was^stirred^24 h at rt. The reaction was diluted with DCM (50^mL) and H2O (10 mL). The pH of the mixture was adjusted to pH 10-12 with 30% NaOH under stirring in an ice bath. The product was extracted with DCM (4 X 50 mL), the combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure to give 3.1 g of crude product. The residue was purified by chromatography on a Macherey Nagel cartridge (40 g of 15-40 µm diol) with 100 / / 0 to 50 / / 50 DCM-DCM / MeOH / H20(80 / 10 / 1) to give an oil. The oil was treated with iPr2O (10 mL), a white solid was filtered and washed with iPr2O (3 x 5 mL) dried in vacuo to give 617 mg of powder.500 mg of this product was purified with C1819 x150 mm 5 µm column, eluted with ammonium bicarbonate 10 mM (pH10) / acetonitrile to afford 188 mg of material, which was dissolved in HCl in MeOH (1.25N) and the mixture was evaporated under reduced pressure. The residue was then dissolved in water, filtrated over a 0.22µm membrane, the filtrate was freeze - dried to give 190 mg (39.5 %, yield) Example 16A, under hydrochloric acid form (2HCl).1H NMR (400 MHz, δ in ppm, DMSO-d6):0.87 (q. J=13 Hz. 2 H); 0.94 (t. J=7 Hz. 3 H); 1.12 (q. J=13 Hz.2 H); 1.33 to 1.48 (m.8 H); 1.51 to 1.63 (m, 3 H); 1.66 to 1.92 (m, 5 H); 2.63 (t, J=6 Hz, 2 H); 2.93 (t, J=8 Hz, 2 H); 4.21 (d, J=7 Hz, 2 H); 5.24 (quin, J=6 Hz, 1 H); 7.90 (s broad, 3 H); 8.57 (s broad, 2 H); 13.89 (s, 1 H) MS method N: RT (min): 0.83; [M+H]+375 Example^(16B): Preparation of Compound 20: Trans^4- (aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine 2,2,2-trifluoroacetate Step 1 :^tert-butyl (4-(4-(bis(4-methoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)methyl)carbamate To a suspension of 2-butyl-7-isopropoxy-N,N-bis(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine, Intermediate (R) (414 mg, 0.85 mmol) in THF (23 mL) was added Cs2CO3(827 mg, 2.54 mmol). The mixture was stirred 30 min at rt. Then, tert-butyl N- ([(1r,4r)-4(bromomethyl)cyclohexyl]methyl)carbamate (545 mg, 1.69 mmol) and DMF (6 mL) was added. The mixture was stirred 5 min at rt then heated 1 h at 100°C under microwave. The reaction mixture was filtered, the filtrate was diluted with EtOAc (200 mL), washed with water and brine, concentrated under reduced pressure to give 820 mg of crude product. The residue was purified by chromatography on a Merck cartridge (50 g of 15- 40 μm silica) with a 10 / 90 to 80 / 20 EtOAc / Heptane elution. Expected product (233 mg, 39% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.78 (m, 2 H) ; 0.86 (t, J=7.5 Hz, 3 H) ; 1.08 (m, 2 H) ; 1.23 to 1.41 (m, 3 H) ; 1.36 (s, 9 H) ; 1.37 (d, J=6.2 Hz, 6 H) ; 1.49 (m, 2 H) ; 1.63 to 1.82 (m, 5 H) ; 2.73 (t, J=6.1 Hz, 2 H) ; 2.83 (t, J=7.6 Hz, 2 H) ; 3.71 (s, 6 H) ; 4.14 (d, J=7.2 Hz, 2 H) ; 4.97 (s, 4 H) ; 5.41 (sept, J=6.2 Hz, 1 H) ; 6.78 (t, J=6.1 Hz, 1 H) ; 6.84 (d, J=8.8 Hz, 4 H) ; 7.17 (d, J=8.8 Hz, 4 H) MS method N: RT (min): 1.82; [M+H]+715; ES-[MH-+HCO2H]- : m / z 759 Step 2: Example^(16B): Preparation of Compound 20: 4- (aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine 2,2,2-trifluoroacetate

[0023] To a solution of tert-butyl (4-((4-(bis(4-methoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)methyl)carbamate of Step 1 (230 mg, 0.32 mmol) in DCM (4 mL) was added 2,2,2-trifluoroacetic acid (4 mL, 0.32 mmol). The mixture was stirred 6 days at rt. The reaction was diluted with EtOAc (120 mL) and extracted with H2O (100 mL). The aqueous phase was freeze-dried, to give 123 mg of crude product. The residue was poured into saturated solution of NaHCO3, and extracted with EtOAc (3 X 50 mL), dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure. Example^(16B) (50 mg, 37 %, yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.80 (m, 2 H) ; 0.93 (t, J=7.5 Hz, 3 H) ; 1.10 (m, 2 H) ; 1.30 (m, 1 H) ; 1.36 (d, J=6.2 Hz, 6 H) ; 1.41 (m, 2 H) ; 1.50 (m, 2 H) ; 1.71 to 1.82 (m, 5 H) ; 2.46 (d, J=6.9 Hz, 2 H) ; 2.83 (m, 2 H) ; 4.13 (d, J=7.4 Hz, 2 H) ; 4.74 (m, 3 H) ; 5.39 (sept, J=6.2 Hz, 1 H) ; 5.87 (s, 2 H) MS method N: RT (min): 0.80; [M+H]+ 375; ES+ [M+2H-iPr]2+ : m / z 167 Example (17A): Preparation of Compound 21: 1-(4-(aminomethyl)benzyl)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: tert-butyl (4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imida zo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate To a suspension of 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine, intermediate (M) (1 g, 1.82 mmol) in Me-THF (30 mL)^was added^Cs2CO3(1.78 g, 5.46 mmol). The mixture was^stirred^30 min^at^rt, ^tert-butyl 4- (bromomethyl)benzylcarbamate^(819 mg, 2.73 mmol)^was then added. The mixture was stirred at^rt for 16 h. The reaction mixture was diluted with 150 mL of Me-THF and washed with water and brine, dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 1.73 g of crude product. The residue was purified by chromatography on a Merck cartridge (50 g of 15-40µm silica) with 100 / 0 to 50 / 50 DCM- DCM / MeOH(90 / 10). Expected product (1.34 g, 96 %, yield) was obtained as a white foam.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.76 (t, J=7 Hz, 3 H); 1.21 (m, 8 H); 1.37 (s, 9 H); 1.55 (quin, J=7 Hz, 2 H); 2.74 (t, J=7 Hz, 2 H); 3.71 (s, 12 H); 4.07 (d, J=6 Hz, 2 H); 5.01 (s, 4 H); 5.31 (quin, J=6 Hz, 1 H); 5.55 (s, 2 H); 6.39 (dd, J=2 et & 8 Hz, 2 H); 6.52 (d, J=2 Hz, 2 H); 6.97 (d, J=8 Hz, 2 H); 7.03 (d, J=8 Hz, 2 H); 7.19 (d, J=8 Hz, 2 H); 7.34 (t, J=6 Hz, 1 H) MS method N: RT (min): 1.87; [M+H]+769 Step 2 : Example (17A): Preparation of Compound 21: 1-(4-(aminomethyl)benzyl)-2- butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of tert-butyl (4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 1 (684 mg, 0.889 mmol)^in DCM (10 mL) cooled in an ice bath was added 1,3-dimethoxybenzene (349 µL, 2,67 mmol) and 2,2,2-trifluoroacetic acid (10 mL, 129.8 mmol). After 15 minutes, the ice bath was removed and the mixture was^stirred^16 hours^at^rt.^The reaction mixture was diluted with DCM (100^mL) and H2O (50 mL), the aqueous phase was washed by DCM (2 x 50 mL). The pH of the aqueous layer was adjusted to pH 11 with 30% NaOH under stirring in an ice bath. The product was extracted with DCM (4 x 50 mL), the combined organic layer was dried over MgSO4, filtered and concentrated under reduced pressure to give 306 mg of crude product, which was purified by chromatography on a Macherey Nagel cartridge (26 g of 15-40 µm diol) with 100 / 0 to 0 / 100 DCM-DCM / MeOH (90 / 10), to give 91 mg of purified compound, which was further purified with C1819 x150 mm 5 µm column, eluted with ammonium bicarbonate 10 mM (pH10) / acetonitrile to afford 64 mg (19.5 %, yield) of Example (17A).1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7 Hz, 3 H); 1.21 (s, 3 H); 1.23 (s, 3 H); 1.33 (m, 2 H); 1.63 (m, 2 H); 1.97 (m, 2 H); 2.79 (d, J=15 Hz, 2 H); 3.66 (s, 2 H); 5.33 (spt, J=6 Hz, 1 H); 5.54 (s, 2 H); 5.91 (s, 2 H); 7.01 (d, J=8 Hz, 2 H); 7.28 (d, J=8 Hz, 2 H) MS method N: RT (min): 0.76; [M+H]+369 The following compounds may be made by analogy to Example 17A: 158 and 160. Example (17B): Preparation of Compound 22: 1-(4-(aminomethyl)benzyl)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate Step 1: tert-butyl (4-((4-(bis(4-methoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imida zo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate To a suspension of 2-butyl-7-isopropoxy-N,N-bis(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine, intermediate (R) (133 mg, 0.27 mmol) in THF (7 mL) was added Cs2CO3(266 mg, 0.81 mmol). The mixture was stirred 15 min at rt, tert-butyl 4- (bromomethyl)benzylcarbamate (163 mg, 0.52 mmol) was then added. The mixture was stirred at rt for 20 h. The reaction mixture was filtered, and the filtrate was concentrated under reduced pressure to give 269 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with a 10 / 90 to 60 / 40 EtOAc / Heptane elution. Expected product (83 mg, 43 %, yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6) : 0.78 (t, J=7.4 Hz, 3 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.28 (m, 2 H) ; 1.36 (s, 9 H) ; 1.60 (m, 2 H) ; 2.79 (t, J=7.6 Hz, 2 H) ; 3.71 (s, 6 H) ; 4.07 (d, J=6.2 Hz, 2 H) ; 4.98 (s, 4 H) ; 5.34 (sept, J=6.2 Hz, 1 H) ; 5.59 (s, 2 H) ; 6.85 (d, J=8.8 Hz, 4 H) ; 7.04 (d, J=8.2 Hz, 2 H) ; 7.18 (d, J=8.8 Hz, 4 H) ; 7.20 (d, J=8.2 Hz, 2 H) ; 7.35 (t, J=6.2 Hz, 1 H) MS method N: RT (min): 1.67 ; [M+H]+709; ES-[2MH-+HCO2H]- : m / z 1462 ; ES-[MH- +HCO2H]-: m / z 753 Step 2: Example (17B) Preparation of Compound 22: 1-(4-(aminomethyl)benzyl)-2- butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate

