Azolo compounds for treating fibrotic diseases

Abstract

The present invention relates to azolo compounds of formula (I) for the treatment of fibrosis, which normalize type I collagen mRNA levels in TGFβ-activated fibroblasts, restoring collagen production to normal levels seen in unstimulated fibroblasts. TIFF2025517407000026.tif4444

Description

[Technical field]

[0001] The present invention relates to antifibrotic agents which can be used in the treatment of fibrosis, particularly cardiac fibrosis. [Background technology]

[0002] Fibrosis remains one of the largest groups of diseases for which there is still no effective treatment, although several potential therapeutic targets have been discussed (Leask, Circulation Research 2010, 106, 1675).

[0003] Fibrotic diseases are known to cause severe illness when they occur in vital organs. When collagen infiltration is increased in muscles and organs that have essential functions in the body, their functions may be completely stopped. Known examples include infiltration of connective tissue in the liver, kidneys, lungs, and heart, where the majority of fibrosis occurs, resulting in over 800,000 deaths per year worldwide. In particular, myocardial fibrosis, which leads to hardening of the myocardium, is one of the main causes of end-stage heart failure (Mozaffarian et al., Heart disease and stroke statistics, Rep. Am. Heart Assoc. infiltration 2016, 133, e38-e360). The infiltration of connective tissue seen in these fibroses is characterized by abnormal and excessive production of collagen by endogenous fibroblasts.

[0004] However, despite the high medical need, no established treatments are known. Most proposed treatments are indirect and rely on suppressing general, non-specific activators of collagen production by fibroblasts or removing overactivated fibroblasts at deleterious intervention points (Hinderer and Schenke-Leyland, Advanced Drug Delivery Reviews 2019, 146, 77; Fan and Guan, Biomaterials Res. 2016, 20, 13 / 1-13; Frangogiannis, Molecular Aspects of Medicine 2019, 65, 70).

[0005] Since elevated blood pressure is known to exert mechanical stress on smooth muscle cells and may cause fibroblast activation, the general use of antihypertensive drugs may also reduce the risk of developing fibrosis. Representative methods for lowering blood pressure include angiotensin-converting enzyme inhibitors, aldosterone antagonists, angiotensin receptor blockers, and calcium antagonists (RG Gourdie, S. Dimmeler, P. Kohl Nat. Rev. Drug Disc. 2016, 15, 620; Y. Shibasaki et al., Hypertens. Res. 2005, 28, 787). Although these drugs provide improvements in general conditions, especially cardiovascular conditions, they are not specific methods for controlling excessive fibroblast activity. These drugs have not been generalized for the prevention and treatment of fibrosis in view of the fine adjustments required in the complex treatment of hypertension, the interactions between known drugs, and the fact that the drugs only mitigate one of many fibroblast activation factors. These considerations also apply to finerenone, a nonsteroidal mineralocorticoid receptor antagonist that may have antifibrotic properties (B. Pitt et al. N Engl J Med 2021,385:2252).

[0006] Certain methods also rely on the inhibition of growth factors that play a general role in cell activation and intracellular signaling, targets that have been primarily investigated or targeted for cancer therapy. These include MMP inhibitors (FG Spinale, Phys. Rev. 2007, 87, 1285), mast cell function inhibitors (S. Oyamada, S. Bianchi, S. Takai, LM Chu, J. Pharm. Exp. Ther. 2011, 339, 143), monoclonal antibodies neutralizing MCP1 (S. Hayashidani et al. Circulation 2003, 108, 2134), CXC chemokine ligand 10 (M. Bujak, Circ. Res. 2009, 105, 973), endothelin pathway inhibitors (F. Rodriguez-Pascual, O. Busnadiego, J. Gonzales-Santamaria, Life Sci. 2014, 118, 156), and WNT signaling modulators (Daskalopoulos et al. al. Trends Cardiovasc. Med. 2013, 23, 121). These intervention points do not exploit cell type specific interactions. These drugs are unlikely to be successful in the long-term treatment of fibrosis due to known side effects. Antiproliferative compounds do not reflect important normal functions of fibroblasts.

[0007] In the healthy heart, fibroblasts are the major cell type responsible for the formation and maintenance of connective tissue (KE Porter, NA Turner Pharmacol. Ther. 2009, 123, 255). This tissue contains cellular and non-cellular components with an extracellular matrix (ECM) that provides a flexible scaffold for individual myocytes and the heart as a whole (JB Caulfield, TK Borg, Lab. Invest. 1979, 40, 364). This highly organized, collagen-rich meshwork laid down by fibroblasts stabilizes the myocardial wall and supports force transmission, yet allows complex patterns of tissue deformation (PW Hales et al., Prog. Biophys. Mol. Biol. 2012, 110, 319). After myocardial injury, endothelial cells undergo endothelial-mesenchymal transition (EndMT), which may contribute to fibrosis (EM Zeisberg et al., Nat Med. 2007, 13, 952). During this process, endothelial cells lose their endothelial identity and acquire mesenchymal or myofibroblast markers, such as expression of αSMA and secretion of collagen type I. Prevention of smooth muscle cell transformation and excessive collagen production after cardiac injury, for example after multiple cell death due to ischemia, is an important indicator of a non-toxic anti-fibrotic compound.

[0008] Hydralazine and dihydralazine, two drugs that have been in clinical use since 1952 to treat hypertension, were found in 2019 to exhibit antifibrotic effects. For example, low doses of dihydralazine have a protective effect by inducing endogenous Tet3 / Tdg-mediated DNA demethylation activity, which reverses aberrant promoter CpG island methylation (B. Tampe, D. Tampe, EM Zeisberg, GA Mueller, W. Bechtel-Walz, M. Koziolek, R. Kalluri, M. Zeisberg, EBioMedicine 2015, 2, 19; G. Hasenfuss et al. DE 102019126517 A1 2021.04 01). However, despite their strong antihypertensive effects, these two compounds have problems such as large interpatient variability (JR Batchelor et al., Lancet 1980, 1(8178), 1107; AM Shepherd et al., Clin. Res. 1980, 28, 244A) and drug-induced lupus (M. Bourdi et al., Mol. Pharmacol. 1992, 42, 280; C. Chang, M. Gershwin, J. Autoimmunity 2010, 34, J266).

[0009] In conclusion, there are currently no compounds that treat fibrosis itself, and most of the proposed treatments are indirect, relying on the inhibition of general, but not specific, activators of fibroblast collagen production, or the elimination of overactivated fibroblasts at harmful intervention points. WO2016 / 085981A1 proposes the use of isoprenoid compounds, in particular geranyl-geranylacetone, for the inhibition, reduction, or treatment of fibrosis. WO2016 / 046130A1 proposes the use of monoacylglycerol lipase (MGL) inhibitors. WO2021 / 089828A1 discloses nucleic acid ligase inhibitors as potential therapeutic agents for fibrosis. The mechanism of action is generally antiproliferative, and like typical cancer treatments, has known undesirable side effects.

[0010] The main factor activating fibroblasts is the increase in endogenous TGFβ, which induces increased collagen production by inducing increased mRNA levels of type I collagen (M. Lodyga and B. Hinz, Semin. Cell. Dev. Biol. 2020, 101, 123; JM Carthy, J. Cell. Physiol. 2018, 233(1), 98). This has been demonstrated in vivo as well as in cell culture (Lijnen, Pedrov, and Fagard, Molecular Genetics and Metabol. 2000, 71, 418), and thus TGFβ stimulation of human renal fibroblast cell lines (tFKIF and tNKF) has created an in vitro model that represents the pathophysiological mechanisms of renal interstitial fibrosis, thereby allowing the identification of potential therapeutic approaches (GA Mueller et al., Exp. Nephrol. 1995, 3, 127).

[0011] Thus, there is a need for compounds for treating fibrosis that can effectively reduce the formation of fibrotic fibers without causing adverse side effects to the patient. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] International Publication No. 2016 / 085981 [Patent Document 2] International Publication No. 2016 / 046130 [Patent Document 3] International Publication No. 2021 / 089828 [Patent Document 4] DE 102019126517 [Non-patent literature]

[0013] [Non-Patent Document 1] Leask, Andrew. "Potential therapeutic targets for cardiac fibrosis: TGFβ, angiotensin, endothelin, CCN2, and PDGF, partners in fibroblast activation." Circulation research 106.11 (2010): 1675-1680. [Non-Patent Document 2] Mozaffarian, Dariush, et al. "Heart disease and stroke statistics-2016 update: a report from the American Heart Association." Circulation 133.4 (2016): e38-e360. [Non-Patent Document 3] Hinderer, Svenja, and Katja Schenke-Layland. "Cardiac fibrosis-A short review of causes and therapeutic strategies." Advanced drug delivery reviews 146 (2019): 77-82. [Non-Patent Document 4] Fan, Zhaobo, and Jianjun Guan. "Antifibrotic therapies to control cardiac fibrosis." Biomaterials research 20.1 (2016): 1-13. [Non-Patent Document 5] Frangogiannis, Nikolaos G. "Cardiac fibrosis: cell biological mechanisms, molecular pathways and therapeutic opportunities." Molecular aspects of medicine 65 (2019): 70-99. [Non-Patent Document 6] Gourdie, Robert G., Stefanie Dimmeler, and Peter Kohl. "Novel therapeutic strategies targeting fibroblasts and fibrosis in heart disease." Nature reviews Drug discovery15.9 (2016): 620-638.

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[0014] Surprisingly, the inventors have discovered compounds of general formula I: [ka] were found to normalize type I collagen mRNA levels in TGFβ-activated fibroblasts and restore their collagen production to normal levels seen in unstimulated fibroblasts. Examples 60 to 62 demonstrate the biological properties of the azolo compounds of the present invention.

[0015] As already mentioned, fibrosis is characterized by the abnormal and excessive production of collagen by endogenous fibroblasts. A suitable treatment for this disease must normalize fibroblast activity without toxicity to the phenotype of the cells and without interfering with their normal function for connective tissue regeneration, for example after wounds or tissue damage. The inventors have unexpectedly found that compounds of general formula I meet this requirement. In particular, these structures attenuate and normalize the increased collagen production and revert the fibrous phenotype of overactive fibroblasts to that of non-activated fibroblasts. This effect is not achieved by a deleterious mechanism of action, since it occurs at effective levels without signs of cytotoxicity. In this way, compounds of general formula (I) revert the typical elongated fibrous phenotype of activated fibroblasts to normal. This remarkable and potent effect is usually expressed at concentrations where no attenuation of classical housekeeping enzymes and proteins such as GAPDH (Western blot) and reductase (MTT assay) is observed.

[0016] Therefore, the compounds of general formula I are of great value in the prevention and treatment of fibrosis that is life-threatening or significantly reduces the quality of life, such as, but not limited to, renal fibrosis, hepatic fibrosis, pulmonary fibrosis, and especially cardiac fibrosis.

[0017] The present invention therefore relates to an azolo compound (I) for use in a method for the treatment or prevention of fibrosis. [ka] And, During the ceremony, R is H, D, CN, NHR 5 , N.D.R. 5 , Cl, OR 3 , S.R. 3 and C 1-4 - alkyl, in particular methyl, X is N or CR 1 (wherein the nitrogen atom and the carbon atom are aromatic atoms), W is a covalent bond, CR4 (wherein the carbon atom is an aromatic ring atom), CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR 2 is selected from the group consisting of X 1 is a covalent bond, CR 4 (wherein the carbon atom is an aromatic ring atom), CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR 2 is selected from the group consisting of Y is a covalent bond, CR 4 (wherein the carbon atom is an aromatic ring atom), CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR 2 is selected from the group consisting of Z is covalent bond, CR 4 (wherein the carbon atom is an aromatic ring atom), CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR 2 is selected from the group consisting of In the formula, the dashed line represents a single or double bond. W, X 1 Y and Z are selected to form the same ring, said ring being 5- or 6-membered; W, X 1 , Y and Z are selected so that the ring does not contain more than two nitrogen atoms; 1 , Y and Z are selected such that the ring does not contain an acetal, thioacetal, aminal or hydrazine group; The compound does not contain a peroxide group or a disulfide group; R 1 OH, halogen, OR 3 may be substituted by H, D, CD 3 , C.H.D. 2 , C.H. 2 D, C.F. 3 , CHF 2 , C.H. 2 F, CDF 2 , CD 2 F and C 1-4 -alkyl, R2 CHO, COCH 3 , COC 2 H 5 , COC 3 H 7 , COCH(CH 3 ) 2 , COC 4 H 9 , COC(CH 3 ) 3 is selected from the group consisting of R 3 is C 1-4 -alkyl, R 4 are H, D, F, Cl, methyl, CH 2 F, CHF 2 , C.F. 3 , O.C.H. 3 , OCD 3 is selected from the group consisting of R 5 may be substituted with OH 1-4 -alkyl.

