AZO(hetero)ARYL derivatives for use as radioswitchs and their use in therapy

Abstract

The present invention concerns novel azo(hetero)aryl derivatives, their process of preparation, and their therapeutic use in particular in combination with irradiation.

Description

[0001] TITLE: AZO(HETERO)ARYL DERIVATIVES FOR USE AS RADIOSWITCHS AND THEIR USE IN THERAPY

[0002] Technical field

[0003]

[0001] The present invention relates to the therapeutic treatment of pathologies such as cancer, by means of compounds that are switchable by ionizing radiation.

[0004] Background of the invention

[0005]

[0002] Redox and light-sensitive systems have been developed for more than a century and are used to trigger complex actions, such as specific bond cleavage or configuration switching, which can be used to effect the release of active molecules, control protein activity and gene expression, etc. Unfortunately, clinical applications of these sensitive systems are still limited to topical or ophthalmic treatment, due to the current paucity of techniques capable of activating these systems at depths greater than a few hundred micrometres below the body surface, except for the use of invasive electrodes or optical fibres. Indeed, all the photosensitive molecules developed so far are only sensitive to UV, visible or near infrared radiation, whose penetration into the tissues is intrinsically limited.

[0006]

[0003] The activation of compounds triggered by ionizing radiation has been proposed in WO 2011 / 158189. However, efficacy is extremely limited and requires doses that are too high to be applied clinically.

[0007]

[0004] WO 2020 / 161308 discloses unsaturated derivatives that can be activated by ionizing radiations: the radiation induces the conversion of the cis form of the molecule into its trans active form that triggers cell permeability and cell death.

[0008]

[0005] However, the disclosed compounds comprise a metal chelating group that limits the interests of the compounds in terms of toxicity, costs and synthesis. Description of the invention

[0009]

[0006] It is therefore an object of the invention to provide unsaturated derivatives that can be activated by irradiation.

[0010]

[0007] It is another object of the invention to provide compounds that can be activated by ionizing radiation to trigger cell permeability or toxicity without restricting depth in the targeted biological tissues.

[0008] According to a first object, the present invention therefore relates to a compound of formula (I):

[0011] Where

[0012] Each A identical or different independently represents -O-, -NR-, -C1-C16 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;

[0013] Each B, which may be the same or different, independently represents -O-, -NR- , -C1 -C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O- , or -SR-;

[0014] Each X and X’, identical or different is independently selected from H; halogen atoms; -OR, -SR, -C1-C9 alkyl, -NRR’, -N+RR’R”, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;

[0015] Y and Y’ identical or different are independently chosen from N or OR;

[0016] Z is selected from the group consisting in H, COOR, OR, -SO2OR, -SOOR, - PO3R2, N3, halogen atoms, NRR’, -N+RR’R”, SeO2OR; SeOOR, or a biologically active moiety; Each R1 , R1’ identical or different is independently chosen from H, halogen atoms, -COOR, -CONRR’, NRC(=O)R’, -COSR, SC(=O)R, -SO2OR, -PO3R2,- OR, -NRR’, -N+RR’R”, -SR, -CN, -C1-C16 alkyl, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from a halogen atom, COOR, CONRR’, NRR’CO, COSR, SRCO, OR, NRR’, SR, CN;

[0017] R2 is chosen from H; C1-C16 alkyl; and a biologically active moiety;

[0018] R, R’ and R” identical or different are chosen from H, O, C1-C9 alkyl; m, n and n’, identical or different are integers comprised between 0 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is an integer comprised between 0 and 4; if q is comprised between 3 to 4, A is not a chain comprising more than three consecutive atoms other than -C1-C16 alkyl-; if m is comprised between 3 to 6, B is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O;

[0019] Or a salt thereof;

[0020] In the form of the cis and / or trans isomers and mixtures thereof;

[0021] For use as a medicament wherein its in vivo biological activity is triggered upon exposure to ionizing radiations or endogeneous reactive nitrogen / oxygen species.

[0022]

[0009] According to an embodiment, the compound is a compound of formula (I’):

[0023] Where

[0024] Each A identical or different independently represents -O-, -NR-, -C1-C9 alkyl-, - 3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;

[0025] Each B, which may be the same or different, independently represents -O-, -NR- , -C1-C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O- , or -SR-;

[0026] Each X and X’, identical or different is independently selected from H; halogen atoms; -OR, -SR, -C1-C9 alkyl, -NRR’, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;

[0027] Y and Y’ identical or different are independently chosen from N or OR;

[0028] Z is selected from the group consisting in COOR, OR, -SO2OR, -SOOR, - PO3R2, halogen atoms, NRR’, N3, SeO2OR; SeOOR, N3 or a biologically active moiety;

[0029] Each R1 , R1’ identical or different is independently chosen from H, halogen atoms, -COOR, -CONRR’, NRC(=O)R’, -COSR, S C(=O)R, -OR, -NRR’, -SR, - CN, -C1-C9 alkyl, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12- membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from a halogen atom, COOR, CONRR’, NRR’CO, COSR, SRCO, OR, NRR’, SR, CN; R2 is chosen from H; C1-C9 alkyl; and a biologically active moiety;

[0030] R and R’, identical or different are chosen from H, O, C1-C9 alkyl; m, n and n’, identical or different are integers comprised between 0 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is an integer comprised between 0 and 4; if q is comprised between 3 to 4, A is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-; if m is comprised between 3 to 6, B is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O;

[0031] Or a salt thereof;

[0032] In the form of the cis and / or trans isomers and mixtures thereof;

[0033] For use as a medicament wherein its in vivo biological activity is triggered upon exposure to ionizing radiations.

[0034]

[0010] The above compounds are radio-sensitive in that their action is triggered by ionizing radiation.

[0035]

[0011] Thus, they may exert their biological activity through cell killing, protein and / or oligonucleotide targeting, direct or indirect protein destruction or gradation or gene silencing, or other pharmacological effects that are activated by applying radiations and thus inducing molecular changes, from cis to trans configuration.

[0036]

[0012] They may also be able to induce the permeability and / or death of cancer cells when activated by ionizing radiation.

[0037]

[0013] Typically, after introduction of the inactive (cis) form, irradiation of the target site with ionizing radiation is applied. This radiation induces a conversion of the molecule into its active form (trans) leading to specific pharmacological effects due to the change in the lipophilic balance, size and / or dipole moment of the molecule. The rays used to activate the molecule penetrate biological tissues without depth restriction, making the activation technique perfectly suited for clinical applications, unlike traditional photosensitive tools whose activation is limited to UV to near-infrared irradiation (penetration of less than 1 cm of biological tissue).

[0038]

[0014] The above compounds therefore represent a promising tool for the control and modulation of therapeutic actions in real time.

[0039]

[0015] The above compounds can be used to effectively reach deep tissue, where the high energy of the radiation will be used locally to specifically activate redox / photosensitive therapeutic systems.

[0040]

[0016] According to the invention, the azo(hetero)aryl moiety acts as a radiosensitive switch (ie) that can be activated by ionizing radiations. Said radiations are highly penetrating and activation is efficient at moderate doses compatible with clinical applications.

[0041]

[0017] According to the invention the compounds can be satisfyingly activated in the absence of a molecular energy converter such as metal chelate.

[0018] According to an embodiment, the above compounds do not comprise metal atoms such as Fe, Cu, Zn, Ga, Y, Zr, Tc, Ru, Pd, Ag, In, Eu, Gd, Tb, Dy, Ho, Yb, Hf, W, Os, Ir, Pt, Au or Bi.

[0042]

[0019] In the above and the following:

[0043]

[0020] "Alkyl" means an aliphatic hydrocarbon group which may be linear or branched having about 1 to about 16 carbon atoms in the chain. Preferred alkyl groups have 1 to about 12 carbon atoms, and more preferably 1 to 9 carbon atoms in the chain, even more preferably 1 to 6, and even more preferably 1 to 4. Branched means that one or more lower alkyl groups, such as methyl, ethyl or propyl, are linked to a linear alkyl chain.

[0044]

[0021] “OAlkyl" means an alkoxy group, wherein the alkyl group is as described above. Typical examples of alkoxy groups include methoxy, ethoxy, n- propoxy, i-propoxy, n-butoxy and heptoxy.

[0045]

[0022] “Cycloalkyl" means a non-aromatic mono- or multi-cyclic ring system of about 3 to about 10 carbon atoms, preferably of about 5 to about 6 carbon atoms. Preferred ring sizes of the ring system include about 5 to about 6 ring atoms. Example monocyclic cycloalkyls include cyclopentyl and cyclohexyl.

[0046]

[0023] "Aryl" means an aromatic monocyclic or multicyclic ring system with about 5 to about 12 carbon atoms, preferably with about 6 to about 10 carbon atoms. Typical examples of aryl groups include phenyl and naphthyl.

[0047]

[0024] "Heteroaryl" means an aromatic monocyclic or multicyclic ring system of about 5 to about 12 atoms, preferably of about 5 to about 10 carbon atoms, wherein one or more of the carbon atoms in the ring system is / are a hetero element(s) other than carbon, e.g. nitrogen, oxygen or sulphur. Preferred ring sizes of the ring system include about 5 to about 6 ring atoms. Example heteroaryl groups include pyrazinyl, thienyl, isothiazolyl, oxazolyl, pyrazolyl, furazanyl, pyrrolyl, 1 ,2,4-thiadiazolyl, pyridazinyl, quinoxalinyl, phthalazinyl, imidazo[1 ,2- a]pyridine, imidazo[2,1-b]thiazolyl, benzofurazanyl, azaindolyl, benzimidazolyl, benzothienyl, thienopyridyl, thienopyrimidinyl pyrrolopyridyl, imidazopyridyl, benzoazaindole, 1 ,2,4-triazinyl, benzthiazolyl, furanyl, imidazolyl, indolyl, indolizinyl, isoxazolyl, isoquinolinyl, isothiazolyl, oxadiazolyl, pyrazinyl, pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, 1 ,3,4- thiadiazolyl, thiazolyl, thienyl and triazolyl.

[0048]

[0025] "Halogen" means fluorine, chlorine, bromine or iodine. Preferred are fluorine, chlorine or bromine, especially fluorine.

[0049]

[0026] "Biological active moiety" means a biological active moiety constituted of chemical structures able to interact with components of biological tissues to induce a pharmacological and / or a biological effect.

[0050]

[0027] As mentioned herein « salts » include acid and base addition salts.

[0051]

[0028] Acid addition salts can be formed with the useful compounds according to the invention in which a base function such as an amino, alkylamino or dialkylamino group is present. Typically, the acid addition salts include an ammonium group and its negative counter ion.

[0052]

[0029] Counter ions include CI-, Br-, I-, trifluoroacetate (TFA)

[0053]

[0030] Pharmaceutically acceptable, i.e. non-toxic, acid addition salts are preferred. The selected salts are optimally chosen to be compatible with the usual pharmaceutical vehicles and suitable for parenteral administration.

[0031] The acid addition salts of the compounds useful in the present invention can be prepared by reaction of the free base with the appropriate acid, by the application or adaptation of known methods. For example, the acid addition salts of the compounds useful in this invention can be prepared either by dissolving the free base in water or in an aqueous alcoholic solution or suitable solvents containing the appropriate acid and isolating the salt by evaporating the solution, or by reacting the free base and the acid in an organic solvent, in which case the salt separates directly or can be obtained by concentration of the solution.

[0054]

[0032] The compounds useful in this invention can be regenerated from the salts by the application or adaptation of known methods. For example, the parent compounds useful in the invention can be regenerated from their acid addition salts by treatment with an alkali, for example an aqueous sodium bicarbonate solution or an aqueous ammonia solution.

[0055]

[0033] Base addition salts can be formed when the useful compound according to the invention contains a carboxyl (COOH), phoshonyl (PO3RH, PO3H2) and / or sulfonyl (SO3H, SO2RH) group. The corresponding base addition will result in a deprotonated anion group together with a positive counter ion.

[0056]

[0034] Typical counter ion include alcaline metal ions, such as Na+, Li+, K+and alkaline earth metal ions such as Mg2+, Ca2+.

[0057]

[0035] Bases which may be used to prepare base addition salts preferably include those which produce, when combined with a free acid, pharmaceutically acceptable salts.

[0058]

[0036] Base include sodium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminium hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, ammonia, ethylenediamine, N-methyl-glucamine, lysine arginine, ornithine, choline, N,N'-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, diethylamine, piperazine, tris(hydroxymethyl)-aminomethane, tetramethylammonium hydroxide, meglumine and analogues.

[0059]

[0037] The useful compounds according to this invention can be regenerated from their base addition salts by the application or adaptation of known methods. For example, useful parent compounds according to the invention can be regenerated from their base addition salts by treatment with an acid, for example hydrochloric acid.

[0060]

[0038] Pharmaceutically acceptable salts designate salts which are not toxic to the patient in the pharmaceutical doses of the salts, so that the beneficial inhibitory effects inherent in the free compound are not cancelled out by the side effects attributable to the counter ions.

[0061]

[0039] According to an embodiment, in Formula (I):

[0062] Each A identical or different independently represents -O- or -NR- or -C1-C16 alkyl-; and / or

[0063] Each B, which may be the same or different, independently represents -O-, -C1- C6 alkyl-; and / or

[0064] Each X and X’ is H or C1 -C6 alkyl; and / or

[0065] Each Y and Y’ is N or CR; and / or

[0066] Z is H, COOH, -SO2OH, -PO3H2, N3, halogen atoms, NH2 or a biologically active moiety; and / or

[0067] Each R1 , R1’ is H; and / or

[0068] R2 is H or -C1-C16 alkyl-; and / or

[0069] R, R’ and R”, identical or different are chosen from H, C1-C6 alkyl; and / or m, n and n’, identical or different are integers comprised between 0 to 2; and / or p and p’ identical or different are independently chosen from 0 and 1 ; and / or q is 1 .

[0070]

[0040] According to an embodiment, in Formula (I’):

[0071] Each A identical or different independently represents -O- or -C1 -C6 alkyl-; and / or Each B, which may be the same or different, independently represents -O-, -C1- C6 alkyl-; and / or

[0072] Each X and X’ is H or C1 -C6 alkyl; and / or

[0073] Each Y and Y’ is N or CR; and / or

[0074] Z is COOH, -SO2OH, -PO3H2, halogen atoms, NH2 or a biologically active moiety; and / or

[0075] Each R1 , R1’ is H; and / or

[0076] R2 is H; and / or

[0077] R and R’, identical or different are chosen from H, C1-C6 alkyl; and / or m, n and n’, identical or different are integers comprised between 0 to 2; and / or p and p’ identical or different are independently chosen from 0 and 1 ; and / or q is 1.

[0078]

[0041] According to a still further embodiment, in Formula (I):

[0079] Each Y is N, p=0, and / or

[0080] Either each Y’ is N and p’ is 0 or Y’ is CH and p’ is 1 .

[0081]

[0042] According to a still further embodiment, in Formula (I’):

[0082] Each Y is N, p=0, and / or

[0083] Either each Y’ is N and p’ is 0 or Y’ is CH and p’ is 1 .

[0084]

[0043] Preferably, in Formula (I) and in Formula (I’), n’ is 0.

[0085]

[0044] According to an embodiment, in formula (I) Z is the lenalidomide moiety of formula (II):

[0086]

[0045] According to an embodiment, in formula (I’) Z is the lenalidomide moiety of formula (II):

[0087]

[0046] According to a particular embodiment, said compound of formulas (I) and (I’) may be selected from:

[0088]

[0089] Or a salt thereof;

[0090] In the form of the cis and / or trans isomers and mixtures thereof.

[0047] According to a particular embodiment, said compound of formulas (I) and (I’) may be selected from:

[0091]

[0092] Or a salt thereof;

[0093] In the form of the cis and / or trans isomers and mixtures thereof.

[0094]

[0048] According to a particular embodiment, said compound of formulas (I) and (I’) may be selected from:

[0095]

[0096] Or a salt thereof;

[0097] In the form of the cis and / or trans isomers and mixtures thereof.

[0098]

[0049] In the aforementioned general formulas (I) and (I’), the following embodiments are envisaged, separately or in any combination thereof.

[0099]

[0050] Some compounds of formulas (I) and (I’) are novel.