[0024] To a solution of tert-butyl (4-((4-(bis(4-methoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 1 (70 mg, 0.099 mmol) in DCM (1.2 mL) was added 2,2,2-trifluoroacetic acid (1.2 mL, 15.51 mmol). The mixture was stirred 8 days at rt. The reaction was diluted with DCM (80 mL) and extracted with H2O (200 mL). The aqueous phase was washed by EtOAc (2 x 50 mL). The aqueous phase was freeze-dried overnight. Example (17B) (75 mg, 93%, yield) was obtained as a white lyophilizate.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.4 Hz, 3 H) ; 1.22 (d, J=6.2 Hz, 6 H) ; 1.33 (m, 2 H) ; 1.66 (m, 2 H) ; 2.87 (m, 2 H) ; 4.02 (m, 2 H) ; 5.16 (m, 1 H) ; 5.67 (s, 2 H) ; 7.18 (d, J=8.5 Hz, 2 H) ; 7.42 (d, J=8.5 Hz, 2 H) ; 8.13 (s, 3 H) ; 8.47 (m, 2 H) MS method N: RT (min): 0.68; [M+H]+369 Example (18): Preparation of Compound 23: 1-(((1S,3R)-3-aminocyclohexyl)methyl)- 2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine (and enantiomer) Step 1: tert-butyl ((1R,3S)-3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate (and enantiomer) To a suspension of intermediate (M) (500 mg, 0.91 mmol) in Me-THF (15 mL) was added Cs2CO3(449.05 mg, 1.36 mmol). The mixture was stirred at rt during 30 min. Tert-butyl [cis-3-(bromomethyl)cyclohexyl]carbamate (419.70 mg, 1.36 mmol) was then added, which was stirred at rt for 20h and then heated at 60°C for 5 days. The mixture was diluted with Me-THF (250 mL) then washed with H2O (2 x 80 mL), brine (80 mL), dried over anhydrous MgSO4, and filtered. The filtrate was concentrated under reduced pressure to give 940 mg of crude product, which was purified by chromatography on a Merck cartridge (50 g of 15- 40 μm silica) with a 10 / 90 to 80 / 20 EtOAc / Heptane elution. Expected compound (490 mg, 71% yield) was obtained as a white solid.1H NMR (400MHz, δ in ppm, DMSO-d6): 0.80 to 1.44 (m, 7 H) ; 0.83 (t, J=7.5 Hz, 3 H) ; 1,34 (s, 9 H) ; 1.35 (d, J=6.2 Hz, 3 H) ; 1.38 (d, J=6.2 Hz, 3 H) ; 1.57 (m, 1 H) ; 1.61 to 1.76 (m, 4 H) ; 1.85 (m, 1 H) ; 2.78 (t, J=7.4 Hz, 2 H) ; 3.12 (m, 1 H) ; 3.70 (s, 6 H) ; 3.71 (s, 6 H) ; 4.12 (m, 2 H) ; 5.00 (s, 4 H) ; 5.38 (sept, J=6.2 Hz, 1 H) ; 6.38 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.76 (d, J=7.9 Hz, 1 H) ; 6.95 (d, J=8;4 Hz, 2 H) MS method N: RT (min): 1.83; [M+H]+761 Step 2: Example (18) Preparation of Compound 23: 1-(((1S,3R)-3- aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine (and enantiomer) To a solution of tert-butyl ((1R,3S)-3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate (and enantiomer) of Step 1 (480 mg, 0.63 mmol) in DCM (2.5 mL) was added 2,2,2- trifluoroacetic acid (2.5 mL, 32.65 mmol). The mixture was stirred at room temperature for 24 hours. The reaction was poured into DCM (100 mL) and washed with H2O (2 x 80 mL). The aqueous phase was neutralized by addition of sodium hydroxide 5M, and was extracted by EtOAc (3 x 75 mL). The organic phase was washed with H2O, brine, dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 115 mg (50.7% yield) of Example (18) as a white powder.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.75 to 1.00 (m, 2 H) ; 0.93 (t, J = 7.4 Hz, 3 H) ; 1.15 (m, 1 H) ; 1.33 to 1.54 (m, 9 H) ; 1.63 to 1.89 (m, 5 H) ; 2.07 (m broad, 2 H) ; 2.45 (m, 3 H) ; 2.83 (m, 2 H) ; 4.11 (m, 2 H) ; 5.38 (sept, J = 6.2 Hz, 1 H) ; 5.85 (s, 2 H) MS method N: RT (min): 0.85; [M+H]+361; ES+ [M+2H]2+: m / z 181 Example (19):^ Preparation of Compound 24: 1-(4-amino-2-butyl-7-isopropoxy-1H- imidazo[4.5-d]pyridazin-1-yl)-2-methylpropan-2-ol Step1: 1-(4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)-2-methylpropan-2-ol To a suspension of intermediate (M) (500 mg, 91 mmol) in Me-THF (15 mL), was added Cs2CO3(900 mg, 2.73 mmol). The mixture was stirred 30 min at rt. Then, 2.2- dimethyloxirane (125 µL, 1.37 mmol) was added. The mixture was heated 20 h under microwave at 60°C, then concentrated under reduced pressure. The residue was diluted in MeCN (15 mL), 2.2-dimethyloxirane (250 µL, 2.74 mmol) was added, and the mixture was heated 48 h under microwave at 90°C. The reaction mixture was then diluted with Me- THF (250 mL), washed with water and brine, dried over MgSO4, filtered and concentrated under reduced pressure to give 533 mg of crude product, which was purified by chromatography on a Merck cartridge (40 g of 15-40 μm silica) with a 10 / 90 to 60 / 40 EtOAc / Heptane elution. Expected product (236 mg, 42 %, yield) was obtained as a white amorphous solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.83 (t, J=7.4 Hz, 3 H) ; 1.09 (s broad, 6 H) ; 1.29 (m, 2 H) ; 1.36 (d, J=6.2 Hz, 6 H) ; 1.64 (m, 2 H) ; 2.95 (t, J=7.6 Hz, 2 H) ; 3.70 (s, 6 H) ; 3.71 (s, 6 H) ; 4.29 (s broad, 2 H) ; 4.76 (s, 1 H) ; 5.01 (s, 4 H) ; 5.38 (sept, J=6.2 Hz, 1 H) ; 6.39 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.96 (d, J=8.4 Hz, 2 H) MS method N: RT (min): 1.59; [M+H]+622; ES-[M-H+HCO2H]- : m / z 666 Step 2: Example (19): Preparation of Compound 24: 1-(4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)-2-methylpropan-2-ol To a solution of 1-(4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)-2-methylpropan-2-ol of Step 1 (230 mg, 0.37 mol) in DCM (2 mL) was added 2,2,2-trifluoroacetic acid (1.5 mL, 20.19 mmol). The mixture was stirred 5 h at rt. The reaction mixture was diluted with DCM (100 mL) and extracted with H2O (2 x 80 mL). The aqueous phase was neutralized with NaOH (5 M) up to pH 10, extracted with EtOAc (3 x 75 mL), the organic phase was washed with water and brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. Example (19), (37 mg, 31 %, yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.92 (t, J=7.3 Hz, 3 H) ; 1.09 (s broad, 6 H) ; 1.36 (d, J=6.2 Hz, 6 H) ; 1.39 (m, 2 H) ; 1.75 (m, 2 H) ; 3.01 (m, 2 H) ; 4.28 (s, 2 H) ; 4.78 (s, 1 H) ; 5.36 (sept, J=6.2 Hz, 1 H) ; 6.24 (s, 2 H) MS method N: RT (min): 1.1; [M+H]+322 The following compounds may be made by analogy to Example 19: 74, 75, 76, 80, 81. Example (20): Preparation of Compound 25: Trans 1-(4-aminocyclohexyl)methyl)-2- butyl-7-isopropoxy-1H-imidazo [4,5-d]pyridazin-4-amine Step1: tert-butyl 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate To a suspension of intermediate (M) (400 mg, 0.73 mmol) in Me-THF (15 mL), was added Cs2CO3(720 mg, 2.19 mmol). The mixture was stirred 30 min at rt. Then, tert-butyl 4- (bromomethyl)cyclohexyl)carbamate (320 mg, 1.10 mmol) was added. The mixture was stirred at rt for 24h, then heated at 90°C under microwave 18h. After, the reaction mixture was diluted with Me-THF (Methyltetrahydrofuran) (250 mL), washed with water and brine, dried over MgSO4, filtered and concentrated under reduced pressure to give 692 mg of crude product, which was purified by chromatography on a Merck cartridge (40 g of 15-40 μm silica) with a 10 / 90 to 100 / 00 EtOAc / Heptane elution. Expected product (357 mg, 64 %, yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.83 (t, J=7.5 Hz, 3 H) ; 1.04 (m, 2 H) ; 1.14 (m, 2 H) ; 1.09 (m, 2 H) ; 1.36 (s, 9 H) ; 1.37 (d, J=6.2 Hz, 6 H) ; 1.47 (m, 2 H) ; 1.60 to 1.79 (m, 5 H) ; 2.77 (t, J=7.4 Hz, 2 H) ; 3.17 (m, 1 H) ; 3.70 (s, 6 H) ; 3.71 (s, 6 H) ; 4.10 (d, J=7.2 Hz, 2 H) ; 5.00 (s, 4 H) ; 5.38 (sept, J=6.2 Hz, 1 H) ; 6.39 (dd, J=2.5 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.5 Hz, 2 H) ; 6.68 (d, J=7.9 Hz, 1 H) ; 6.96 (d, J=8.4 Hz, 2 H) MS method N: RT (min): 1.79; [M+H]+761 Step 2: Example (20): Preparation of Compound 25: Trans 1-(4- aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo [4,5-d]pyridazin-4-amine To a solution of tert-butyl 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate of Step 1 (345 mg, 0.45 mmol) in DCM (2 mL) was added 2,2,2-trifluoroacetic acid (2 mL, 26.66 mmol). The mixture was^stirred^24 hours at rt. The reaction mixture was diluted with DCM (100^mL) and extracted with H2O (2 x 80 mL). The aqueous phase was neutralized with NaOH (5M) up to pH 10, extracted with EtOAc (3 x 75 mL), the organic phase was washed with water and brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. Example (20) (142 mg, 87 %, yield) was obtained as a white solid.^1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.92 (t, J=7.3 Hz, 3 H) ; 0.94 (m, 2 H) ; 1.12 (m, 2 H) ; 1.34 to 1.48 (m, 5 H) ; 1.36 (d, J=6.2 Hz, 6 H) ; 1.65 to 1.81 (m, 5 H) ; 2.82 (m, 2 H) ; 2.95 (m broad, 2 H) ; 4.10 (d, J=7.5 Hz, 2 H) ; 5.39 (sept, J=6.2 Hz, 1 H) ; 5.85 (s, 2 H) MS method N: RT (min): 0.78; [M+H]+361; ES+ [M+2H]2+: m / z 181 ) The following compounds may be made by analogy to Example 20: 77, 78, 79, 146, 149, 165. Example (21A): Preparation of Compound 261-((5-(aminomethyl)pyridin-2-yl)methyl)- 2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine and Example (21B): Preparation of Compound 27: -((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)nicotinonitrile Step 1: 6-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)nicotinonitrile

[0025] To a suspension of intermediate (M) (500 mg, 0.91 mmol) in Me-THF (15 mL), was added Cs2CO3(898 mg, 2.73 mmol). The mixture was stirred 30 min at rt, then 6- (bromomethyl)nicotinonitrile (285 mg, 1.37 mmol) was added. The mixture was stirred 1h at rt. After, the reaction mixture was diluted with Me-THF, washed with water and brine, dried over MgSO4, filtered and concentrated under reduced pressure to give 661 mg of crude product, which was purified by chromatography on a Merck cartridge (50 g of 15- 40 μm silica) with a 10 / 90 to 80 / 20 EtOAc / Heptane elution. Expected product (467 mg, 77% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.80 (t, J=7.5 Hz, 3 H) ; 1.06 (d, J=6.2 Hz, 6 H) ; 1.28 (m, 2 H) ; 1.61 (m, 2 H) ; 2.81 (t, J=7.6 Hz, 2 H) ; 3.71 (s, 6 H) ; 3.72 (s, 6 H) ; 5.02 (s, 4 H) ; 5.18 (sept, J=6.2 Hz, 1 H) ; 5.75 (s, 2 H) ; 6.40 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.53 (d, J=2.4 Hz, 2 H) ; 6.98 (d, J=8.4 Hz, 2 H) ; 7.49 (dd, J=0.9 & 8.3 Hz, 1 H) ; 8.33 (dd, J=2.2 & 8.3 Hz, 1 H) ; 8.90 (dd, J=0.9 & 2.2 Hz, 1 H) MS method O: RT (min): 2.96; [M+H]+666 Step 2: 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-N,N-bis(2,4-dimethoxybenzyl)- 7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of 6-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)nicotinonitrile of Step 1 (460 mg, 0.69 mmol) in EtOH (10 mL) was added Pd / C10% (46 mg, 0.43 mmol). The mixture was hydrogenated under 17 bars at 25°C for 6 h and filtered. The filtrate was concentrated under vacuum to give 413 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15- 40 μm silica) with 99 / 1 / 0.1 to 93 / 7 / 0.1 DCM / MeOH / NH4OH elution. Expected product (178 mg, 38% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.79 (t, J=7.4 Hz, 3 H) ; 1.17 (d, J=6.2 Hz, 6 H) ; 1.27 (m, 2 H) ; 1.61 (m, 2 H) ; 1.95 (m broad , 2 H) ; 2.83 (t, J=7.6 Hz, 2 H) ; 3.67 (s, 2 H) ; 3.71 (s, 6 H) ; 3.72 (s, 6 H) ; 5.01 (s, 4 H) ; 5.24 (sept, J=6.2 Hz, 1 H) ; 5.61 (s, 2 H) ; 6.39 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.97 (d, J=8.4 Hz, 2 H) ; 7.16 (dd, J=0.8 & 8.1 Hz, 1 H) ; 7.73 (dd, J=2.3 & 8.1 Hz, 1 H) ; 8.37 (dd, J=0.8 & 2.3 Hz, 1 H) MS method N: RT (min): 1.32; [M+H]+670; ES+[M+2H]2+: m / z 335.7 Step 3 (I): Example (21A): Preparation of Compound 26: 1-((5-(aminomethyl)pyridin- 2-yl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-N,N-bis(2,4- dimethoxybenzyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine, of Step 2 (175 mg, 0.26 mmol) in DCM (1.2 mL) was added 2,2,2-trifluoroacetic acid (1.20 mL, 15.68 mmol). The mixture was stirred 24 h at rt. The reaction mixture was diluted with DCM (100 mL) and extracted with H2O (2 x 80 mL). The aqueous phase was adjusted to pH 10 with 5 N sodium hydroxide solution, extracted with EtOAc (3 x 75 mL), the organic phase was washed with water and brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. Example (21A) (79 mg, 82% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7.4 Hz, 3 H) ; 1.16 (d, J=6.2 Hz, 6 H) ; 1.35 (m, 2 H) ; 1.68 (m, 2 H) ; 2.67 (m, 2 H) ; 2.87 (m, 2 H) ; 3.70 (s, 2 H) ; 5.25 (sept, J=6.2 Hz, 1 H) ; 5.61 (s, 2 H) ; 5.89 (s, 2 H) ; 7.12 (d, J=8.1 Hz, 1 H) ; 7.73 (dd, J=2.3 & 8.1 Hz, 1 H) ; 8.38 (d, J=2.3 Hz, 1 H) MS method N: RT (min): 0.46; [M+H]+370 Step 3 (II): Example (21-B): Preparation of Compound 27: 6-((4-amino-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)nicotinonitrile To a solution of 6-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)nicotinonitrile, of Step 1 (225 mg, 0.34 mmol) in DCM (1.5 mL) was added 2,2,2-trifluoroacetic acid (1.50 mL, 19.59 mmol). The mixture was stirred 24 h at rt. The reaction mixture was diluted with DCM (100 mL) and extracted with H2O (2 x 80 mL). The aqueous phase was adjusted to pH 12 with 5 N sodium hydroxide solution, saturated with NaCl, extracted with EtOAc (3 x 75 mL), the organic phase was washed with water and brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. Example (21B), (110 mg, 89% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7 Hz, 3 H); 1.05 (d, J=6 Hz, 6 H); 1.35 (dq, J=7 & 15 Hz, 2 H); 1.68 (dt, J=8 & 15 Hz, 2 H); 2.87 (t, J=8 Hz, 2 H); 5.19 (spt, J=6 Hz, 1 H); 5.75 (s, 2 H); 5.92 (s, 2 H); 7.45 (dd, J=1 & 8 Hz, 1 H); 8.33 (dd, J=2 & 8 Hz, 1 H); 8.90 (dd, J=1 & 2 Hz, 1 H) MS method N: RT (min): 1.10; [M+H]+m:z 366 Example (22): Preparation of Compound 28: N-(4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5d]pyridazin-1-yl)methyl)benzyl)acetamide To a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine (Example (17A)) (200 mg, 0.54 mmol) in DMF (6 mL) was added DIPEA (95 µL, 0.54 mmol), and acetic anhydride (61 µL, 0.65 mmol). The solution was stirred at rt for 2 h and then was poured into a mixture water (30 mL) and ice (30 g) which was stirred at rt 30 min. Then solid NaHCO3was added until pH 8. The solution was extracted with EtOAc (3 x 40 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 139 mg of white solid, which was dissolved in MeOH (10 mL). Potassium carbonate (108 mg) was added and the suspension was stirred at room temperature for 18h. The reaction mixture was concentrated under vacuum, dissolved in DCM (10 mL) washed with water (5 mL), and brine (5 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give the crude product, which was stirred 15 min at room temperature in diisopropyl ether (2 mL). The suspension was filtered. The solid was washed with diisopropyl ether (2 x 1 mL) and dried under vacuum. Example (22) (70 mg, 65% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.5 Hz, 3 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.32 (m, 2 H) ; 1.63 (m, 2 H) ; 1.83 (s, 3 H) ; 2.79 (m, 2 H) ; 4.19 (d, J=6.0 Hz, 2 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.55 (s, 2 H) ; 5.91 (s, 2 H) ; 7.03 (d, J=8.4 Hz, 2 H) ; 7.20 (d, J=8.4 Hz, 2 H) ; 8.29 (t, J=6.0 Hz, 1 H) MS method N: RT (min): 1.09; [M+H]+411 Example (23): Preparation of Compound 29: N-(4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)undecanamide To a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine (Example (17A)) (127 mg, 0.35 mmol) in DMF (3 mL) was added Undecanoic acid (65 µL, 0.35 mmol), and TEA (345 µL, 0.35 mmol). The solution was stirred 5 min at rt. Then HBTU (167 mg, 0.43 mmol) was added. The mixture was stirred at rt for 2 hours. The reaction mixture was poured into a mixture water (30 mL) and ice (30 g) and was stirred at rt for 30 min, then extracted with EtOAc (3 x 30 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 200 mg of the crude product, which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with DCM / MeOH (93 / 7) elution to obtain colorless gum. This gum was dissolved in MeOH (2.5 mL) and filtered through Amberlist A-26 OH column. The MeOH filtrate was concentrated under vacuum to give a gum (48 mg), which was stirred at room temperature for 15 min with diisopropyl ether. The supernatant solution was eliminated, and the gum was dried under vacuum. Example (23) was obtained (31 mg, 15% yield) as a colorless gum.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 0.85 (t, J=6.9 Hz, 3 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.22 (s broad, 14 H) ; 1.32 (m, 2 H) ; 1.48 (m, 2 H) ; 1.62 (m, 2 H) ; 2.08 (t, J=7.4 Hz, 2 H) ; 2.79 (m, 2 H) ; 4.20 (d, J=6.1 Hz, 2 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.54 (s, 2 H) ; 5.91 (s, 2 H) ; 7.02 (d, J=8.4 Hz, 2 H) ; 7.19 (d, J=8.4 Hz, 2 H) ; 8.24 (t, J=6.1 Hz, 1 H) MS method N: RT (min): 1.59; [M+H]+537; ES- [M-H+HCO2H]- : m / z 581 The following compounds may be made by analogy to Example 23: 84, 103, 106 and 107. Example (24): Preparation of Compound 30: N-(4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)pentanamide To a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine (Example (17A)) (200 mg, 0.42 mmol) in THF (5 mL) was added Valeric acid (51 µL, 0.46 mmol), EDCI (238 mg, 1.24 mmol), HOBt (95 mg, 1.5 eq), and dropwise DIPEA (290 µl, 4 eq). The solution was stirred at rt for 2h. The reaction mixture was diluted with EtOAc (50 mL), washed with water (25 mL), saturated aqueous sodium hydrogen carbonate (25 mL), and water (2 x 25 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 156 mg of crude product which was purified by chromatography on Merck cartridge (10 g of 15-40 μm silica) with DCM / MeOH / CH3CN (90 / 5 / 5) elution to give Example (24) (94 mg, 50% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.83 (t, J=7.4 Hz, 6 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.23 (m, 2 H) ; 1.32 (m, 2 H) ; 1.47 (m, 2 H) ; 1.62 (m, 2 H) ; 2.09 (t, J=7.5 Hz, 2 H) ; 2.79 (m, 2 H) ; 4.20 (d, J=6.0 Hz, 2 H) ; 5.31 (sept, J=6.2 Hz, 1 H) ; 5.55 (s, 2 H) ; 5.96 (s, 2 H) ; 7.02 (d, J=8.3 Hz, 2 H) ; 7.19 (d, J=8.3 Hz, 2 H) ; 8.25 (t, J=6.0 Hz, 1 H) MS method N: RT (min): 1.23; [M+H]+453; ES- [M-H+HCO2H]- : m / z 497 Example (25): Preparation of Compound 31: N-(4-((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)-3-(2-methoxyethoxy)propanamide