[0018] The present invention further relates to a compound having the structure (I) of claim 1: [ka] and a pharma- ceutically acceptable carrier, preferably for use in the treatment of fibrosis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention relates to such novel azolo compounds of structure (I) and in particular to their use in the treatment of fibrotic diseases. [ka]

[0020] In general, compounds of formula I can be prepared by methods well known in the art (Druey and Rinigier, Helv. Chim. Acta, 34 (1951), 195; Zimmer, Kokosa, and Shah, J. Org. Chem. 40 (1975), 2901). When X represents nitrogen (tetrazolo compound), there are two typical methods shown in Scheme I: the chloropyridazine of formula II is reacted with a metal azide in a dipolar aprotic solvent at elevated temperature (Method A). The preferred metal azide is sodium azide, and the preferred conditions are DMF as solvent at a temperature of about 120° C. for several hours. Method A is exemplified in Examples 2 and 35. [ka]

[0021] Another method uses hydrazine compounds of formula III and reacts them with nitrous acid generated in situ from sodium nitrite under acidic conditions (Badr 1984) (Method B). Preferred conditions use dilute acetic acid and a slight excess of nitrite at 0° C. to room temperature. Method B is exemplified in Examples 1 and 17.

[0022] When X in formula I represents a substituted carbon atom, several known methods can be applied (Druey 1951). Representative methods are shown in Scheme 2. Thus, compounds of formula III can be reacted with reactive carboxylic acids (Method C1) or activated carboxylic acid derivatives (Methods C2, C3). Reactive carboxylic acids are lower alkyl carboxylic acids (e.g., formic acid, acetic acid, propionic acid, etc.) or carboxylic acids bearing electron-withdrawing substituents (halogens, oxygen, etc.) at the alpha position. Preferred conditions include heating at reflux for several hours using the carboxylic acid as the solvent. Method C1 is exemplified in Examples 10 and 12.

[0023] Activated carboxylic acid derivatives include anhydrides (Badr, El-Sherief, El-Naggar, and Mahgoub, J. Heterocycl. Chem. (1984), 21, 471) (Method C2), formates, orthoesters (Method C3), or carboxylic acid derivatives with a suitable leaving group. Preferred conditions are reaction with orthoesters or reflux with excess anhydride in an alcohol solvent at room temperature. Method C2 is exemplified in Example 4. Method C3 is exemplified in Examples 3 and 15.

[0024] [ka]

[0025] Alternatively, chloroazines of formula II can be reacted with carboxylic acid hydrazides in aprotic solvents at higher temperatures (Method C4). Preferred conditions are 100-120° C., with typical solvents being DMF or dioxane. Method C4 is exemplified in Examples 5, 11 and 13.

[0026] WX 1 When -YZ represents a fused heterocycle such as a thiophene or a furan, the intermediates required for the synthesis of compounds of general formula I can be obtained by a directed ortho-metallation (DoM) reaction. Either a thiophene carboxylic acid or a furan carboxylic acid is treated with a strong base such as butyllithium. The lithiated heterocycle is quenched with DMF to give the ortho-formyl acid (Method D1) or with dry ice (carbon dioxide) to give the corresponding ortho-dicarboxylic acid (Method D2) (Scheme 3). [ka]

[0027] The resulting ortho-formyl carboxylic acids are readily converted to the phthalazinones by heating with aqueous hydrazine and treatment with phosphorus oxychloride gives the dichlorophthalazines IIb (Method D1). Dichloroazines IIa are prepared in a similar manner (Method D2).

[0028] In the first embodiment, in the general formula (I), R is H, D, CN, NHR 5 , N.D.R. 5 , Cl, OR 3 , S.R. 3 and C 1-4 -alkyl. That is, when R=H, H is covalently bonded to a carbon atom of the ring (-H). Similarly, when R=D, D is covalently bonded to a carbon atom of the ring (-D). Similarly, when R=CN, CN is covalently bonded to a carbon atom of the ring (-CN). Similarly, when R=NHR, 5 In the case of NHR 5 is covalently bonded to a carbon atom in the ring (-NHR 5 This is true for any group that is an option for R. R is preferably H, CH 3 , Cl, CN, OCH 3 , O.C. 2 H 5 , N.H.C. 2 H 4 OH, NHCH 3 R is more preferably selected from the group consisting of H and CH 3 In a most preferred embodiment, R is H.

[0029] The term "alkyl," as used herein, refers to a straight-chain or branched hydrocarbon substituent; examples of alkyl groups include methyl, ethyl, propyl, butyl, isopropyl, sec-butyl, isobutyl, tert-butyl, and the like.

[0030] In the general formula (I), W is a covalent bond, CR 4 where the carbon atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms, CH 2, S, O, N (wherein the nitrogen atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms), NH and NR 2 When W is selected as a covalent bond (whereas X 1 , Y and Z are not covalent bonds), W, X 1 The ring formed by Y, Z and the two bridging carbon atoms is a five-membered ring. Preferably, W is CH (bonded to its adjacent atoms by single and double bonds), CH 2 (bonded to its adjacent atom by two single bonds), N (bonded to its adjacent atom by a single and a double bond), NH (bonded to its adjacent atom by two single bonds), O, S, and a covalent bond.

[0031] Similarly, X 1 is a covalent bond, CR 4 where the carbon atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms, CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms), NH and NR 2 X may be selected from the group consisting of 1 is selected as a covalent bond (whereas W, Y and Z are not covalent bonds), W, X 1 The ring formed by X, Y, Z and the two bridging carbon atoms is a five-membered ring. 1 is CH (bonded to its neighboring atoms by single and double bonds), CH 2 (bonded to its adjacent atom by two single bonds), N (bonded to its adjacent atom by a single and a double bond), NH (bonded to its adjacent atom by two single bonds), O, S, and a covalent bond.

[0032] Similarly, Y is a covalent bond, CR 4 where the carbon atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms, CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms), NH and NR 2When Y is selected as a covalent bond (whereas W, X 1 and Z is not a covalent bond), W, X 1 The ring formed by Y, Z and the two bridging carbon atoms is a five-membered ring. Preferably, Y is CH (bonded to its adjacent atoms by single and double bonds), CH 2 (bonded to its adjacent atom by two single bonds), N (bonded to its adjacent atom by a single and a double bond), NH (bonded to its adjacent atom by two single bonds), O, S, and a covalent bond.

[0033] Similarly, Z is a covalent bond, CR 4 where the carbon atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms, CH 2 , S, O, N (wherein the nitrogen atom is an aromatic ring atom, i.e., has single and double bonds to its neighboring atoms), NH and NR 2 When Z is selected as a covalent bond (whereas W, X 1 and Y is not a covalent bond), W, X 1 The ring formed by Y, Z and the two bridging carbon atoms is a five-membered ring. Preferably, Z is CH (bonded to its adjacent atoms by single and double bonds), CH 2 (bonded to its adjacent atom by two single bonds), N (bonded to its adjacent atom by a single and a double bond), NH (bonded to its adjacent atom by two single bonds), O, S, and a covalent bond.

[0034] Also in general formula (I), the dashed lines represent single bonds (single line) or double bonds (double line). A single bond can be directly adjacent to either a single bond or a double bond, but a double bond cannot be selected to be directly adjacent to an adjacent double bond.

[0035] As shown in general formula (I), W, X 1 , Y and Z are selected to form the same ring, the ring being 5 or 6 membered. That is, when W is selected as a covalent bond (single or double), X 1Neither X, Y nor Z can be selected as a covalent bond (either single or double). 1 If is selected as a covalent bond, then none of W, Y, or Z can be selected as a covalent bond. Similarly, if Y is selected as a covalent bond, then W, X, 1 , Z may not be selected as a covalent bond. Similarly, if Z is selected as a covalent bond, then W, Y, X, 1 None of the above can be selected as a covalent bond.

[0036] Furthermore, in the general formula (I), W, X 1 , Y and Z are W, X 1 , Y and Z and the two bridging carbon atoms are selected so that each ring formed does not contain more than two nitrogen atoms in the ring.

[0037] Furthermore, in the general formula (I), W, X 1 , Y and Z are selected such that the ring does not contain acetal, thioacetal, aminal or hydrazine groups and the compound does not contain peroxide or disulfide groups.

[0038] In the general formula (I), R 1 OH, halogen, OR 3 may be substituted by H, D, CD 3 , C.H.D. 2 , C.H. 2 D, C.F. 3 , CHF 2 , C.H. 2 F, CDF 2 , CD 2 F and C 1―4 -alkyl. Preferably, R 1 are H, D, and CH 3 , CD3, CF 3 , C.H. 2 OCH 3 , cyclopropyl, i.e., R 1 In the case of =H, H is covalently bonded to a carbon atom in the ring (-H), and R 1The same is true for any group that is an option.

[0039] In the general formula (I), R 2 CHO, COCH 3 , COC 2 H 5 , COC 3 H 7 , COCH(CH 3 ) 2 , COC 4 H 9 , COC(CH 3 ) 3 Preferably, R 2 CHO and COCH 3 That is, R 2 In the case of =CHO, CHO is covalently bonded to the nitrogen atom of the ring (-CHO) and R 2 The same is true for any group that is an option.

[0040] In the general formula (I), R 3 is C 1-4 -alkyl, preferably C 1-4 -alkyl, more preferably methyl. That is, R 3 =C 1 Alkyl (i.e. CH 3 / methyl), CH 3 is covalently bonded to a sulfur atom (-CH 3 ), and R 3 The same is true for any group that is an option.

[0041] In the general formula (I), R 4 are H, D, F, Cl, methyl, CH 2 F, CHF 2 , C.F. 3 , O.C.H. 3 , OCD 3 Preferably, R 4 is H, F, Cl and OCH 3 , optionally selected from the group consisting of H, F and Cl. That is, R 4In the case of =H, H is covalently bonded to a carbon atom in the ring (-CH 3 ), and R 4 Optionally, when X=N, R 4 OCH 3 But O.C.D. 3 That is, optionally, if X=N, then R 4 are H, D, F, Cl, methyl, CH 2 F, CHF 2 , and C.F. 3 is selected from the group consisting of:

[0042] In the general formula (I), R 5 may be substituted with OH 1-4 -alkyl. That is, R 5 =C 1 Alkyl (i.e. CH 3 / methyl), CH 3 is covalently bonded to the nitrogen atom (-CH 3 ), and R 5 The same is true for any group that is an option.

[0043] In the context of the present invention, all "embodiments" described herein can be combined with each other. That is, as an example, in one "embodiment", 1 If is defined, then R 2 or any other substituent.

[0044] The azolo compound of general formula (I) is used for treating fibrosis.The examples of fibrosis include but are not limited to renal fibrosis, hepatic fibrosis, pulmonary fibrosis and cardiac fibrosis, optionally cardiac fibrosis.Cardiac fibrosis can contribute to heart failure and other cardiac complications in hypertensive heart disease patients.