[0100]

[0051] According to a further object, the present invention also concerns a compound of formula (I) which is formula (la): (la)

[0101] Wherein

[0102] Y is N;

[0103] P=0;

[0104] Each Y’ is CH; p’ is 1 ;

[0105] Each X is H;

[0106] Z is NRR’ or -N+RR’R”; m=0; n=2; n’ is 0-6, preferably 0; each R1 , R1’ is H;

[0107] Each X’, identical or different is independently selected from H; halogen atoms; - OR, -SR, -C1-C9 alkyl, -NRR’, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;

[0108] Z is selected from the group consisting in NRR’;

[0109] Each A identical or different independently represents -O-, -NR-, -C1-C16 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;

[0110] R2 is chosen from H; C1-C16 alkyl; and a biologically active moiety;

[0111] R, R’ and R”, identical or different are chosen from H, C1-C6 alkyl; q is an integer comprised between 0 and 4; if q is comprised between 3 to 4, A is not a chain comprising more than three consecutive atoms other than -C1-C16 alkyl-;

[0112] Or a salt thereof;

[0113] In the form of the cis and / or trans isomers and mixtures thereof.

[0114]

[0052] According to a further object, the present invention also concerns a compound of formula (I’) which is formula (la’):

[0115]

[0116] Wherein

[0117] Y is N;

[0118] P=0;

[0119] Each Y’ is CH; p’ is 1 ;

[0120] Each X is H;

[0121] Z is NRR’; m=0; n=2; n’ is 0-6, preferably 0; each R1 , R1’ is H;

[0122] Each X’, identical or different is independently selected from H; halogen atoms; - OR, -SR, -C1-C9 alkyl, -NRR’, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;

[0123] Z is selected from the group consisting in NRR’;

[0124] Each A identical or different independently represents -O-, -NR-, -C1-C9 alkyl-, - 3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;

[0125] R2 is chosen from H; C1-C6 alkyl; and a biologically active moiety;

[0126] R and R’, identical or different are chosen from H, C1-C6 alkyl; q is an integer comprised between 0 and 4; if q is comprised between 3 to 4, A is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-;

[0127] Or a salt thereof;

[0128] In the form of the cis and / or trans isomers and mixtures thereof.

[0053] According to an embodiment, representative compounds of formula Or a salt thereof;

[0129] In the form of the cis and / or trans isomers and mixtures thereof.

[0130]

[0054] According to an embodiment, representative compounds of formula

[0131] Or a salt thereof;

[0132] In the form of the cis and / or trans isomers and mixtures thereof.

[0133]

[0055] According to another object, the present invention also concerns a compound of formula (lb): (lb)

[0134] Wherein

[0135] When present A represents -O- or -NR- or -CH2-;

[0136] Each B, which may be the same or different, independently represents -O- or - C1-C9 alkyl-;

[0137] Each X and X’, identical or different is independently selected from H or -C1-C9 alkyl;

[0138] Y and Y’ identical or different are independently chosen from N or CR;

[0139] Z is selected from the group consisting in COOR, -SO2OR, -PO3R2, NRR’, N+RR’R” SeO2OR; SeOOR;

[0140] R2 is chosen from C1-C16 alkyl;

[0141] R, R’ and R”, identical or different are chosen from H, C1-C9 alkyl; n=0; n’ is 0-6, preferably 0;

[0142] R1’ is defined as in Formula (I); m is an integer comprised between 1 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is 0 or 1 ; if m is comprised between 3 to 6, B is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-;

[0143] Or a salt thereof;

[0144] In the form of the cis and / or trans isomers and mixtures thereof.

[0145]

[0056] According to another object, the present invention also concerns a compound

[0146] Wherein

[0147] When present A represents -O-; Each B, which may be the same or different, independently represents -O- or - C1-C9 alkyl-;

[0148] Each X and X’, identical or different is independently selected from H or -C1-C9 alkyl;

[0149] Y and Y’ identical or different are independently chosen from N or CR;

[0150] Z is selected from the group consisting in COOR, -SO2OR, -PO3R2, NRR’, SeO2OR; SeOOR;

[0151] R2 is chosen from C1-C9 alkyl;

[0152] R and R’, identical or different are chosen from H, C1-C9 alkyl; n=0; n’ is 0-6, preferably 0;

[0153] R1’ is defined as in Formula (I); m is an integer comprised between 1 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is 0 or 1 ; if m is comprised between 3 to 6, B is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-;

[0154] Or a salt thereof;

[0155] In the form of the cis and / or trans isomers and mixtures thereof.

[0156]

[0057] According to an embodiment, the compound of formulas (lb) and (lb’) is selected from:

[0157]

[0158]

[0159] Or a salt thereof;

[0160] In the form of the cis and / or trans isomers and mixtures thereof.

[0161]

[0058] According to an embodiment, the compound of formulas (lb) and (lb’) is selected from:

[0162]

[0163] Or a salt thereof;

[0164] In the form of the cis and / or trans isomers and mixtures thereof.

[0165]

[0059] According to another object, the present invention also relates to the method for preparing the compounds of formula (I), said method comprising:

[0166] - the step (a) of derivatizing a compound of formula (Ila):

[0167] Where A, B, X, X’, Y, Y’, Z, R1, R2, R, R’, m, n, p, p’, q are defined as in Formula (I), And T is a terminal group suitable for addition or substitution, such as a halogen atom, a -OH, -NH2, SH group or a protecting group thereof,

[0168] To replace T function with the desired -(B)m-(R1’)n’-Z group as defined in formula (i);

[0169] - the possible UV irradiation (b) of the product obtained, in order to predominantly obtain the cis isomer.

[0170]

[0060] According to another object, the present invention also relates to the method for preparing the compounds of formula (I’), said method comprising:

[0171] - the step (a) of derivatizing a compound of formula (Ila’) :

[0172] And T is a terminal group suitable for addition or substitution, such as a halogen atom, a -OH, -NH2 group or a protecting group thereof,

[0173] To replace T function with the desired -(B)m-(R1’)n’-Z group as defined in formula

[0174] - the possible UV irradiation (b) of the product obtained, in order to predominantly obtain the cis isomer.

[0175]

[0061] Said derivatization (a) may be conducted by reacting said compound of formula (Ila) with the appropriate reagent carrying said -(B)m-(R1’)n-Z group, or with a reagent carrying a precursor Z’ of Z followed by further modification of Z’ into Z.

[0176]

[0062] Said derivatization (a) may be conducted by reacting said compound of formula (Ila’) with the appropriate reagent carrying said -(B)m-(R1’)n-Z group, or with a reagent carrying a precursor Z’ of Z followed by further modification of Z’ into Z.

[0063] According to an embodiment, the -(B)m-(R1’)n-Z group may be introduced by reacting a compound of formula (Ila) with the corresponding reagent of formula (Illa):

[0177] Hal-(B)m-(R1’)n-Z (llla) where Hal represents a halogen atom, such as Br, or a salt thereof.

[0178]

[0064] According to an embodiment, the -(B)m-(R1’)n-Z group may be introduced by reacting a compound of formula (Ila’) with the corresponding reagent of formula (Illa’):

[0179] Hal-(B)m-(R1’)n-Z (Illa’) where Hal represents a halogen atom, such as Br, or a salt thereof.

[0180]

[0065] For instance, when Z is -SO2OR, said process comprises reacting the compound of formula (II) with a reagent of formula (lllb):

[0181] Hal-(B)m-(R1’)n'-SO2OR (lllb) or a salt thereof,

[0182] Where Hal is a halogen atom such as Br. Said reaction may be typiacally conducted in an organic solvent, such as acetone, in the presence of a base, such as a weak base, e.g. K2CO3.

[0183]

[0066] For instance, when Z is -SO2OR, said process comprises reacting the compound of formula (IT) with a reagent of formula (lllb’):

[0184] Hal-(B)m-(R1’)n-SO2OR (lllb’) or a salt thereof,

[0185] Where Hal is a halogen atom such as Br. Said reaction may be typiacally conducted in an organic solvent, such as acetone, in the presence of a base, such as a weak base, e.g. K2CO3.

[0186]

[0067] In another instance, where Z is a -COOR group, said process comprises reacting the compound of formula (II’) with a reagent of formula (I He):

[0187] Hal-(B)m-(R1’)n-COOR (lllc) or a salt thereof,

[0188] Where Hal is a halogen atom such as Cl. Said reaction may be typiacally conducted in an organic solvent, such as acetone, in the presence of a base, such as a weak base, e.g. K2CO3.

[0068] In another instance, where Z is a -COOR group, said process comprises reacting the compound of formula (II’) with a reagent of formula (lllc’):

[0189] Hal-(B)m-(R1’)n-COOR (lllc’) or a salt thereof,

[0190] Where Hal is a halogen atom such as Cl. Said reaction may be typiacally conducted in an organic solvent, such as acetone, in the presence of a base, such as a weak base, e.g. K2CO3.

[0191]

[0069] According to another embodiment, the -(B)m-(R1’)n-Z group may be introduced by reacting a compound of formula (II) with the corresponding compound of formula (Hid):

[0192] Hal-(B)m-(R1’)n-Z’ (Hid) where Hal represents a halogen atom, such as Br, and Z’ is a precursor of Z , such as a halogen atom, a NH2 group, or a salt thereof, followed by substituting the Z’ function with the desired Z function.

[0193]

[0070] According to another embodiment, the -(B)m-(R1’)n-Z group may be introduced by reacting a compound of formula (IT) with the corresponding compound of formula (Hid’):

[0194] Hal-(B)m-(R1’)n-Z’ (Hid’) where Hal represents a halogen atom, such as Br, and Z’ is a precursor of Z , such as a halogen atom, a NH2 group, or a salt thereof, followed by substituting the Z’ function with the desired Z function.

[0195]

[0071] Intermediates obtained following reacting a compound (Ha) with a compound (Illa) include the following:

[0073] For instance, when Z represents a -PO3R2 function, said derivatization may be carrying out by reacting a compound of formula (Ila) with the corresponding compound of formula (llle):

[0196] Hal-(B)m-(R1’)n-Br (llle) where B, m are defined as in formula (I) and Hal is a halogen atom, followed by reacting the obtained product with PO3R3 (IVa) where R is defined as in Formula (I), optionally followed when R is H by reacting a cleaving reagent such as bromotrimethylsilane (Br-SiMes).

[0197]

[0074] For instance, when Z represents a -PO3R2 function, said derivatization may be carrying out by reacting a compound of formula (Il’a) with the corresponding compound of formula (lll’e):

[0198] Hal-(B)m-(R1’)n-Br (lll’e) where B, m are defined as in formula (I) and Hal is a halogen atom, followed by reacting the obtained product with PO3R3 (IV’a) where R is defined as in Formula (I’), optionally followed when R is H by reacting a cleaving reagent such as bromotrimethylsilane (Br-SiMes).

[0199]

[0075] In another instance, when Z represents a -N3 function, said derivatization may be carrying out by reacting a compound of formula (Ila) with the corresponding compound of formula (llle):

[0200] Hal-(B)m-(R1’)n’-Br (llle) where B, m are defined as in formula (I), followed by reacting the obtained product with NaNs (IVb).

[0201]

[0076] In another instance, when Z represents a -N3 function, said derivatization may be carrying out by reacting a compound of formula (Il’a) with the corresponding compound of formula (lll’e):

[0202] Hal-(B)m-(R1’)n-Br (lll’e) where B, m are defined as in formula (I’), followed by reacting the obtained product with NaNs (IV’b).

[0203]

[0077] In a still further instance, when Z represents SeCbR, the process may comprise reacting said compound of formula (Ila) with the corresponding compound of formula (llle):

[0204] Hal-(B)m-(R1’)n-Br (llle) where B, m are defined as in formula (I), followed by reacting the obtained product with selenium sodium methoxide hydrazine (IVc), followed by reacting H2O2.

[0205]

[0078] In a still further instance, when Z represents SeCteR, the process may comprise reacting said compound of formula (Il’a) with the corresponding compound of formula (lll’e):

[0206] Hal-(B)m-(R1’)n-Br (lll’e) where B, m are defined as in formula (I’), followed by reacting the obtained product with selenium sodium methoxide hydrazine (IV’ c), followed by reacting H2O2.

[0207]

[0079] The UV irradiation is optional and may be desired when the product obatined following derivatization is in the form of the trans isomer of the N=N bond or in the form of a mixture comprising said trans form.

[0208]

[0080] According to an embodiment, the process of preparation may also comprise the step of preparing a compound of formula (Ila).

[0209]

[0081] According to an embodiment, the process of preparation may also comprise the step of preparing a compound of formula (Il’a).

[0210]

[0082] According to a representative embodiment, preferably when Y is -CH- , the compounds of formula (Ila) may be typically obtained by coupling a compound of formula (A):

[0211] With a compound of formula (B):

[0212]

[0213] Where T, A, X, X’, Y, Y’, R1, R2, n, p, p’ are defined as in Formula (Ila), in the presence of NaNCb and a base, such as NaOH.

[0214]

[0083] According to a representative embodiment, preferably when Y is -CH-

[0215] , the compounds of formula (Il’a) may be typically obtained by coupling a compound of formula (A’):

[0216] With a compound of formula

[0217] Where T, A, X, X’, Y, Y’, R1, R2, n, p, p’ are defined as in Formula (Il’a), in the presence of NaNCb and a base, such as NaOH.

[0218]

[0084] According to an alternative representative embodiment, preferably when Y is -N-, the compounds of formula (Ila) may be typically obtained by alkylating a compound of formula (C):

[0219]

[0220] With a compound of formula (D):

[0221] Where T, A, X, X’, Y, Y’, R1, R2, n, p, p’ are defined as in Formula (Ila), Optionally followed by the deprotection where T is a protecting group Pg.

[0222]

[0085] A suitable amino protecting group is for example as tertbutyloxycarbonyl (BOC).

[0223]

[0086] According to an alternative representative embodiment, preferably when Y is -N-, the compounds of formula (Il’a) may be typically obtained by alkylating a compound of formula (O’):

[0224] With a compound of formula (D’):

[0225] Where T, A, X, X’, Y, Y’, R1, R2, n, p, p’ are defined as in Formula (Il’a),

[0226] Optionally followed by the deprotection where T is a protecting group Pg.

[0087] A suitable ammo protecting group is for example as tertbutyloxycarbonyl (BOC).

[0227]

[0088] Said coupling reaction may typically be conducted in the presence of a base, such as potassium carbonate.

[0228]

[0089] Deprotection may typically be conducted in the presence of an acid, such as trifluoroacetic acid.

[0229]

[0090] The compound of formula (C) may be obtained by coupling a compound of formula (E):

[0230] With a compound of formula (F):

[0231] Where A, X, X’, Y, Y’, R2, p, p’ are defined as in Formula (I), in the presence of an acid, such as a weak acid, preferably acetic acid.

[0232]

[0091] The compound of formula (C’) may be obtained by coupling a compound of formula (E’): (E’)

[0233] With a compound of formula

[0234] Where A, X, X’, Y, Y’, R2, p, p’ are defined as in Formula (I’), in the presence of an acid, such as a weak acid, preferably acetic acid.

[0235]

[0092] The reaction may be conducted in an organic solvent such as a non polar aprotic solvent, or mixtures thereof, for example in a mixture of dichloromethane and chloroform.

[0236]

[0093] Alternatively, compounds of formula (I) and / or (Ila) can be prepared by applying and / or adapting the synthetic method described below in the examples.

[0237]

[0094] Alternatively, compounds of formula (I’) and / or (Il’a) can be prepared by applying and / or adapting the synthetic method described below in the examples.

[0238]

[0095] In general, the starting products, reagents and intermediates of the compounds useful in the invention can be prepared by the application or adaptation of known methods heretofore in use or described in the literature, for example those described by R.C. Larock in Comprehensive Organic Transformations, VCH Publishers, 1989.

[0239]

[0096] In reactions, it may be necessary to protect reactive functional groups, e.g. hydroxy, amino, imino, thio, and carboxy groups, when they are desired in the final product, to avoid their undesirable involvement in the reactions. Traditional protection groups can be used according to standard practice; for examples see T.W. Green and P.G.M. Wuts in "Protective Groups in Organic Chemistry", John Wiley and Sons, 1991 ; J.F.W. McOmie in "Protective Groups in Organic Chemistry", Plenum Press, 1973.

[0240]

[0097] Unless specifically stated, there is no particular restriction on the nature of the solvent to be used, provided that it has no adverse effect on the reaction or on the reagents involved. Examples of suitable solvents include: hydrocarbons, which may be aromatic, aliphatic or cycloaliphatic hydrocarbons, such as hexane, cyclohexane, benzene, toluene and xylene; amides, in particular fatty acid amides, such as dimethylformamide, and ethers, such as diethyl ether and tetrahydrofuran.

[0241]

[0098] Reactions can take place at a wide range of temperatures, typically between about 0°C and 150°C (preferably between about room temperature and about 100°C). The time required for the reaction can also vary considerably, depending on many factors, including the reaction temperature and the nature of the reagents.