[0026] To a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine (Example (17A)) (200 mg, 0.42 mmol) in THF (5 mL) was added 3- (2-methoxyethoxy) propanoic acid (65 mg, 0.41 mmol), EDCI (238 mg, 1.24 mmol), HOBT (95 mg, 1.5 eq) and dropwise DIPEA (290 µl, 4 eq). The solution was stirred at rt for 2 hours. The reaction mixture was diluted with EtOAc (50 mL), washed with water (25 mL), saturated aqueous solution sodium hydrogen carbonate (25 mL), and water (2 x 25 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 182 mg of crude product which was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with DCM / Methanol / Acetonitrile (85 / 7.5 / 7.5) elution to give Example (25) (58.5 mg, 28% yield) as a colorless gum.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.4 Hz, 3 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.32 (m, 2 H) ; 1.63 (m, 2 H) ; 2.34 (t, J=6.5 Hz, 2 H) ; 2.78 (t, J=7.6 Hz, 2 H) ; 3.16 (s, 3 H) ; 3.37 (m, 2 H) ; 3.46 (m, 2 H) ; 3.60 (t, J=6.5 Hz, 2 H) ; 4.23 (d, J=6.1 Hz, 2 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.55 (s, 2 H) ; 5.91 (s, 2 H) ; 7.02 (d, J=8.3 Hz, 2 H) ; 7.20 (d, J=8.3 Hz, 2 H) ; 8.31 (t, J=6.1 Hz, 1 H) MS method N: RT (min): 1.11; [M+H]+499 Example (26): Preparation of Compound 32: 1-(((1S,3S)-3-aminocyclohexyl)methyl)-2- butyl-7-isopropoxy-1H-imidazo[4,5-]pyridazin-4-amine (and enantiomer) Step 1: tert-butyl N-[(1S,3S)-3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate (and enantiomer)

[0027] To a suspension of intermediate (M) (500 mg, 0.91mmol) in Me-THF (15 mL) was added Cs2CO3 (898 mg, 2.73 mmol).�e mixture was stirred 30 min at rt.�en tert-butyl[trans-3- (bromomethyl)cyclohexyl]carbamate (410 mg, 1.36 mmol) was added.�e mixture was stirred 4 days at rt, then heated under microwave at 90°C for 9 hours.�e reaction mixture was diluted with Me-THF (250 mL), washed with water and brine, dried over MgSO4,filtered and concentrated under reduced pressure to give 1.23 g of crude product, which was purified by chromatography on a Merck cartridge (70 g of 15-40 μm silica) with a 50 / 50 to 100 / 0 EtOAc / Heptane elution. Expected product (434 mg, 63% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.5 Hz, 3 H) ; 1.08 (m, 1 H) ; 1.20 to 1.55 (m, 9 H) ; 1.32 (s, 9 H) ; 1.36 (d, J=6.2 Hz, 3 H) ; 1.38 (d, J=6.2 Hz, 3 H) ; 1.66 (m, 2 H) ; 2.11 (m, 1 H) ; 2.78 (t, J=7.5 Hz, 2 H) ; 3.68 (m partially hidden, 1 H) ; 3.70 (s, 6 H) ; 3.71 (s, 6 H) ; 4,11 (d, J=7.2 Hz, 2 H) ; 5.00 (s, 4 H) ; 5.36 (sept, J=6.2 Hz, 1 H) ; 6.38 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.73 (d, J=7.2 Hz, 1 H) ; 6.95 (d, J=8.4 Hz, 2 H) MS method N: RT (min): 1.82; [M+H]+761 Step 2: Example (26): Preparation of Compound 32: 1-(((1S,3S)-3- aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-]pyridazin-4-amine (and enantiomer)

[0028] To a solution of tert-butyl 3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)cyclohexyl)carbamate (435 mg, 0.57 mmol) in DCM (2.5 mL) was added 2,2,2-trifluoroacetic acid (2.5 mL, 32.65 mmol). The mixture was^stirred^24 hours at rt. The reaction mixture was diluted with DCM (100^mL) and extracted with H2O (2 x 80 mL). The aqueous phase was adjusted to pH 10 with 5 N sodium hydroxide solution, extracted with EtOAc (3 x 75 mL). the organic phase was washed with water and brine, dried over MgSO4, filtered and evaporated under reduced pressure. Example (26) (136 mg, 66% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.93 (t, J=7.4 Hz, 3 H) ; 1.07 (m, 1 H) ; 1.26 to 1.62 (m, 15 H) ; 1.78 (m, 2 H) ; 1.90 (m broad, 2 H) ; 2.22 (m, 1 H) ; 2.82 (m, 2 H) ; 3.09 (m, 1 H) ; 4.11 (m, 2 H) ; 5.38 (sept, J=6.2 Hz, 1 H) ; 5.84 (s, 2 H) MS method N: RT (min): 0.90; [M+H]+361; ES+ [M+2H]2+: m / z 181 Example (27): Preparation of Compound 33: 1-(3-(aminomethyl)benzyl)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate Step 1: tert-butyl (3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate

[0029] To a suspension of intermediate (M) (200 mg, 0.36 mmol) in THF (11 mL) was added Cs2CO3(356 mg, 1.09 mmol). The mixture was stirred 30 min at rt. Then, tert-butyl 3- bromomethyl)benzylcarbamate (230 mg, 0.73 mmol) was added. The mixture was stirred 20 hours at rt, then filtered, and the filtrate was concentrated under reduced pressure to give 526 mg of crude product. The residue was dissolved in EtOAc, washed with water and brine, concentrated under reduced pressure to give 428 mg of crude product, which was purified by chromatography on a Merck cartridge (30 g of 15-40 μm silica) with a 10 / 90 to 80 / 20 EtOAc / Heptane elution. Expected product (61 mg, 22% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.77 (t, J=7.5 Hz, 3 H) ; 1.22 (d, J=6.2 Hz, 6 H) ; 1.24 (m, 2 H) ; 1.34 (s, 9 H) ; 1.56 (m, 2 H) ; 2.75 (t, J=7.6 Hz, 2 H) ; 3.71 (s, 12 H) ; 4.06 (d, J=6.4 Hz, 2 H) ; 5.01 (s, 4 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.56 (s, 2 H) ; 6.39 (dd, J=2.5 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.5 Hz, 2 H) ; 6.94 (d broad, J=7.9 Hz, 1 H) ; 6.98 (d, J=8.4 Hz, 2 H) ; 7.03 (s broad, 1 H) ; 7.14 (d broad, J=7.9 Hz, 1 H) ; 7.28 (t, J=7.9 Hz, 1 H) ; 7.32 (t, J=6;4 Hz, 1 H) MS method O: RT (min): 3.22; [M+H]+769 Step 2:^Example (27): Preparation of Compound 33: 1-(3-(aminomethyl)benzyl)-2- butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate

[0030] To a solution of tert-butyl (3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 1 (60 mg, 0.08 mmol) in DCM (1 mL) was added 2,2,2-trifluoroacetic acid (1 mL, 13 mmol). The mixture was^stirred^8 hours at rt. The reaction was diluted with DCM (100^mL) and extracted with H2O (2 x 50 mL). The aqueous phase was neutralized with a saturated solution of K2CO3up to pH 8 and extracted^by^EtOAc^(3 x 75 mL), the organic phase was dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure. ^Example (27) (24 mg, 83% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.86 (t, J=7.4 Hz, 3 H) ; 1.22 (d, J=6.2 Hz, 6 H) ; 1.34 (m, 2 H) ; 1.67 (m, 2 H) ; 2.80 (m, 2 H) ; 3.94 (s, 2 H) ; 5.32 (sept, J= 6.2 Hz, 1 H) ; 5.59 (s, 2 H) ; 5.98 (s, 2 H) ; 7.11 (t, J=2.0 Hz, 1 H) ; 7.14 (td, J=2.0 et 7.8 Hz, 1 H) ; 7.36 (td, J=2.0 et 7.8 Hz, 1 H) ; 7.41 (t, J=7.8 Hz, 1 H) ; 7.86 (m, 3 H) MS method N: RT (min): 0.81; [M+H]+369 Example (28): Preparation of Compound 34: 4-((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde Step 1: 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzaldehyde

[0031] To a suspension of intermediate (M) (2.2 g, 3.12 mmol) in Me-THF (21 mL) was added 4- (bromomethyl)benzaldehyde (847 mg, 4.26 mmol) and Cs2CO3(1.32 g, 4.11 mmol)). The mixture was stirred at rt during 24h. The mixture was poured into Me-THF (15 mL) then washed with H2O (15 mL), dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 3 g of crude product, which was purified by chromatography on a Merck cartridge (150 g of 15-40 μm silica) with EtOAc / Heptane (38 / 62) elution. Expected product (1.5 g, 71% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.76 (t, J=7.4 Hz, 3 H) ; 1.13 (d, J=6.2 Hz, 6 H) ; 1.24 (m, 2 H) ; 1.56 (m, 2 H) ; 2.77 (t, J=7.5 Hz, 2 H) ; 3.71 (s, 12 H) ; 5.02 (s, 4 H) ; 5.26 (sept, J=6.2 Hz, 1 H) ; 5.69 (s, 2 H) ; 6.40 (dd, J=2.5 & 8.4 Hz, 2 H) ; 6.53 (d, J=2.5 Hz, 2 H) ; 6.99 (d, J=8.4 Hz, 2 H) ; 7.25 (d, J=8.3 Hz, 2 H) ; 7.89 (d, J=8.3 Hz, 2 H) ; 9.97 (s, 1 H) MS method N: RT (min): 1.66 ; [M+H]+668; ES- [2M-H+HCO2H]- : m / z 1379 Step 2: Example (28) Preparation of Compound 34: 4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde To a solution of 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 (110 mg, 0.17 mmol) in DCM (1.6 mL) was added 2,2,2-trifluoroacetic acid (1.6 mL, 21 mmol). The mixture was stirred at rt for 24 h. The reaction was poured into DCM (10 mL) and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 96 mg of crude product. The crude product was purified by chromatography on a Merck cartridge (5 g of 15-40 μm silica) with DCM / MeOH (96 / 4) elution. Example (28) (23 mg, 36.8% yield) was obtained as a solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.5 Hz, 3 H) ; 1.12 (d, J=6.2 Hz, 6 H) ; 1.33 (m, 2 H) ; 1.64 (m, 2 H) ; 2.83 (m, 2 H) ; 5.26 (m, 1 H) ; 5.69 (s, 2 H) ; 5.97 (s, 2 H) ; 7.23 (d, J=8.2 Hz, 2 H) ; 7.89 (d, J=8.2 Hz, 2 H) ; 9.98 (s, 1 H) MS method N: RT (min): 1.21; [M+H]+368 Example (29): Preparation of Compound 35: (4-((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)phenyl)methanol. To a solution of compound 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 in Example (28) (200 mg, 0.30 mmol) in DCM (3 mL) was added 2,2,2-trifluoroacetic acid (1.6 mL, 21 mmol) and triethylsilane (145 µL, 0.90 mmol). The mixture was stirred at room temperature for 24 hours. The reaction was poured into DCM and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 200 mg of crude product, which was purified by preparative HPLC at room temperature by using a 250 x 50 mm, 5 µm CSH column (WATERSTM) and a water / acetonitrile gradient with 0.1% formic acid (t=0min : 10% of acetonitrile; t=5min: 10% and t= 25min: 30%). The compound was eluted at 18.8 min and lyophilized to afford 22 mg (19.8% yield) of Example (29) as a white foam.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.28 Hz, 3 H) 1.21 (d, J=6.27 Hz, 6 H) 1.32 (sxt, J=7.65 Hz, 2 H) 1.63 (quin, J=7.59 Hz, 2 H) 2.79 (t, J=7.81 Hz, 2 H) 4.45 (s, 2 H) 5.13 (br s, 1 H) 5.32 (spt, J=6.15 Hz, 1 H) 5.56 (s, 2 H) 5.92 (s, 2 H) 7.02 (d, J=8.28 Hz, 2 H) 7.27 (d, J=8.28 Hz, 2 H) MS method A: RT (min): 0.73; [M+H]+370 Example (30): Preparation of Compound 36: 2-butyl-1-(4- ((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: 2-butyl -1-(4-((cyclopropylamino)methyl)benzyl)-N,N-bis(2,4-dimethoxybenzyl)- 7-sopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine

[0032] To a solution of 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 in Example (28) (200 mg, 0.30 mmol) in MeOH (2 mL) was added cyclopropylamine (25.41 µL, 0.36 mmol) and acetic acid (34.29 µL, 0.60 mmol). The mixture was stirred at rt during 10 min and then sodium cyanoborohydride (29.72 mg, 0.45 mmol) was added. The mixture was stirred at rt during 3h. The reaction was poured into H2O and adjusted pH to 8 by addition of ammonia solution (35%). Then the mixture was extracted by EtOAc. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 0.25 g of oil. The product was purified by chromatography on a Merck cartridge (20 g of 15- 40 μm silica) with [(EtOAc / EtOH 3 / 1) 40% - Heptane 60%] elution. Expected product (154 mg, 72.4 % yield) was obtained as a solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.19 (m, 2 H) ; 0.29 (m, 2 H) ; 0.76 (t, J=7.4 Hz, 3 H) ; 1.21 (d, J=6.2 Hz, 6 H) ; 1.24 (m, 2 H) ; 1.54 (m, 2 H) ; 1.97 (m, 1 H) ; 2.56 (m, 1 H) ; 2.75 (t, J=7.6 Hz, 2 H) ; 3.65 (d, J=5.4 Hz, 2 H) ; 3.71 (s, 12 H) ; 5.01 (s, 4 H) ; 5.31 (sept, J=6.2 Hz, 1 H) ; 5.56 (s, 2 H) ; 6.39 (dd, J=2.5 & 8.5 Hz, 2 H) ; 6.52 (d, J=2.5 Hz, 2 H) ; 6.97 (d, J=8.5 Hz, 2 H) ; 7.02 (d, J=8.3 Hz, 2 H) ; 7;27 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 1.57; [M+H]+709; ES+[M+2H]2+: m / z 355 Step 2: Example (30) Preparation of Compound 36: 2-butyl-1-(4- ((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-N,N-bis(2,4- dimethoxybenzyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine of Step 1 (140 mg, 0.20 mol) in DCM (2 mL) was added 2,2,2-trifluoroacetic acid (910 µL, 11.81 mmol). The mixture was stirred at rt for 24h. The reaction was poured into DCM (10 mL) and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 90 mg of crude product. The crude product was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with DCM / MeOH / NH4OH (95 / 5 / 0.2) elution, to afford Example (30) (40 mg, 49% yield) as a solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.17 to 0.32 (m, 4 H) ; 0.83 (t, J=7.3 Hz, 3 H) ; 1.20 (d, J=6.2 Hz, 6 H) ; 1.31 (m, 2 H) ; 1.61 (m, 2 H) ; 1.97 (m, 1 H) ; 2.60 (m, 1 H) ; 2.80 (m, 2 H) ; 3.66 (s, 2 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.55 (s, 2 H) ; 5.92 (m, 2 H) ; 7.00 (d, J=8.3 Hz, 2 H) ; 7.27 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 0.83; [M+H]+409 ; ES+ [M+2H-iPr]2+: m / z 184 The following compounds may be made by analogy to Example 30: 82, 83, 100, 101, 102. Example (31): Preparation of Compound 37: 3-((4-((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-yl)methyl)benzyl)amino)thietane 1,1-dioxide. Step 1: 3-((4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- ]pyridazin-yl)methyl)benzyl)amino)thietane 1,1-dioxide. To a solution of 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 in Example (28) (810 mg, 1.21 mmol) in MeOH (10 mL) was added 3-aminothietane 1,1-dioxide hydrochloride (301.85 mg, 1.82 mmol), triethylamine (338.13 µL, 2.43 mmol) and acetic acid (208.31 µL, 3.64 mmol). The mixture was stirred at rt^during 10 min and then sodium cyanoborohydride (114.33 mg, 1.82 mmol) was added. The mixture was stirred at rt during 4 h. The reaction was poured into water and pH adjusted to 8 by addition of ammonia solution (35%). Then the mixture was extracted by EtOAc. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to afford 1 g of crude product, which was used in the next step without further purification. Step 2: Example (31) Preparation of Compound 37: 3-((4-((4-amino-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-yl)methyl)benzyl)amino)thietane 1,1-dioxide. To a solution of 3-((4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)amino)thietane 1,1-dioxide of Step 1 (150 mg, 0.19 mmol) in DCM (5 mL) was added 2,2,2-trifluoroacetic acid (897.05 µl, 11.64 mmol). The mixture was stirred at rt for 24 hours. The reaction was poured into DCM and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 99 mg of white foam. The crude product was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with DCM / MeOH / NH4OH (95 / 5 / 0.2) elution, to afford Example (31) (61 mg, 66 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.4 Hz, 3 H) ; 1.20 (d, J=6.2 Hz, 6 H) ; 1.32 (m, 2 H) ; 1.62 (m, 2 H) ; 2;80 (m, 2 H) ; 2.91 (m, 1 H) ; 3.44 (m, 1 H) ; 3.59 (s, 2 H) ; 3.84 to 3.91 (m, 2 H) ; 4.17 to 4.25 (m, 2 H) ; 5.32 (sept, J=6.2 Hz, 1 H) ; 5.56 (s, 2 H) ; 5.94 (s, 2 H) ; 7,02 (d, J=8.2 Hz, 2 H) ; 7.28 (d, J=8.2 Hz, 2 H) MS method N: RT (min): 0.99; [M+H]+473 Example (32): Preparation of Compound 38: N-(4-((4-amino-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide. Step 1: N-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide To a solution of 3-((4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)amino)thietane 1,1-dioxide of Step 1 in Example (31) (300 mg, 0.39 mmol) in Pyridine (3 mL), was added acetic anhydride (109.86 µL, 1.16 mmol). The mixture was stirred at rt for 48 h. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure. The residue was poured into EtOAc and washed with water. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 308 mg of white foam. The crude product was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with DCM / MeOH (95 / 5) elution, to afford 275 mg of expected product as a white foam. The compound was used into the next step without further purification. Step 2: Example (32) Preparation of Compound 38: N-(4-((4-amino-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)-N-(1,1-dioxidothietan-3- yl)acetamide. To a solution of N-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide of Step 1 (270 mg, 0.33 mol) in DCM (7 mL) was added 2,2,2-trifluoroacetic acid (1 mL, 12.98 mmol). The mixture was stirred at rt for 24 h. The reaction was poured into DCM and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 220 mg of white foam. The crude product was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with CH2Cl2 / MeOH / NH4OH (93 / 7 / 0.2) elution, to afford 110 mg (64.5 %, yield) of Example (32) as a white foam.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.82 (t, J=7 Hz, 3 H); 1.17 (d, J=6 Hz, 6 H); 1.30 (dq, J=7 & 15 Hz, 2 H); 1.59 (quin, J=8 Hz, 2 H); 1.96 (s, 2 H); 2.19 (s broad, 1 H); 2.81 (t, J=8 Hz, 2 H); 4.06 to 4.79 (m, 6 H); 5.05 (m, 1 H); 5.30 (quin, J=6 Hz, 1 H); 5.57 (s broad, 2 H); 5.92 (s, 2 H); 6.94 to 7.26 (m, 4 H) MS method N: RT (min): 1.08; [M+H]+m / z 515, ES- [M-H+HCO2H]- : m / z 559 Example (33): Preparation of Compound 39: 2-butyl-7-isopropoxy-1-(4-(((1- methylcyclobutyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine. Step 1: 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1-(4-(((1-methylcyclobutyl) amino)methyl)benzyl) -1H-imidazo[4,5-d]pyridazin-4-amine. To a solution of 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 in Example (28) (300 mg, 0.45 mmol) in methanol (2 mL) was added 1-methylcyclobutanamine hydrochloride (86.26 mg, 0.67 mmol), triethylamine (125.23 µL, 0.90 mmol) and acetic acid (77.15 µL, 1.35 mmol). The mixture was stirring at rt during 10 min and then sodium cyanoborohydride (43.21 mg, 0.67 mmol) was added. The mixture was stirred at rt during 5 h. The reaction was poured into water and adjusted pH to 8 by addition of ammonia solution (35%). Then the mixture was extracted by EtOAc. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 0.45 g of oil. The crude product was purified by chromatography on a Merck cartridge (30 g of 15- 40 μm silica) with [(EtOAc / EtOH 3 / 1) 50%- Heptane 50%] elution, to afford expected product (146 mg, 44.1 % yield) as a solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.76 (t, J=7.5 Hz, 3 H) ; 1.18 (s, 3 H) ; 1.23 (d, J=6.2 Hz, 6 H) ; 1.25 (m, 2 H) ; 1.55 (m, 2 H) ; 1.58 to 1.72 (m, 4 H) ; 1.85 to 2.01 (m, 3 H) ; 2.74 (t, J=7.6 Hz, 2 H) ; 3.56 (d, J=6.4 Hz, 2 H) ; 3.71 (s, 12 H) ; 5;01 (s, 4 H) ; 5.33 (sept, J=6.2 Hz, 1 H) ; 5.55 (s, 2 H) ; 6.39 (dd, J=2.4 & 8.4 Hz, 2 H) ; 6.52 (d, J=2.4 Hz, 2 H) ; 6.97 (d, J=8.4 Hz, 2 H) ; 7.02 (d, J=8.3 Hz, 2 H) ; 7.30 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 1.32; [M+H]+737; ES+[M+2H]2+: m / z 369 Step 2: Example (33): Preparation of Compound 39: 2-butyl-7-isopropoxy-1-(4-(((1- methylcyclobutyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine. To a solution de 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1-(4-(((1-methyl cyclobutyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine of Step 1 (140 mg, 0.19 mmol) in DCM (4 mL) was added 2,2,2-trifluoroacetic acid (878 µL, 11.40 mmol). The mixture was stirred at rt for 24 hours. The reaction was poured into DCM and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 83 mg of white solid. The crude product was purified by chromatography on a Merck cartridge (10 g of 15-40 μm silica) with CH2Cl2 / MeOH / NH4OH (94 / 6 / 0.2) elution, to afford Example (33) (66 mg, 79.7 % yield) as a white solid.1H RMN (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7.4 Hz, 3 H) ; 1.19 (s, 3 H) ; 1.22 (d, J=6.2 Hz, 6 H) ; 1.33 (m, 2 H) ; 1.58 to 1.73 (m, 6 H) ; 1.93 (m, 2 H) ; 2.09 (m broad, 1 H) ; 2.80 (m, 2 H) ; 3.58 (s, 2 H) ; 5.33 (sept, J=6.2 Hz, 1 H) ; 5.56 (s, 2 H) ; 5.92 (s, 2 H) ; 7.01 (d, J=8.3 Hz, 2 H) ; 7.31 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 0.9; [M+H]+437; ES+[M+C5H8]+: m / z 369 The following compounds may be made by analogy to Example 33: 85, 87, 88, 89, 90, 91. Example (34): Preparation of Compound 40: 2-butyl-7-isopropoxy-1-(4-(piperazin-1- ylmethyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: tert-butyl 4-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)piperazine-1-carboxylate To a solution of 4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 in Example (28) (200 mg, 0.30 mmol) in methanol (2.5 mL) was added 1-Boc-piperazine (85.38 mg, 0.45 mmol), acetic acid (34.29 µL, 0.60 mmol). The mixture was stirring at rt during 10 min and then sodium cyanoborohydride (28.23 mg, 0.45 mmol) was added. The stirring was continued at rt during 4.5 h. The reaction was poured into water and pH adjusted to 9 by addition of ammonia solution (35%). Then the mixture was extracted by EtOAc. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 0.45 g of oil. The crude product (289 mg) as white gum was used directly in the next step. Step 2: Example (34) Preparation of Compound 40: 2-butyl-7-isopropoxy-1-(4- (piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine To a solution of tert-butyl 4-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)piperazine-1-carboxylate of Step 1 (250 mg, 0.3 mmol) in DCM (6.3 mL) was added 2,2,2-trifluoroacetic acid (919.29 µL, 11.93 mmol). The mixture was stirred at rt for 24 hours. The reaction was poured into DCM and washed with sodium hydroxide 1M. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 145 mg of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15- 40 μm silica) with CH2Cl2 / MeOH / NH4OH (90 / 10 / 0.2) elution, to afford Example (34) (45 mg, 35 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.81 (t, J=7 Hz, 3 H); 1.17 (d, J=6 Hz, 6 H); 1.29 (dq, J=7 & 15 Hz, 2 H); 1.59 (quin, J=8 Hz, 2 H); 2.22 (s broad, 4 H); 2.63 (t, J=5 Hz, 4 H); 2.81 (t, J=7 Hz, 2 H); 3.36 (s, 2 H); 5.30 (spt, J=6 Hz, 1 H); 5.55 (s, 2 H); 5.94 (s, 2 H); 7.00 (d, J=8 Hz, 2 H); 7.24 (d, J=8 Hz, 2 H) MS method N: RT (min): 0.80; [M+H]+438 Example (35): Preparation of Compound 41: 2-butyl-N7,N7,1-trimethyl-1H- imidazo[4,5-d]pyridazine-4,7-diamine A mixture of Intermediate (K) (95 mg, 0.40 mmol) in DMF (1 mL) and Dimethylamine (7 mL, 40% in Water) were introduced into an autoclave and heated 6 hours at 160 °C. The reaction mixture was poured into water (100 mL) and extracted with EtOAc (3 x 30 mL). The organic layer was collected and dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 40 mg of crude product which was purified by chromatography on a Merck cartridge (2.5 g, 15-40 µm silica) with a DCM / Methanol (93 / 7) elution to afford Example (34) (13 mg, 14 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.4 Hz, 3 H); 1.43 (m, 2 H); 1.77 (m, 2 H) ; 2.77 (s, 6 H) ; 2.86 (m, 2 H) ; 3.95 (s, 3 H) ; 6.06 (s, 2 H) MS method N: RT (min): 0.88; [M+H]+249 Example (36): Preparation of Compound 42: 2-butyl-1-methyl-7-(pyrrolidin-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine A mixture of Intermediate (K) (50 mg, 0.21 mmol), water (1 mL) and pyrrolidine (1 mL) were introduced into a microwave vial. The suspension was heated at 160 °C during 7 hours under microwave. The reaction mixture was concentrated under vacuum to give 100 mg of crude product, which was purified by chromatography on a Merck cartridge (10g 15-40µm silica) with a DCM / MeOH / MeCN (85 / 7.5 / 7.5) elution to afford Example (36) (32 mg, 55% yield) as a yellow amorphous solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.4 Hz, 3 H) ; 1.43 (m, 2 H) ; 1.77 (m, 2 H) ; 1.89 (m, 4 H) ; 2.88 (m, 2 H) ; 3.30 (m, 4 H) ; 3.96 (s, 3 H) ; 6.88 (s, 2 H) MS method P: RT (min): 1.85; [M+H]+275 Example (37): Preparation of Compound 43: 2-butyl-N7-(4- ((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7- diamine A mixture of Intermediate (K) (200 mg, 0.83 mmol), dimethyl((4- [(methylamino)methyl]phenyl)methyl)amine (783 mg, 4.17 mmol), 1-Butanol (2 mL) and 3-chloropyridine hydrochloride (413 mg, 2.75 mmol) were introduced into microwave vial. The suspension was heated at 160 °C during 3 hours under microwave. The reaction mixture was concentrated under vacuum to give 1.2 g of crude product. This material was dissolved in EtOAc (25 mL) and washed with water (20 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 381 mg of crude compound, which was purified by chromatography on a Merck cartridge (20 g 15-40 µm silica) with a DCM / Methanol (8 / 2) elution, to afford Example (37) (83 mg, 26 % yield) as a yellow solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.4 Hz, 3 H) ; 1.42 (m, 2 H) ; 1.76 (m, 2 H) ; 2.12 (s, 6 H) ; 2.67 (s, 3 H) ; 2.86 (m, 2 H) ; 3.34 (s, 2 H) ; 4.01 (s, 3 H) ; 4.31 (s, 2 H) ; 6.05 (s, 2 H) ; 7.22 (d, J=8.2 Hz, 2 H) ; 7.29 (d, J=8.2 Hz, 2 H). MS method N: RT (min): 0.84; [M+H]+382 ; ES+ [M+2H]2+: m / z 191.5 Example (38): Preparation of Compound 44: 2-butyl-N7,1-dimethyl-N7-(4- (morpholinomethyl)benzyl)-1H-imidazo[4,5-d]pyridazine-4,7-diamine A mixture of Intermediate (K) (100 mg, 0.42 mmol), Methyl-(4-morpholin-4-ylmethyl- benzyl)-amine (484 mg, 2.09 mmol), 1-Butanol (2 mL), 3-chloropyridine hydrochloride (206.5 mg, 1.38 mmol) were introduced into a microwave vial. The suspension was heated at 160 °C during 6 hours in microwave. The reaction mixture was concentrated under vacuum to give 604 mg of crude product. This material was dissolved in EtOAc (50 mL) and washed with water (50 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 221 mg of yellow solid, which was purified by chromatography on a Merck cartridge (15 g 15-40 µm silica) with a DCM / MeOH (9 / 1) elution to afford 75 mg as beige solid, which was stirred for 1 hour with isopropyl ether (2 mL). After filtration and drying, Example (38) (55 mg, 35 % yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.3 Hz, 3 H) ; 1.42 (m, 2 H) ; 1.76 (m, 2 H) ; 2.32 (m, 4 H) ; 2.66 (s, 3 H) ; 2.86 (m, 2 H) ; 3.41 (s, 2 H) ; 3.56 (m, 4 H) ; 4.00 (s, 3 H) ; 4.30 (s, 2 H) ; 6.02 (s, 2 H) ; 7.23 (d, J=8.3 Hz, 2 H) ; 7.29 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 0.73; [M+H]+424; ES+ [M+2H]2+: m / z 212.5 Example (39A): Preparation of Compound 45: 4-(((4-amino-2-butyl-1-methyl-1H- imidazo[4,5-d]pyridazin-7-yl)(methyl)amino)methyl)benzonitrile and Example (39B): Preparation of Compound 46: N7-(4-(aminomethyl)benzyl)-2-butyl- N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine Step 1: Example (39A): Preparation of Compound 45: 4-(((4-amino-2-butyl-1-methyl- 1H-imidazo[4,5-d]pyridazin-7-yl)(methyl)amino)methyl)benzonitrile A mixture of Intermediate (K) (400 mg,1.67 mmol), 4-(methylaminomethyl)benzonitrile (1.28 g, 8.34 mmol), 1-Butanol (10 mL), 3-chloropyridine hydrochloride (826 mg, 5.51 mmol) were introduced into a microwave vial. The suspension was heated at 160 °C during 5 hours under microwave. The reaction mixture was concentrated under vacuum to give 1.9 g of crude product. This material was dissolved in EtOAc (100 mL) and washed with water (100 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 703 mg of yellow solid, which was purified by chromatography on a Merck cartridge (40 g 15-40 µm silica) with a DCM / Methanol / Acetonitrile (96 / 2 / 2) elution to afford Example (39A) (124 mg, 21 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.4 Hz, 3 H) ; 1.42 (m, 2 H) ; 1.76 (m, 2 H) ; 2.71 (s, 3 H) ; 2.86 (m, 2 H) ; 4.00 (s, 3 H) ; 4.45 (s, 2 H) ; 6.03 (s, 2 H) ; 7.55 (d, J=8.5 Hz, 2 H) ; 7.76 (d, J=8.5 Hz, 2 H) MS method N: RT (min): 1.12; [M+H]+350 Step 2: Example (39B) Preparation of Compound 46: N7-(4-(aminomethyl)benzyl)-2- butyl-N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine To a solution of 4-(((4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin 7yl)(methyl)amino)methyl)benzonitrile of Step 1 (104 mg, 0.30 mmol) in THF (4 mL) was added dropwise BH3-THF 1M (893 µL, 0.89 mmol). The solution was heated under reflux 18 hours. Then Methanol-HCl 1M (3 mL) was added and the mixture was heated 24 hours under reflux. The reaction mixture was concentrated under reduced pressure to give 414 mg of white solid. The residue was dissolved in DCM (10 mL) and washed with water (10 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 114 mg of white solid, which was purified by chromatography on a Macherey Nagel Chromabond Sorbenz NH2cartridge (16.4 g) with DCM / Methanol (95 / 5) elution to obtain Example (39B) (13 mg, 12% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.5 Hz, 3 H) ; 1.42 (m, 2 H) ; 1.76 (m, 2 H) ; 2.09 (m, 2 H) ; 2.66 (s, 3 H) ; 2.85 (m, 2 H) ; 3.66 (s, 2 H) ; 4.00 (s, 3 H) ; 4.29 (s, 2 H) ; 6.00 (s, 2 H) ; 7.14 to 7.30 (m, 4 H) MS method N: RT (min): 0.73; [M+H]+354; ES+[M+2H-NH3]2+: m / z 169 Example (40): Preparation of Compound 47: 2-butyl-N7-(4-(((2- methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine A mixture of Intermediate (K) (100 mg, 0.42 mmol), 2-methoxy-N-methyl-N-(4- ((methylamino)methyl)benzyl)ethan-1-amine (464 mg, 2.09 mmol), 1-Butanol (2 mL), and 3-chloropyridine hydrochloride (206.5 mg, 1.38 mmol) were introduced into a microwave vial. The suspension was heated at 160 °C during 3 hours under microwave. The reaction mixture was concentrated under vacuum to give 731 mg of crude product. This material was dissolved in EtOAc (25 mL) and washed with water (20 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 244 mg of crude compound, which was purified by chromatography on a Merck cartridge (20g 15-40µm silica) with DCM / MeOH (9 / 1) elution to afford Example (40) (32 mg, 18% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.94 (t, J=7.4 Hz, 3 H) ; 1.41 (m, 2 H) ; 1.75 (m, 2 H) ; 2.12 (s, 3 H) ; 2.50 (m hidden, 2 H) ; 2.66 (s, 3 H) ; 2.85 (m, 2 H) ; 3.21 (s, 3 H) ; 3.43 (t, J=6.0 Hz, 2 H) ; 3.45 (s, 2 H) ; 4.00 (s, 3 H) ; 4.30 (s, 2 H) ; 6.01 (s, 2 H) ; 7.21 (d, J=8.2 Hz, 2 H) ; 7.28 (d, J=8.2 Hz, 2 H) MS method N: RT (min): 0.72; [M+H]+426; ES+[M+2H]2+: m / z 213.5 Example (41): Preparation of Compound 104: 2-butyl-7-isopropoxy-1-(4-(((2- methoxyethyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Under argon, to a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (200 mg, 0.54 mmol (Example (17A)) in 3 mL of DMF was added Cs2CO3 (531 mg, 1.63 mmol) and the mixture was stirred for 30 mins. 2- Bromomethyl methyl ether (80.00 µl, 0.80 mmol) was then added and the mixture was stirred at rt for 24 h. The reaction mixture was poured into 50 ml of iced water. The aqueous solution was extracted with EtOAc (3 x 25 ml), the organic layers were combined and washed brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 244 mg of crude compound, which was purified by chromatography on a Merck cartridge (20g 15-40µm silica) with DCM / DCM-MeOH(8-2) / NH3.H2O (90 / 10 / 0.015 to 80 / 200.015) elution to afford Example (41) (72 mg, 31 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.83 (t, J=7 Hz, 3 H), 1.20 (d, J=6 Hz, 6 H), 1.24 - 1.41 (m, 2 H), 1.55 - 1.67 (m, 2 H), 2.59 (t, J=6 Hz, 2 H), 2.75 - 2.86 (m, 2 H), 3.20 (s, 3 H), 3.33 - 3.41 (m partially hidden, 2 H), 3.67 (s, 2 H), 5.32 (spt, J=6 Hz, 1 H), 5.55 (s, 2 H), 5.93 (s, 2 H), 7.01 (d, J=8 Hz, 2 H), 7.27 (d, J=8 Hz, 2 H) MS method N: RT (min): 0.80; [M+H]+427 The following compounds may be made by analogy to Example 41: 108, 109, 110, 116, 117, 119. Example (42): Preparation of Compound 105: 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2- [2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[ 4,5-d]pyridazin-7-amine Step 1: tert-butyl N-[[4-[[7-[bis[(2,4-dimethoxyphenyl)methyl]amino]-2-butyl-4-propan-2- yloxyimidazo[4,5-d]pyridazin-3-yl]methyl]phenyl]methyl]-N-[2-[2-[2-[2-[2-(2 methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethyl]carbamate