[0045] The azolo compounds of general formula (I) can be used in the treatment of fibrosis, either as a single compound or as a mixture of any two or more compounds. Optionally, the azolo compounds are administered in combination with an excipient selected from inorganic or organic excipients or combinations thereof. Inorganic excipients include calcium phosphate, calcium carbonate, calcium sulfate, halides, metal oxides, talc, etc. Organic excipients include sugars, sugar alcohols, carbohydrates such as starch, cellulose ethers, cellulose esters, carboxymethylcellulose, microcrystalline cellulose, petrochemicals, povidone, acrylic polymers, etc.

[0046] As mentioned above, in general formula (I), the dashed lines represent a single bond (single line) or a double bond (double line) or an aromatic ring system. 1 For the carbon atoms connecting the ring containing Y and Z to the adjacent ring to which it is directly bonded, a single bond (single line) or a double bond (double line) is shown. The structure formed by the general formula (I) is, [ka] and [ka] Includes.

[0047] W, X 1 The structures preferably formed by selecting W, X, and Z can be represented by the general formulas (IIa-c) and (IIIa-d). The general formula (IIa-c) represents W, X, 1 , Y and Z and two bridging carbon atoms form a six-membered ring, and general formula (IIIa-d) represents W, X 1 , Y and Z and the five-membered ring formed by the two bridging carbon atoms. [ka]

[0048] Regarding the general formula (IIb), W, X 1 , one of Y and Z is N, and the rest are CH groups.

[0049] Regarding the general formula (IIc), W, X 1 , one of Y and Z is NH and the rest are CH 2 It is based on [ka]

[0050] Regarding the general formula (IIIa), Z is S, W, X 1 and one of Y is a covalent bond and the rest are CH groups.

[0051] Regarding the general formula (IIIb), W is S and X 1 , one of Y and Z is a covalent bond, and the rest are CH groups.

[0052] Regarding the general formula (IIIc), Y or X 1 Either of these is S and X 1 , one of Y and Z is a covalent bond, and the rest are CH groups.

[0053] Regarding the general formula (IIId), W is O and X 1 , one of Y and Z is a covalent bond, and the rest are CH groups.

[0054] It should be noted that no hydrogen atoms are shown in formula (I). Furthermore, any atom in general formula (I) can be replaced by any of its isotopes. That is, any hydrogen atom (not shown in formula (I)) in general formula (I) can be replaced (partially or completely) by deuterium D. The preferred positions for replacing hydrogen with deuterium are as defined in the claims. For example, R can be selected from the group including hydrogen and deuterium, as defined in the claims. Furthermore, R 1 can be selected from the group consisting of hydrogen and deuterium, as defined in the claims.1 Any alkyl group in R may be optionally fully or partially substituted with deuterium instead of hydrogen. 4 may be selected from the group consisting of hydrogen and deuterium, as defined in the claims. 1 =CD 3 , or R=D, and / or R 4 =D.

[0055] Furthermore, any carbon atom in the general formula (I) may be any of its isotopes, preferably 13 In addition, any nitrogen atom in general formula (I) can be substituted (partially or fully) with 15 It can be substituted (partially or completely) with N.

[0056] In a second embodiment, R is H, CN, NHR 5 , Cl, OR 3 , methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl and SR 3 is selected from the group consisting of:

[0057] In a further embodiment, R 1 is OH, halogen or OR 3 may be substituted by H, D, CD 3 , C.H.D. 2 , C.H. 2 D, C.F. 3 , CHF 2 , C.H. 2 F, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, and cyclopropyl; and optionally, R 1 is H, methyl, CD 3 , C.F. 3 , C.H. 2 OH, ethyl, CH 2 OCH 3 and cyclopropyl.

[0058] In a further embodiment, R3 is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl.

[0059] In a further embodiment, R 5 is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl, optionally substituted with OH.

[0060] In a further embodiment, W, X 1 , Y and Z are selected such that the compound does not contain a peroxide group and / or such that the compound does not contain a disulfide group.

[0061] In a further embodiment, X is N or CR 1 R 1 is H, methyl, CH 2 F, C.D. 2 F, CHF 2 , CDF 2 and CF 3 and preferably, X is selected from the group consisting of CR 1 and R is H or D. Optionally, when X=N, R 4 is OCH 3 But O.C.D. 3 That is, optionally, if X=N, then R 4 are H, D, F, Cl, methyl, CH 2 F, CHF 2 , and C.F. 3 is selected from the group consisting of:

[0062] In a further embodiment, W, X 1 , Y and Z are selected such that the ring consists of carbon atoms or such that the ring consists of carbon atoms and one heteroatom.

[0063] In a further embodiment, W, X 1 , Y and Z are selected such that the ring is aromatic or non-aromatic.

[0064] In a further embodiment, W, X 1 , Y and Z are arranged in a moiety (W…X) according to one of the following ring atom arrangements: 1 ...Y...Z). C...C...C...C, N...C...C...C, C...N...C...C, C...C...N...C, C...C...C...N, S...C...C...C, C...S...C...C, C...C...S...C, C...C...C...S, O...C...C...C, C...O...C...C, C...C...O...C, C...C...C...O, C...C...C, N...C...C, C...N...C, C...C...N, S...C...C, C...S...C, C...C...S, O...C...C, C...O...C, C...C...O (where "..." represents a single or double bond).

[0065] In a further embodiment, W, X 1 , Y and Z are independently selected such that the ring forms a pyrrolidine, dihydrofuran, dihydrothiophene, pyrrole, furan, thiophene, oxazole, thiazole, tetrahydrobenzene, oxane, thiane, benzene, pyridine, pyran, thiopyran, preferably a benzene, pyridine, dihydropyridine, thiophene or furan structure.

[0066] In a further embodiment, W, X 1 , Y and Z are independently CH=CH-CH=CH (forming an aromatic ring), CH=N-CH=CH (forming an aromatic ring), N=CH-CH=CH (forming an aromatic ring), CH=CH-CH=N (forming an aromatic ring), NH-CH 2 -CH 2 -CH 2 , C.H. 2 -NH-CH 2 =CH 2 , C.H. 2 -NCOCH 3 -CH 2 -CH 2 , S-CH=CH, CH=CH-S, CH-S-CH, CH=CH-O; 1 ...Y...Z), preferably CH=CH-CH=CH (forming an aromatic ring) or CH-S-CH.

[0067] In a further embodiment, R=H, X=CH, and W, X 1 , Y and Z are independently selected to contain one or two of CF or C-Cl.

[0068] In a further embodiment, R=H and X=CH, and W, X 1 , Y and Z are independently selected to form the moiety CH=CH-CH=CH.

[0069] In a further embodiment, R=H and X=C-CH 3 or N, and W, X 1 , Y and Z are independently selected to form the moiety CH=CH-CH=CH.

[0070] In a further embodiment, R=H and X=C-CH 3 or N, and W, X 1 , Y and Z are independently selected to form the moiety CH-S-CH.

[0071] In a further embodiment, X and R are independently selected such that the following compounds are excluded: X=C-CH 3 , R=CH, and W, X 1 , Y and Z=CH.

[0072] In a further embodiment, W, X 1 , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H and X is N.

[0073] In a further embodiment, W, X 1 , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H, and X is C-CH 3 It is.

[0074] In a further embodiment, W, X 1 , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H and X is CH.

[0075] In a further embodiment, W, X 1 , Y and Z are selected to form the moiety CH-S-CH, R=H, and X is C-CH 3 It is.

[0076] In a further embodiment, W, X 1 , Y and Z are selected to form the moiety CH-S-CH, R=H and X is N.

[0077] In a further embodiment, X is C-CH 3 R is H, and W, X 1 , Y and Z are groups CR 4 =CR 4 -CR 4 =CR 4 (R 4 One of the groups is F, Cl, and OCH 3 The remaining three R 4 The group is hydrogen.

[0078] In a further embodiment, X is C-CH 3 R is H, and W, X 1 , Y and Z are groups CR 4 =CR 4 -CR 4 =CR 4 (R 4 Two of the groups are independently F, Cl and OCH 3 The remaining two R 4 The group is hydrogen.

[0079] In a further embodiment, the azolo compound (I) is selected from the group consisting of: [ka] [ka] [ka]

[0080] The azolo compounds of general formula (I) are used in a method for the treatment or prevention of fibrosis. In a further embodiment, the fibrosis is selected from the group consisting of renal fibrosis, hepatic fibrosis, pulmonary fibrosis and cardiac fibrosis, optionally cardiac fibrosis.

[0081] In further embodiments, one or more of the carbon (C) and nitrogen (N) atoms of the embodiments disclosed herein are 13 C isotope, and N atom is 15 N isotope, 13 C isotopes and 15 It is possible to have compounds with H / D, C, and N isotopes. Furthermore, varying the isotopic composition of H / D, C, and N can be applied to the pharmacological evaluation of drugs to determine the pharmacokinetic profile and mechanism of action of the drug substance. Secondly, stable isotopes can be used as internal standards to assess the concentration of drugs and their metabolites in blood and urine using analytical quantification by LC-MS, HPLC-MS, LC-MS-MS, or HPLC-MS-MS methods.

[0082] In a further embodiment, there is provided a pharmaceutical composition for treating fibrosis comprising an azolo compound or a mixture of azolo compounds having structure (I) as defined in claim 1 and a pharma- ceutically acceptable carrier. [ka] In general formula (I), the dashed lines represent single bonds (single line) or double bonds (double line) or aromatic ring systems. 1 For the carbon atoms connecting the ring containing Y and Z to the adjacent ring to which it is directly bonded, a single bond (single line) or a double bond (double line) is shown.

[0083] In a further embodiment, the pharmaceutical composition is an oral solid formulation and / or the azolo compound is present in an effective amount. The effective amount of the azolo compound is 5 to 500 mg, preferably 10 to 200 mg. The compounds of the present invention and their pharma- ceutically acceptable salts can be used as medicaments, for example in the form of pharmaceutical compositions. The pharmaceutical compositions can be administered orally, for example in the form of tablets, coated tablets, dragees, hard and soft gelatin capsules, solutions, emulsions or suspensions. Alternatively, they can be administered parenterally, for example in the form of injection solutions.

[0084] The above pharmaceutical compositions can be obtained by processing the compounds of the present invention with pharma- ceutically acceptable inorganic or organic carriers. Lactose, corn starch or its derivatives, talc, stearic acid or its salts, etc. can be used as, for example, carriers for tablets, coated tablets, dragees, hard gelatin capsules, etc. Suitable carriers for soft gelatin capsules include, for example, vegetable oils, waxes, fats, semi-solid and liquid polyols, etc. Depending on the nature of the active ingredient, carriers are usually not necessary for soft gelatin capsules. Suitable carriers for the preparation of solutions and syrups include, for example, water, polyols, glycerol, vegetable oils, etc. Suitable carriers for suppositories include, for example, natural or hardened oils, waxes, fats, semi-liquid or liquid polyols, etc. The pharmaceutical composition may further comprise preservatives, solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorings, salts for changing the osmotic pressure, buffers, masking agents or antioxidants. The pharmaceutical composition may also contain other therapeutically valuable substances. The pharmaceutical compositions may include, for example: a) Tablet formulation (wet granulation) JPEG2025517407000017.jpg3479b) Capsule formulation JPEG2025517407000018.jpg3479

[0085] As used herein, the term "therapeutically effective amount" of a compound means an amount of compound effective in preventing, alleviating or ameliorating symptoms of disease or prolonging the survival of the subject being treated. Determination of a therapeutically effective amount is within the skill of the art.

[0086] The therapeutically effective amount or dosage of the compound of the present invention may vary within a wide range and may be determined by methods known in the art. Such dosage is adjusted to the individual requirements of each particular case, including the patient to be treated, the specific compound to be administered, the route of administration, the condition to be treated, etc. In general, for oral or parenteral administration to an adult weighing about 70 kg, the daily dosage may be considered to be therapeutically effective in the range of about 5 mg to about 500 mg, preferably about 10 mg to about 200 mg, although this upper limit may be exceeded if indicated. The daily dosage may be administered in a single dose or in divided doses, or may be administered parenterally as continuous infusion.