[0242]

[0099] The compounds thus prepared can be recovered from the reaction mixture by conventional means. For example, the compounds can be recovered by distilling the solvent from the reaction mixture or if necessary after distilling the solvent from the solution mixture, pouring the remainder into water followed by extraction with a water-immiscible organic solvent, and distilling the solvent from the extract. In addition, the product can, if desired, be further purified by various techniques, such as recrystallization, reprecipitation or various chromatographic techniques, including column chromatography or preparative thin-layer chromatography.

[0243]

[0100] The present invention also relates to the therapeutic indications of the compounds according to the invention.

[0244]

[0101] According to another object, the present invention relates to pharmaceutical compositions comprising a compound of formula (I) and at least one pharmaceutically acceptable excipient.

[0245]

[0102] According to another object, the present invention relates to pharmaceutical compositions comprising a compound of formula (I’) and at least one pharmaceutically acceptable excipient.

[0246]

[0103] According to an embodiment, said composition said compound is predominantly in cis form.

[0247]

[0104] According to another object, the present invention relates to a compound of formula (I) in cis and / or trans form for use in the treatment of cancer.

[0248]

[0105] The compounds of formula (I) below are activatable by ionizing irradiation orendogeneous reactive nitrogen / oxygen species, the cis double bond switching to the active trans form. In this sense, the compounds having a cis configuration may be qualified as pro-drugs of the active compounds having a trans configuration.

[0249]

[0106] According to another object, the present invention relates to a compound of formula (I’) in cis and / or trans form for use in the treatment of cancer.

[0250]

[0107] The compounds of formula (I’) below are activatable by ionizing irradiation, the cis double bond switching to the active trans form. In this sense, the compounds having a cis configuration may be qualified as pro-drugs of the active compounds having a trans configuration.

[0251]

[0108] Said use therefore comprises administering a compound of formula (I), preferably in a predominantly cis form, and applying irradiation to the target site so as to form the trans form compound in situ.

[0252]

[0109] Said use also includes monitoring of the compound biodistribution and / or of the treatment by in vivo MRI, PET, X-ray or SPECT imaging.

[0253]

[0110] According to one embodiment, said use comprises administering an effective amount of a compound of formula (I), preferably in cis form, to a patient in need thereof.

[0254]

[0111] Said use therefore comprises administering a compound of formula (I’), preferably in a predominantly cis form, and applying irradiation to the target site so as to form the trans form compound in situ.

[0255]

[0112] Said use also includes monitoring of the compound biodistribution and / or of the treatment by in vivo MRI, PET, X-ray or SPECT imaging.

[0256]

[0113] According to one embodiment, said use comprises administering an effective amount of a compound of formula (I’), preferably in cis form, to a patient in need thereof.

[0257]

[0114] According to one embodiment, the administration of said compound of formula (I) may generally be carried out parenterally or intravenously.

[0258]

[0115] According to one embodiment, the administration of said compound of formula (I’) may generally be carried out parenterally.

[0116] The ionizing radiation considered generally corresponds to the radiation used in radiotherapy treatments.

[0259]

[0117] Such actions induced by an external stimulus allow temporal and spatial control and can be adjusted on demand in real time to achieve optimal therapeutic efficacy. These include ionizing radiation that that can be used in clinic. Such ionizing radiations include in particular those radiations with energy ranging from 1 keV to 300 MeV, such as photons (X-rays and y-rays with energies ranging from 1 keV to 25 MeV), electrons and hadrons (such as helium, protons or carbons with energies ranging from 1 to 300 MeV, preferably 60 to 300 MeV), and in particular X-rays (1-200 keV), gamma rays (662 keV) and electron beams (4500-7000 keV).

[0260]

[0118] This radiation allows the desired activation to be achieved at low, conventional or high-dose rates, such as FLASH treatment. Preferred doses are low doses of between 0.1 and 20 Gy, particularly between 2 and 20 Gy, more particularly between 2 and 10 Gy, and even more particularly between 2 and 5 Gy.

[0261]

[0119] Without being bound by theory, the compounds of the invention may exert their biological activity through cell killing, protein and / or oligonucleotide targeting, direct or indirect protein destruction or gradation or gene silencing, or other pharmacological effects that are activated by applying radiations and thus inducing molecular changes, from cis to trans configuration.

[0262]

[0120] The therapeutic indication may include various cancers. These include lung cancer, pancreatic cancer, liver cancer, spleen cancer, small cell lung carcinoma, prostate cancer, rhabdomyosarcoma, stomach cancer, gastrointestinal cancer, colorectal cancer, kidney cancer, breast cancer, ovarian cancer, testicular cancer, thyroid cancer, head and neck cancer, skin cancer, soft tissue sarcoma, bladder carcinoma, bone cancers, myeloma, plasmacytoma, germ cell cancer, uterine cancer, leukemia, lymphoma, neuroblastoma, osteosarcoma, retinoblastoma, central nervous system cancers, Wilms' tumors and especially pancreatic cancer or leukemia. The metastases resulting from these cancers could also be addressed similarly.

[0121] According to one embodiment, the compounds of the invention may be administered in combination with one or more anti-cancer agents, e.g. chemotherapy or immunotherapy such as immune checkpoint inhibitors like anti- CTLA4, anti-PD-L1 and anti-PD1.

[0263]

[0122] "Effective amount" means an amount of a compound / composition according to the present invention effective at producing the desired therapeutic effect.

[0264]

[0123] "Formulations suitable for parenteral administration" means formulations that are in a form suitable for parenteral administration to a patient. Formulations are sterile and include emulsions, suspensions, aqueous and nonaqueous injection solutions, which may contain suspending and thickening agents and anti-oxidants (after checking that the potentially radioprotective effect of these does not prevent the desired effect under radiation), buffers, bacteriostats and solutes that make the formulation isotonic, and have a pH adjusted appropriately, with the desired recipient blood.

[0265]

[0124] The formulation is preferably administered by injection, including transmuscular, intravenous, intraperitoneal, and subcutaneous. For injection, the useful compounds according to the invention can be formulated in liquid solutions, preferably in physiologically compatible buffers such as Hank's solution or Ringer's solution. In addition, the compounds can be formulated in solid form and redissolved or suspended immediately before use. Freeze-dried forms are also included.

[0266]

[0125] The choice of vehicle and the content of the active substance in the vehicle are generally determined by the solubility and chemical properties of the active compound, the particular mode of administration and the provisions to be observed in pharmaceutical practice.

[0267]

[0126] The formulations may be prepared in individual pharmaceutical form by any of the methods well known in the art of pharmacy. These methods include the step of combining the active ingredient and the carrier which constitutes one or more accessory ingredients. In general, formulations are prepared by uniformly and intimately combining the active ingredient and liquid carriers or finely fractionated solid carriers or both and then, if necessary, shaping the product.

[0127] The actual dosage levels of an active ingredient in the compositions of the invention may vary in order to obtain an effective amount of active ingredient to achieve a desired therapeutic response for a particular composition and mode of administration. The dosage level chosen therefore depends on the desired therapeutic effect, the mode of administration, the desired duration of treatment, and other factors.

[0268]

[0128] The dosage unit compositions may contain such quantities of such sub-multiples thereof as may be used to constitute the daily dose. It will be understood, however, that the specific dose level for any particular patient will depend on a variety of factors including body weight, general health, gender, diet, timing and method of administration, rates of absorption and excretion, combination with other drugs and the severity of the disease being treated.

[0269]

[0129] The amount of each component administered is determined by the treating physicians taking into account the etiology and severity of the disease, the condition and age of the patient, the potency of each component and other factors.

[0270]

[0130] Formulations can be presented in single- or multi-dose containers, e.g. ampoules and vials sealed with elastomeric closures, and can be stored in freeze- dried form requiring only the addition of a sterile liquid carrier, e.g. water for injections, just prior to use. Extemporaneously prepared solutions in injections and suspensions may be prepared from sterile powders, granules and tablets of the type described above.

[0271]

[0131] "Liquid dose form" means that the dose of the active compound to be administered to the patient is in liquid form, for example, emulsions, solutions, suspensions, syrups and pharmaceutically acceptable elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art, such as water or other solvents, solubilizing agents and emulsifiers, e.g. ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1 ,3-butylene glycol, dimethylformamide, oils (after checking that the potentially radioprotective effect of these does not prevent the desired effect under radiation), in particular cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil and sesame oil, glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and sorbitan fatty acid esters or mixtures of these substances, and the like.

[0272]

[0132] "Patient" includes both a human and other mammals.

[0273]

[0133] "Pharmaceutical composition" means a composition comprising a compound of formula I and at least one component selected from the group consisting of pharmaceutically acceptable carriers, diluents, adjuvants, excipients, or vehicles, such as preservatives, fillers, wetting agents, emulsifying agents, suspending agents, antibacterial agents, antifungal agents, lubricating agents, and dispersing agents, depending on the nature of the mode of administration and the dosage forms Examples of suspending agents include ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminium metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances. Prevention of the action of microorganisms can be provided by various antibacterial and antifungal agents, e.g. parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride, and the like. Examples of suitable carriers, diluents, solvents or vehicles include water, ethanol, polyols, suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate.

[0274]

[0134] "Pharmaceutically acceptable" means that it is, within the scope of sound medical judgement, suitable for use in contact with human and lower animal cells without undue toxicity, irritation, allergic response or the like, and is commensurate with a reasonable risk / benefit ratio.

[0275]

[0135] The term "pharmaceutically acceptable salts" refers to the relatively non-toxic inorganic and organic acid addition salts and base addition salts of the compounds of the present invention. These salts can be prepared in situ during the final isolation and purification of the compounds. In particular, acid addition salts can be prepared by separately reacting the purified compound in its purified form with an organic or inorganic acid and isolating the resulting salt. Examples of acid addition salts include the salts described by, for example, S.M. Berge et al. "Pharmaceutical Salts" J. Pharm. Sci, 66:p.1-19 (1977). Acid addition salts can also be prepared by separately reacting the purified compound in its acid form with an organic or inorganic base and isolating the resulting salt. Suitable inorganic base addition salts are prepared from metal bases which include sodium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminium hydroxide, lithium hydroxide, magnesium hydroxide, and zinc hydroxide. Suitable base amino addition salts are prepared from amines that have sufficient alkalinity to form a stable salt, and preferably include those amines that are often used in medicinal chemistry due to their low toxicity and acceptability for medical use.

[0276]

[0136] It should be understood that the present invention covers all suitable combinations of the particular and / or preferred individual embodiments mentioned herein.

[0277] Brief description of the figures:

[0278]

[0137] Figure 1 shows the absorbance difference (365 nm) of medium containing different compounds (50 pM) before and after gamma-ray irradiation (a) or without any irradiation (b). c,d : Examples of absorbance spectra of the cisisomer compounds Z=SO3' (c) and Z=PO32' (d) recorded after gamma-ray irradiation at 2, 5, 10 and 20 Gy. The photostationary states 1 (PSS1) and 2 (PPS2) are defined for the c / s-isomer and trans-isomer major respectively. OD: optical density.

[0279]

[0138] Figure 2 shows the chemical structures of the compounds assessed for activation upon ionizing radiation and cytotoxicity.

[0280]

[0139] Figure 3 shows a table enumerating the structures of compounds derived from the formula (I), associated with a reference number. The atoms or chemical groups A, B, X, Y, Z, R1and R2are related to the ones in Figure 2.

[0281]

[0140] Figure 4 shows the activation of the c / s-isomers of compounds 1 , 2, 3, 4 and 5 (50 pM, cf. Figure 3) in phosphate buffer (10 mM, pH 7.4) upon electron beam (5 MeV). Activation was determined by subtracting the residual transisomer present in the starting material (primarily c / s-isomer) and the trans-isomer produced through thermal back relaxation. The degradation of compounds was not considered (about 12-25% at 20 Gy).

[0282]

[0141] Figure 5 shows the relative absorbance difference of the c / s-isomers of compounds 9, 19, 12, 1 and 14 (a, cf. Figure 3) at their respective Amax in PBS (50 pM) before and after electron beam irradiation or without any irradiation (b). The relative optical density (OD) difference was obtained by dividing the OD difference before and after electron beam irradiation at 2, 5, 10 and 20 Gy by the OD difference before and after UV light exposure (5 min, 365 nm, 0.817 mW.cnr2).

[0283]

[0142] Figure 6 shows the relative absorbance difference of the c / s-isomers of compounds 26, 27, 28, 25, 8, 17, 23 and 21 (a, cf. Figure 3) and of compounds 11 , 24, 13, 18, 6, 7, 9, 20, 22, 15 and 16 (c, cf. Figure 3) at their respective Amax in chloroform (50 pM) before and after electron beam irradiation or without any irradiation (b, d). The relative optical density (OD) difference was obtained by dividing the OD difference before and after electron beam irradiation at 2, 5, 10 and 20 Gy by the OD difference before and after UV light exposure (5 min, 365 nm, 0.817 mW.cm’2).

[0284]

[0143] Figure 7 shows the absorbance spectra of the c / s-isomers of compound 9 (a in chloroform, c in PBS, cf. Figure 3) and of compound 14 (e in chloroform, g in PBS, cf. Figure 3) recorded before and after electron beam irradiation or without any irradiation (b, d and f, h). PSS1 ( / s major) was obtained by irradiation of the starting material (SM, trans major) upon UV (5 min, 365 nm, 0.817 mW.cm’2). Due to solubility issues of 14 in chloroform, its activation could only be qualitatively observed under electron beam irradiation.

[0285]

[0144] Figures 8 shows the absorbance spectra of the c / s-isomers of compounds 17 (a), 12 (c), 16 (e) and 29 (g) (cf. Figure 3) recorded before and after electron beam irradiation or without any irradiation (b, d, f, h). PSS1 (cis major) was obtained by irradiation of the starting material (SM, trans major) upon UV (5 min, 365 nm, 0.817 mW.cm’2). Due to solubility issues of 29 in chloroform, its activation could only be qualitatively observed under electron beam irradiation. The activation of non-alkylated arylazopyrazole structures such as compound 16 was probably associated with a prototropic effect resulting in a Amax shift systematically observed under electron beam irradiation for these structures.

[0286]

[0145] Figures 9 shows the cell viability of cancer cells (PANC-1 in the upper part, A549 in the lower part) 3 days after treatment with solutions of compounds 19, 23 and 17 (cf. Figure 3) in both cis and trans configurations at 0, 25, 50, 100, 200 μM.

[0287]

[0146] Figures 10 shows the cell viability of cancer cells (PANC-1 in the upper part, A549 in the lower part) 3 days after treatment with solutions of compounds 9 and 14 (cf. Figure 3) in both cis and trans configurations at 0, 25, 50, 100, 200 μM.

[0288]

[0147] Examples

[0289]

[0148] All the refrence numbers of molecules used in the description of syntheses are not related to the refrence numbers of molecules used to identifyied them in the caracterisation experiments (activation upon ionizing radiation and cytotoxicity). The refrence numbers of molecules used to identifyied them in the caracterisation experiments are described in Figure 3.

[0290]

[0149] Synthesis of 4-hydroxy-4’-butoxyazobenzene (1 )

[0291] 4-butoxyaniline (2.00 mL, 12.0 mmol) and sodium nitrite (0.854 g, 12.0 mmol, I .O equiv) were dissolved in ethanol:water 1 :1 (24 mL) and the mixture was cooled down to 0 °C. Ice (12 g) was introduced in the mixture before careful addition of HCI cc (2.6 mL). An aqueous solution (6.3 mL) of phenol (1.14 g, 12.0 mmol, I .O equiv) and NaOH (0.960 g, 24.0 mmol, 2.0 equiv) previously prepared and cooled down to 0 °C was carefully introduced in the mixture at 0 °C. The mixture was stirred for 20 min at 0 °C and for 70 min at rt. After adjusting the pH to 1 (HCI cc), the mixture was left to stand for 30 min at rt and was then filtrated. The precipitate was washed with water (4x50 mL), solubilised in DCM and the organic solvent was dried over MgSO4 before concentration. 1 (2.76 g, 10.2 mmol, 85%) was isolated as a black amorphous powder.

[0292] 1H NMR (400 MHz, CDCI3) δ (ppm): 7.87 (d, J = 8.9 Hz, 2H), 7.82 (d, J = 8.8 Hz, 2H), 6.98 (d, J = 8.9 Hz, 2H), 6.91 (d, J = 8.8 Hz, 2H), 4.03 (t, J = 6.5 Hz, 2H), 1 .85 - 1 .75 (m, 2H), 1 .58 - 1 .45 (m, 2H), 0.99 (t, J = 7.4 Hz, 3H).