[0033] Under argon, to a solution of tert-butyl (4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 1 in Example (17A) (200 mg, 0.26 mmol) in DMF (3 ml) was added sodium hydride (31 mg, 0.78 mmol) at rt and the mixture was stirred till the end of gas bubbling. M-PEG6-Bromide (123 µl, 0.39 mmol) was then added and the mixture was stirred at rt overnight. A second portion of sodium hydride (31 mg, 0.78 mmol) was added and the mixture was stirred again for 24 h. The reaction mixture was poured into 100 ml of iced water. The aqueous solution was extracted with DCM (100 ml) and MeTHF (100ml), the organic layers were combined and concentrated under vacuum to give 65 mg of crude compound. The aqueous phase was concentrated under vacuum to give 404 mg of crude compound, which were treated with a mixture of EtOAc / EtOH, after filtration of insoluble residues, the filtrate was concentrated under vacuum and combined with the 65 mg of crude compound from organic phase. The crude materiel then was purified by chromatography on a Merck cartridge (10g 15-40µm silica) with EtOAc / EtOH 98 / 2 to 90 / 10 elution to afford expected compound (54 mg, 20 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.75 (t, J=7.4 Hz, 3 H) 1.12 - 1.47 (m, 17 H) 1.55 (m, 2 H) 2.77 (m, 2 H) 3.21 (m, 3 H) 3.38 - 3.55 (m, 24 H) 3.71 (s, 12 H) 4.38 (s, 2 H) 5.01 (s, 4 H) 5.31 (m, 1 H) 5.57 (s, 2 H) 6.39 (m, J=8.3 Hz, 2 H) 6.53 (d, J=2.3 Hz, 2 H) 6.97 (m, J=8.3 Hz, 2 H) 7.05 (d, J=8.3 Hz, 2 H) 7.19 (d, J=8.3 Hz, 2 H) MS method N: RT (min): 1.79; [M+H]+1047 Step 2: Example^(42): Preparation of Compound 105: 2-butyl-4-isopropoxy-3-[[4-[[2- [2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[ 4,5-d]pyridazin-7-amine Under argon, to a solution of tert-butyl N-[[4-[[7-[bis[(2,4- dimethoxyphenyl)methyl]amino]-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl]methyl]phenyl]methyl]-N-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethyl]carbamate of Step 1 (50 mg, 0.048 mmol) in DCM (0.2 ml) was added TFA (203 µl. 2.63 mmol) at rt, resulting a purple solution, which was stirred for 48 h. The reaction mixture was then concentrated under vacuum and taken into MeOH (3 ml), the insoluble residues were then filtrated and washed with MeOH. The methanolic solution was concentrated and loaded over of 5g SCX cartridge, which was eluted with 100 ml MeOH and 100 ml MeOH / NH3 (2M). The MeOH / NH3 phase was concentrated under vacuum to give Example (42) (29.3 mg, 95% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7 Hz, 3 H), 1.21 (d, J=6 Hz, 6 H), 1.26 - 1.38 (m, 2 H), 1.63 (t, J=8 Hz, 2 H), 2.59 (t, J=6 Hz, 2 H), 2.70 - 2.90 (m, 2 H), 3.22 - 3.25 (m, 3 H), 3.39 - 3.55 (m, 22 H), 3.67 (s, 2 H), 5.78 (m, 1 H), 5.56 (s, 2 H), 5.90 (s, 2 H), 7.02 (d, J=8 Hz, 2 H), 7.28 (d, J=8 Hz, 2 H) MS method N: RT (min): 1.01; [M+H]+647 The following compounds may be made by analogy to Example 42: 118, 120, 121, 122, 123. Example (43): Preparation of Compound 111: ethyl (4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate Under argon, to a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (Example (17A)) (200 mg, 0.54 mmol) in anhydrous THF (5 ml) was added DIPEA (114 µl, 0.65 mmol) and followed by dropwise addition of Ethyl Chloroformate (64 µl, 0.65 mmol). The reaction mixture, a colourless solution containing a gummy white solid, was stirred for 1 h.5 ml of HCl (1M) and 10 ml EtOAc were added to the reaction mixture and transferred to a separating funnel. After decantation, the aqueous phase was extracted with EtOAc (2 x 10 ml). The organic layers were combined, dried over anhydrous MgSO4, filtered and concentrated under vacuum to give 154 mg of crude compound, which was purified by chromatography on a Merck cartridge (10g 15-40µm silica) with DCM / MeOH / CH3CN (90 / 5 / 5) elution to afford Example (43) (40 mg, 17 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7 Hz, 3 H), 1.14 (t, J=7 Hz, 3 H), 1.20 (d, J=6 Hz, 6 H), 1.26 - 1.37 (m, 2 H), 1.62 (m, 2 H), 2.79 (m, 2 H), 3.97 (q, J=7 Hz, 2 H), 4.12 (d, J=6 Hz, 2 H), 5.32 (spt, J=6 Hz, 1 H), 5.55 (s, 2 H), 5.91 (s, 2 H), 7.02 (d, J=8 Hz, 2 H), 7.20 (d, J=8 Hz, 2 H), 7.59 (t, J=6 Hz, 1 H) MS method N: RT (min): 1.21; [M+H]+441 The following compounds may be made by analogy to Example 43: 112, 114. Example (44): Preparation of Compound 113: 1-(4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)-3-ethylurea Under argon, to a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (Example (17A)) (150 mg, 0.41 mmol) in anhydrous DCM (5 ml) was added Ethyl Isocyanate (39.5µl, 0.49 mmol). The reaction mixture, a colourless solution, was stirred for 4 h at rt. The reaction mixture was then concentrated under vacuum to give 188 mg of crude compound, which was purified by chromatography on a Merck cartridge (10g 15-40µm silica) with DCM / MeOH (93 / 7) elution to afford Example (44) (155 mg, 87% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7 Hz, 4 H), 0.97 (t, J=7 Hz, 3 H), 1.21 (d, J=6 Hz, 6 H), 1.32 (m, 2 H), 1.63 (quin, J=8 Hz, 2 H), 2.79 (m, 2 H), 3.00 (m, 2 H), 4.15 (d, J=6 Hz, 2 H), 5.32 (spt, J=6 Hz, 1 H), 5.55 (s, 2 H), 5.84 (t, J=6 Hz, 1 H), 5.94 (s, 2 H), 6.24 (t, J=6 Hz, 1 H), 7.02 (d, J=8 Hz, 2 H), 7.19 (d, J=8 Hz, 2 H) MS method N: RT (min): 1.07; [M+H]+440 Example (45): Preparation of Compound 115: N-(4-((4-amino-2-butyl-7-isopropoxy- 1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)methanesulfonamide Under argon, to a solution of 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (Example (17A)) (150 mg, 0.41 mmol) in anhydrous pyridine (10 ml) was added Methanesulfonyl Chloride (35 µl, 0.45 mmol). The reaction mixture, a limpid yellow solution, was stirred for 5 h at rt. The reaction mixture was then diluted in 50 ml EtOAc, charged into a separating funnel and washed brine (2 x 20ml). The organic layer was dried over MgSO4, filtered and concentrated under vacuum to give 121 mg of crude yellowish compound, which was purified by chromatography on a Merck cartridge (10g 15-40µm silica) with DCM / MeOH (93 / 7) elution to afford Example (45) (82 mg, 45% yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.85 (t, J=7 Hz, 3 H), 1.21 (d, J=6 Hz, 6 H), 1.28 - 1.38 (m, 2 H), 1.64 (quin, J=8 Hz, 2 H), 2.73 - 2.87 (m, 5 H), 4.12 (d, J=6 Hz, 2 H), 5.32 (spt, J=6 Hz, 1 H), 5.58 (s, 2 H), 5.93 (s, 2 H), 7.06 (d, J=8 Hz, 2 H), 7.31 (d, J=8 Hz, 2 H), 7.52 (t, J=6 Hz, 1 H) MS method N: RT (min): 1.07; [M+H]+447 Example (46): Preparation of Compound 124: 2-butyl-7-isopropoxy-1-(3- ((methylamino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: 3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzaldehyde To a suspension of intermediate (M) (1.0 g, 1.82 mmol) in Me-THF (10 mL) was added 4- (bromomethyl)benzaldehyde (0.507 g, 2.73 mmol) and Cs2CO3(0.889 g, 2.73 mmol). The mixture was stirred at rt overnight. Additional 4-(bromomethyl)benzaldehyde (0.110 g, 0.553 mmol) and Cs2CO3(0.178 g, 0.546 mmol) were then added and the mixture was stirred for 2 h 30 mins at rt. The mixture was poured into Me-THF (15 mL), washed with H2O (15 mL), dried over anhydrous MgSO4, and filtered. The filtrate was concentrated under reduced pressure to give 1.7 g of crude product, which was purified by chromatography on a Merck cartridge (150 g of 15-40 μm silica) with EtOAc / Heptane (30 / 70 to 50 / 50) elution. Expected product (0.73 g, 60% yield) was obtained as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.76 (t, J=7.4 Hz, 3 H), 1.13 - 1.32 (m, 2 H), 1.16 (d, J=6.3 Hz, 5 H), 1.52 - 1.61 (m, 2 H), 2.81 (t, J=7.4 Hz, 2 H), 3.71 (s, 12 H), 5.02 (s, 4 H), 5.25 - 5.34 (m, 1 H), 5.68 (s, 2 H), 6.40 (dd, J=8.4, 2.4 Hz, 2 H), 6.53 (d, J=2.5 Hz, 2 H), 6.98 (d, J=8.3 Hz, 2 H), 7.43 (d, J=8.0 Hz, 1 H), 7.58 - 7.65 (m, 2 H), 7.85 (d, J=7.8 Hz, 1 H), 9.98 (s, 1 H) MS method N: RT(min):1.22; [M+H]+668 Step 2: 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1-(3- ((methylamino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine To a round bottomed flask containing 3-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7- isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzaldehyde of Step 1 (0.180 g, 0.270 mmol), was added a 2N solution of methylamine in ethanol (3.6 ml, 7.2 mmol), the mixture was stirred under argon at rt overnight. Sodium borohydride (0.015 g, 0.404 mmol) was then added. The resulting suspension was stirred for 1 h at rt and diluted in EtOAc and washed with water. The organic phase was dried over anhydrous MgSO4, filtered and the filtrate was concentrated under reduced pressure to give 0.18 g of crude product, which was purified by chromatography on a Merck cartridge (20 g of 15-40 μm silica) with EtOAc / Heptane (30 / 70) to DCM / MeOH (90 / 10) elution. Expected product (0.17g, 92 % yield) was obtained as a colorless oil.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.76 (t, J=7.4 Hz, 3 H) 1.14 - 1.30 (m, 2 H) 1.21 (d, J=6 Hz, 6 H) 1.55 (quin, J=7.44 Hz, 2 H) 2.19 (s, 3 H) 2.70 - 2.83 (m, 2 H) 3.59 (s, 2 H) 3.71 (s, 12 H) 5.01 (s, 4 H) 5.32 (spt, J=6.2 Hz, 1 H) 5.57 (s, 2 H) 6.39 (dd, J=8.4, 2.4 Hz, 2 H) 6.53 (d, J=2.4 Hz, 2 H) 6.92 (b d, J=7.5 Hz, 1 H) 6.97 (d, J=8.4 Hz, 2 H) 7.11 (b s, 1 H) 7.18 - 7.32 (m, 2 H) MS method N: RT(min): 1.22; [M+H]+683 The following compounds may be made by analogy to Example 46: 125, 126, 127, 128, 129, 130, 131. Step 3: Example^(46) Preparation of Compound 124: 2-butyl-7-isopropoxy-1-(3- ((methylamino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine Under argon, to a solution of 2-butyl-N,N-bis(2,4-dimethoxybenzyl)-7-isopropoxy-1-(3- ((methylamino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine (0.17 g, 0.249 mmol) of Step 2, in DCM (5 ml) was added TFA (1.2 ml, 15.8 mmol) at rt and the resulting purple solution was stirred for 18 h. The reaction mixture was diluted in DCM, washed with a 1 N NaOH solution, the organic phase we dried over MgSO4, filtered, and evaporated to dryness. The crude product was treated with 2N HCl, which gave a white powder. After a further treatment with SCX cartridge (2g), it yielded Example (46) under free base (44 mg, 46 % yield) as a white solid.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.82 (t, J=7 Hz, 3 H), 1.19 (d, J=6 Hz, 6 H), 1.30 (dq, J=15, 7 Hz, 2 H), 1.56 - 1.65 (m, 2 H), 2.07 (s, 6 H), 2.81 (t, J=8 Hz, 2 H), 3.31 (s partially hidden, 2 H), 5.31 (spt, J=6 Hz, 1 H), 5.58 (s, 2 H), 5.94 (s, 2 H), 6.94 (d, J=8 Hz, 1 H), 7.04 (s, 1 H), 7.18 (d, J=8 Hz, 1 H), 7.28 (t, J=8 Hz, 1 H) MS method N: RT (min): 0.77; [M+H]+383 Example (47): Preparation of Compound 132: (E)-1-(4-(aminomethyl)benzyl)-2-butyl- 7-(3-methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine Step 1: tert-butyl (4-((2-butyl-4,7-dichloro-1H-imidazo[4,5-d]pyridazin-1-yl)methyl) benzyl)carbamate To a solution of 2-butyl-dichloro-1H-imidazo[4,5-d]pyridazine (Intermediate (E)) (3.0 g, 12.25 mmol) in Acetonitrile (75 ml) was added tert-butyl (4- (bromomethyl)benzyl)carbamate (4.34 g, 14.45 mmol) and then K2CO3(5.08g, 36.74 mmol). The resulting mixture was stirred at rt for 48 hrs. Then it was added EtOAc (100 ml) and H2O (100 ml). The phase aqueous was separated and it was extracted again with EtOAc. The organic layers were combined and washed brine, the organic layer was separated, dried over MgSO4, filtered and evaporated to give 6.09 g of crude material. The crude materiel was purified by a silica gel column using as eluent a mixture DCM / Acetone (97 / 3) to give 2.21 g of the expected product (38% Yield) as a white foam.1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.84 (t, J=7.34 Hz, 3 H) 1.20 - 1.44 (m, 11 H) 1.68 (m, 2 H) 2.85 - 2.97 (m, 2 H) 4.09 (d, J=6.11 Hz, 2 H) 5.80 (s, 2 H) 7.03 (d, J=8.31 Hz, 2 H) 7.19 (d, J=8.07 Hz, 2 H) 7.39 (t, J=6.24 Hz, 1 H) MS method O: RT (min): 3.49; [M+H]+464 Step 2: tert-butyl (4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-chloro-1H-imidaz o[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate In a round-bottom flask was added tert-butyl (4-((2-butyl-4,7-dichloro-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 1 (2.18g, 4.71 mmol), n-Butanol (30 ml) and DIPEA (8.23 ml), and bis(2,4-dimethoxybenzyl)amine (412.5 mg, 1.24 mmol)). The resulting mixture was heated at reflux for 1 hr. It was then added 412.5 mg of bis(2,4- dimethoxybenzyl)amine, and heated at reflux for 15 mins, this operation was repeated twice again (2 X 412.5 mg). The mixture was heated at reflux for 52 hrs. The solvent was then evaporated, the brown residue was diluted with Ethyl acetate and washed with brine. The organic layer was separated, dried over MgSO4, filtered and evaporated. The crude material was purified by a silica gel column (Merck) using as solvent Heptane / Acetone (70 / 30) to give 1.42 g of expected product (40.4 % Yield).1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.74 (t, J=7.3 Hz, 3 H) 1.22 (m, 2 H) 1.37 (s, 9 H) 1.45 - 1.66 (m, 2 H) 2.75 (t, J=7.4 Hz, 2 H) 3.72 (s, 12 H) 4.08 (d, J=6.11 Hz, 2 H) 5.10 (br s, 4 H) 5.70 (s, 2 H) 6.41 (dd, J=8.3, 2.4 Hz, 2 H) 6.55 (d, J=2.4 Hz, 2 H) 6.95 (d, J=8 Hz, 2 H) 6.99 (d, J=8.3 Hz, 2 H) 7.20 (d, J=8.31 Hz, 2 H) 7.37 (t, J=6.24 Hz, 1 H) MS method O: RT (min): 3.80; [M+H]+745 Step 3: tert-butyl (E)-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-(3-methylbut-1- en-1-yl)-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate In a microwave vial was prepared a solution of tert-butyl (4-((4-(bis(2,4- dimethoxybenzyl)amino)-2-butyl-7-chloro-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl) carbamate of Step 2 (150 mg, 0.201 mmol) in 1,4-dioxane (3 ml). Then it was added (E)-4,4,5,5-tetramethyl-2-(3-methylbut-1-en-1-yl)-1,3,2-dioxaborolane (78.93 mg, 0.402 mmol), Pd(PPh3)4 (36.72 mg, 0.030 mmol) and 2M solution of Cs2CO3(0.402 ml, 0.805 mmol). The solution was purged with Argon for 5 minutes. Then it was heated in the microwave system at 130 °C during 1 h 30 min. The reaction mixture was diluted with EtOAc and washed with H2O and brine. The organic layer was separated, dried over MgSO4, filtered and evaporated. The crude material was purified by a silica gel column (Merck) using as eluent a mixture Heptane / EtOAc (60 / 40) to give 67 mg of the expected product (42.7 % yield).1H NMR (400 MHz, δ in ppm, DMSO-d6): 0.77 (t, J=7 Hz, 3 H) 0.89 (d, J=7 Hz, 6 H) 1.18 - 1.41 (m, 11 H) 1.54 - 1.66 (m, 2 H) 2.27 (m, 1 H) 2.79 (t, J=7 Hz, 2 H) 3.73 (d, J=8 Hz, 12 H) 4.07 (d, J=6 Hz, 2 H) 5.13 (br s, 4 H) 5.59 (s, 2 H) 6.40 (dd, J=8, 2 Hz, 2 H) 6.45 - 6.53 (m, 2 H) 6.55 (d, J=2 Hz, 2 H) 6.89 (m, J=8 Hz, 2 H) 6.99 (d, J=8 Hz, 2 H) 7.20 (m, J=8 Hz, 2 H) 7.37 (t, J=6 Hz, 1 H) MS method N: RT (min): 1.74; [M+H]+779 Step 4: Example (47): Preparation of Compound 132 : (E)-1-(4-(aminomethyl)benzyl)- 2-butyl-7-(3-methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine

[0034] To a solution of tert-butyl (E)-(4-((4-(bis(2,4-dimethoxybenzyl)amino)-2-butyl-7-(3- methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-1-yl)methyl)benzyl)carbamate of Step 3 (108 mg, 0.138 mmol) in DCM (1 ml) was added dropwise TFA (486 µl, 6.48 mmol). The mixture was stirred at rt for 4hrs. The reactio...

Claims

CLAIMS 1. A compound of formula (I) or a pharmaceutically acceptable salt thereof:wherein: R1 represents: - a hydrogen atom, or - a group selected from: a) - a (C1-C6)alkyl- group; - a hydroxy-(C1-C6)alkyl- group; - a NH2-(C1-C6)alkyl- group; - a NH-(C1-C6)alkyl-(C1-C6)alkyl- group;- a N((C1-C6)alkyl)2-(C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; b) - a phenyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b1) - a (C1-C6)alkoxy- group; b2) - a hydroxyl group; b3) a -C(O)-H group; and b4) - a (C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from: b4.1) - a hydroxyl group; and b4.2) - a -NR4R5group wherein R4and R5, being independently from each other selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, a (C1-C6)alkoxy(C1-C6)alkyl- group, or a (C1-C6)alkoxy(C1-C6)alkoxy(C1-C6)alkyl- group; b4.2.4) - a (C1-C6)alkyl-S(O2)- group; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group;b4.2.7) - a (C1-C16)alkyl-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30; b4.2.9) - a (C3-C10)cycloalkyl- group being unsubstituted or substituted by at least one substituent selected from: - a hydroxyl group; and - a (C1-C6)alkyl- group; or b4.2.10) - a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(O)- and -SO2-; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.13) - a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.14) - a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur, said (C3-C10)membered heterocycloalkyl- group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group being unsubstituted or substituted by at least one substituent selected from -NH2and a NH2-(C1-C6)alkyl- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; and e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heteroaryl being unsubstituted or substituted by at least one substituent selected from: - a (C1-C6)alkyl- group; - a NH2-(C1-C6)alkyl- group and - a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur; g) - a (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one to four heteroatoms selected from oxygen, nitrogen, S(O), SO2and sulfur;R2 represents a halogen atom, or a group selected from: - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C1-C6)alkylthio- group; - a (C1-C6)alkylthio(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O)- group; - a (C1-C6)alkyl-S(O2)- group; - a (C1-C6)alkyl-S(O)-(C1-C6)alkyl- group; - a (C1-C6)alkyl-S(O2)-(C1-C6)alkyl- group; - a (C1-C6)alkoxy- group; - a (C1-C6)alkoxy(C1-C6)alkyl- group; - a (C1-C6)haloalkoxy(C1-C6)alkyl- group; - a (C3-C5)cycloalkyl-O-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group; - a ((C1-C6)alkyl)2-N-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH- group; and - a ((C1-C6)alkyl)2N- group; R3represents: - a deuterium atom; - a hydrogen atom or a group selected from: a) - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; and -a (C1-C6)alkylthio- group; b) - a -OR6group wherein R6is selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; - a (C2-C6)alkenyl- group; - a (C2-C6)alkynyl- group; - a (C3-C10)cycloalkyl- group; - a phenyl group; - a phenyl(C1-C6)alkyl- group; and- a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, sulfur, -S(=O)- and -S(=O)2-; c) - a -NR7R8group wherein R7and R8being, independently from each other, selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; - a (C1-C6)alkyl- group unsubstituted or substituted by - a (C5-C10)membered heteroaryl group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; or - a phenyl group being unsubstituted or substituted by at least one substituent selected from: - a cyano group and - a NR9R10-(C1-C6)alkyl- group wherein: R9and R10being, independently from each other, selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30, or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C3-C10)membered heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from a (C1-C6)alkyl- group, and a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; or R7and R8form together with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent selected from: - a phenyl group and - a hydroxy(C1-C6)alkyl-phenyl- group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one to four heteroatoms selected from oxygen, nitrogen and sulfur; e) - a (C5-C10)membered heteroaryl- group comprising one to four heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group;f) - a -(C6-C10)membered aryl group; and g) - a (C3-C10)cycloalkyl- group.

2. The compound of formula (I) or a pharmaceutically acceptable salt thereof according to claim 1, provided that at least one of R1, and R3is other than a hydrogen atom.

3. The compound of formula (I) or a pharmaceutically acceptable salt thereof according to claim 1 or claim 2, wherein R1represents: - a hydrogen atom or - a group selected from: a) - a (C1-C6)alkyl- group; - a hydroxy-(C1-C6)alkyl- group or - a NH2-(C1-C6)alkyl- group; b) - a phenyl(C1-C6)alkyl- group being unsubstituted or substituted by one substituent, selected from: b1) - a (C1-C6)-alkoxy- group; b3) - a -C(O)-H group and b4) - a (C1-C6)alkyl- group substituted by at least one substituent selected from: b4.1) - a hydroxyl group; b4.2) - a -NR4R5group wherein R4and R5, being independently from each other, selected from: b4.2.1) - a hydrogen atom; b4.2.2) - a (C1-C16)alkyl- group; b4.2.3) - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30, a (C1C6)alkoxy(C1-C6)alkyl- group, or a (C1-C6)alkoxy(C1-C6)alkoxy(C1- C6)alkyl- group; b4.2.4) - a (C1-C6)alkyl-S(O2)- group; b4.2.5) - a (C1-C6)alkyl-NH-C(O)- group; b4.2.6) - a (C1-C16)alkyl-C(O)- group; b4.2.7) - a (C1-C16)alkyl-O-C(O)- group; b4.2.8) - a CH3-[O-(CH2)2]n-C(O)- group with n being an integer from 1 to 30; b4.2.9) - a (C3-C10)cycloalkyl- group being unsubstituted or substituted by at least one a (C1-C6)alkyl group or a hydroxyl group;b4.2.10) - a (C3-C10)membered heterocycloalkyl- group comprising from one to four heteroatoms selected from oxygen, nitrogen and -SO2-; b4.2.11) - a phenyl-C(O)- group; b4.2.12) - a (C1-C6)alkoxy-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.13) - a (C1-C16)alkyl-C(O)-NH-phenyl-(C1-C6)alkyl-O-C(O)- group; b4.2.14) - a (C1-C16)alkyl-O-C(O)-(C1-C6)alkyl- group; or R4and R5form together with the nitrogen atom to which they are attached a (C3C10)membered heterocycloalkyl- group comprising one to two heteroatoms selected from oxygen and nitrogen; c) - a (C3-C10)cycloalkyl(C1-C6)alkyl- group being unsubstituted or substituted by one substituent selected from -NH2, and a NH2-(C1-C6)alkyl- group; d) - a (C3-C10)membered heterocycloalkyl(C1-C6)alkyl- group, unsubstituted comprising one to two nitrogen heteroatoms; e) - a (C5-C10)membered heteroaryl(C1-C6)alkyl- group comprising one nitrogen heteroatom, said heteroaryl being unsubstituted or substituted by at least one substituent selected from: - a NH2-(C1-C6)alkyl- group and - a cyano group; f) - a (C3-C10)membered heterocycloalkyl-NH-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one heteroatom selected from oxygen, nitrogen, S(O), SO2and sulfur; g) - a (C3-C10)membered heterocycloalkyl-N(C(O)-(C1-C6)alkyl)-(C1-C16)alkyl- group, said heterocycloalkyl group comprising one heteroatom selected from oxygen, nitrogen, S(O), SO2and sulfur.