[0087] As used herein, "pharmaceutically acceptable carrier" is intended to include any material compatible with pharmaceutical administration, including solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and other materials and compounds compatible with pharmaceutical administration. Except insofar as any conventional media or agent is incompatible with the active compound, its use in the compositions of the present invention is contemplated. Supplementary active compounds can also be incorporated into the compositions.

[0088] The compounds of the present invention can be present and administered in the form of their pharma- ceutically acceptable salts or esters. The term "pharma- ceutically acceptable salts" refers to conventional acid addition salts that retain the biological effectiveness and properties of the compounds of formula I and are formed from suitable non-toxic organic or inorganic acids. Examples of acid addition salts include those derived from inorganic acids such as hydrochloric acid, sulfuric acid, and those derived from organic acids such as p-toluenesulfonic acid, naphthalenesulfonic acid, naphthalenedisulfonic acid, methanesulfonic acid, ethanesulfonic acid, and the like. Chemical modification of pharmaceutical compounds (i.e. drugs) into salts is a technique well known to medicinal chemists to improve the physical and chemical stability, hygroscopicity, flowability, and solubility of the compounds (see, for example, Bastin, RJ, et al., Organic Proc. Res. Dev. 4 (2000) 427-435). Suitable examples include pharma- ceutically acceptable salts formed with p-toluenesulfonic acid, naphthalenesulfonic acid, naphthalenedisulfonic acid, methanesulfonic acid, sulfuric acid, and hydrochloric acid.

[0089] In a preferred embodiment, the azolo compounds defined in the claims are administered in the form of tablets. EXAMPLES

[0090] Synthesis of compounds Example 1 Tetrazolo[5,1-a]phthalazine 1 370 mg (5.35 mmol) of sodium nitrite dissolved in a minimum amount of water was added to a stirred solution of 982 mg (5.00 mmol) of hydralazine hydrochloride and 450 mg (5.50 mmol) of sodium acetate in 10 ml of 2N acetic acid at 0° C. A precipitate formed immediately. After 30 min, the precipitate was isolated by filtration and washed with a small amount of ice water. Drying in vacuum at 40° C. gave 784 mg (86%) of 1. The combined filtrate was extracted with ethyl acetate to give an additional 60 mg (6%) of 1. 1 H-NMR (300MHz, CDCl 3): δ = 8.03 (td, J = 7.7, 1.3 Hz, 1H), 8.14 (mc, 2H), 8.76 (d, J = 7.9 Hz, 1H), 8.96 (s, 1H, 6H).

[0091] Example 2 6-Methyl-tetrazolo[5,1-a]phthalazine 2 A mixture of 200 mg (3.1 mmol) sodium azide, 264 mg (1.48 mmol) 1-chloro-4-methylphthalazine, and 10 ml DMF was heated to 120° C. for 5 h. After addition of 20 ml water at 0° C., the pale yellow precipitate that formed was sucked off. After washing twice with 5 ml ice water and drying in vacuum, 230 mg (84%) of 2 was obtained as colorless felted needles. 1 H-NMR (300MHz, CDCl 3 ): δ = 3.02 (s, 3H, CH 3 ) 8.03 (td, J = 7.5, 1.4 Hz, 1H), 8.10 (td, J = 7.5, 1.4 Hz, 1H), 8.22 (d, J = 7.6 Hz, 1H), 8.77 (d, J = 7.8 Hz, 1H).

[0092] Example 3 3-Methyl-1,2,4-trizolo[3,4-a]phthalazine 3 To a mixture of 983 mg (5.00 mmol) of hydralazine hydrochloride and 10 mL of methanol, 1.01 mL (5.50 mmol) of triethyl orthoacetate was added and stirred at room temperature. After 15 min, the suspension was removed and a new precipitate started. After 1 h, another 10 mL of methanol was added and stirring was continued for 1 h, after which the mixture was evaporated. The residue was taken up in 40 mL of water and solid NaHCO 3 The pH was adjusted to 7 with 50 mL of ethyl acetate. The precipitate that formed was isolated by filtration, washed with ice-cold water and sucked dry. Drying in vacuum at 50° C. gave 833 mg (90%) of 3. The combined filtrates were extracted with 40 mL of ethyl acetate to give an additional 30 mg (3%) of 3. 1 H-NMR (300MHz,): δ = 2.83 (s, 3H, CH 3), 7.79 (ddd, J = 8.3, 7.4, 1.2 Hz, 1H), 7.93 (td, J = 8.7, 1.2 Hz, 1H), 7.99 (td, J = 7.6, 1.2 Hz, 1H), 8.61 (s, 1H), 8.63 (dd, J = 9.1, 1.2 Hz, 1H).

[0093] Example 4 6-Chloro-3-methyl-1,2,4-triazolo[3,4-a]phthalazine 4 A mixture of 2.58 g (13.0 mmol) of 1,4-dichlorophthalazine, 50 ml of ethanol, and 5.0 ml of 55% hydrazine was heated at reflux for 30 min. After cooling to room temperature (rt), the felt precipitate was sucked off and washed twice with ice-cold ethanol. After washing with 10 ml of tert-butyl methyl ether and 10 ml of pentane, the residue was dried in vacuum. 2.23 g (84%) of 1-chloro-4-hydrazinylphthalazine was obtained.

[0094] The above analytical sample (211 mg, 1.08 mmol) was treated with 0.9 mL (1.12 mmol) of 1.25 M hydrochloric acid in methanol and evaporated to dryness in vacuo to give the hydrochloride salt of 1-chloro-4-hydrazinylphthalazine. 1 H-NMR (300MHz, D 2 O): δ = 7.97-8.29 (m, 4H).

[0095] To a suspension of 195 mg (1.00 mmol) of 1-chloro-4-hydrazinylphthalazine in 6.0 mL of dioxane was added acetic anhydride (0.5 mL, 5 mmol) and the mixture was heated at reflux for 1 h. After evaporation, the residue was treated with 10 mL of ice water and the pH was adjusted to 7 by adding sodium bicarbonate. After extraction with two 25 mL portions of dichloromethane and evaporation, the remaining solid was purified (silica, dichloromethane / methanol 20:1). After drying in vacuum, the yield was 198 mg of 4. 1 H-NMR (300MHz, CDCl 3 ): δ = 2.82 (s, 3H, CH 3), 7.86 (ddd, J = 8.3, 7.4, 1.2Hz, 1H), 8.00 (td, J = 7.6, 1.2 Hz, 1H), 8.26(ddd, J = 8.2, 1.3, 0.6 Hz, 1H), 8.67 (ddd, J = 8.0, 1.3, 0.7 Hz, 1H).

[0096] Example 5 3,6-Dimethyl-1,2,4-triazolo[3,4-a]phthalazine 5 A mixture of 174 mg (0.97 mmol) 1-chloro-3-methylphthalazine, 150 mg (2.02 mmol) acetic hydrazide, and 5.0 ml dioxane was heated at reflux for 1 h. After cooling to room temperature, the mixture was evaporated and the residue was treated with 30 ml water. Extraction with 30 ml dichloromethane twice and evaporation gave 219 mg of residue. After purification by flash chromatography on silica (eluent: dichloromethane / methanol 20:1), 176 mg (90%) of the title compound 5 was obtained. 1 H-NMR (300MHz, CDCl 3 ): δ = 2.80 (s, 3H, CH 3 ), 2.83 (s, 3H, CH 3 ), 7.78 (ddd, J = 8.6, 7.4, 1.3 Hz, 1H), 7.90 (td, J = 7.7, 1.2 Hz, 1H) 7.98 (ddd, J = 8.0, 7.7, 1.2 Hz, 1H), 8.64 (ddd, J = 8.0, 1.4, 0.6 Hz, 1H).

[0097] Example 6 3-Methyl-1,2,4-triazolo[3,4-a]phthalazine-6-carbonitrile 6 A mixture of 135 mg (1.20 mmol) potassium cyanide, 127 mg (0.58 mmol) of 4, and 5.0 ml of DMSO was heated to 100° C. for 2 h. After cooling to room temperature, 20 ml of water was added and the mixture was extracted twice with 50 ml of dichloromethane. The combined dichloromethane extracts were washed with 10 ml of water, dried with sodium sulfate, and evaporated. Purification by column chromatography on silica (eluent: dichloromethane / methanol 20:1) and drying in vacuum gave 110 mg (83%) of 6. 1 H-NMR (300MHz, CDCl 3 ): δ = 2.87 (s, 3H, CH 3 ), 7.96 (ddd, J = 8.3, 7.4, 1.2 Hz, 1H), 8.09 (ddd, J = 8.0, 7.7, 1.2 Hz, 1H), 8.27 (dt, J = 8.3, 1.0 Hz, 1H), 8.71 (dt, J = 8.1, 1.0 Hz, 1H).

[0098] Example 7 2-[(3-methyl-1,2,4-triazolo[3,4-a]phthalazin-6-yl)amino]-ethanol 7 A mixture of 70 mg (mmol) of 4 (DHY5), 0.6 ml of ethanolamine, and 3.0 ml of dioxane was kept at 100° C. After 20 min a precipitate formed and heating was continued for another 2 h. After evaporation the residue was purified by chromatography on silica (eluent: dichloromethane / methanol 20:1→10:1). Yield 62 mg (80%) of 7 was obtained. 1 H-NMR (300MHz, d 4 -acetic acid): δ = 2.66 (s, 3H, CH 3 ), 3.73 (t, J = 5.2 Hz, 2H), 4.03 (t, J = 5.2 Hz, 2H), 7.79 (t, J = 7.8 Hz, 1H), 7.88 (t, J = 7.5 Hz, 1H), 8.05 (d, J = 8.1 Hz, 1H), 8.51 (d, J = 7.2 Hz, 1H).

[0099] Example 8 6-Methoxy-3-methyl-1,2,4-triazolo[3,4-a]phthalazine 8 Compound 4 from Example 4 (0.050 g, 0.22 mmol, 1.0 equiv.) was dissolved in MeOH (3 mL) and Pd-C (10%) (50 mg) was added. The reaction mixture was stirred at room temperature for 24 h. The product was collected by filtration and dried under vacuum (41 mg, 84%)8. 1 H-NMR (400 MHz, CDCl 3 ): δ = 8.56 (ddd, J = 8.0, 1.3, 0.7 Hz, 1H), 8.14 (ddd, J = 8.1, 1.3, 0.7 Hz, 1H), 7.87 (ddd, J = 8.0, 7.3, 1.2 Hz, 1H), 7.72 (ddd, J = 8.1, 7.3, 1.3 Hz, 1H), 4.18 (s, 3H), 2.74 (s, 3H). 13 C-NMR (126 MHz, CDCl 3 ): δ= 158.4, 147.8, 142.6, 133.7, 130.4, 125.1, 124.7, 123.22, 118.69, 55.30, 9.92. HRMS (ESI): cal. mass C 11 H 10 N 4 O [M-1] - 213.0782, found [M-1] - 213.0781.

[0100] Example 9 8,9-Dimethoxy-3-methyl-1,2,4-triazolo[3,4-a]phthalazine 9 A mixture of 57 mg (0.25 mmol) of 1-chloro-6,7-dimethoxyphthalazine, 100 mg (1.3 mmol) of acetic hydrazide, and 6.0 ml of dioxane was heated at reflux for 12 h. After evaporation, the residue was purified by column chromatography on silica (dichloromethane / methanol 20:1) to give 38 mg (61%) of 9. 1 H-NMR (300MHz, CDCl 3 ): δ = 2.80 (s, 3H, CH 3 ), 4.04 (s, 3H, OCH 3 ), 4.10 (s, 3H, OCH3 ), 7.22 (s, 1H), 7.96 (s, 1H), 8.48 (s, 1H).