[0293] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.51 , 158.38, 146.89, 146.63, 124.81 , 124.56, 116.07, 114.92, 68.22, 31.35, 19.33, 13.96.

[0294]

[0150] Synthesis of 2-(4-((4- butoxyphenyl)diazenyl)phenoxy)ethanesulfonate (2)

[0295] 1 (1.00 g, 3.70 mmol) and potassium carbonate (1.07 g, 7.77 mmol, 2.0 equiv) were dissolved in acetone: MilliQ water 97:3 (12.5 mL). After 15 min stirring at rt, sodium 2-bromoethanesulphonate (2.34 g, 11.1 mmol, 3 equiv) and potassium iodide (6.14 g, 4.09 mL, 36.9 mmol, 10 equiv) were introduced in the mixture and the reaction was left stirring at reflux (70 °C) for 48 h. Then, cold acetone was added to the mixture, and the precipitate was isolated and washed with cold acetone and diethyl ether. The crude was solubilized in DMSO and purified by reverse phase flash chromatography. 2 (75 mg, 0.2 mmol, 5%) was isolated as an electrostatic yellow powder.

[0296] 1H NMR (300 MHz, DMSO-d6) δ (ppm): 7.83 (d, J=8.9, 4H), 7.09 (d, J=8.9, 4H), 4.30 (t, 2H), 4.07 (t, J=6.5, 2H), 2.94 (t, 2H), 1 .79 - 1 .67 (m, 2H), 1 .53 - 1 .38 (m, 2H), 0.94 (t, J=7.4, 3H).

[0297] 13C NMR (75 MHz, DMSO-d6) δ (ppm): 160.98, 160.58, 146.19, 146.12, 124.21 , 124.20, 115.02, 114.99, 67.67, 65.04, 50.36, 30.72, 18.77, 13.76.

[0298]

[0151] Synthesis of 1-(4-(2-bromoethoxy)phenyl)-2-(4- butoxyphenyl)diazene (3)

[0299] 1 1 ,2-dibromoethane 90 C, overnight

[0300] 3

[0301] 1 (6.79 g, 25.1 mmol) and K2CO3 (11.0 g, 79.9 mmol, 3.2 equiv) were dissolved in anhydrous DMF (75 mL) under argon atmosphere. After 30 min stirring at rt, 1 ,2-dibromoethane (76.1 g, 35.0 mL, 405 mmol, 16 equiv) was introduced in the mixture and the reaction was stirred at 90 °C overnight. DMF was evaporated, and the crude was extracted with DCM. The organic phase was washed with water and dried over MgSO4 before concentration. 3 was purified by flash column chromatography (silica gel, cyclohexane:AcOEt gradient 100:0 to 80:20) and was isolated as an electrostatic orange powder (3.71 g, 9.83 mmol, 40%).

[0302] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.88 (d, J=9.0, 2H), 7.87 (d, J=9.0, 2H), 7.02 - 6.98 (m, 4H), 4.36 (t, J=6.3, 2H), 4.04 (t, J=6.5, 2H), 3.67 (t, J=6.3, 2H), 1 .85 - 1 .76 (m, 2H), 1 .56 - 1 .46 (m, 2H), 1 .00 (t, J=7.4, 3H).13C NMR (75 MHz, CDCI3) 5 (ppm): 161.47, 160.02, 147.64, 146.96, 124.55, 124.48, 115.00, 114.80, 68.15, 68.11 , 31.39, 28.99, 19.37, 14.01.

[0303]

[0152] Synthesis of [4-(2-azidoethoxy)phenyl](4-butoxyphenyl)diazene

[0304] (4)

[0305] 3 (307 mg, 0.810 mmol) and sodium azide (72.7 mg, 0.037 mL, 1.07 mmol, 1.3 equiv) were mixed in DMF (2.87 mL) and heated at 80 °C overnight under argon atmosphere. DMF was evaporated, and the crude was extracted with DCM. The organic phase was washed with water and dried over MgSO4 before concentration. 4 was isolated as an amorphous orange powder (225 mg, 0.663 mmol, 82%).

[0306] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.88 (d, J=9.0, 2H), 7.87 (d, J=9.0, 2H), 7.02 (d, J=9.0, 2H), 6.99 (d, J=9.0, 2H), 4.23 (t, J=5.0, 2H), 4.04 (t, J=6.5, 2H), 3.65 (t, J=5.0, 2H), 1 .85 - 1 .76 (m, 2H), 1 .58 - 1 .46 (m, 2H), 1 .00 (t, J=7.4, 3H).

[0307] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.47, 160.16, 147.63, 146.97, 124.55, 124.48, 114.89, 114.81 , 68.15, 67.31 , 50.27, 31.39, 19.38, 14.01.

[0308]

[0153] Synthesis of diethyl (2-(4-((4- butoxyphenyl)diazenyl)phenoxy)ethyl)phosphonate (5)

[0309] 3 triethyl phosphite

[0310] 5

[0311] 3 (220 mg, 0.580 mmol) and triethyl phosphite (9.69 g, 10.0 mL, 58.3 mmol, 100 equiv) was stirred at 100 °C for 72 h under argon atmosphere. T riethyl phosphite was then evaporated and the crude was purified by flash chromatography (silica gel, cyclohexane:AcOEt gradient 40:60 to 0:100). The compound 5 (208 mg, 0.480 mmol, 82%) was obtained as a light orange oil.

[0312] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.86 (2d, J=8.9, 4H), 6.99 (d, J=8.8, 2H), 6.98 (d, J=8.9, 2H), 4.35 - 4.26 (m, 2H), 4.22 - 4.09 (m, 4H), 4.03 (t, J=6.6, 2H), 2.40 - 2.29 (m, 2H), 1 .85 - 1 .75 (m, 2H), 1 .58 - 1 .48 (m, 2H), 1 .36 (t, J=7.1 , 6H), 0.99 (t, J=7.4, 3H).

[0313] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.41 , 160.19, 147.44, 146.96, 124.50, 124.45, 114.82, 114.78, 68.12, 62.50, 62.04 (d,2JP-c=6.4), 31.38, 26.75 (d,1JP. c=140.7), 19.36, 16.61 (d,3JP-C=6.1), 14.00.

[0154] Synthesis of diethyl (2-(4-((4- butoxyphenyl)diazenyl)phenoxy)ethyl)phosphonate (6) Bromotrimethylsilane (4.64 g, 4.00 mL, 30.3 mmol, 70 equiv) was added to a solution of 5 (188 mg, 0.43 mmol) in DCM (10 mL) at 0 °C under argon. A rapid change into red-brownish color was observed. The mixture was then warm to 25 °C and stirred for 72 h. Then, the mixture was concentrated, and water (30 mL) was added to the yellow oily liquid and stirred for 30 min. The crude was then purified by reverse phase flash chromatography (silica gel C18, hLCLMeCN 100:0 to 0: 100). 6 was obtained as a yellow amorphous powder (100 mg, 0.264 mmol, 61 %).

[0314] 1H NMR (300 MHz, DMSO-d6) δ (ppm): 7.79 (2d, J=8.7, 4H), 7.06 (2d, J=9.0, 4H), 4.28 - 4.20 (m, 2H), 4.04 (t, J=6.5, 2H), 2.10 - 1 .98 (m, 2H), 1 .77 - 1 .68 (m, 2H), 1.51 - 1.39 (m, 2H), 0.94 (t, J=7.4, 3H).

[0315] 13C NMR (75 MHz, DMSO-d6) δ (ppm): 160.95, 160.53, 146.17, 146.10, 124.20, 124.18, 114.99, 114.95, 67.66, 64.24, 30.72, 28.81 (determined by HMQC), 18.76, 13.75.

[0316]

[0155] Synthesis 1,2-bis(2-(4-((4- butoxyphenyl)diazenyl)phenoxy)ethyl)diselane (7) selenium sodium methoxyde rt 3 h

[0317] 3 (103 mg, 0.272 mmol) was added to a freshly prepared DMSO solution (0.43 mL) of selenium (53.6 mg, 0.679 mmol, 2.5 equiv) in the presence of sodium methoxide (18.5 mg, 0.342 mmol, 1.3 equiv) and aqueous hydrazine (95%, 5.5 mg, 0.10 mmol, 0.3 equiv) under argon atmosphere. The mixture was stirred for 3 h at rt. The solvent was evaporated, and the crude was extracted with DCM. The organic phase was washed with water and dried over MgSO4 before concentration. The crude product was purified by flash column chromatography (silica gel, cyclohexane: AcOEt 99:1 to 70:30). 7 was isolated as an orange amorphous powder (78.3 mg, 0.102 mmol, 75%).

[0318] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.85 (2d, J=8.8, 4H), 6.99 (d, J=8.6, 2H), 6.97 (d, J=8.6, 2H), 4.38 - 4.36 (t, J=6.8, 4H), 4.03 (t, J=6.5, 4H), 3.32 (t, J=6.8, 4H), 1 .85 - 1 .76 (m, 4H), 1 .57 - 1 .46 (m, 4H), 1 .00 (t, J=7.4, 6H).

[0319] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.40, 160.31 , 147.46, 147.00, 124.53, 124.50, 114.95, 114.78, 68.14, 68.09, 31.40, 28.09, 19.38, 14.01.

[0320]

[0156] Synthesis of 2-(4-((4- butoxyphenyl)diazenyl)phenoxy)ethaneselenonic acid (8)

[0321] Hydrogen peroxide (69 mg, 0.048 mL, 0.61 mmol, 5 equiv) was added to a suspension of 7 (92 mg, 0.12 mmol) in DCM (1.2 mL) at 0 °C and the mixture was stirred for 1 h at rt. Hydrogen peroxide (69 mg, 0.048 mL, 0.61 mmol, 5 equiv) was then added to the mixture which was stirred for 1 h more at rt. The crude was then concentrated and solubilized in MeOH before purification by reverse phase flash chromatography (solid deposit, gradient from H2O:MeOH 95:5 to 5 / 95). 8 was isolated as an orange amorphous powder (5.0 mg, 0.012 mmol, 10%).

[0322] 1H NMR (300 MHz, DMSO-d6) δ (ppm): 7.83 (2d, J=8.7, 4H), 7.11 (d, J=8.7, 2H), 7.08 (d, J=8.9, 2H), 4.45 (bs, 2H), 4.07 (t, J=6.5, 2H), 3.24 (determined by COSY, masked by H2O signal, 2H), 1.78 - 1.68 (m, 2H), 1.52 - 1.39 (m, 2H), 0.95 (t, J=7.4, 3H).

[0323] 13C NMR (75 MHz, DMSO-d6) δ (ppm): 161.02, 160.23, 146.37, 146.10, 124.22, 124.17, 115.17, 114.99, 67.67, 62.92, 54.77, 30.70, 18.75, 13.87 (determined by HMQC).

[0324]

[0157] Synthesis of 2-(4-((4-butoxyphenyl)diazenyl)phenoxy)propanoic acid (9)

[0325] Chloropropionic acid

[0326] Aceto n 60 °C

[0327] 1 (1.00 g, 3.70 mmol) and potassium carbonate (2,31 g, 16,7 mmol, 4.5 equiv) were dissolved acetone (10 mL) under argon and the mixture was stirred for 30 min at rt. Chloropropionic acid (1.20 g, 14.8 mmol, 4.0 equiv) was then added and the mixture was stirred at reflux (60 °C) for 15 h. A second addition of chloropropionic acid (401 mg, 1 equiv) was carried out to the mixture which was stirred at reflux (60 °C) for 5 h more. The mixture was then cold to 0 °C and filtrated. The precipitate was successively washed with 3x50 mL of cold diethyl ether, basic aqueous solution (0.4 M NaOH, 250 mL) and neutral water (500 mL). The precipitate was then introduced into an acidic aqueous solution (1 M HCI, 100 mL) and was extracted with DCM (100 mL). The organic phase was successively washed with acidic aqueous solution (1 M HCI, 3x50 mL) and neutral water (5x100 mL). 9 was isolated as an amorphous yellow powder (582 mg, 1.70 mmol, 46%).

[0328] 1H NMR (400 MHz, MeOD) δ (ppm) 7.86 (2d, J=0.5, 4H), 7.09 (2d, J=2, 4H), 7.09 (2d, J=2, 4H), 4.35 (t, J=2, 2H), 4.11 (t, J=2, 2H), 2.73 (t, J=2, 2H), 1.74 - 1.93 (m, J=2, 2H), 1 .53 - 1 .68 (m, J=2, 2H), 1 .05 (t, J=2.5, 3H).

[0329] 13C NMR (100 MHz, CDCI3) δ (ppm) = 178.91 , 162.78, 162.74, 148.21 , 125.27, 25.22, 115.85, 115.75, 69.09, 66.93, 38.73, 32.46, 20.30, 14.17.

[0330]

[0158] Synthesis of 4-hydroxy-4’-pentylazobenzene (14)

[0331] 4-pentylaniline (12.0 mmol) and sodium nitrite (12.0 mmol, 1.0 equiv.) were dissolved in ethanokwater 1 :1 (24 mL) and the mixture was cooled down to 0 °C. Ice (12 g) was introduced in the mixture before careful addition of HCI (37%, 2.6 mL). An aqueous solution (6.3 mL) of phenol (12.0 mmol, 1 .0 equiv.) and sodium hydroxide (24.0 mmol, 2.0 equiv.) previously prepared and cooled down to 0 °C was carefully introduced in the mixture at 0 °C. The mixture was stirred for 20 min at 0 °C and for 70 min at rt. After adjusting the pH to 1 (HCI 37%), the mixture was left to stand for 30 min at rt and was then filtrated. The precipitate was washed with water (4x50 mL), solubilised in dichloromethane and the organic solvent was dried over MgSO4 before concentration (14) (10.2 mmol, 85%) was isolated as a black amorphous powder.

[0332] 1H NMR (400 MHz, CDCI3) δ (ppm): 7.86 (d, J = 8.9 Hz, 2H), 7.79 (d, J = 8.4 Hz, 2H), 7.30 (d, J = 8.4 Hz, 2H), 6.93 (d, J = 8.9 Hz, 2H), 5.15 (s, 1 H), 2.67 (t, J = 8.0 Hz, 2H), 1.66 (dt, J = 15.0, 7.5 Hz, 2H), 1.42 - 1.24 (m, 4H), 0.90 (t, J = 7.0 Hz, 3H).

[0333] HRMS (m / z): calc, for C17H20N2O, 269.1648 ([M+H]+). Found 269.1640.

[0334]

[0159] Synthesis of 4-(A / -(tert-butyloxycarbonyl)-ethoxyamine)-4’- pentylazobenzene (15)

[0335] (14) (3.2 mmol) and potassium carbonate (4.8 mmol, 1.5 equiv.) were dissolved in acetone (25 mL). After 30 min stirring at rt under argon, tert-butyl N-(2- bromoethyl)carbamate (9.6 mmol, 3.0 equiv.) was introduced in the mixture. After stirring at reflux for 18 h, the mixture was concentrated and the product (15) was isolated by flash chromatography (SiO2, dichloromethane) as a yellow amorphous powder (1.48 mmol, 46%).

[0336] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.00 (d, J = 9.0 Hz, 2H), 7.88 (d, J = 8.4 Hz, 2H), 7.40 (d, J = 8.4 Hz, 2H), 7.09 (d, J = 9.0 Hz, 2H), 5.10 (s, 1 H), 4.20 (t, J = 5.1 Hz, 2H), 3.73 - 3.61 (m, 2H), 2.77 (t, J = 7.5 Hz, 2H), 1 .83 - 1 .69 (m, 2H), 1 .55 (s, 9H), 1.50 - 1 .37 (m, 4H), 1 .00 (t, J = 6.9 Hz, 3H).

[0337] HRMS (m / z): calc, for C24H34N3O3, 412.2595 ([M+H]+). Found 412.2602.

[0338]

[0160] Synthesis of 4-aminoethoxy-4’-pentylazobenzene (16)

[0339] (15) (1.65 mmol) was dissolved in dichloromethane:trifluoroacetic acid 4:1 (34 mL) and the mixture was stirred for 1.5 h at rt. After concentration, diethyl ether (100 mL) was introduced and the formed precipitate was crushed for 20 min before filtration and washed with diethyl ether (4x25 mL). (16) (1.64 mmol, 99%, TFA salt) was isolated as a yellow amorphous powder.