4. The compound of formula (I) or a pharmaceutically acceptable salt thereof according to anyone of claims 1 to 3, wherein R2 represents: - a (C1-C6)alkyl- group; - a (C1-C6)alkylthio- group; - a (C1-C6)alkyl-S(O)- group; - a (C1-C6)alkyl-NH-(C1-C6)alkyl- group; - a (C1-C6)alkyl-NH- group; and - a (C1-C6)alkoxy(C1-C6)alkyl- group.

5. The compound of formula (I) or a pharmaceutically acceptable salt thereof according to anyone of claims 1 to 4, wherein R3 represents: - a hydrogen atom or - a group selected from:a) - a (C1-C6)alkyl- group; - a (C2-C6)alkenyl- group; - a (C1-C6)alkylthio- group; b) - a -OR6group wherein R6is selected from: - a hydrogen atom; - a (C1-C6)alkyl- group; - a CH3-[O-(CH2)2]n- group with n being an integer from 1 to 30; - a (C2-C6)alkenyl group; - a (C3-C10)cycloalkyl group; - a phenyl group; - a phenyl(C1-C6alkyl)- group; and - a (C3-C10)membered heterocycloalkyl- group comprising one heteroatom selected from oxygen, sulfur, -S(O)- and -SO2-; c) - a -NR7R8group wherein R7and R8, being independently from each other, selected from: - a hydrogen atom; - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; - a (C1-C6)alkyl- group unsubstituted or substituted by: - a (C5-C10)membered heteroaryl- group comprising one oxygen atom; or - a phenyl group being unsubstituted or substituted by at least one substituent selected from: - a cyano group and - a NR9R10-(C1-C6)alkyl- group wherein R9and R10being, independently from each other, selected from: - a hydrogen atom; - a -(C1-C6)alkyl group or - a CH3-[O-(CH2)2]n- with n being an integer from 1 to 30; or R9and R10together form with the nitrogen atom to which they are attached a (C3-C10)membered heterocycloalkyl- group comprising one to two heteroatoms selected from oxygen, and nitrogen, said (C3-C10)membered heterocycloalkyl- group being substituted by at least one (C1- C6)alkyl- group, for instance one to three (C1-C6)alkyl- groups, such as one (C1-C6)alkyl- group; or R7and R8form together with the nitrogen atom to which they are attached a (C3C10)membered heterocycloalkyl- group comprising one nitrogen heteroatom, said heterocycloalkyl group being unsubstituted or substituted by at least one substituent, for instance one to three substituents, such as one substituent selected from: - a phenyl group and- a hydroxy(C1-C6)alkyl-phenyl- group; d) - a (C3-C10)membered heterocycloalkyl- group comprising one heteroatom selected from oxygen and nitrogen; e) - a (C5-C10)membered heteroaryl- group comprising one to two heteroatoms selected from oxygen, nitrogen, and sulfur, said (C5-C10)membered heteroaryl- group being unsubstituted or substituted by at least one (C1-C6)alkyl- group, for instance one to three a (C1-C6)alkyl- groups, such as one (C1- C6)alkyl- group; f) - a (C6-C10)membered aryl- group and g) - a (C3-C10)cycloalkyl- group.

6. The compound of formula (I) or a pharmaceutically acceptable salt thereof according to anyone of claims 1 to 5, said compound being selected from: (1) 2-butyl-7-isopropoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (2) 2-butyl-N7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4,7-diamine; (3) 2-butyl-7-(isopropylthio)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (4) 2-butyl-1-(4-methoxybenzyl)-7-(2-methoxyethoxy)-1H-imidazo[4,5- d]pyridazin-4-amine; (5) 2-butyl-1-(4-methoxybenzyl)-7-propoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (6) 7-(allyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (7) 7-(sec-butoxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (8) 7-butoxy-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (9) 2-butyl-7-(cyclopentyloxy)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d] pyridazin-4-amine; (10) 2-butyl-1-(4-methoxybenzyl)-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine;(11) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-3-yl)-1H- imidazo[4,5d] pyridazin-4-amine; (12) (E)-2-butyl-1-(4-methoxybenzyl)-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (13) 2-butyl-7-isopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (14) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (15) 2-butyl-7-(cyclopent-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (16) 2-butyl-7-cyclopentyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (17) 2-butyl-1-(4-methoxybenzyl)-7-(prop-1-en-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (18) 2-butyl-7-isopropyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (19) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride; (20) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate; (21) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d] pyridazin-4-amine; (22) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (23) 1-(((1S,3R)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (and enantiomer); (24) 1-(4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)-2- methylpropan-2-ol; (25) Trans 1-(4-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (26) 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (27) 6-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)nicotinonitrile; (28) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5d]pyridazin-1- yl)methyl)benzyl)acetamide; (29) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)undecanamide; (30) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)pentanamide; (31) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-(2-methoxyethoxy)propanamide;(32) 1-(((1S,3S)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-]pyridazin-4-amine (and enantiomer); (33) 1-(3-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (34) 4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzaldehyde; (35) (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)phenyl)methanol; (36) 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (37) 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (38) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-N-(1,1-dioxidothietan-3-yl)acetamide; (39) 2-butyl-7-isopropoxy-1-(4-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine; (40) 2-butyl-7-isopropoxy-1-(4-(piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (41) 2-butyl-N7,N7,1-trimethyl-1H-imidazo[4,5-d]pyridazin-4,7-diamine; (42) 2-butyl-1-methyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5-d]pyridazin-4- amine; (43) 2-butyl-N7-(4-((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H- imidazo[4,5-d]pyridazin-4,7-diamine; (44) 2-butyl-N7,1-dimethyl-N7-(4-(morpholinomethyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (45) 4-(((4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)(methyl)amino)methyl)benzonitrile; (46) N7-(4-(aminomethyl)benzyl)-2-butyl-N7,1-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (47) 2-butyl-N7-(4-(((2-methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1- dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (48) 2-butyl-7-ethoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (49) 2-butyl-1-(4-methoxybenzyl)-N7-(2-methoxyethyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (50) 2-butyl-7-methoxy-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (51) 2-butyl-7-cyclohexyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (52) 7-(benzyloxy)-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine;(53) 2-butyl-1-(4-methoxybenzyl)-N7-methyl-1H-imidazo[4,5-d]pyridazine- 4,7-diamine; (54) (S)-2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (55) 2-butyl-7-(furan-2-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazine- 4-amine; (56) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrofuran-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (57) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydro-2H-pyran-4-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (58) 2-butyl-1-(4-methoxybenzyl)-7-((tetrahydrothiophen-3-yl)oxy)-1H- imidazo[4,5-d]pyridazin-4-amine; (59) 2-butyl-1-(4-methoxybenzyl)-7-(tetrahydrofuran-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (60) 2-butyl-1-(4-methoxybenzyl)-7-(2-methylprop-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (61) 2-butyl-7-isobutyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4- amine; (62) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (63) 2-butyl-1-(4-methoxybenzyl)-7-(thiophen-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (64) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrrol-2-yl)-1H-imidazo[4,5- d]pyridazin-4-amine hydrochloride; (65) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer A; (66) 2-butyl-7-(cyclohex-1-en-1-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (67) 2-butyl-7-(furan-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin- 4-amine; (68) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1,1-dioxide; (69) 3-((4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7- yl)oxy)tetrahydrothiophene 1-oxide isomer B; (70) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrrol-2-yl)-1H- imidazo[4,5-d]pyridazin-4-amine hydrochloride; (71) 2-butyl-1-(4-methoxybenzyl)-N7,N7-dimethyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (72) 2-butyl-1-(4-methoxybenzyl)-7-phenoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (73) 2-butyl-7-(2,5-dihydrofuran-3-yl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazin-4-amine;(74) 2-butyl-7-isopropoxy-1-(pyridin-3-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (75) 2-butyl-7-isopropoxy-1-(pyridin-2-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (76) 2-butyl-7-isopropoxy-1-(pyridin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (77) 1-(5-aminopentyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4- amine; (78) 2-butyl-7-isopropoxy-1-(2-(piperidin-4-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (79) 2-butyl-7-isopropoxy-1-(2-(piperazin-1-yl)ethyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (80) 1-benzyl-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride; (81) 2-butyl-1-(cyclohexylmethyl)-7-isopropoxy-1H-imidazo[4,5-d]pyridazin- 4-amine hydrochloride; (82) 2-butyl-7-isopropoxy-1-(4-(((tetrahydro-2H-pyran-4- yl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine hydrochloride; (83) 2-butyl-7-isopropoxy-1-(4-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride; (84) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)heptanamide; (85) (4-(1-(4-amino-2-butyl-1-methyl-1H-imidazo[4,5-d]pyridazin-7- yl)pyrrolidin-3-yl)phenyl)methanol hydrochloride; (86) 2-butyl-7-isopropoxy-1-methyl-1H-imidazo[4,5-d]pyridazin-4-amine; (87) N7-(4-(aminomethyl)benzyl)-2-butyl-1-methyl-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (88) 2-butyl-N7-isopropyl-1-methyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (89) 2-butyl-1-methyl-7-(3-phenylpyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (90) N7-benzyl-2-butyl-N7,1-dimethyl-1H-imidazo[4,5-d]pyridazine-4,7- diamine; (91) 2-butyl-1-methyl-N7-(4-((4-methylpiperazin-1-yl)methyl)benzyl)-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (92) 2-butyl-1-(4-methoxybenzyl)-7-phenyl-1H-imidazo[4,5-d]pyridazin-4- amine; (93) 4-amino-2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-7-ol; (94) 2-butyl-N7-(3-(furan-2-yl)propyl)-1-(4-methoxybenzyl)-1H-imidazo[4,5- d]pyridazine-4,7-diamine; (95) 2-butyl-1-(4-methoxybenzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (96) 2-butyl-1-(4-methoxybenzyl)-7-(1H-pyrazol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine;(97) 2-butyl-1-(4-methoxybenzyl)-7-(1-methyl-1H-pyrazol-4-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (98) 2-butyl-N7-isopropyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (99) 2-butyl-7-(isopropylthio)-1H-imidazo[4,5-d]pyridazin-4-amine; (100) (1R,3R)-3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)cyclobutan-1-ol dihydrochloride salt; (101) 2-butyl-7-isopropoxy-1-(4-(pyrrolidin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (102) 2-butyl-7-isopropoxy-1-(4-(morpholinomethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (103) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)propionamide; (104) 2-butyl-7-isopropoxy-1-(4-(((2-methoxyethyl)amino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (105) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[ 4,5-d]pyridazin-7-amine; (106) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)benzamide; (107) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-methoxypropanamide; (108) 2-butyl-7-isopropoxy-1-(4-(((2-(2- methoxyethoxy)ethyl)amino)methyl)benzyl)-1H-imidazo[4,5-d]pyridazin-4-amine; (109) 2-butyl-1-(4-((hexylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (110) 2-butyl-1-(4-((decylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (111) ethyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)carbamate; (112) 4-methoxybenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (113) 1-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)-3-ethylurea; (114) 4-acetamidobenzyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)carbamate; (115) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)methanesulfonamide; (116) 2-butyl-1-(4-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (117) tert-butyl (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)glycinate;(118) 2-butyl-7-isopropoxy-1-(4-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (119) tert-butyl 3-((4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-1-yl)methyl)benzyl)amino)propanoate; (120) 1-(4-(5,8,11-trioxa-2-azadodecyl)benzyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (121) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethylamino]methyl]phenyl]methyl]imidazo[4,5- d]pyridazin-7-amine; (122) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethylamino]methyl]phenyl] methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2-trifluoroacetate; (123) 2-butyl-4-isopropoxy-3-[[4-[[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-(2- methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethox y]ethylamino]methyl]phenyl]methyl]imidazo[4,5-d]pyridazin-7-amine di2,2,2- trifluoroacetate; (124) 2-butyl-7-isopropoxy-1-(3-((methylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (125) 2-butyl-1-(3-((dimethylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (126) 2-butyl-1-(3-((cyclobutylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (127) 2-butyl-1-(3-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (128) 2-butyl-7-isopropoxy-1-(3-((isopropylamino)methyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (129) 3-((3-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)benzyl)amino)thietane 1,1-dioxide; (130) 2-butyl-7-isopropoxy-1-(3-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (131) 2-butyl-7-isopropoxy-1-(3-(piperazin-1-ylmethyl)benzyl)-1H- imidazo[4,5-d]pyridazin-4-amine; (132) (E)-1-(4-(aminomethyl)benzyl)-2-butyl-7-(3-methylbut-1-en-1-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (133) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopentyl-1H-imidazo[4,5- d]pyridazin-4-amine; (134) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(pyrrolidin-1-yl)-1H-imidazo[4,5- d]pyridazin-4-amine; (135) 1-(4-(aminomethyl)benzyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (137) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-((E)-3- methylbut-1-en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine(138) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopentyl- 1H-imidazo[4,5-d]pyridazin-4-amine; (139) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-((E)-3-methylbut-1- en-1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (140) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-isopentyl-1H- imidazo[4,5-d]pyridazin-4-amine; (141) 1-(((1R,4R)-4-aminocyclohexyl)methyl)-2-butyl-7-(1H-pyrrol-3-yl)-1H- imidazo[4,5-d]pyridazin-4-amine; (142) 1-(((1R,4R)-4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-(pyrrolidin- 1-yl)-1H-imidazo[4,5-d]pyridazin-4-amine; (143) 3-[(4-aminocyclohexyl)methyl]-2-butyl-4-pyrrolidin-1-yl-imidazo[4,5- d]pyridazin-7-amine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (145) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-pyrrolidin-3-yl- imidazo[4,5-d]pyridazin-4-amine; (146) 3-(6-aminohexyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7- amine dihydrochloride salt; (147) 2-butyl-4-isopropoxy-3-[6-(tetrahydropyran-4- ylamino)hexyl]imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (148) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-tetrahydropyran-4-yl-acetamide; (149) 3-(4-aminobutyl)-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-7-amine dihydrochloride salt; (150) 2-butyl-4-isopropoxy-3-[4-(tetrahydropyran-4- ylamino)butyl]imidazo[4,5-d]pyridazin-7-amine hydrochloride salt; (151) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-tetrahydropyran-4-yl-acetamide; (152) 2-butyl-3-[4-[(1,1-dioxothietan-3-yl)amino]butyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (153) N-[4-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)butyl]-N-(1,1-dioxothietan-3-yl)acetamide; (154) 2-butyl-3-[6-[(1,1-dioxothietan-3-yl)amino]hexyl]-4-isopropoxy- imidazo[4,5-d]pyridazin-7-amine; (155) N-[6-(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)hexyl]-N-(1,1-dioxothietan-3-yl)acetamide hydrochloride salt; (156) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3-yl)methyl]- 2-methyl-propane-1,3-diol hydrochloride salt; (157) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)methyl]propane-1,3-diol hydrochloride salt; (158) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-propyl-1H-imidazo[4,5- d]pyridazin-4-amine;(159) 1-(4-(aminomethyl)benzyl)-2-(ethoxymethyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (160) 1-(4-(aminomethyl)benzyl)-7-isopropoxy-2-methyl-1H-imidazo[4,5- d]pyridazin-4-amine; (161) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfanyl- imidazo[4,5-d]pyridazin-7-amine; (162) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfinyl- imidazo[4,5-d]pyridazin-7-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine; and (165) 2-butyl-7-isopropoxy-1-(piperidin-4-ylmethyl)-1H-imidazo[4,5- d]pyridazin-4-amine.