[0101] Example 10 3-Trifluoromethyl-1,2,4-triazolo[3,4-a]phthalazine 10 237 mg (1.21 mmol) of hydralazine hydrochloride and 5.0 ml of trifluoroacetic acid were heated to 70° C. for 4 hours. The mixture was evaporated and 5.0 ml of water was added. After adjusting the pH to 5, the product was extracted twice with 20 ml of dichloromethane. Drying (Na 2 SO 4 After evaporation, 273 mg (92%) of a yellow solid was obtained, which was purified by column chromatography on silica (dichloromethane / methanol 50:1). Yield 263 mg (89%) of colorless 10 was obtained. 1 H-NMR (300MHz, CDCl 3 ): δ = 7.97 (dd, J = 8.4, 7.0 Hz, 1H), 8.07 (d, J = 8.0 Hz, 1H), 8.09 (td, J = 7.2, 1.4 Hz, 1H), 8.79 (dd, J = 7.9, 1.2 Hz), 8.84 (s, 1H).

[0102] Example 11 3-Methoxymethyl-1,2,4-triazolo[3,4-a]phthalazine 11 100 mg (mmol) of 1-chlorophthalazine and 200 mg (mmol) of methoxyacetic acid hydrazide were suspended in 5.0 ml of dioxane and heated to reflux for 2 h. The reaction mixture was evaporated and the residue was partitioned between 20 ml of water and 20 ml of dichloromethane. The aqueous phase was extracted with 20 ml of dichloromethane and the combined organic phases were washed with 10 ml of water. After drying over sodium sulfate and evaporation, the residue was purified on a silica column (eluent: ethyl acetate). A yield of 112 mg (82%) of 11 was obtained. 1 H-NMR (300MHz, CDCl 3 ): δ = 3.49 (s, 3H, OCH 3 ), 5.05 (s, 2H, CH 2O), 7.82 (td, J = 7.5, 1.2 Hz), 7.95 (d, J = 7.5 Hz, 1H), 7.96 (td, J = 7.5, 1.1Hz, 1H), 8.67 (dd, J = 7.1, 1.2 Hz, 1H), 8.68 (s, 1H).

[0103] Example 12 3-D 3 -Methyl-1,2,4-triazolo[3,4-a]phthalazine 12 314 mg (1.60 mmol) of hydralazine hydrochloride and 2.5 ml of acetic acid-d 4 The mixture was heated to 120 °C for 6 h. After evaporation, 5.0 ml of water was added and NaHCO 3 The pH was adjusted to 7 by adding 50 ml of dichloromethane twice, and the mixture was dried (Na 2 SO 4 ) and evaporation gave a yellow solid containing d3-acetic acid. Purification by double column chromatography on silica (first column: dichloromethane / methanol 30:1, second column: ethyl acetate) gave 236 mg (75%) of 12 as a colorless solid. 1 H-NMR (300MHz, CDCl 3 ): δ = 7.75(t, J = 7.4 Hz, 1H), 7.88 (m, 2H), 8.56 (d, J = 7.4 Hz, 1H), 8.57 (s, 1H).

[0104] Example 13 1,2,4-Triazolo[3,4-a]phthalazin-3-yl-methanol 13 302 mg (1.83 mmol) of 1-chlorophthalazine and 349 mg (3.87 mmol) of hydroxyacetic acid hydrazide were added to 5.0 ml of dioxane and heated under reflux for 4 hours. After evaporation, the residue was taken up in 10 ml of water and the resulting suspension was extracted 7 times with 50 ml of dichloromethane. 2 SO 4 After evaporation, the residue was purified by column chromatography on silica (dichloromethane / methanol 20:1) to give 349 mg (90%) of 13 as a colorless solid. 1 H-NMR (300MHz, CDCl3 ): δ = 4.95 (s, 2H), 5.70 (br, s, 1H, OH), 7.94 (td, J = 7.7, 1.2 Hz, 1H), 8,06 (td, J = 7.6, 1.2 Hz, 1H), 8.22 (d, J = 7.8 Hz, 1H), 8.51 (d, J = 7.9 Hz, 1H), 9.09 (s, 1H).

[0105] Example 14 3-Ethyl-1,2,4-triazolo[3,4-a]phthalazine 14 A solution of 376 mg (1.91 mmol) of hydralazine hydrochloride in 3.0 ml of propionic acid was heated to 120° C. for 4 hours. After cooling to room temperature, 20 ml of water was added and NaHCO 3 The solution was neutralized by adding 20 ml of dichloromethane. 2 SO 4 Drying and evaporation using hexanes gave a tan residue which was purified by column chromatography on silica (dichloromethane→dichloromethane / methanol 20:1) to give 38 mg of 14. 1 H-NMR (300MHz, CDCl 3 ): δ = 1.50(t, J = 7.6 Hz, 3H, CH 3 ), 3.23 (q, J = 7.6 Hz, 2H, CH 2 ), 7.78 (ddd, J = 7.2, 6.8, 1.2 Hz, 1H), 7.91 (d, J = 7.4 Hz, 1H), 7.92 (t, J = 7.9 Hz, 1H), 8.52 (s, 1H), 8.53 (d, J = 7.9 Hz, 1H).

[0106] Example 15 1,2,4-Triazolo[3,4-a]phthalazine 15 0.55 ml (3.0 mmol) of triethyl orthoformate was added to a solution of 500 mg (2.54 mmol) of hydralazine hydrochloride in 5.0 ml of methanol. Stirring was continued at room temperature for 2 hours. A fine crystalline precipitate formed within 1 hour. After evaporation, 5 ml of water was added and solid NaHCO 3The pH was adjusted to 5 with 20 ml of dichloromethane. After extraction with 20 ml of dichloromethane three times, the organic phase was dried (Na 2 SO 4 ), and evaporated. Drying in vacuo gave 401 mg (87%) of 15. 1 H-NMR (300MHz, CDCl 3 ): δ = 7.83 (ddd, J = 8.2, 7.3, 1.2 Hz, 1H), 7.96(d, J = 7.9 Hz, 1H), 7.98 (td, J = 7.5, 1.2 Hz, 1H), 8.64 (s, 1H), 8.68 (dd, J = 7.6, 1.2 Hz, 1H), 9.04 (s, 1H).

[0107] Example 16 3-Cyclopropyl-[1,2,4]triazolo[3,4-a]phthalazine 16 178 mg NaHCO 3 A solution of 180 mg of cyclopropanecarboxylic acid in 20 ml of methanol was added and evaporated. To the residue was added 188 mg of hydralazine hydrochloride, 500 mg of cyclopropanecarboxylic acid, and 10 ml of dioxane. The mixture was heated at reflux for 6 hours. Two column chromatography runs on silica (first: ethyl acetate / hexane 2:1, second: dichloromethane / methanol 50:1) gave 18 mg of 16. 1 H NMR (300 MHz, CDCl 3 ) δ 8.63 (d, J = 7.9 Hz, 1H), 8.60 (s, 1H), 7.92 (t, J = 7,5 Hz 1H), 7,91 (d, J = 7,7 Hz, 1H), 7.79 (dd, J = 8.5, 6.6 Hz, 1H), 2.50 (tt, J = 8.5, 5.0 Hz, 1H), 1.39 (dt, J = 6.4, 3.3 Hz, 2H), 1.21 (dt, J = 8.5, 3.3 Hz, 2H).

[0108] Example 17 6-Chloropyrido[4,3-d]tetrazolo[1,5-b]pyridazine 17a and 6-chloropyrido[3,4-d]tetrazolo[1,5-b]pyridazine 17b 2,3-Dihydropyrido[3,4-d]pyridazine-1,4-dione(i) 3,4-Pyridinedicarboxylic acid (8.61 g, 51.51 mmol, 1.0 equiv.) was dissolved in acetic anhydride (30 mL, 319.42 mmol, 6.2 equiv.) and the mixture was heated to reflux with stirring for 1 h. After cooling to room temperature, 30 mL of hydrazine (55% in water) was added and the mixture was refluxed with stirring for 4 h. The product was collected by suction filtration, washed with water and dried to give amorphous solid (i) (7.94 g, 95%). 1 H NMR (300 MHz, DMSO): δ= 11.90 (s, 2H), 9.32 (s, 1H), 9.02 (d, J = 5.3 Hz, 1H), 7.89 (d, J = 5.3 Hz, 1H).

[0109] 1,4-Dichloropyrido[3,4-d]pyridazine(ii) A mixture of 2,3-dihydropyrido[3,4-d]pyridazine-1,4-dione (i) (6.52 g, 39.96 mmol, 1.0 equiv.) (0.04 mol) and phosphorus oxychloride (18.6 mL, 189.84 mmol, 4.75 equiv.) in pyridine (6.46 mL, 79.93 mmol, 2.0 equiv.) was heated to reflux and stirred for 8 h. The mixture was then poured onto 400 g of ice slush and diluted with NaHCO 3 The mixture was neutralized with ethyl acetate (3×100 mL) and extracted with ethyl acetate (3×100 mL). The organic phase was separated, washed with water and 2 SO 4 The crude product was purified by column chromatography using dichloromethane to give (ii) as a yellow amorphous solid (4.01 g, 50%). 1 H NMR (300 MHz, CDCl 3 ), main isomer: δ= 9.75 (d, J = 1.0 Hz, 1H), 9.24 (d, J = 5.6 Hz, 1H), 8.07 (dd, J = 5.6, 1.0 Hz, 1H).

[0110] 4-Chloro-1-hydrazinylpyrido[3,4-d]pyridazine (iiia) and 1-chloro-4-hydrazinylpyrido[3,4-d]pyridazine (iiib) To a solution of 1,4-dichloropyrido[3,4-d]pyridazine (ii) (1.0 g, 4.99 mmol, 1.0 equiv.) in methanol (15 mL), hydrazine (55% in water) (0.32 g, 9.99 mmol, 2.0 equiv.) was slowly added and the reaction mixture was refluxed for 10 min to give a yellow precipitate. The product was collected by suction filtration and dried to give the product as a mixture of isomers (iiia / iiib). This product was subsequently used without further purification. HRMS (ESI): cal. mass C 7 H 6 N 5 Cl [M+1] + 196.0390, found [M+1] + 196.0382.

[0111] 6-Chloropyrido[4,3-d]tetrazolo[1,5-b]pyridazine 17a and 6-chloropyrido[3,4-d]tetrazolo[1,5-b]pyridazine 17b A solution of the mixture of isomers (iiia and iiib) (0.20 g, 1.02 mmol, 1.0 equiv.) in acetic acid (5 mL, 2N) was cooled in ice water and then added NaNO 2 (84 mg, 1.22 mmol, 1.2 equiv. in 2 mL water) was added dropwise with stirring. Stirring was continued at room temperature for 1 h. The product was extracted with dichloromethane (3×25 mL). The organic phase was diluted with Na 2 SO 4 Drying at rt and evaporation gave amorphous solid 17a / 17b (181 mg, 86%). 1 H NMR (300 MHz, DMSO): δ= 10.05 (s, 1H), 9.77 (s, 0.4H), 9.36-9.34 (m, 1.4H), 8.65 (d, J = 5.4 Hz, 0.4H), 8.36 (d, J = 5.4 Hz, 1H). HRMS (ESI): cal. mass C 7 H 3 N6 Cl [M+1] + 207.0186, found [M+1] + 207.0181.