[0340] 1H NMR (300 MHz, MeOD) δ (ppm): 7.92 (d, J = 9.0 Hz, 2H), 7.80 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.4 Hz, 2H), 7.17 (d, J = 9.0 Hz, 2H), 4.34 (t, J = 5.1 Hz, 2H), 3.42 (t, J = 5.1 Hz, 2H), 2.71 (t, J = 7.8 Hz, 2H), 1 .68 (m, 2H), 1 .44 - 1 .29 (m, 4H), 0.93 (t, J = 7.0 Hz, 3H).

[0341] HRMS (m / z): calc, for C19H26N3O, 312.2070 ([M+H]+). Found 312.2076.

[0342]

[0161] General protocols for the synthesis of the arylazo- dimethylpyrazole derivatives

[0343]

[0162] General protocol for the synthesis of the arylazo- dimethylpyrazole derivatives (17 and 18)

[0344] Aniline (12.00 mmol) was dissolved in acetic acid (18 mL) and HCI (37%, 2.8 mL) was added before cooling the mixture to 0 °C. A solution of sodium nitrite (14.00 mmol, 1.2 equiv.) dissolved in a minimum volume of water was added to the mixture. Sodium acetate (36.00 mmol, 3 equiv.) was added to a solution of 2-4- pentanedione (15.60 mmol, 1.3 equiv.) in EtOH:H2O 3:2 (24 mL). The two solutions were mixed and stirred for 1 h at rt. A precipitate was formed and was collected by filtration. It was successively washed with water, EtOH / H2O 1 :1 and hexane. Product (17) was dried and used without further purification (yields from 33% to quantitative).

[0345] (17) (12.00 mmol) was dissolved in EtOH (12 mL) and hydrazine monohydrate (12.0-18.0 mmol, 1 .0-1.5 equiv.) was added in the mixture before heating at 80°C during 18 h. The mixture was then concentrated, and dissolved into dichloromethane before washing the organic phase with water. The organic phase was dried over MgSO4, filtered and concentrated to obtain the product (18) as a dry amorphous powder (yields from 93% to quantitative).

[0346]

[0163] General protocol for the alkylation of the arylazo- dimethylpyrazole derivatives (19)

[0347] In a solution of (18) (3.20 mmol) in acetone (13 mL), tert-butyl N-(2- bromoethyl)carbamate (4.80 mmol, 1.5 equiv.) and potassium carbonate (9.60 mmol, 3 equiv.) were added and the mixture was stirred upon argon atmosphere at reflux for 5 to 18 h before concentration. The crude was then purified by flash column chromatography (SiCk) and the protected alkylated arylazo- dimethylpyrazole derivative (19) was isolated as a brown powder (yields from 60% to 69%).

[0348]

[0164] General protocol for the deprotection of the alkylated arylazo- dimethylpyrazole derivatives (20) The protected arylazo-dimethylpyrazole derivative (19) (1.6 mmol) was solubilized in dichloromethane:trifluoroacetic acid (8:2, 34 mL) and was stirred at rt for 1 to 3 h before concentration. Diethylether (200 mL) was then introduced to concretize a precipitate which was isolated by filtration to isolate the unprotected alkylated arylazo-dimethylpyrazole derivative (20) (90% to quantitative yields).

[0349]

[0165] Compound 17 with A = Oand X = H

[0350] 1H NMR (300 MHz, CDCI3) δ (ppm): 14.92 (s, 1 H), 7.37 (d, J = 9.0 Hz, 2H), 6.95 (d, J = 9.0 Hz, 2H), 4.00 (t, J = 6.5 Hz, 2H), 2.62 (s, 3H), 2.49 (s, 3H), 1.86 - 1 .74 (m, 2H), 1 .60 - 1 .45 (m, 2H), 1 .01 (t, J = 7.4 Hz, 3H).

[0351] HRMS (m / z): calc, for C15H21N2O3, 277.1547 ([M+H]+). Found 277.1542.

[0352]

[0166] Compound 17 with A = Cand X = H

[0353] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.33 (d, J = 8.6 Hz, 2H), 7.21 (d, J = 8.4 Hz, 2H), 2.61 (t, J = 7.7 Hz, 2H), 2.60 (s, 3H), 2.48 (s, 3H), 1.62 (m, 2H), 1.41 - 1.24 (m, 4H), 0.89 (t, J = 6.9 Hz, 3H).

[0354] HRMS (m / z): calc, for Ci6H22N2NaO2, 297.1573 ([M+Na]+). Found 297.1585.

[0355]

[0167] Compound 17 with A = Oand X = F

[0356] 1H NMR (300 MHz, CDCI3) δ (ppm): 14.49 (s, 1 H), 6.58 (d, J = 10.5 Hz, 2H), 3.96 (t, J = 6.5 Hz, 2H), 2.62 (s, 3H), 2.41 (s, 3H), 1 .80 (m, 2H), 1 .59 - 1 .41 (m, 2H), 1.01 (t, J = 7.4 Hz, 3H).

[0357] HRMS (m / z): calc, for Ci5Hi8F2N2NaO3, 335.1178 ([M+Na]+). Found 335.1182.

[0358]

[0168] Compound 18 with A = Oand X = H

[0359] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.80 (d, J = 9.0 Hz, 2H), 6.99 (d, J = 9.0 Hz, 2H), 4.05 (t, J = 6.5 Hz, 2H), 2.58 (s, 6H), 1 .89 - 1 .72 (m, 2H), 1 .62 - 1 .46 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H).

[0360] HRMS (m / z): calc, for C15H21N4O, 273.1710 ([M+H]+). Found 273.1715.

[0361]

[0169] Compound 18 with A = Cand X = H

[0362] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.64 (d, J = 8.4 Hz, 2H), 7.20 (d, J = 7.4 Hz, 2H), 2.59 (t, J = 7.8 Hz, 2H), 2.52 (s, 6H), 1 .64 - 1 .51 (m, 2H), 1 .32 - 1 .16 (m, 4H), 0.83 (t, J = 6.8 Hz, 3H).13C NMR (75 MHz, CDCI3) δ (ppm): 151.79, 144.88, 134.71 , 129.15, 128.93, 121.77, 35.78, 31.46, 31.09, 22.55, 14.03, 12.15.

[0363] HRMS (m / z): calc. for C16H23N4, 271.1917 ([M+H]+). Found 271.1909.

[0364]

[0170] Compound 18 with A = O and X = F

[0365] 1H NMR (300 MHz, CDCI3) δ (ppm): 6.55 (d, J = 10.8 Hz, 2H), 4.00 (t, J = 6.5 Hz, 2H), 2.56 (s, 6H), 1.92 - 1 .68 (m, 2H), 1 .63 - 1 .39 (m, 2H), 1 .01 (t, J = 7.3 Hz, 3H).

[0366] HRMS (m / z): calc, for C15H19F2N4O, 309.1521 ([M+H]+). Found 309.1507.

[0367]

[0171] Compound 19 with A = Oand X = H

[0368] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.76 (d, J = 9.0 Hz, 2H), 6.96 (d, J = 9.0 Hz, 2H), 4.15 (t, J = 5.6 Hz, 2H), 4.03 (t, J = 6.5 Hz, 2H), 3.62 - 3.49 (m, 2H), 2.56 (s, 3H), 2.49 (s, 3H), 1 .87 - 1 .71 (m, 2H), 1 .54 - 1 .46 (m, 2H), 1 .44 (s, 9H), 0.99 (t, J = 7.4 Hz, 3H).

[0369] HRMS (m / z): calc, for C22H34N5O3, 416.2656 ([M+H]+). Found 416.2653.

[0370]

[0172] Compound 19 with A = Cand X = H

[0371] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.70 (d, J = 8.4 Hz, 2H), 7.26 (d, J = 8.4 Hz, 2H), 4.15 (t, J = 5.6 Hz, 2H), 3.64 - 3.52 (m, 2H), 2.66 (t, J = 7.8 Hz, 2H), 2.57 (s, 3H), 2.49 (s, 3H), 1.71 - 1 .60 (m, 2H), 1 .44 (s, 9H), 1 .44 - 1 .26 (m, 4H), 0.90 (t, J = 6.8 Hz, 3H).

[0372] HRMS (m / z): calc, for C23H36N5O2, 414.2864 ([M+H]+). Found 414.2872.

[0373]

[0173] Compound 19 with A = O and X = F

[0374] 1H NMR (400 MHz, MeOD) δ (ppm): 6.70 (d, J = 11 .0 Hz, 2H), 4.19 (t, J = 5.7 Hz, 2H), 4.08 (t, J = 6.4 Hz, 2H), 3.48 (t, J = 5.7 Hz, 2H), 2.59 (s, 3H), 2.44 (s, 3H), 1 .90 - 1 .73 (m, 2H), 1 .54 (m, 2H), 1.45 (s, 9H), 1 .04 (t, J = 8.8 Hz, 3H).

[0375] HRMS (m / z): calc, for C22H32F2N5O3, 452.2468 ([M+H]+). Found 452.2457.

[0376]

[0174] Compound 20 with A = O and X = H

[0377] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.78 (d, J = 9.0 Hz, 2H), 6.98 (d, J = 9.0 Hz, 2H), 4.17 (t, J = 5.6 Hz, 2H), 4.05 (t, J = 6.5 Hz, 2H), 3.60 - 3.51 (m, 2H), 2.59 (s, 3H), 2.52 (s, 3H), 1 .89 - 1 .74 (m, 2H), 1.59 - 1 .50 (m, 2H), 1 .01 (t, J = 7.4 Hz, 3H).

[0378] HRMS (m / z): calc, for C17H26N5O, 316.2132 ([M+H]+). Found 316.2141.

[0379]

[0175] Compound 20 with A = Cand X = H

[0380] 1H NMR (300 MHz, MeOD) δ (ppm): 7.72 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.4 Hz, 2H), 4.42 (s, 2H), 3.62 (s, 2H), 2.67 (t, J = 7.5 Hz, 2H), 2.62 (s, 3H), 2.51 (s, 3H), 1.74 - 1 .57 (m, 2H), 1 .42 - 1 .26 (m, 2H), 0.90 (t, J = 6.8 Hz, 3H).

[0381] HRMS (m / z): calc. for Cw^sNs, 314.2339 ([M+H]+). Found 314.2338.

[0382]

[0176] Compound 20 with A = O and X = F

[0383] 1H NMR (400 MHz, MeOD) δ (ppm): 6.70 (d, J = 11 .0 Hz, 2H), 4.19 (t, J = 5.7 Hz, 2H), 4.08 (t, J = 6.4 Hz, 2H), 3.48 (t, J = 5.7 Hz, 2H), 2.59 (s, 3H), 2.44 (s, 3H), 1 .90 - 1 .73 (m, 2H), 1 .54 (m, 2H), 1.45 (s, 9H), 1 .04 (t, J = 8.8 Hz, 3H).

[0384] HRMS (m / z): calc, for C17H24F2N5O, 352.1943 ([M+H]+). Found 352.1928.

[0385]

[0177] Synthesis of 1-(4-(bromopolyethylene glycol)phenyl)-2-(4- butoxyphenyl)diazene (38) reflux

[0386] (18) (3.2 mmol) and potassium carbonate (1.5 equiv.) were dissolved in acetone (13 mL). After 30 min stirring at rt under argon, Bromo-PEG2-bromide (3.0 equiv.) was introduced in the mixture. After stirring at reflux for 18 h, the mixture was concentrated and the product (38) was isolated by flash chromatography (SiO2).

[0387]

[0178] Synthesis of 1-(4-(polyethylene glycol)phenyl)-2-(4- butoxyphenyl)diazene (39) reflux

[0388] (18) (3.2 mmol) and potassium carbonate (1.5 equiv.) were dissolved in acetone (13 mL). After 30 min stirring at rt under argon, PEG1 -bromide (3.0 equiv.) was introduced in the mixture. After stirring at reflux for 18 h, the mixture was concentrated and the product (39) was isolated by flash chromatography (SiCte).

[0389]

[0179] Synthesis of 2-(4-((4-butoxyphenyl)diazenyl)-1H-pyrazol-1- yl)polyethylene glycol-1 -sulfonic acid (40)

[0390] To a solution of (39) (77 pmol) and potassium carbonate (2.1 equiv.) in DMF (0.5 mL) were added sodium 2-bromoethanesulphonate (3 equiv.) and potassium iodide (10 equiv.). The reaction mixture was then stirred at 120 °C under argon and under micro-wave activation (88 W) for 15 min. Afterthe mixture cooled down to rt, it was precipitated in cold diethyl ether. The precipitate was filtered and washed with diethyl ether until the paste became a dry solid. The crude was then purified over reverse phase flash column chromatography and the sulfonic acid derivative (40) was isolated.

[0391]

[0180] Synthesis of (2-(4-((4-butoxyphenyl)diazenyl)-1H-pyrazol-1- yl)polyethylene glycol-1 )phosphonic acid (41)

[0392] Triethyl phosphite (33 equiv.) was added to (38) (0.12 mmol) under argon. The mixture was then heated to 110 °C and stirred for 26 h before concentration under vacuum. The crude was then purified by flash column chromatography (SiCk) to isolate the phosphonate derivative.

[0393] To a solution of the phosphonate derivative (41.0 pmol) dissolved in the minimum amount of dry dichloromethane (90 pL), bromotrimethylsilane (37 equiv.) was added dropwise at 0 °C under argon. The mixture was stirred at 0 °C for 20 min before warming up to rt and stirred overnight. The mixture was concentrated, and methanol was added to the flask. The mixture was stirred for approximatively 1 h before concentration. The crude was purified by reverse phase flash chromatography and the phosphonic acid derivative (41) was isolated.

[0181] Synthesis of (2-(4-((4-butoxyphenyl)diazenyl)-1H-pyrazol-1- yl)polyethylene glycol-1)selenonic acid (42) (38) (0.27 mmol) was added to a freshly prepared DMSO solution (0.43 mL) of selenium (2.5 equiv.) in the presence of sodium methoxide (1.3 equiv.) and aqueous hydrazine (95%, 0.3 equiv.) under argon atmosphere. The mixture was stirred for 3 h at rt. The solvent was evaporated, and the crude was extracted with DCM. The organic phase was washed with water and dried over MgSO4 before concentration. The crude product was purified by flash column chromatography (SiO2) to isolate the diselenide derivative.

[0394] Hydrogen peroxide (5 equiv.) was then added to a suspension of the diselenide derivative (0.12 mmol) in DCM (1.2 mL) at 0 °C and the mixture was stirred for 1 h at rt. The crude was then concentrated and solubilized in MeOH before purification by reverse phase flash chromatography to isolate the selenonic acid derivative (42).

[0395]

[0182] General protocol for the synthesis of the nitroso derivatives (10)

[0396] In a solution of the aniline derivative (6.1 mmol) in methanol (20.2 mL), hydrogen peroxide (30 w% in water, 4.20 mL, 41.2 mmol, 6.8 equiv.) and Au / TiC>2 (1 w% Au, 1 g / g aniline) were added and the mixture was stirred at rt for 24 h. Then, the mixture was filtrated (silica gel) and concentrated to obtain the nitroso derivative (10) that was used without further purification.

[0397]

[0183] General protocol for the synthesis of the arylazopyrazole derivatives (11 )

[0398] In a solution of the nitroso derivative (10) (1.2 mmol) in dichloromethane:chloroform (1 :1 , 3.1 mL), acetic acid (0.23 mL, 4.0 mmol, 3.3 equiv.), then 4 -aminopyrazole (101.7 mg, 1.2 mmol, 1 equiv.) were added and the mixture was stirred upon argon at 40 °C for 2 h before concentration. The crude was then purified by flash column chromatography (silica gel, cyclohexane:ethyl acetate 70:30) and the arylazopyrazole derivatives (11) was isolated as a yellow powder (-1.1 mmol, -86%).

[0399]

[0184] General protocol for the alkylation of the arylazopyrazole derivatives (12)

[0400] In a solution of the arylazopyrazole derivatives (11) (0.39 mmol) in acetone (3.2 mL), tert-butyl / V-(2-bromoethyl)carbamate (87.9 mg, 0.39 mmol, 1 equiv.) and potassium carbonate (163 mg, 1.2 mmol, 3 equiv.) were added and the mixture was stirred upon argon atmosphere at reflux for 5 h before concentration. The crude was then purified by flash column chromatography (alumina, dichloromethane) and the protected alkylated arylazopyrazole derivatives (12) was isolated as a brown powder (-0.38 mmol, -98%).

[0401]

[0185] General protocol for the deprotection of the alkylated arylazopyrazole derivatives (13)

[0402] The protected arylazopyrazole derivatives (12) (1.6 mmol) was solubilized in dichloromethane:trifluoroacetic acid (8:2, 34 mL) and was stirred at rt for 3 h before concentration. Diethylether (200 mL) was then introduced to concretize a precipitate which was isolated by filtration to isolate the unprotected alkylated arylazopyrazole derivatives (13) (-1 .5 mmol, -90%).