7. The Compound of formula (I) or a pharmaceutically acceptable salt thereof, according to any one of claims 1 to 6, said compound being selected from: (19) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine dihydrochloride salt; (20) 4-(aminomethyl)cyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine 2,2,2-trifluoroacetate; (21) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine; (22) 1-(4-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (23) 1-(((1S,3R)-3-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine (and enantiomer); (24) 1-(4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1-yl)-2- methylpropan-2-ol; (25) Trans 1-(4-aminocyclohexyl)methyl)-2-butyl-7-isopropoxy-1H- imidazo [4,5-d]pyridazin-4-amine; (26) 1-((5-(aminomethyl)pyridin-2-yl)methyl)-2-butyl-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (28) N-(4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5d]pyridazin-1- yl)methyl)benzyl)acetamide; (33) 1-(3-(aminomethyl)benzyl)-2-butyl-7-isopropoxy-1H-imidazo[4,5- d]pyridazin-4-amine 2,2,2-trifluoroacetate; (35) (4-((4-amino-2-butyl-7-isopropoxy-1H-imidazo[4,5-d]pyridazin-1- yl)methyl)phenyl)methanol; (36) 2-butyl-1-(4-((cyclopropylamino)methyl)benzyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine;(39) 2-butyl-7-isopropoxy-1-(4-(((1-methylcyclobutyl)amino)methyl)benzyl)- 1H-imidazo[4,5-d]pyridazin-4-amine; (40) 2-butyl-7-isopropoxy-1-(4-(piperazin-1-ylmethyl)benzyl)-1H-imidazo[4,5- d]pyridazin-4-amine; (43) 2-butyl-N7-(4-((dimethylamino)methyl)benzyl)-N7,1-dimethyl-1H- imidazo[4,5-d]pyridazine-4,7-diamine; (47) 2-butyl-N7-(4-(((2-methoxyethyl)(methyl)amino)methyl)benzyl)-N7,1- dimethyl-1H-imidazo[4,5-d]pyridazine-4,7-diamine; (144) 1-[[4-(aminomethyl)phenyl]methyl]-2-butyl-7-(2,5-dihydro-1H-pyrrol-3- yl)imidazo[4,5-d]pyridazin-4-amine; (156) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3-yl)methyl]- 2-methyl-propane-1,3-diol hydrochloride salt; (157) 2-[(7-amino-2-butyl-4-isopropoxy-imidazo[4,5-d]pyridazin-3- yl)methyl]propane-1,3-diol hydrochloride salt; (159) 1-(4-(aminomethyl)benzyl)-2-(ethoxymethyl)-7-isopropoxy-1H- imidazo[4,5-d]pyridazin-4-amine; (161) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-2-propylsulfanyl- imidazo[4,5-d]pyridazin-7-amine; (163) 3-[[4-(aminomethyl)phenyl]methyl]-4-isopropoxy-N2-propyl- imidazo[4,5-d]pyridazine-2,7-diamine; and (164) 3-[[4-(aminomethyl)phenyl]methyl]-2-(ethylaminomethyl)-4- isopropoxy-imidazo[4,5-d]pyridazin-7-amine.

8. A process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 7, comprising at least the following steps: (iB) providing a compound of formula (II),(iiB) cyclization of the compound of formula (II) provided in step (iB) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in any one of claims 1 to 7 in order to obtain a compound of formuwherein R2is as defined in any one of claims 1 to 7; (iiiB) hydrolyzis of nitrile groups present on the compound of formula (III) obtained from step (iiB) in order to obtain a compound of formula (IV),wherein R2is as defined in any one of claims 1 to 7; (ivB) esterification of carboxylic acid functions present on the compound of formula (IV) obtained from step (iiiB) in order to obtain a compound of formula (V),wherein R is a (C1-C4)alkyl- group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in any one of claims 1 to 7; (vB) optionally reacting the compound of formula (V) obtained from step (ivB) with R1-X wherein R1is as defined in any one of claims 1 to 7, and X represents a halogen atom, for instance chlorine, iodine or bromine atom in order to obtain a compound of formula (Vb),wherein R is a (C1-C4)alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R1and R2are as defined in any one of claims 1 to 7;(viB) cyclization of the compound of formula (Vb) obtained from step (vB) or the compound of formula (V) (in which R1is a hydrogen atom) obtained from step (ivB) in order to obtain a compound of formula (VIb),wherein R1and R2are as defined in any one of claims 1 to 7; (viiB) dihalogenation of the compound of formula (VIb) obtained from step (viB) in order to obtain a compound of formula (VIIa),wherein R1 and R2 are as defined in any one of claims 1 to 7 and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (viiiB) nucleophilic aromatic substitution of the compound of formula (VIIa) obtained from step (viiB) in order to obtain a compound of formula (VIIIa),(VIIIa) wherein R1and R2are as defined in any one of claims 1 to 7 and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom; (ixB) substitution and / or coupling of the compound of formula (VIIIa) obtained from step (viiiB) in order to obtain a compound of formula (Ia),wherein R1and R2are as defined in any one of claims 1 to 7, and R3arepresents R3as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group; (xB) when R3ais other than R3as defined in any one of claims 1 to 7, then reacting the compound of formula (Ia) obtained from step (ixB) with any suitable reagents and in any suitable conditions in order to obtain a compound of formula (I) as defined in any one of claims 1 to 7.

9. A process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 7, comprising at least the following steps: (i) providing a compound of formula (II),(ii) cyclization of the compound of formula (II) provided in step (i) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom in order to obtain a compound of formula (III),wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom; (iii) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (ii) in order to obtain a compound of formula (IV),wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom; (iv) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iii) in order to obtain a compound of formula (V),wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom; (v) cyclization of the compound of formula (V) obtained from step (iv) in order to obtain a compound of formula (wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom; (vi) dihalogenation of the compound of formula (VI) obtained from step (v) in order to obtain a compound of formula (VII),wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom and HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (vii) nucleophilic aromatic substitution of the compound of formula (VII) obtained from step (vi) with a compound of formula (AA)wherein the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, in order to obtain a compound of formula (VIII),is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom, and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group; (viii) substitution and / or coupling reaction of the compound of formula (VIII) obtained from step (vii) in order to obtain a compound of formula (IX),wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom, R3arepresents R3as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group; then either (ixAlpha, also named ixα) reacting the compound of formula (IX) obtained from step (viii) with R1a-X wherein R1ais R1as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate in order to obtain a compound of formula (X),represents R3 as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1ais as defined above in this step (ixAlpha);or (ixBeta, also named ixβ) reacting the compound of formula (IX) obtained from step (viii) with an epoxide of formulain which R’ and R’’ are independently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group in order to obtain a compound of formula (X),wherein R2is as defined in anyone of claims 1 to 7 or is a hydrogen atom, R3arepresents R3as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1ais as defined above in the step (ixAlpha); and either (x) deprotecting the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (I) as defined in anyone of claims 1 to 7; and when R2is a hydrogen atom in compound of formula (X), before deprotection, the hydrogen was transformed to R2as defined in formula (I) through chemistry modification, such as metalation, followed for example either by reaction with alkyldisulfide, or dimethylformamide, or N-Bromosuccinimide, which was further submitted to other chemistry reaction, if necessary, such as oxidation, or reduction amination or nucleophilic substitution, to give requisite R2; or (x) deprotecting the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (XI)wherein R3arepresents R3as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in anyone of claims 1 to 7 and R1bis R1aas defined in anyone of claims 1 to 7 or R1awith a function such as an amino group, an alcohol, and an aldehyde; and then (xi) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (XI) obtained from this step (x) in order to obtain a compound of formula (I) as defined in anyone of claims 1 to 7; or (Gamma, also named γ) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (X) obtained from step (ixAlpha) or (ixBeta) in order to obtain a compound of formula (XII)wherein R3arepresents R3as defined in anyone of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2as defined in anyone of claims 1 to 7, the two G1 represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1bis a derivative of R1ais as defined in anyone of claims 1 to 7 through reductive amination, reduction, substitution, and / or oxydation; and then (x) deprotecting the compound of formula (XII) obtained from step (Gamma) in order to obtain a compound of formula (I) as defined in anyone of claims 1 to 7.

10. A process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 7, comprising at least the following steps: (iA) providing a compound of formula (II),(iiA) cyclization of the compound of formula (II) provided in step (iA) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in any one of claims 1 to 7 in order to obtain a compound of formuwherein R2is as defined in any one of claims 1 to 7; (iiiA) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (iiA) in order to obtain a compound of formula (IV),wherein R2is as defined in any one of claims 1 to 7; (ivA) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iiiA) in order to obtain a compound of formula (V),wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in any one of claims 1 to 7;(vA) cyclization of the compound of formula (V) obtained from step (ivA) in order to obtain a compound of formula (VI),wherein R2is as defined in any one of claims 1 to 7; (viA) dihalogenation of the compound of formula (VI) obtained from step (vA) in order to obtain a compound of formula (VII);wherein R2is as defined in any one of claims 1 to 7, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; (viiA) optionally reacting the compound of formula (VII) obtained from step (viA) with R1-X wherein R1is as defined in any one of claims 1 to 7, and X represents a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom in order to obtain a compound of formula (VIIa);wherein R1and R2are as defined in any one of claims 1 to 7, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms;(viiiA) nucleophilic aromatic substitution of the compound of formula (VIIa) obtained from step (viiA) or of the compound of formula (VII) (in which R1is a hydrogen atom) obtained from step (viA) in order to obtain a compound of formula (VIIIa),(VIIIa) wherein R1and R2are as defined in any one of claims 1 to 7, and HAL is a halogen atom for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example a chlorine atom; (ixA) substitution and / or coupling of the compound of formula (VIIIa) obtained from step (viiiA) in order to obtain a compound of formula (Ia),wherein R3arepresents R3as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and R1and R2are as defined in any one of claims 1 to 7; (xA) when R3ais other than R3as defined in any one of claims 1 to 7, then reacting the compound of formula (Ia) obtained from step (ixA) with any suitable reagents and in any suitable conditions in order to obtain a compound of formula (I) as defined in any one of claims 1 to 7.

11. A process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 7, comprising at least the following steps: (i) providing a compound of formula (II),(ii) cyclization of the compound of formula (II) provided in step (i) by reaction with R2-C(OCH3)3or R2-COCl wherein R2is as defined in any one of claims 1 to 7 in order to obtain a compound of formula (III),wherein R2is as defined in any one of claims 1 to 7; (iii) hydrolysis of nitrile groups of the compound of formula (III) obtained from step (ii) in order to obtain a compound of formula (IV),wherein R2is as defined in any one of claims 1 to 7; (iv) esterification of carboxylic acid functions of the compound of formula (IV) obtained from step (iii) in order to obtain a compound of formula (V),wherein R is a (C1-C4) alkyl group, for instance a methyl group, an ethyl group, a propyl group or a butyl group, such as a methyl group and R2is as defined in any one of claims 1 to 7; (v) cyclization of the compound of formula (V) obtained from step (iv) in order to obtain a compound of formula (VI),wherein R2is as defined in any one of claims 1 to 7; (vi) dihalogenation of the compound of formula (VI) obtained from step (v) in order to obtain a compound of formula (VII),wherein R2is as defined in any one of claims 1 to 7 and HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms; then either (viialpha, also named viiα) reacting the compound of formula (VII) obtained from step (vi) with R1a-X wherein R1ais R1as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, and X represents a halogen atom, a tosylate or a mesylate in order to obtain a compound of formula (VIIIaa),(VIIIaa)wherein R2is as defined in any one of claims 1 to 7, HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms, and R1ais as defined above in this step (viialpha); or (viiBeta, also named viiβ) reacting the compound of formula (VII) obtained from step (vi) with an epoxide of formulain which R’ and R’’ areindependently a hydrogen atom or a (C1-C6)alkyl group, such as a methyl group in order to obtain a compound of formula (VIIIaa),(VIIIaa)wherein R2is as defined in any one of claims 1 to 7, HAL is a halogen atom, for instance a chlorine atom, a fluorine atom, an iodine atom or a bromine atom, for example the two HAL are the same and are chlorine atoms, and R1ais as defined above in the step (viialpha), (viiiAA) nucleophilic aromatic substitution of the compound of formula (VIIIaa) obtained from step (viialpha) or step (viibeta) with a compound of formula (AA)wherein the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, in order to obtain a compound of formula (IXaa),wherein R2is as defined in any one of claims 1 to 7, HAL is a halogen atom for instance a chlorine atom, a fluorine atom, a iodine atom or a bromine atom, for example a chlorine atom, R1ais as defined above in the step (viialpha), and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group;(ixAA) substitution and / or coupling reaction of the compound of formula (IXaa) obtained from step (viiiAA) in order to obtain a compound of formula (X),wherein R2is as defined in any one of claims 1 to 7, R1ais as defined above in the step (viialpha), R3arepresents R3as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group and the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group; and either (x) deprotecting the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formula (I) as defined in any one of claims 1 to 7; or (x) deprotecting the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formulawherein R3arepresents R3as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in any one of claims 1 to 7 and R1bis R1a or R1a with a function such as an amino group, an alcohol, and an aldehyde; and then (xi) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (XI) obtained from this step (x) in order to obtain a compound of formula (I) as defined in any one of claims 1 to 7;or (Gamma, also named γ) reducing, reductive aminating, nucleophilic substituting, and / or oxidating the compound of formula (X) obtained from step (ixAA) in order to obtain a compound of formula (XII),wherein R3arepresents R3as defined in any one of claims 1 to 7 comprising or not a hydroxyl protecting group, an amino protecting group, a carboxylic acid protecting group, an aldehyde protecting group or a ketone protecting group, R2is as defined in any one of claims 1 to 7, the two G1represent independently a hydrogen atom or a methoxy group, for example the two G1are a methoxy group, and R1bis a derivative of R1athrough reductive amination, reduction, substitution, and / or oxidation; and then (x) deprotecting the compound of formula (XII) obtained from step (Gamma) in order to obtain a compound of formula (I) as defined in any one of claims 1 to 7.

12. Compounds or a pharmaceutically acceptable salt thereof selected from:in which: - compounds (H) and (J) or a pharmaceutically acceptable salt thereof belong to formula (VIIa) as defined in anyone of claims 8 and 10, - compounds (Ia) and (K) or a pharmaceutically acceptable salt thereof belong to formula (VIIIa) as defined in anyone of claims 8 and 10, - compounds (L) and (N) or a pharmaceutically acceptable salt thereof belong to formula (VIII) as defined in claim 9 and - compounds (M) and (R) or a pharmaceutically acceptable salt thereof belong to formula (IX) as defined in claim 9.

13. A medicament, comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7.

14. A pharmaceutical composition, comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7, and at least one pharmaceutically acceptable excipient.

15. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7, for use as a medicament.

16. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7, for use as a TLR7 and / or TLR8 agonist.

17. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7, for use in the prevention and / or in the treatment of a disease or a disorder associated with TLR7 and / or TLR8 activity.

18. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7 for use in the prevention and / or treatment of a disease or a disorder associated with TLR7 and / or TLR8 activity such a cell-proliferative disease, a cancer, a chronic myelogenous, a hairy cell leukemia, a dermatological disease such as a skin lesion or a skin cancer (for example an external genital and perianal warts / condyloma acuminate, a genital herpes, an actinic keratosis, a basal cell carcinoma, a cutaneous T-cell lymphoma), an autoimmune disease, an inflammatory disease, a respiratory disease, a sepsis, an allergy (for example an allergic rhinitis or an respiratory allergy), an asthma, a graft rejection, a graft-versus-host disease, and an immunodeficiency.

19. A compound of formula (I) or a pharmaceutically acceptable salt thereof for use according to claim 18, wherein the disease or disorder associated with TLR7 and / or TLR8 activity is cancer.

20. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any of claims 1 to 7, for use in a vaccine.