[0112] Example 18 Pyrido[4,3-d]tetrazolo[1,5-b]pyridazine 18a and pyrido[3,4-d]tetrazolo[1,5-b]pyridazine 18b To a solution of the isomeric mixture 17a / 17b (50 mg, 0.24 mmol, 1.0 equiv.) in ethanol (3 mL), hydrazine (55% in water) (15.5 mg, 0.48 mmol, 2.0 equiv.) was slowly added and the reaction mixture was refluxed for 2 h to give a precipitate. The product was collected by suction filtration and dried. A solution of 0.15 M potassium trimethylsilanolate (TMSOK) (31 mg, 0.24 mmol, 1.0 equiv.) in water (1.6 mL) was then added and the formed slurry was stirred at room temperature for 24 h. The resulting mixture was extracted with dichloromethane (4 x 20 mL). The organic phase was diluted with Na 2 SO 4 Drying at rt and evaporation gave an amorphous solid as isomeric mixture 18a / 18b (14 mg, 34%). 1 H NMR (500 MHz, CDCl 3 ) δ= 10.15 (d, J = 0.9 Hz, 1H), 9.56 (d, J = 1.0 Hz, 0.4H), 9.29 - 9.27 (m, 1.4H), 9.11 (d, J = 0.8 Hz, 0.4H), 9.03 (d, J = 0.7 Hz, 1H), 8.58 (dt, J = 5.4, 0.9 Hz, 0.4H), 7.99 (dt, J = 5.4, 0.8 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ): δ= 153.64, 152.38, 151.05, 148.06, 147.99, 147.73, 140.67, 140.24, 128.74, 127.65, 119.80, 119.19, 117.09, 116.36. HRMS (ESI): cal. mass C 7 H 5 N 6 [M+1] +173.0570, found [M+1] + 173.0568, cal. mass C 7 H 4 N 6 Na [M+Na] + 195.0390, found [M+Na] + 195.0387.

[0113] Example 19 6-Chloro-3-methylpyrido[4,3-d][1,2,4]triazolo[4,3-b]pyridazine 19a and 6-chloro-3-methylpyrido[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 19b The isomeric mixture (iiia / iiib, from Example 17) (0.20 g, 1.02 mmol, 1.0 equiv.) and triethyl orthoacetate (0.25 g, 1.53 mmol, 1.5 equiv.) were refluxed in methanol (5 mL) for 20 min to give a solid product, which was collected by suction filtration and dried to give the isomeric mixture 19a / 19b (0.16 g, 74%). 1 H NMR (300 MHz, DMSO): δ= 9.82 (d, J = 0.9 Hz, 1H), 9.52 (d, J = 0.9 Hz, 0.6H), 9.16 (dd, J = 7.2, 5.4 Hz, 1.7H), 8.41 (dd, J = 5.3, 1.0 Hz, 0.6H), 8.14 (dd, J = 5.5, 0.9 Hz, 1H), 2.71 (broad signal, 5H). HRMS (ESI): cal. mass C 9 H 6 ClN 5 [M+1] + 220.0384, found [M+1] + 220.0386, cal. mass C 9 H 6 ClN 5 Na [M+Na] + 242.0204, found [M+Na] + 242.0206.

[0114] Example 20 3-Methylpyrido[4,3-d][1,2,4]triazolo[4,3-b]pyridazine 20a and 3-Methylpyrido[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 20b A solution of isomer mixture 19 (50 mg, 0.22 mmol, 1.0 equiv.) in ethanol (3 mL) was slowly cooled with N 2 H 4 .H 2 2.0 equiv.) was added and the mixture was refluxed for 2 h to give a precipitate. The product was collected by suction filtration and dried. A solution of 0.15 M TMSOK (30 mg, 0.24 mmol, 1.0 equiv.) in water (1.5 mL) was then added and the slurry was stirred at room temperature for 24 h. The resulting mixture was extracted with dichloromethane (4×20 mL). The organic phase was washed with Na 2 SO 4 Drying at rt and evaporation gave an amorphous solid (20a / 20b) (12 mg, 34%). 1 H NMR (300 MHz, CDCl 3 ): δ= 10.01 (s, 1H), 9.30 (s, 0.5H), 9.07 (d, J = 5.3 Hz, 0.5H), 9.08 (d, J = 5.3 Hz, 1H), 8.75 (s, 0.5H), 8.67 (s, 1H), 8.45 (d, J = 5.3 Hz, 0.5H), 7.75 (d, J = 5.3 Hz, 1H), 2.86 (broad signal, 4.5H). 13 C NMR (126 MHz, CDCl 3 ): δ= 153.12, 150.74, 150.56, 149.33, 148.85, 146.96, 146.11, 145.77, 140.87, 140.37, 129.13, 127.06, 119.74, 117.87, 117.81, 116.15, 10.04, 9.98. HRMS (ESI): cal. mass C 9 H 8 N 5 [M+1] + 186.0774, found [M+1] + 186.0771, cal. mass C 9 H 7 N 5 Na [M+Na] +208.0594, found [M+Na] + 208.0589.

[0115] Example 21 6-Chloropyrido[3,2-d]tetrazolo[1,5-b]pyridazine 21a and 6-chloropyrido[2,3-d]tetrazolo[1,5-b]pyridazine 21b 6,7-Dihydropyrido[2,3-d]pyridazine-5,8-dione(iv) The compound was prepared from the diacid according to compound (i) of Example 17. 1 H NMR (300 MHz, DMSO): δ= 11.63 (s, 2H), 9.11 (dd, J = 4.5, 1.7 Hz, 1H), 8.46 (dd, J = 8.1, 1.7 Hz, 1H), 7.88 (dd, J = 8.1, 4.5 Hz, 1H).

[0116] 5,8-Dichloropyrido[2,3-d]pyridazine(v) The compound was prepared from compound (iv) according to compound (ii) in Example 17. 1 H NMR (300 MHz, CDCl 3 ): δ= 9.41 (dd, J = 4.4, 1.6 Hz, 1H), 8.64 (dd, J = 8.4, 1.6 Hz, 1H), 8.02 (dd, J = 8.4, 4.4 Hz, 1H). 13 C NMR (75 MHz, CDCl 3 ): δ= 154.33, 141.13, 134.38, 129.09, 124.02.

[0117] 6-Chloropyrido[3,2-d]tetrazolo[1,5-b]pyridazine 21a and 6-chloropyrido[2,3-d]tetrazolo[1,5-b]pyridazine 21b Compounds (21a / 21b) were prepared from compound (v) according to compound (iii) in Example 17. 1 H NMR (300 MHz, CDCl 3): δ= 9.42 (dd, J = 4.6, 1.6 Hz, 1H), 9.39 (dd, J = 4.6, 1.6 Hz, 0.45H), 9.08 (dd, J = 8.2, 1.7 Hz, 0.45H), 8.76 (dd, J = 8.2, 1.7 Hz, 1H), 8.11 (dd, J = 8.2, 4.5 Hz, 0.45H), 8.06 (dd, J = 8.2, 4.5 Hz, 1H).

[0118] The isomeric mixture was separated by column chromatography. First eluent isomer: 6-chloropyrido[3,2-d]tetrazolo[1,5-b]pyridazine 21a. 1 H NMR (600 MHz, CDCl 3 ) δ 9.39 (dd, J = 4.5, 1.7 Hz, 1H), 9.09 (dd, J = 8.1, 1.7 Hz, 1H), 8.09 (dd, J = 8.1, 4.5 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 155.56, 154.35, 141.96, 139.60, 133.25, 129.29, 119.72. Second eluent isomer: 6-chloropyrido[2,3-d]tetrazolo[1,5-b]pyridazine 21b. 1 H NMR (600 MHz, CDCl 3 ) δ 9.42 (dd, J = 4.5, 1.6 Hz, 1H), 8.76 (dd, J = 8.4, 1.6 Hz, 1H), 8.06 (dd, J = 8.4, 4.6 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 157.71, 151.65, 142.40, 140.00, 135.96, 127.80, 121.58.

[0119] Example 22 Pyrido[3,2-d]tetrazolo[1,5-b]pyridazine 22a (minor isomer) and pyrido[2,3-d]tetrazolo[1,5-b]pyridazine 22b (major isomer) The compound was prepared from compound 21 according to example 18.1 H-NMR (600 MHz, DMSO): δ= 9.47 (s, 1H), 9.43 (d, J = 0.7 Hz, 0.2H), 9.36 (dd, J = 4.6, 1.7 Hz, 1H), 9.33 (dd, J = 4.5, 1.6 Hz, 0.2H), 9.06 (dd, J = 8.2, 1.6 Hz, 0.2H), 8.81 (dd, J = 8.1, 1.7 Hz, 1H), 8.16 (dd, J = 8.2, 4.6 Hz, 0.2H), 8.11 (dd, J = 8.1, 4.6 Hz, 1H). 13 C-NMR (126 MHz, DMSO): δ= 156.77, 155.57, 151.53, 150.74, 143.20, 142.55, 141.86, 139.83, 137.68, 132.36, 129.15, 127.68, 122.20, 119.41. HRMS (ESI): cal. mass C 7 H 5 N 6 [M+1] + 173.0570, found [M+1] + 173.0571, cal. mass C 7 H 4 N 6 Na [M+Na] + 195.0390, found [M+Na] + 195.0386.

[0120] Example 23 6-Chloro-3-methylpyrido[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 23a and 6-chloro-3-methylpyrido[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 23b In Example 19, compound (v) and compound (23a / 23b) were prepared. 1 H NMR (300 MHz, CDCl 3) δ 9.25 (dd, J = 4.6, 1.6 Hz, 0.6H), 9.17 (dd, J = 4.6, 1.6 Hz, 1H), 8.96 (dd, J = 8.1, 1.7 Hz, 1H), 8.54 (dd, J = 8.1, 1.7 Hz, 0.6H), 7.91 (dd, J = 8.1, 4.5 Hz, 1H), 7.81 (dd, J = 8.1, 4.5 Hz, 0.6H), 2.85 (s, two singlets are merged, 5H).

[0121] The isomeric mixture was separated by column chromatography. First eluent isomer: 1 H NMR (300 MHz, CDCl 3 ) δ 9.17 (dd, J = 4.6, 1.7 Hz, 1H), 8.97 (dd, J = 8.1, 1.7 Hz, 1H), 7.91 (dd, J = 8.1, 4.6 Hz, 1H), 2.85 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 153.37, 151.67, 148.36, 142.07, 137.79, 131.81, 128.70, 121.23, 9.89. Second eluent isomer: 1 H NMR (300 MHz, CDCl 3 ) δ 9.25 (dd, J = 4.6, 1.6 Hz, 1H), 8.54 (dd, J = 8.3, 1.6 Hz, 1H), 7.81 (dd, J = 8.3, 4.6 Hz, 1H), 2.85 (s, 3H).

[0122] Example 24 3-Methylpyrido[3,2-d][1,2,4]triazolo[4,3-b]pyridazine (minor isomer) 24a and 3-methylpyrido[2,3-d][1,2,4]triazolo[4,3-b]pyridazine (major isomer) 24b The compound was prepared from compound 23 according to example 20. 1 H-NMR (500 MHz, CDCl 3): δ= 9.17 (dd, J = 4.7, 1.7 Hz, 1H), 9.06 (dd, J = 4.6, 1.7 Hz, 0.6H), 8.89 (dd, J = 8.2, 1.7 Hz, 0.6H), 8.83 (s, 0.6H), 8.67 (s, 1H), 8.28 (dd, J = 8.1, 1.7 Hz, 1H), 7.82 (dd, J = 8.1, 4.6 Hz, 0.6H), 7.73 (dd, J = 8.0, 4.6 Hz, 1H), 2.83 (broad signal, 4H). 13 C-NMR (126 MHz, CDCl 3 ); δ= 155.78, 153.15, 148.68, 148.66, 148.38, 146.52, 142.80, 141.88, 141.07, 140.04, 135.59, 130.88, 127.69, 125.31, 120.41, 118.86, 9.89, 9.72. HRMS (ESI): cal. mass C 9 H 8 N 5 [M+1] + 186.0774, found [M+1] + 186.0772, cal. mass C 9 H 7 N 5 Na [M+Na] + 208.0594, found [M+Na] + 208.0594.