[0403] When the product could not be isolated by precipitation, the reaction mixture was washed with basic aqueous solution (saturated with sodium bicarbonate). The aqueous phase was washed with dichloromethane and the combined organic phases were dried under reduced pressure to isolate the unprotected alkylated arylazopyrazole derivative (13) (-1.5 mmol, -90%).

[0404]

[0186] Compound 10 with para-chain = -CsHu

[0405] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.24-8.08 (m), 7.83 (d, J=8.5 Hz, 1 H), 7.40 (d, J=8.2 Hz, 1 H), 2.75-2.60 (m, 3H), 1.66 (m, 3H), 1.46-1.34 (m, 3H), 1.33 (s, 3H), 0.95-0.85 (m, 5H). Contains impurities;

[0406] Structure of compound 10 with para-chain =-C5 / - / n .

[0407]

[0187] Compound 10 with para-chain = -OC4H9

[0408] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.90 (d, J=8.5 Hz, 2H), 7.15-6.88 (m, 2H), 4.1 1 (t, J=6.5 Hz, 2H), 1.82 (m, 2H), 1 .52 (m, 2H), 1.00 (t, J=7.4 Hz, 3H).

[0409] 1H NMR (300 MHz, DMSO) δ (ppm): 13.38 (s, 1H), 8.48 (s, 1H), 7.95 (s, 1H),

[0410] 7.73 (d, J =9.27 Hz, 2H), 7.06 (d, J = 8.54 Hz, 2H), 4.04 (t, J = 6.45, 2H), 1.73 (m, 2H), 1.42 (m, 2H), 1.26 (m, 12H), 0.86 (t, J = 6.99, 3H).

[0411] HRMS (m / z) calculated for C19H28 / V4O, 329.2349 ([M+H]+). Found 329.2341.

[0412]

[0191] Compound 11 with para-chain = -C9H19

[0413] 1H NMR (300 MHz, DMSO) δ (ppm): 13.44 (s, 1 H), 8.53 (s, 1 H), 7.98 (s, 1 H), 7.68 (d, J = 8.07, 2H), 7.34 (d, J = 8.08, 2H), 2.64 (t, J = 7.62, 2H), 1.59 (t, J = 7.44, 2H), 1.25 (m, 12H, 2H impurities), 0.85 (t, J = 6.33, 3H).

[0414] 13C NMR (75 MHz, CDCI3) δ (ppm): 151.05, 145.54, 141.42, 129.61 , 122.23, 35.38, 31.75, 31.24, 29.42, 29.33, 29.16, 29.13, 22.57, 14.43.

[0415]

[0192] Compound 11 with para-chain = -NHC4H9

[0416] 1H NMR (300 MHz, DMSO) δ (ppm): 8.08 (s, 2H), 7.72 (d, J = 8.86 Hz, 2H), 6.63 (d, J = 8.91 Hz, 2H), 3.20 (t, J = 7.07 Hz, 2H, 1 H impurities), 1.66 (m, 2H), 1.45 (m, 2H, 1 H impurities), 1.25 (s, 1 H), 0.96 (m, 3H, 3H impurities).

[0417]

[0193] Compound 11 with para-chain = -C5 / - / 11

[0418] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.16 (s, 2H), 7.74 (d, J=8.2 Hz, 2H), 7.29 (d, J=8.0 Hz, 2H), 2.72-2.61 (m, 2H), 1.35-1.25 (m, 5H), 0.95-0.85 (m, 3H).13C NMR (75 MHz, CDCI3) δ (ppm): 151.08, 146.00, 141.67, 129.30, 129.11 , 122.29, 35.84, 31.49, 31.02, 26.93, 22.56, 14.06.

[0419] HRMS (m / z) calculated for C14H19A / 4, 243.1610 ([M+H]+). Found 243.1607.

[0420] Structure of compound 11 with para-chain =-C5 / - / n.

[0421]

[0194] Compound 11 with para-chain =-0CH3

[0422] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.13 (s, 2H), 7.81 (d, J=8.9 Hz, 2H), 6.99

[0423] (d, J=8.9 Hz, 2H), 3.88 (s, 3H).

[0424] HRMS (m / z) calculated for C10H11 / V4O, 203.0933 ([M+H]+). Found 203.0934.

[0425] Structure of compound 11 with para-chain =-OCH3.

[0426]

[0195] Compound 11 with para-chain =-OCAH9

[0427] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.13 (s, 2H), 7.85-7.74 (d, 2H), 7.02- 6.93 (d, 2H), 4.04 (t, J=6.5 Hz, 2H), 1 .80 (m, 2H), 1 .49 (m, 2H), 0.99 (t, J=7.4 Hz, 3H).

[0428] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.28, 146.94, 141.63, 129.10, 124.08, 114.69, 68.03, 31.27, 19.25, 13.88.

[0429] HRMS (m / z) calculated for C13H17A / 4O, 245.1402 ([M+H]+). Found 245.1397.

[0430] Structure of compound 11 with para-chain =-OC4 / - / 9.

[0431]

[0196] Compound 12 with para-chain = -OC4H9

[0432] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.01 (s, 1 H), 7.94 (s, 1 H), 7.77 (d, J = 8.9 Hz, 2H), 6.97 (d, J = 9.0 Hz, 2H), 4.90 (s, 1 H), 4.27 (t, J = 5.6 Hz, 2H), 4.03 (t, J = 6.5 Hz, 2H), 3.61 (d, J = 5.7 Hz, 2H), 1 .79 (m, 2H), 1 .60 - 1 .47 (m, 2H), 1 .44 (s, 9H), 0.99 (t, J = 7.4 Hz, 3H).

[0433] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.30, 155.98, 147.09, 141.75, 133.76, 126.54, 124.08, 114.80, 80.00, 68.13, 52.43, 40.71 , 31.38, 28.48, 19.36, 13.99. HRMS (m / z): calc, for C20H30N5O3, 388.2349 ([M+H]+). Found 388.2355.

[0434]

[0197] Compound 12 with para-chain = -OCaHi?

[0435] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.01 (s, 1 H), 7.94 (s, 1 H), 7.82 - 7.72 (m, 2H), 7.02 - 6.91 (m, 2H), 4.89 (s, 1 H), 4.28 (t, J = 5.6 Hz, 2H), 4.02 (t, J = 6.6 Hz, 2H), 3.61 (m, 2H), 1 .81 (m, 2H), 1 .44 (s, 11 H), 1 .39 - 1 .20 (m, 8H), 0.89 (t, J = 6.0 Hz, 3H).

[0436] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.31 , 155.98, 147.09, 141.76, 133.77, 126.54, 124.09, 114.81 , 79.99, 68.46, 52.44, 40.72, 31.95, 29.49, 29.37, 29.34, 28.48, 26.16, 22.80, 14.25.

[0437]

[0198] Compound 12 with para-chain = -NHC4H9

[0438] 1H NMR (300 MHz, DMSO) δ (ppm): 8.20 (s, 1 H), 7.86 (s, 1 H), 7.57 (d, J = 8.83 Hz, 2H), 6.97 (t, J = 5.70 Hz, 2H), 6.41 (d, J = 8.95 Hz, 2H), 6.41 (t, J = 5.41 , 1 H), 4.18 (t, J = 6.13 Hz, 2H), 3.37 (m, 2H), 3.08 (m, 2H), 2.09 (s, 3H), 1.36 (m, 11 H, 2H impurities), 0.92 (t, J = 7.27 Hz, 3H).

[0439] 13C NMR (75 MHz, DMSO) δ (ppm):156.03, 151.78, 142.92, 141.52, 139.19, 132.42, 126.38, 124.42, 111.90, 105.41 , 78.37, 51.84, 42.69, 31.65, 31.17, 28.64, 20.26, 14.24.

[0440]

[0199] Compound 12 with para-chain =-Cs / - / n

[0441] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.04 (s, 1 H), 7.97 (s, 1 H), 7.75-7.67 (m, 2H), 7.37-7.22 (m, 3H), 4.89 (s, 1 H), 4.29 (t, J=5.7 Hz, 2H), 3.62 (m, 2H), 2.65 (t, J=6.6 Hz, 2H), 1.65 (m, 2H), 1.40-1.20 (m, 5H), 0.90 (td, J=6.8, 3.1 Hz, 3H).

[0442] 13C NMR (75 MHz, CDCI3) δ (ppm): 155.89, 151.12, 145.84, 141.67, 135.27, 133.73, 131.39, 130.13, 129.68, 129.08, 126.83, 122.20, 116.66, 79.86, 64.94, 52.32, 40.59, 35.82, 31.48, 31.02, 28.36, 22.55, 14.05.

[0443] HRMS (m / z) calculated for C21H32A / 5O2, 386.2556 ([M+H]+). Found 386.2556.

[0444] Structure of compound 12 with para-chain =-C5 / - / n.

[0200] Compound 12 with para-chain =-OCH3

[0445] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.02 (s, 1 H), 7.95 (s, 1 H), 7.84-7.73 (m, 2H), 6.98 (m, 2H), 6.82-6.72 (m, 1 H), 4.28 (t, J=5.5 Hz, 1 H), 3.86 (m, 3H), 3.70-3.58 (m, 2H), 3.50 (m, 1 H), 1.43 (s, J=3.1 Hz, 9H).

[0446] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.51 , 155.88, 147.15, 141.61 , 133.62, 126.50, 123.98, 118.47, 115.31 , 114.20, 79.85, 64.90, 55.56, 52.31 , 40.60, 28.37.

[0447] HRMS (m / z) calculated for C17H24 / V5O3, 346.1879 ([M+H]+). Found 346.1889.

[0448] Structure of compound 12 with para-chain =-OCH3.

[0449]

[0201] Compound 13 with para-chain =-OCH3

[0450] 1H NMR (300 MHz, DMSO-d6) δ (ppm): 8.50 (s, 1 H), 8.04 (s, 1 H), 7.93 (s, 2H), 7.81-7.70 (m, 2H), 7.15-7.05 (m, 2H), 4.42 (t, J=6.0 Hz, 2H), 3.84 (s, 3H), 3.34 (s, 21 H).

[0451] 13C NMR (75 MHz, DMSO-d6) δ (ppm): 161.71 , 146.88, 141.53, 133.35, 128.35, 124.09, 115.02, 56.05, 49.69, 40.81.

[0452] HRMS (m / z) calculated for C12H16A / 5O, 246.1355 ([M+H]+). Found 246.1344.

[0453] Structure of compound 13 with para-chain =-OCH3.

[0202] Compound 13 with para-chain =— C5 / - / 11

[0454] 1H NMR (300 MHz, DMSO-d6) δ (ppm): 8.54 (s, 1 H), 8.04 (s, 2H), 7.68 (d, J=8.1 Hz, 1 H), 7.37 (d, J=8.1 Hz, 1 H), 4.45 (t, J=6.1 Hz, 2H), 3.66 (t, J=6.2 Hz, 2H), 3.29 (J=6.5 Hz, 2H), 2.71-2.54 (m, 1 H), 1 .62 (m, 1 H), 1 .40-1 .21 (m, 3H), 0.87 (t, J=6.2 Hz, 2H).

[0455] 13C NMR (75 MHz, DMSO-d6) 5 (ppm): 150.98, 145.90, 141.57, 133.46, 129.70, 128.80, 122.29, 49.72, 35.35, 31.35, 30.92, 29.71 , 22.41 , 14.42.

[0456] HRMS (m / z) calculated for C16H24A / 5, 286.2032([M+H]+). Found 286.2023.

[0457] Structure of compound 13 with para-chain = -C5 / - / n .

[0458]

[0203] Compound 13 with para-chain = -OC4H9

[0459] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.02 (s, 1 H), 8.00 (s, 1 H), 7.77 (d, J = 9.0 Hz, 2H), 6.97 (d, J = 9.0 Hz, 2H), 4.21 (t, J = 5.7 Hz, 2H), 4.03 (t, J = 6.5 Hz, 2H), 3.20 (s, 2H), 1 .79 (m, 2H), 1 .60 - 1 .41 (m, 4H), 0.99 (t, J = 7.4 Hz, 3H).

[0460] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.26, 147.12, 141.75, 133.72, 126.10, 124.07, 114.80, 68.13, 56.05, 42.16, 31.38, 19.36, 13.99.

[0461] HRMS (m / z): calc, for C15H22N5O, 288.1824 ([M+H]+). Found 288.1823.

[0462]

[0204] Compound 13 with para-chain = -OCaHi7

[0463] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.01 (d, J= 6.3 Hz, 2H), 7.82 - 7.71 (m, 2H), 7.02 - 6.91 (m, 2H), 4.21 (t, J = 5.7 Hz, 2H), 4.02 (t, J = 6.5 Hz, 2H), 3.21 (t, J =

[0464] 5.8 Hz, 2H), 1 .87 - 1 .73 (m, 2H), 1 .46 (d, J = 8.9 Hz, 4H), 1 .30 (m, 8H), 0.88 (m, 3H).

[0465] 13C NMR (75 MHz, CDCI3) δ (ppm): 161.26, 147.12, 141.75, 133.72, 126.10, 124.07, 114.80, 68.46, 56.06, 42.16, 31.95, 29.49, 29.37, 29.34, 26.16, 22.80, 14.25.

[0466]

[0205] Compound 13 with para-chain = -OC10H21

[0467] 1H NMR (300 MHz, DMSO) δ (ppm): 8.43 (s, 1 H), 7.95 (s, 1 H), 7.72 (d, J = 8.82, 2H), 7.07 (d, J = 9.34, 2H), 4.16 (t, J = 6.15, 2H), 4.04 (t, J = 6.44, 2H), 2.99 (t, J = 6.15, 2H), 1.73 (m, 2H), 1.42 (m, 2H), 1.32 (m, 14H, 3H impurities), 0.86 (m, 3H).

[0468] 13C NMR (75 MHz, CDCI3) δ (ppm) = 160.98, 146.79, 141.16, 132.57, 127.74, 123.99, 115.36, 68.32, 55.23, 42.00, 31.77, 29.47, 29.42, 29,22, 29.17, 29.06, 14.44.

[0469]

[0206] Compound 13 with para-chain = -C9H19

[0470] 1H NMR (300 MHz, DMSO) δ (ppm): 8.04 (d, J = 3.20 Hz, 2H), 7.71 (d, J = 8.15, 2H), 7.29 (d, J = 8.53 Hz, 2H), 4.22 (t, J = 5.69, 2H), 3.22 (s, 2H), 2.66 (t, J = 7.71 Hz, 2H), 1 .64 (m, 2H), 1 .31 (m, 14H, 1 H impurities), 0.88 (t, J = 6.49 Hz, 3H).

[0207] Compound 13 with para-chain = -NHC4H9

[0471] 1H NMR (300 MHz, DMSO) δ (ppm): 8.10 (s, 1 H), 7.88 (s, 1 H), 7.69 (s, 1 H), 7.33 (d, J = 8.54 Hz, 2H), 6.40 (d, J = 8.53 Hz, 2H), 4.17 (t, J = 5.90, 2H), 3.09 (m,3H), 2.84 (t, J = 6.96 Hz, 2H), 1 .30 (m, 2H), 1 .14 (m, 2H), 0.67 (t, J = 7.26 Hz, 3H).

[0472] 13C NMR (75 MHz, DMSO) δ (ppm): 151.96, 143.21 , 141.77, 133.00, 126.90, 124.54, 111.91 , 49.55, 49.06, 42.66, 31.14, 20.25, 14.23.

[0473]

[0208] Synthesis of / V-butyl-4-[(E)-2-(1 H-pyrazol-4-yl)diazen-1 -yl]aniline

[0474] (21 )

[0475] Nitrosyl tetrafluoroborate (359 mg, 3.07 mmol, 1.1 equiv.) was carefully introduced in a solution 4-aminopyrazole (2.79 mmol) in dry DMF (80 mL). The mixture was stirred upon argon for 2 h at 0 °C. Then, a solution of / V-butylaniline (500 mg, 3.35 mmol, 1 .2 equiv.) was added dropwise and the mixture was stirred for 2 h upon argon at rt. The crude was dried under reduced pressure and solubilized in dichloromethane (100 mL). The organic phase was washed with basic aqueous solution (saturated with sodium bicarbonate, 3x120 mL) and water (2x50 mL). The crude was then purified by flash column chromatography (SiO2, dichloromethane: EtOH 98:2) and the arylazopyrazole derivative (21) was isolated as a yellow powder and used without further purification. Compound 21 is also referred to above as “compound 11 with para-chain = -NHC4H9”.

[0476] 1H NMR (300 MHz, DMSO) δ (ppm): 8.08 (s, 2H), 7.72 (d, J = 8.86 Hz, 2H), 6.63 (d, J = 8.91 Hz, 2H), 3.20 (t, J = 7.07 Hz, 2H, 1 H impurities), 1.66 (m, 2H), 1.45 (m, 2H, 1 H impurities), 1.25 (s, 1 H), 0.96 (m, 3H, 3H impurities).

[0209] Protocols for the syntheses of the (4-butoxyphenyl)diazenyl)-5- methyl-1 H-pyrazol-1 -yl derivatives

[0477]

[0210] 1 -butoxy-4-nitrosobenzene (22)

[0478] 4-butoxyaniline (5.008 g, 23.23 mmol) was dissolved in a mixture of chloroform and ethanol 2:1 (90 mL). In a separate flask, oxone (9.220 g, 60.61 mmol, 2.0 equiv.) was dissolved in water (60 mL). The two solutions were combined, purged with argon and stirred for 3 h at rt. The organic phase was then separated and successively washed with water (100 mL) and brine (100 mL). It was then dried over MgSO4, filtered and concentrated to obtain the nitroso derivative (22) which was used without further purification.

[0479]

[0211] (E)-4-((4-butoxyphenyl)diazenyl)-5-methyl-1 H-pyrazole (23) , overn g

[0480] To a solution of 22 (1.852 g, 10.34 mmol) in dichloromethane:chloroform 1 :1 (40 mL) was added acetic acid (1.241 g, 1.180 mL, 20.67 mmol, 2 equiv.) and 3- methyl-1 H-pyrazol-4-amine (1.205 g, 12.40 mmol, 1.2 equiv.). The reaction mixture was stirred at 40 °C under argon overnight before concentration. The crude was then purified by flash column chromatography (neutral alumina, dichloromethane:ethanol 9:1) and the arylazo-methyl-pyrazole derivative (23) was isolated as a yellow solid and used without further purification.

[0481] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.98 (s, 1 H), 7.80 (d, J = 8.5 Hz, 2H), 6.97 (d, J = 9.0 Hz, 2H), 4.03 (t, J = 6.5 Hz, 2H), 2.66 (s, 3H), 1.88 - 1.72 (m, 2H), 1.61 - 1.42 (m, 2H), 0.99 (t, J = 7.4 Hz, 3H).

[0482] 13C NMR (75 MHz, CDCI3) δ (ppm): 160.99, 147.38, 141.22, 138.25, 128.45, 123.89, 114.74, 68.11 , 31.40, 19.37, 14.00, 10.53.

[0483] HRMS (m / z): calc, for C14H19N4O, 259.1559 ([M+H]+). Found 259.1548.

[0212] (E)-2-(4-((4-butoxyphenyl)diazenyl)-5-methyl-1H-pyrazol-1- yl)ethane-1 -sulfonic acid (24) To a solution of (23) (20 mg, 77 pmol) and potassium carbonate (22.5 mg, 160 pmol, 2.1 equiv.) in DMF (0.5 mL) were added sodium 2-bromoethanesulphonate (49.0 mg, 230 pmol, 3 equiv.) and potassium iodide (128 mg, 770 pmol, 10 equiv.). The reaction mixture was then stirred at 120 °C under argon and under micro-wave activation (88 W) for 15 min. After the mixture cooled down to rt, it was precipitated in cold diethyl ether. The precipitate was filtered and washed with diethyl ether until the paste became a dry solid. The crude was then purified over reverse phase flash column chromatography (watermethanol 5:5) and the sulfonic acid derivative (24) was isolated as a yellow solid (14 mg, 40 pmol, 47%, 2 isomers).1H NMR (300 MHz, DMSO) δ (ppm): 8.20 (s, 1 H), 7.70 (d, J = 8.4 Hz, 2H), 7.05 (d, J = 8.6 Hz, 2H), 4.31 (t, J = 7.8 Hz, 2H), 4.04 (t, J = 6.5 Hz, 2H), 3.00 - 2.89 (m, 2H), 2.42 (s, 3H), 1.79 - 1 .61 (m, 2H), 1.54 - 1 .35 (m, 2H), 0.94 (t, J = 7.4 Hz, 3H).13C NMR (75 MHz, DMSO) δ (ppm): 160.26, 146.69, 144.60, 137.59, 124.13, 123.33, 114.87, 67.57, 51.10, 48.86, 30.73, 18.76, 13.75, 12.37.

[0484] HRMS (m / z): calc, for C16H23N4O4S, 367.1440 ([M+H]+). Found 367.1431.

[0485]

[0213] (E)-1 -(2-bromoethyl)-4-((4-butoxyphenyl)diazenyl)-5-methyl-1 H- pyrazole (25)

[0486] To a solution of (23) (99 mg, 0.38 mmol) in NaOH (40%, 0.5 mL), tetrabutyl ammonium bromide (3.08 mg, 10.0 pmol, 0.025 equiv.) and 1 ,2-dibromoethane (718 mg, 3.82 mmol, 10 equiv.) were added. The mixture was then stirred for 24 h at rt. The two phases were then separated, and the aqueous phase was extracted with dichloromethane twice. The organic phases were combined, dried over MgSO4, filtered and concentrated. The crude was then purified using flash chromatography (SiO2, cyclohexane:ethyl acetate 7:3) to obtain (25) as a yellow solid (100 mg, 270 pmol, 72%, 2 isomers).

[0487] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.88 (d, J = 20.4 Hz, 1 H), 7.78 (ddd, J = 9.9, 4.7, 2.5 Hz, 2H), 7.04 - 6.86 (m, 2H), 4.53 - 4.40 (m, 2H), 4.03 (t, J = 6.5 Hz, 2H), 3.76 (dt, J = 9.2, 6.3 Hz, 2H), 2.56 (s, 3H), 1 .87 - 1 .72 (m, 2H), 1 .52 (dd, J = 10.5, 4.8 Hz, 2H), 0.99 (t, J = 7.4 Hz, 3H).

[0488] 13C NMR (75 MHz, CDCI3) δ 160.95, 147.28, 139.93, 138.58, 123.78, 123.75, 123.00, 114.63, 114.61 , 67.99, 53.97, 31.28, 29.93, 19.26, 13.88, 12.44.

[0489]

[0214] diethyl (E)-(2-(4-((4-butoxyphenyl)diazenyl)-5-methyl-1H-pyrazol- 1-yl)ethyl)phosphonate (26)

[0490]

[0491] Triethyl phosphite (1 .81 g, 1.88 mL, 10.9 mmol, 33 equiv.) was added to (25) (120 mg, 0.330 mmol, 2 isomers) under argon. The mixture was heated to 110 °C and stirred for 5 days before concentration under vacuum. The phosphonate derivative (26), 2 isomers) was used without further purification.

[0492]

[0215] (E)-(2-(4-((4-butoxyphenyl)diazenyl)-5-methyl-1H-pyrazol-1- yl)ethyl)phosphonic acid (27)

[0493] To a solution of (26) (200 mg, 470 pmol, 2 isomers) dissolved in the minimum amount of dry dichloromethane (1.5 mL), bromotrimethylsilane (2.537 g, 2.190 mL, 16.57 mmol, 35 equiv.) was added dropwise at O °C under argon. The mixture was stirred at 0 °C for 20 min before warming up to rt and stirred overnight. The mixture was concentrated, and methanol (1 mL) was added to the flask. The mixture was stirred for approximatively 1 h before concentration. The crude was purified by reverse phase flash chromatography (water: methanol 3:7) and the phosphonic acid derivative (27) was isolated as a yellow powder (95 mg, 0.26 mmol, 55%, 2 isomers).

[0494] 1H NMR (300 MHz, DMSO) δ (ppm): 8.22 (s, 1 H), 7.80 - 7.64 (m, 2H), 7.11 - 6.99 (m, 2H), 4.25 (q, J = 8.4 Hz, 2H), 4.04 (t, J = 6.4 Hz, 2H), 2.60 (s, 1 H), 2.42 (s, 2H), 2.23 - 2.01 (m, 2H), 1 .72 (dq, J = 8.4, 6.5 Hz, 2H), 1.54 - 1 .36 (m, 2H), 0.94 (t, J = 7.3 Hz, 3H).

[0495] 13C NMR (75 MHz, DMSO) δ (ppm): 160.32, 160.26, 146.66, 146.62, 144.76, 139.73, 137.75, 137.65, 128.23, 123.77, 123.38, 123.34, 114.88, 67.57, 47.05, 44.03, 30.73, 18.76, 13.75.

[0496] HRMS (m / z): calc, for C16H24N4O4P, 367.1535 ([M+H]+). Found 367.1524.

[0497]

[0216] Protocols for the syntheses of the 4-((1-pentyl-1H-pyrazol-4- yl)diazenyl)-1 H-pyrazol-1 -yl derivatives

[0498]

[0217] tert-butyl (1 H-pyrazol-4-yl)carbamate (28)

[0499] To a solution of 1 H-pyrazol-4-amine (600 mg, 7.22 mmol) in THF (32 mL), a solution of di-tert-butyl dicarbonate (1.73 g, 1.70 mL, 7.94 mmol, 1.1 equiv.) in THF (10 mL) was slowly added followed by a solution of sodium bicarbonate (1 .51 g, 18.0 mmol, 2.5 equiv.) in water (10 mL). The mixture was stirred for 24 h at rt. The mixture was then extracted 3 times with ethyl acetate. The organic layers were combined, dried over MgSO4, filtered and concentrated. The protected pyrazole derivative (28) was used without further purification.

[0500] 1H NMR (300 MHz, DMSO) δ (ppm): 12.44 (s, 1 H), 9.08 (s, 1 H), 7.46 (s, 2H), 1.43 (s, 9H).

[0501] 13C NMR (75 MHz, DMSO) δ (ppm): 152.88, 136.23, 121.72, 117.22, 78.50, 28.20.

[0502]

[0218] tert-butyl (1 -pentyl-1 H-pyrazol-4-yl)carbamate (29)

[0503] (28) (976 mg, 5.33 mmol) was dissolved in 1 -bromopentane (8.050 g, 6.650 mL, 53.29 mmol, 10 equiv.) and DMF (3.57 mL). Potassium carbonate (1.473 g, 10.66 mmol, 2 equiv.) was added to the mixture, which was stirred overnight at rt. The mixture was then heated at 40 °C for 3 days. Ethyl acetate was added to the mixture and the organic phase was washed with water until the pH was neutral. The organic phase was then dried over MgSO4, filtered and concentrated. The crude was purified using flash column chromatography (alumina, cyclohexane:ethyl acetate) to isolate the alkylated pyrazole derivative (29) as a brown solid (835 mg, 3.30 mmol, 62%).

[0504] 1H NMR (300 MHz, CDCI3) δ (ppm): 7.61 (s, 1 H), 6.62 (s, 1 H), 3.98 (t, J = 7.2 Hz, 2H), 1.86 - 1.70 (m, 2H), 1.45 (s, 9H), 1.31 - 1.18 (m, 4H), 0.84 (t, J = 6.9 Hz, 3H).

[0505] 13C NMR (75 MHz, CDCI3) δ (ppm): 153.26, 129.61 , 121.40, 120.04, 80.27, 52.60, 30.08, 28.79, 28.41 , 22.28, 13.98.

[0506] HRMS (m / z): calc, for C13H24N3O2, 254.1869 ([M+H]+). Found 254.1868.

[0507]

[0219] 1-pentyl-1 H-pyrazol-4-aminium chloride (30)

[0508] (29) (968 mg, 3.82 mmol) was dissolved in a mixture of dichloromethane (6 mL) and dioxane (6 mL). HCI (4 M) was then added, and the mixture was stirred at rt for 2 h before concentration. The aminium derivative (30) was isolated as a purple solid (537 mg, 3.06 mmol, 80%).

[0509] 1H NMR (300 MHz, DMSO) δ (ppm): 10.23 (s, 3H), 7.94 (s, 1 H), 7.51 (s, 1 H), 4.09 (t, J = 7.0 Hz, 2H), 1 .81 - 1 .66 (m, 2H), 1 .37 - 1 .08 (m, 2H), 1 .22 - 1.09 (m, 2H), 0.83 (t, J = 7.1 Hz, 3H).

[0510] 13C NMR (75 MHz, DMSO) δ (ppm): 133.11 , 124.99, 112.70, 51.63, 29.39, 28.01 , 21.55, 13.80.

[0511]

[0220] sodium 1,3-dioxopropan-2-ide (31 )

[0512] 1) HCI (1 M)

[0513] 1 ,1 ,3,3-tetramethoxypropane (1.485 mg, 1.500 mL, 9.044 mmol) was stirred with HCI (1 M, 0.8 mL) at rt for 90 min. The pH was then adjusted to 7-8 by adding NaOH (3 M). Acetone (10 mL) was added to the mixture which was kept at 0 °C for 1 h. The mixture was then filtered, and the malonaldehyde sodium salt (31) was isolated as a white powder and was used without further purification.

[0514]

[0221] 2-(2-(1-pentyl-1H-pyrazol-4-yl)hydrazineylidene)malonaldehyde

[0515] (32)

[0516] 1) AcOH, HCI (37%)

[0517] (30) (268 mg, 1 .53 mmol) was dissolved in acetic acid (2.340 mL) and HCI (37%, 1 .011 mL) at 0 °C. A solution of NaNO2 (126 mg, 1 .83 mmol, 1 .2 equiv.) dissolved in a minimum amount of water at 0 °C was slowly added to the mixture. The mixture was then stirred at 0 °C for 30 min. A solution of potassium acetate (449 mg, 4.58 mmol, 3 equiv.) dissolved in a minimum amount of water at 0 °C and

[0518] (31) (215 mg, 2.29 mmol, 1.5 equiv.) were added in sequence. The mixture was then allowed to warm to rt and stirred for 1 day. The resulting mixture was filtered, and the precipitate was washed with water. The malonaldehyde derivative (32) obtained as a yellow solid was then used without further purification.

[0519]

[0222] (E)-4-((1 H-pyrazol-4-yl)diazenyl)-1 -pentyl-1 H-pyrazole (33)

[0520] To a solution of (32) (364 mg, 1.54 mmol) in EtOH (15.7 mL) at 0 °C, hydrazine hydrate (92.6 mg, 90.0 pL, 1.85 mmol, 1.2 equiv.) was added dropwise and the reaction mixture was stirred overnight at rt. The reaction was then quenched by adding water and the mixture was extracted 3 times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated to isolate the bis-pyrazole derivative (33) as a yellow solid, which was used without further purification.1H NMR (300 MHz, CDCI3) δ (ppm): 8.08 (s, 2H), 7.95 (s, 1 H), 7.90 (s, 1 H), 4.14 (t, J = 7.1 Hz, 2H), 1 .98 - 1 .82 (m, 2H), 1 .45 - 1 .21 (m, 4H), 0.89 (t, J = 6.8 Hz, 3H).

[0521] 13C NMR (75 MHz, CDCI3) δ (ppm): 141.69, 141.56, 132.78, 128.79, 125.38, 53.04, 29.94, 28.77, 22.31 , 14.03.

[0522] HRMS (m / z): calc. for CuHiyNe, 233.1515 ([M+H]+). Found 233.1512.

[0523]

[0223] (E)-2-(4-(( 1 -pentyl-1 H-pyrazol-4-yl)diazenyl)-1 H-pyrazol-1 - yl)ethane-1 -sulfonic acid (34)

[0524] To a solution of (33) (60 mg, 0.26 mmol) and potassium carbonate (75 mg, 0.54 mmol, 2.1 equiv.) in DMF (2.5 mL), sodium 2-bromoethanesulphonate (164 mg, 0.770 mmol, 3 equiv.) and potassium iodide (429 mg, 290 pL, 2.58 mmol, 10 equiv.) were added. The reaction mixture was stirred at 120 °C under argon and under micro-wave activation (88 W) for 15 min. After the mixture cooled down to rt, it was precipitated in cold diethyl ether. The precipitate was filtered and washed with diethyl ether until the paste became a dry solid. The crude was then purified by reverse phase flash column chromatography (water: methanol) and the sulfonic acid derivative (34) was isolated as a yellow solid (45 mg, 0.12 mmol, 48%).