[0123] Example 25 Preparation of single isomers 3-Methylpyrido[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 25 Furo[3,4-b]pyridin-5(7H)-one (vi) 2,3-Pyridinedicarboxylic acid (2.0 g, 11.97 mmol, 1.0 equiv.) was dissolved in acetic anhydride (4.88 g, 47.87 mmol, 4 equiv.) and the mixture was heated to reflux and stirred for 4 h. The acetic anhydride was evaporated to dryness to give quinolinic anhydride (1.82 g, 97%). This compound was subsequently used without further purification.

[0124] NaBH 4 (0.46 g, 12.15 mmol, 1.0 equiv) was added to a solution of quinolinic anhydride (1.81 g, 12.15 mmol, 1.0 equiv) in THF (10 mL) under argon at 15° C. Acetic acid (1.45 g, 1.38 mL, 24.30 mmol, 2.0 equiv.) was added dropwise and the resulting mixture was stirred at 15° C. for 4 h. The solvent was removed in vacuo. The residue was dissolved in acetic acid (6 mL) and acetic anhydride (6 mL) and the resulting solution was stirred at 100° C. for 3 h. The mixture was concentrated in vacuo and the residue was dissolved in NaCl solution (20 mL). The aqueous phase was diluted with CHCl 3 (3×40 mL) and the combined organic layers were concentrated. i Recrystallization from -PrOH gave compound (vi) (0.52 g, 32%) as a pale yellow solid. 1 H NMR (300 MHz, CDCl 3 ) δ 8.88 (dd, J = 4.9, 1.6 Hz, 1H), 8.22 (dd, J = 7.8, 1.6 Hz, 1H), 7.49 (dd, J = 7.8, 4.9 Hz, 1H), 5.35 (s, 2H). 13 C NMR (75 MHz, CDCl 3 ) δ 169.11, 166.54, 155.39, 134.15, 124.00, 119.81, 70.61.

[0125] 7-Bromofuro[3,4-b]pyridin-5(7H)-one (vii) Compound (vi) (0.500 g, 3.67 mmol, 1.0 equiv.) was dissolved in dry CCl 4 (20 mL) with NBS (0.72 g, 4.04 mmol, 1.1 equiv.) and AIBN (10 mg) was heated at reflux for 2 h. The reaction mixture was cooled to room temperature, the succinate salt was filtered off, and the filtrate was concentrated and purified by silica gel column chromatography (DCM) to give product (vii) (0.42 g, 54%) as an oil. 1 H NMR (300 MHz, CDCl 3) δ 8.99 (dd, J = 4.9, 1.5 Hz, 1H), 8.25 (dd, J = 7.8, 1.6 Hz, 1H), 7.58 (dd, J = 7.8, 4.8 Hz, 1H), 7.39 (s, 1H).

[0126] Pyrido[2,3-d]pyridazin-5(6H)-one (viii) Compound (vii) (0.38 g, 1.78 mmol, 1.0 equiv.) was dissolved in 5% hydrochloric acid (5 mL / mmol) and stirred at reflux for 2 h, after which the reaction was cooled to room temperature. After cooling, the appropriate hydrazine (68.5 mg, 2.14 mmol, 1.2 equiv.) was added to the solution and the reaction was stirred at room temperature for an additional 2 h. The resulting precipitate was then collected and recrystallized from hot ethanol to give pure compound (viii) (0.17 g 66%). 1 H NMR (300 MHz, DMSO) δ 12.97 (s, 1H), 9.11 (dt, J = 4.6, 1.3 Hz, 1H), 8.57 (dd, J = 8.1, 1.7 Hz, 1H), 8.40 (s, 1H), 7.83 (ddd, J = 8.1, 4.6, 0.9 Hz, 1H).

[0127] 5-Chloropyrido[2,3-d]pyridazine (IX) A mixture of compound (viii) (0.147 g, 1.0 mmol, 1.0 equiv.) and phosphorus oxychloride (0.382 g, 2.5 mmol, 2.5 equiv.) in pyridine (0.2 mL) was heated to reflux and stirred for 8 h. The mixture was then poured onto 50 g of ice slush and diluted with NaHCO 3 The mixture was neutralized with ethyl acetate (3×100 mL) and extracted with ethyl acetate (3×100 mL). The organic phase was separated, washed with water and 2 SO 4 The crude product was purified by column chromatography using dichloromethane to give a yellow amorphous solid (ix) (36 mg, 22%). 1 H NMR (300 MHz, CDCl 3) δ 9.73 (s, 1H), 9.32 (dd, J = 4.4, 1.6 Hz, 1H), 8.61 (dd, J = 8.5, 1.5 Hz, 1H), 7.93 (dd, J = 8.4, 4.4 Hz, 1H).

[0128] 3-Methylpyrido[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 25 Compound (ix) (30 mg, 0.18 mmol, 1.0 equiv.) and acetic hydrazide (27 mg, 0.36 mmol, 2.0 equiv.) were refluxed in dioxane (3 mL) for 2 hours. The reaction mixture was extracted with dichloromethane (4×20 mL). The organic phase was diluted with Na 2 SO 4 The mixture was dried at 40° C. and evaporated to dryness, and the crude product was purified by column chromatography using dichloromethane to give an amorphous solid (25) (21 mg, 65%). 1 H NMR (400 MHz, CDCl 3 ) δ 9.07 (dd, J = 4.6, 1.7 Hz, 1H), 8.91 (ddd, J = 8.2, 1.6, 0.7 Hz, 1H), 8.85 (d, J = 0.7 Hz, 1H), 7.82 (dd, J = 8.2, 4.6 Hz, 1H), 2.84 (s, 3H). 13 C NMR (101 MHz, CDCl 3 ) δ 153.31, 148.86, 148.60, 142.08, 140.26, 131.10, 127.86, 120.65, 9.92.

[0129] Example 26 N,3-Dimethylpyrido[3,4-d][1,2,4]triazolo[4,3-b]pyridazin-6-amine 26b (major isomer) and N,3-Dimethylpyrido[4,3-d][1,2,4]triazolo[4,3-b]pyridazin-6-amine 26a (minor isomer) To a solution of compound 19 (0.050 g, 0.22 mmol, 1.0 equiv.) in isopropanol (25 mL) was added the appropriate methylamine solution (30%) (0.5 mL). The reaction mixture was refluxed for 3 h. Afterwards, the mixture was cooled and poured into ice water (20 mL). The precipitate formed was filtered, washed with water and crystallized from ethanol to give an isomeric mixture of 26a / 26b (ratio 0.7:1.0) (29 mg, 60%). 1 H NMR (600 MHz, DMSO) δ 9.61 (d, J = 0.9 Hz, 1H), 9.49 (d, J = 0.9 Hz, 0.7H), 8.97 - 8.96 (m, 1.7H), 8.20 (dd, J = 5.3, 0.9 Hz, 0.7H), 8.12 (dd, J = 5.7, 0.9 Hz, 1H), 7.98 - 7,85 (m, 1.7H), 2.96 (t, J = 4.6 Hz, 5H), 2.57 (d, J = 5.1 Hz, 5H). 13 C NMR (126 MHz, DMSO) δ 151.85, 151.20, 150.73, 150.07, 147.05, 146.93, 146.51, 145.42, 139.60, 139.04, 128.82, 123.85, 117.99, 116.74, 115.32, 113.37, 28.19, 28.12, 9.32, 9.30. HRMS (ESI): cal. mass C 10 H 10 N 6 [M+1] + 215.1040, found [M+1] + 215.1041, cal. mass C 10 H 10 N 6 Na [M+Na] + 237.0859, found [M+Na] + 237.0859.

[0130] Example 27 N-Methylpyrido[2,3-d]tetrazolo[1,5-b]pyridazin-6-amine 27 To a solution of compound 21b (0.050 g, 0.22 mmol, 1.0 equiv.) in isopropanol (25 mL) was added the appropriate methylamine solution (30%) (0.5 mL). The reaction mixture was refluxed for 3 h. After that, the mixture was cooled and poured into ice water (20 mL). The precipitate formed was filtered, washed with water, and crystallized from ethanol to give single isomer 27 (25 mg, 61%). 1 H NMR (600 MHz, DMSO) δ 9.15 (dd, J = 4.6, 1.6 Hz, 1H), 8.88 (dd, J = 8.1, 1.6 Hz, 1H), 8.44 (q, J = 4.9 Hz, 1H), 8.06 (dd, J = 8.1, 4.6 Hz, 1H), 3.03 (d, J = 4.9 Hz, 3H). 13 C NMR (126 MHz, DMSO) δ 153.62, 153.18, 139.49, 136.44, 132.60, 128.23, 117.82, 28.04. HRMS (ESI): cal. mass C 8 H 7 N 7 [M+1] + 202.0836, found [M+1] + 202.0837, cal. mass C 8 H 7 N 7 Na [M+Na] + 224.0655, found [M+Na] + 224.0655.

[0131] Example 28 6-ethoxy-3-methylpyrido[4,3-d][1,2,4]triazolo[4,3-b]pyridazine 28a (major isomer) and 6-ethoxy-3-methylpyrido[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 28b (minor isomer) Compound (19) (0.050 g, 0.22 mmol, 1.0 equiv.) was dissolved in ethanol (3 mL) and KCN (0.016 mg, 0.25 mmol, 1.1 equiv.) was added. The reaction mixture was refluxed for 4 h. After that, the mixture was cooled, poured into ice water (20 mL) and extracted with DCM (3×20 mL). The organic solvent was evaporated under vacuum and crystallized from DCM to give product (28a / 28b) (36 mg, 69%). 1H NMR (300 MHz, CDCl 3 ) δ 9.90 (s, 1H), 9.45 (s, 0.5H), 9.03 (d, J = 5.4 Hz, 0.5H), 8.98 (d, J = 5.4 Hz, 1H), 8.34 (d, J = 5.4 Hz, 0.5H), 7.94 (d, J = 5.4 Hz, 1H), 4.61 (m, 3H), 2.74 (m, 5H), 1.58 (m, 5H). HRMS (ESI): cal. mass C 11 H 11 N 5 O [M+1] + 230.1036, found [M+1] + 230.1037, cal. mass C 11 H 11 N 5 ONa [M+Na] + 252.0856, found [M+Na] + 252.0852.

[0132] Example 29 6-Isopropoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 29 Example 4 (70 mg, 0.32 mmol, 1.0 equiv.) and K 2 CO 3 (88 mg, 0.64 mmol, 2.0 equiv.) was refluxed in isopropanol (5 mL) for 48 h and then concentrated under reduced pressure. The reaction mixture was extracted with dichloromethane (4×40 mL). The organic phase was washed with Na 2 SO 4 The mixture was dried at 40° C. and concentrated by rotary evaporation. The crude product was purified by column chromatography using dichloromethane to give an amorphous solid (91%). 1 H NMR (300 MHz, CDCl 3) δ 8.56 (dd, J = 8.0, 1.2 Hz, 1H), 8.15 (dd, J = 8.0, 1.2 Hz, 1H), 7.86 (td, J = 7.7, 1.3 Hz, 1H), 7.72 (td, J = 7.7, 1.3 Hz, 1H), 5.45 (hept, J = 6.2 Hz, 1H), 2.72 (s, 3H), 1.52 (d, J = 6.2 Hz, 6H). 13 C NMR (126 MHz, CDCl 3 ) δ 157.16, 147.60, 142.46, 133.44, 130.23, 125.28, 124.74, 123.10, 119.17, 71.53, 21.84, 9.87. HRMS (ESI): cal. mass C 13 H 14 N 4 O [M+1] + 243.1240, found [M+1] + 243.1241, cal. mass C 13 H 14 N 4 O [M+Na] + 265.1067, found [M+Na] + 265.1060.