[0525] 1H NMR (300 MHz, DMSO) δ (ppm): 8.37 (d, J = 12.9 Hz, 2H), 7.83 (d, J = 5.6 Hz, 2H), 4.45 - 4.34 (m, 2H), 4.12 (t, J = 6.9 Hz, 2H), 3.05 - 2.93 (m, 2H), 1 .79 (p, 2H), 1.39 - 1.12 (m, 4H), 0.84 (t, J = 7.1 Hz, 3H).

[0526] 13C NMR (75 MHz, DMSO) δ (ppm): 140.80, 140.78, 131.47, 131.31 , 127.10, 126.44, 51.75, 51.17, 49.01 , 29.24, 28.08, 21.61 , 13.86.

[0527] HRMS (m / z): calc, for C13H21N6O3S, 341.1396 ([M+H]+). Found 341.1396.

[0224] (E)-1 -(2-bromoethyl)-4-((1 -pentyl-1 H-pyrazol-4-yl)diazenyl)-1 H- pyrazole (35)

[0528] To a solution of (33) (60 mg, 0.26 mmol) in NaOH (40%, 0.5 mL), tetrabutyl ammonium bromide (2.1 mg, 6.4 pmol, 0.025 equiv.) and 1 ,2-dibromoethane (483 mg, 220 pL, 2.57 mmol, 10 equiv.) were added. Dichloromethane was used to adjust solubility and the mixture was stirred at rt overnight. Water (10 mL) and dichloromethane (10 mL) were then successively poured into the medium and the aqueous phase was extracted twice with dichloromethane (2 x 10 mL). The combined organic layers were dried over MgSO4, filtered and concentrated. The crude was purified by flash column chromatography (SiO2, cyclohexane:ethyl acetate 7:3) and the bis-pyrazole derivative (35) was isolated as a yellow powder (46 mg, 0.14 mmol, 53%).

[0529] 1H NMR (300 MHz, CDCI3) δ (ppm): 8.11 - 7.75 (m, 4H), 4.52 (t, J = 6.2 Hz, 2H), 4.13 (t, J = 7.1 Hz, 2H), 3.76 (t, J = 6.2 Hz, 2H), 1.98 - 1.82 (m, 2H), 1.45 - 1.21 (m, 4H), 0.89 (t, J = 6.9 Hz, 3H).

[0530] 13C NMR (75 MHz, CDCI3) δ (ppm): 141.64, 133.59, 132.82, 126.54, 125.27, 54.23, 53.06, 30.02, 29.95, 28.80, 22.33, 14.06.

[0531] HRMS (m / z): calc, for Ci3H2oBrN6, 327.0820 ([M+H]+). Found 327.0822.

[0532]

[0225] diethyl ( E)-(2-(4-(( 1 -pentyl-1 H-pyrazol-4-yl)diazenyl)-1 H-pyrazol-

[0533] 1-yl)ethyl)phosphonate (36)

[0534] Triethyl phosphite (676 mg, 700 pL, 4.07 mmol, 33 equiv.) was added to (35) (41 mg, 0.12 mmol) under argon. The yellow mixture was then heated to 110 °C and stirred for 26 h before concentration under vacuum. The crude was then purified by flash column chromatography (SiO2, ethyl acetate) to isolate the phosphonate derivative (36) as a yellow oil (21.8 mg, 55.0 pmol, 45%).1H NMR (300 MHz, CDCI3) δ (ppm): 7.99 - 7.88 (m, 3H), 7.86 (s, 1 H), 4.41 (dt, J = 11.9, 7.6 Hz, 2H), 4.18 - 4.00 (m, 6H), 2.41 (dt, J = 18.4, 7.6 Hz, 2H), 1.90 (p, J = 7.2 Hz, 2H), 1.45 - 1.21 (m, 10H), 0.89 (t, J = 6.9 Hz, 3H).

[0535] 13C NMR (75 MHz, CDCI3) δ (ppm): 141.67, 141.54, 133.25, 132.74, 125.73, 125.18, 62.16, 62.08, 53.00, 47.02, 29.91 , 28.75, 27.98, 26.12, 22.29, 16.52, 16.44, 14.00.

[0536] HRMS (m / z): calc, for C17H30N6O3P, 397.2117 ([M+H]+). Found 397.2134.

[0537]

[0226] (E)-(2-(4-(( 1 -pentyl-1 H-pyrazol-4-yl)diazenyl)-1 H-pyrazol-1 - yl)ethyl)phosphonic acid (37)

[0538] To a solution of (36) (16.4 mg, 41.0 pmol) dissolved in the minimum amount of dry dichloromethane (90 pL), bromotrimethylsilane (232 mg, 200 pL, 1.52 mmol, 37 equiv.) was added dropwise at 0 °C under argon. The mixture was stirred at 0 °C for 20 min before warming up to rt and stirred overnight. The mixture was concentrated, and methanol (1 mL) was added to the flask. The mixture was stirred for approximatively 1 h before concentration. The crude was purified by reverse phase flash chromatography (watermethanol 3:7) and the phosphonic acid derivative (37) was isolated as a yellow oil (5.6 mg, 20 pmol, 40%).

[0539] 1H NMR (300 MHz, DMSO) δ (ppm): 8.38 (d, J = 15.4 Hz, 2H), 7.84 (s, 2H), 4.31 (d, J = 8.1 Hz, 2H), 4.13 (t, J = 7.0 Hz, 2H), 2.15 (dt, J = 17.3, 8.0 Hz, 2H), 1.80 (p, J = 7.1 Hz, 2H), 1 .37 - 1 .12 (m, 4H), 0.85 (t, J = 7.0 Hz, 3H).

[0540] 13C NMR (75 MHz, DMSO) δ (ppm): 140.80, 131.49, 126.79, 126.50, 51.78, 47.26, 29.26, 28.10, 21.63, 13.89.

[0541] HRMS (m / z): calc, for C13H22N6O3P, 341.1491 ([M+H]+). Found 341.1490.

[0542]

[0227] The following compounds are also prepared by application and / or adaptation of the procedures disclosed above:

[0543]

[0544]

[0228] Characterization of activation upon gamma-ray irradiation

[0545]

[0230] The compound (50 pM, 200 pL, H2O:DMSO 99:1 v / v) were introduced in two 96-well microplates. Both microplates were irradiated by UV (365 nm, 0.817 mW.cnr2, 5 min) to obtain the photostationary state 1 (PSS1) containing a majority of the c / s-isomer. One microplate was kept in the dark and used as control (non-irradiated by ionising radiation) whereas the second microplate was irradiated upon incremental doses of gamma rays (2, 3, 5 and 10 Gy). After each irradiation, absorbance analyses were performed on the non-irradiated and irradiated compounds.

[0546]

[0231] Results are illustrated in Figure 1 . These results demonstrate that the molecules with Z=SO3_and Z=PO32' exhibit an activation efficiency that is similar to the GdAzo compounds.

[0547]

[0232] Compounds activation upon ionizing radiation

[0548]

[0233] The trans-isomers of the compounds (50 pM, 200-700 pL, phosphate buffer pH 7.4 or PBS or chloroform) were introduced in a 96-well microplate or a quartz cuve before UV irradiation (365 nm, 0.817 mW.cm-2, 1-15 min, c / s-isomer major at the photostationary state). The compounds were then irradiated by ionizing radiation (gamma ray (662 keV) or electron beam (5 MeV), from 2 to 20 Gy) and absorbance and / or high-performance liquid chromatography (HPLC) analyses were carried out to determine the conversion efficacy of the c / s-isomers into the trans-isomers. When absorbance spectra were recorded, the activation efficacy was established by absorbance difference (at the maximal absorption for each compound) of medium before and after ionizing radiation-activation, and comparison with c / s-GdAzo activation. When HPLC analyses were carried out, the activation percentage of the c / s-isomers of the compounds induced by ionizing radiation was determined.

[0549]

[0234] Cytotoxicity of c / s-isomers and trans-isomers.

[0550]

[0235] The cells (PANC-1 and / or A549) were seeded (3,000 to 5,000 cells in 100 pL / well) in 96-well microplate and maintained in culture medium in a humid atmosphere at 37 °C with 5% CO2. 24 h post-seeding, culture medium was replaced by a solution of c / s-isomer or trans-isomer of the compounds (20 pL, final concentration 0 to 1 mM, PBS). After 30 min in the dark at rt, culture medium was introduced (80 pL, final concentration 0 to 200 pM) and the cells were maintained in a humid atmosphere at 37 °C with 5% CO2 for 3 days. The cytotoxicity was determined using a cell viability assay (CellTiter-Glo®, Promega). The cell viability was expressed as the ratio of the signal emitted by the living cells after treatment to living cells without any treatment (no compound added).

[0551]

[0236] Cytotoxicity of c / s-isomers upon ionizing radiations.

[0552]

[0237] The cells (PANC-1 and / or A549) were seeded (3,000 to 5,000 cells in 100 pL / well) in 96-well microplate and maintained in culture medium in a humid atmosphere at 37 °C with 5% CO2. 24 h post-seeding, culture medium was replaced by a solution of c / s-isomer of the compounds (20 pL, final concentration 0 to 1 mM, PBS). The compounds were irradiated (X-ray, gamma ray or electron beam, from 2 to 20 Gy). Culture medium was introduced (80 pL, final concentration 0 to 200 pM) and the cells were maintained in a humid atmosphere at 37 °C with 5% CO2 for 3 days. The cytotoxicity was determined using a cell viability assay (CellTiter-Glo®, Promega). The cell viability was expressed as the ratio of the signal emitted by the living cells after treatment to living cells without any treatment (no compound added).

Claims

CLAIMS1. A compound of formula (I):WhereEach A identical or different independently represents -O-, -NR-, -C1-C16 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;Each B, which may be the same or different, independently represents -O-, -NR- , -C1 -C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O- , or -SR-;Each X and X’, identical or different is independently selected from H; halogen atoms; -OR, -SR, -C1-C9 alkyl, -NRR’, -N+RR’R”, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;Y and Y’ identical or different are independently chosen from N or OR;Z is selected from the group consisting in H, COOR, OR, -SO2OR, -SOOR, - PO3R2, N3, halogen atoms, NRR’, -N+RR’R”, SeO2OR; SeOOR, or a biologically active moiety;Each R1 , R1’ identical or different is independently chosen from H, halogen atoms, -COOR, -CONRR’, NRC(=O)R’, -COSR, SC(=O)R, -SO2OR, -PO3R2,- OR, -NRR’, -SR, -CN, -C1-C9 alkyl, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from a halogen atom, COOR, CONRR’, NRR’CO, COSR, SRCO, OR, NRR’, SR, CN;R2 is chosen from H; C1-C16 alkyl; and a biologically active moiety;R, R’ and R”, identical or different are chosen from H, O, C1-C9 alkyl; m, n and n’, identical or different are integers comprised between 0 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is an integer comprised between 0 and 4; if q is comprised between 3 to 4, A is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-; if m is comprised between 3 to 6, B is not a chain comprising more than three consecutive atoms other than -C1-C9 alkyl-, -3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O;Or a salt thereof;In the form of the cis and / or trans isomers and mixtures thereof;For use as a medicament wherein its in vivo biological activity is triggeredupon exposure to ionizing radiations or endogeneous reactive nitrogen / oxygen species.

2. The compound of formula (I) for use according to claim 1 , whereinEach A identical or different independently represents -O- or -C1-C6 alkyl-;Each B, which may be the same or different, independently represents -O- or - NR- or -C1-C6 alkyl-;Each X and X’ is H or C1 -C6 alkyl;Each Y and Y’ is N or CR;Z is H, COOH, -SO2OH, -PO3H2, halogen atoms, NH2 or a biologically active moiety;Each R1 , RT is H;R2 is H or -C1-c16 alkyl-;R and R’, identical or different are chosen from H, C1-C6 alkyl; m, n and n’, identical or different are integers comprised between 0 to 2; and / or p and p’ identical or different are independently chosen from 0 and 1 ; q is 1.

3. The compound of formula (I) for use according to anyone of the preceding claims wherein:Each Y is N, p=0, andEither each Y’ is N and p’ is 0 or Y’ is CH and p’ is 1 .

4. The compound of formula (I) for use according to anyone of the preceding claims wherein Z is the lenalidomide moiety of formula (II):

5. The compound of formula (I) for use according to anyone of the preceding claims where said compound of formula (I) is selected from:Or a salt thereof;In the form of the cis and / or trans isomers and mixtures thereof.

6. A compound of formula (I) as defined in anyone of claims 1 to 5 which is formula (la):WhereinY is N;P=0;Each Y’ is CH; p’ is 1 ;Each X is H;Z is NRR’ or NRR’R”; m=0; n=2; n’ is 0-6, preferably 0; each R1 , R1’ is H;Each X’, identical or different is independently selected from H; halogen atoms; - OR, -SR, -C1-C9 alkyl, -NRR’, -CN, -C3-C10 cycloalkyl, 3 to 10 membered heterocycle, 5- to 12-membered aryl and heteroaryl, each optionally substituted with one or more group(s) chosen from halogen atoms, COOR, CONRR’, COSR, OR, NRR’, SR, CN;Z is selected from the group consisting in NRR’ or NRR’R”;Each A identical or different independently represents -O-, -NR-, -C1-C9 alkyl-, - 3 to 12 membered aryl or heteroaryl-, -C3-C10 cycloalkyl-, -C=O-, or -SR-;R2 is chosen from H; C1-C16 alkyl; and a biologically active moiety;R, R’ and R”, identical or different are chosen from H, C1-C6 alkyl; q is an integer comprised between 0 and 4;Or a salt thereof;In the form of the cis and / or trans isomers and mixtures thereof.

7. A compound of formula (I) as defined in anyone of claims 1 to 6, which is of formula (lb):WhereinWhen present A represents -O-;Each B, which may be the same or different, independently represents -O- or - C1-C9 alkyl-;Each X and X’, identical or different is independently selected from H or -C1-C9 alkyl;Y and Y’ identical or different are independently chosen from N or CR;Z is selected from the group consisting in COOR, -SO2OR, -PO3R2, NRR’, NRR’R” SeO2OR; SeOOR;R2 is chosen from C1-C9 alkyl;R, R’ and R”, identical or different are chosen from H, C1-C9 alkyl; n=0; n’ is 0-6, preferably 0;R1’ is H; m is an integer comprised between 1 to 6; p and p’ identical or different are integers independently chosen from 0 and 1 ; q is 0 or 1 ;Or a salt thereof;In the form of the cis and / or trans isomers and mixtures thereof.

8. A compound of formula (I) according to claim 7 which is selected from:Or a salt thereof;In the form of the cis and / or trans isomers and mixtures thereof.

9. Process of preparation of a compound of formula (I) according to anyone of the preceding claims, said process for preparing the compounds of formula (I), said process comprising:- the step (a) of derivatizing a compound of formula (Ila):Where A, B, X, X’, Y, Y’, Z, R1, R2, R, R’, m, n, p, p’, q are defined as in Formula (I),And T is a terminal group suitable for addition or substitution, such as a halogen atom, a -OH, -NH2 group or a protecting group thereof,To replace T function with the desired -(B)m-(R1’)n’-Z group as defined in formula (i);- the possible UV or visible or another appropriate wavelength for the conversion irradiation (b) of the product obtained, in order to predominantly obtain the cis isomer.

10. A pharmaceutical composition comprising a compound of formula (I) as defined in any one of claims 1 to 7 predominantly in cis form, and at least one pharmaceutically acceptable excipient.

11. A compound of formula (I) as defined in any of claims 1 to 8 for use in the treatment of primary or metastatic cancer such as lung cancer, pancreatic cancer, liver cancer, spleen cancer, small cell lung carcinoma, prostate cancer, rhabdomyosarcoma, stomach cancer, gastrointestinal cancer, colorectal cancer, kidney cancer, breast cancer, ovarian cancer, testicular cancer, thyroid cancer, head and neck cancer, skin cancer, soft tissue sarcoma, bladder carcinoma, bone cancers, myeloma, plasmacytoma, germ cell cancer, uterine cancer, leukemia, lymphoma, neuroblastoma, osteosarcoma, retinoblastoma, central nervous system cancers, Wilms' tumors.

12. A compound of formula (I) for use according to claim 11 , comprising administration of compound (I) mainly in cis form and irradiation of the tumor with ionizing radiations.

13. A compound of formula (I) for use according to any of claims 10 to 12 said use further comprising monitoring said treatment and / or compound biodistribution by in vivo medical imaging such as PET, X-ray or SPECT.

14. A compound of formula (I) for use according to any of claims 10 to 13 said use further comprising administering one or more anti-cancer agents, such as chemotherapy or immunotherapy such as immune checkpoint inhibitors such as anti-CTLA4, anti-PD-L1 and anti-PD1.

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