[0133] Example 30 3-Methyl-7,8,9,10-tetrahydropyrido[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 30 A solution of compound 23 (50 mg) in methanol was pumped through a CatCart (Pd-C) using a Thales Nano H-Cube device at a liquid flow rate of 1.0 mL / min at 60 °C. The crude product was purified by column chromatography using dichloromethane and methanol to give 32 mg (74%) of compound 30 as a white amorphous solid. 1 H NMR (600 MHz, MeOD) δ 8.01 (s, 1H), 3.39 (ddd, J = 7.0, 4.0, 1.0 Hz, 2H), 2.85 (tt, J = 6.5, 1.0 Hz, 2H), 2.63 (s, 3H), 2.02 - 1.95 (m, 2H). 13C NMR (126 MHz, MeOD) δ 147.31, 146.78, 142.26, 139.08, 104.02, 41.37, 20.82, 20.41, 9.25. HRMS (ESI): cal. mass C 9 H 12 N 5 [M+1] + 190.1087, found [M+1] + 190.1092, cal. mass C 9 H 11 N 5 Na [M+Na] + 212.0907, found [M+Na] + 212.0908.

[0134] Example 31 7,8,9,10-Tetrahydropyrido[3,2-d]tetrazolo[1,5-b]pyridazine 31a and 7,8,9,10-tetrahydropyrido[2,3-d]tetrazolo[1,5-b]pyridazine 31b The compound was prepared from 50 mg of compound 21 under the same conditions as in Example 30, with a yield of 30 mg (72%). 1 H-NMR (600 MHz, DMSO) δ 8.25 (s, 1H), 8.22 (s, 0.2H), 7.35 (s, 1H), 3.36 - 3.30 (m, 2H), 2.85 (t, J = 6.3 Hz, 2H), 2.73 (t, J = 6.2 Hz, 0.4H), 1.88 (h, J = 5.7 Hz, 2.4H).

[0135] Example 32 3-Methyl-7,8,9,10-tetrahydropyrido[4,3-d][1,2,4]triazolo[4,3-b]pyridazine 32a and 3-methyl-7,8,9,10-tetrahydropyrido[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 32b The compound was prepared from 50 mg of compound 19 under the same conditions as in Example 30, with a yield of 25 mg (60%). 1 H NMR (300 MHz, CD 3OD_SPE) δ 8.36 (s, 1H), 8.34 (s, 0.5H), 4.25 (t, J = 2.1 Hz, 2H), 4.05 (t, J = 2.1 Hz, 1H), 3.29 - 3.21 (m, 3H), 3.14 - 3.03 (m, 1H), 2.88 - 2.83 (m, 2H), 2.76 (s, broad signal, 4H).

[0136] Example 33 1-(9,10-dihydropyrido[4,3-d]tetrazolo[1,5-b]pyridazin-8(7H)-yl)ethan-1-one 33a and 1-(7,10-dihydropyrido[3,4-d]tetrazolo[1,5-b]pyridazin-9(8H)-yl)ethan-1-one 33b 7,8,9,10-Tetrahydropyrido[4,3-d]tetrazolo[1,5-b]pyridazine(x) Compound (x) was prepared from 50 mg of compound 17 under the same conditions as in the synthesis of Example 30 (yield 22 mg, 52%). 1 H NMR (300 MHz, DMSO) δ 8.77 (s, 0.5H), 8.76 (s, 1H), 4.03 (d, J = 2.4 Hz, 2H), 3.90 (s, 0H), 3.14 - 2.96 (m, 4H).

[0137] Compound (x) (1.0 equiv.) was dissolved in dichloromethane and diluted with Et 3 N (1.2 equiv.) and acetyl chloride (1.2 equiv.) were added and stirred at room temperature for 6 h. The reaction mixture was extracted with DCM and water. The crude product was purified by column chromatography using DCM and MeOH (9:1) to give amorphous solid 33a / 33b (25 mg, 48%). 1 H NMR (300 MHz, CDCl 3 ) δ 8.47 (s, 0.5H), 8.44 (s, 1H), 5.19 - 5.03 (m, 2H), 4.95 - 4.78 (m, 1H), 4.01 - 3.98 (m, 1H), 3.93 - 3.82 (m, 2H), 3.38 - 3.23 (m, 1H), 3.07 - 3.00 (m, 2H), 2.25 (s, broad signal, 5H).

[0138] Example 34 3-Methylthieno[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 34 2-Formylthiophene-3-carboxylic acid n-BuLi (15.60 mL, 39.01 mmol, 2.5 mol / L, 2.5 equiv.) was added dropwise to a stirred solution of commercially available thiophene-3-carboxylic acid 1 (2.0 g, 15.60 mmol, 1.0 equiv.) in dry THF (40 mL) at -78 °C. After 2 h, DMF (6 mL, 78.03 mmol, 5.0 equiv.) was added. After an additional 1 h, the cooling bath was removed and the mixture was stirred at ambient temperature for 16 h. HCl (aq, 1 M, 60 mL) was added. The mixture was extracted with ethyl acetate (3 × 30 mL), dried (Na 2 SO 4 ) and concentrated in vacuo The resulting yellow solid (xi) (yield 2.20 g, 91%) was used without further purification. 1 H NMR (300 MHz, CDCl 3 ) δ 10.60 (s, 1H), 7.72 - 7.65 (m, 2H). HRMS (ESI): cal. mass C 6 H 4 O 3 S [M+1] + 156.9954, found [M+1] + 156.9951, cal. mass C 6 H 4 O 3 SNa [M+Na] + 178.9773, found [M+Na] + 178.9772.

[0139] Thieno[2,3-d]pyridazin-4(5H)-one (xii) A round bottom flask was fitted with a stir bar and reflux condenser. The flask was charged with the product of (xi) (1.9 g, 12.16 mmol, 1.0 equiv.), hydrazine hydrate (55%) (1.52 g, 30.41 mmol, 2.5 equiv.), and EtOH (5 mL) and refluxed for 3 h. The reaction was cooled to room temperature and concentrated by rotary evaporation. Water (20 mL) was added and the filtrate was separated from the insoluble solid. The aqueous layer was concentrated by rotary evaporation to give a pale yellow solid. The solid was dried in a vacuum oven at 50° C. overnight. The desired compound (xii) was obtained (yield 1.56 g, 84%). 1 H NMR (500 MHz, DMSO) δ 12.84 (s, 1H), 8.57 (s, 1H), 8.04 (d, J = 5.2 Hz, 1H), 7.63 (d, J = 5.1 Hz, 1H). 13 C NMR (126 MHz, DMSO) δ 158.38, 140.71, 135.85, 133.50, 133.08, 123.93. HRMS (ESI): cal. mass C 6 H 4 N 2 OS [M+1] + 153.0117, found [M+1] + 153.0119, cal. mass C 6 H 4 N 2 OSNa [M+Na] + 174.9937, found [M+Na] + 174.9936.

[0140] 4-Chlorothieno[2,3-d]pyridazine (xiii) A round bottom flask was fitted with a stir bar and a reflux condenser. The flask was charged with the product of (xii) (1.3 g, 8.54 mmol, 1.0 equiv.), phosphorus oxychloride (8 mL, 85.43 mmol, 10.0 equiv.), and pyridine (1.4 mL, 17.08 mmol, 2.0 equiv.) and refluxed for 24 h. The reaction was cooled to room temperature, poured onto ice, and diluted with NaHCO 3The mixture was separated and the aqueous layer was extracted with chloroform (4×30 mL). The organic layers were combined and dried (Na 2 SO 4 ), and concentrated by rotary evaporation to give a yellow solid (xiii) (yield 0.73 g, 50%). 1 H NMR (400 MHz, CDCl 3 ) δ 9.58 (d, J = 0.8 Hz, 1H), 7.96 (d, J = 5.3 Hz, 1H), 7.63 (dd, J = 5.3, 0.8 Hz, 1H). 13 C NMR (101 MHz, CDCl 3 ) δ 151.33, 145.69, 140.39, 136.00, 134.23, 122.44. HRMS (EI): cal. mass C 6 H 3 ClN 2 S [M] + 169.9700, found [M] + 169.9698.

[0141] 3-Methylthieno[3,2-d][1,2,4]triazolo[4,3-b]pyridazine 34 Compound (xiii) (75 mg, 0.43 mmol, 1.0 equiv.) and acetic acid hydrazide (65 mg, 0.87 mmol, 2.0 equiv.) were refluxed in dioxane (3 mL) for 3 h. The reaction mixture was extracted with dichloromethane (4×20 mL). The organic phase was diluted with Na 2 SO 4 The mixture was dried at 40° C. and evaporated to dryness. The crude product was purified by column chromatography using dichloromethane to give amorphous solid 34 (72 mg, 87%). 1 H NMR (400 MHz, CDCl 3 ) δ 8.73 (d, J = 0.7 Hz, 1H), 8.07 (dd, J = 5.2, 0.8 Hz, 1H), 8.00 (d, J = 5.3 Hz, 1H), 2.84 (s, 3H). 13 C NMR (101 MHz, CDCl 3) δ 147.65, 142.51, 140.03, 134.99, 131.53, 130.12, 122.73, 10.28. HRMS (ESI): cal. mass C 8 H 6 N 4 S [M+1] + 191.0386, found [M+1] + 191.0388, cal. mass C 8 H 6 N 4 SNa [M+Na] + 213.0205, found [M+Na] + 213.0208.

[0142] Example 35 Tetrazolo[1,5-b]thieno[3,2-d]pyridazine 35 Compound (xiii) (70 mg, 0.41 mmol, 1.0 equiv.) was dissolved in DMF (1 mL) and sodium azide (32 mg, 0.48 mmol, 1.2 equiv.) was added. The reaction mixture was heated at 120° C. for 3 h. The reaction was cooled to room temperature and poured into water. The mixture was separated and the aqueous layer was extracted with chloroform (4×20 mL). The organic layers were combined, dried (Na 2 SO 4 ), and concentrated by rotary evaporation to give a yellow amorphous solid 35 (yield 70 mg, 97%). 1 H NMR (300 MHz, DMSO) δ 9.55 (s, 1H), 8.63 (d, J = 5.2 Hz, 1H), 8.19 (d, J = 5.2 Hz, 1H). 13 C NMR (75 MHz, DMSO) δ 143.62, 141.48, 140.39, 134.60, 130.26, 122.42. HRMS (ESI): cal. mass C 6 H 3 N 5 S [M+1] + 178.0182, found [M+1] + 178.0184, cal. mass C 6 H 3 N 5SNa [M+Na] + 200.0001, found [M+Na] + 200.0006.

[0143] Example 36 3-Methylthieno[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 36 3-Formylthiophene-2-carboxylic acid (xiv) Compound (xiv) was prepared from thiophene-2-carboxylic acid according to compound (xi) in Example 34. 1 H NMR (300 MHz, CDCl 3 ) δ 10.48 (s, 1H), 7.64 - 7.59 (m, 2H). HRMS (ESI): cal. mass C 6 H 4 O 3 S [M+1] + 156.9954, found [M+1] + 156.9948, cal. mass C 6 H 4 O 3 SNa [M+Na] + 178.9773, found [M+Na] + 178.9770.

[0144] Thieno[2,3-d]pyridazin-7(6H)-one (xv) Compound (xv) was prepared from compound (xiv) according to compound (xii) in Example 34. 1 H NMR (500 MHz, DMSO) δ 12.93 (s, 1H), 8.44 (s, 1H), 8.19 (d, J = 5.1 Hz, 1H), 7.58 (d, J = 5.1 Hz, 1H). 13 C NMR (126 MHz, DMSO) δ 158.19, 139.97, 136.24, 135.83, 134.55, 124.82. HRMS (ESI): cal. mass C 6 H 4 N 2 OS [M+1] + 153.0117, found [M+1]+ 153.0118, cal. mass C 6 H 4 N 2 OSNa [M+Na] + 174.9937, found [M+Na] + 174.9942.

[0145] 7-Chlorothieno[2,3-d]pyridazine (xvi) Compound (xvi) was prepared from compound (xv) according to the procedure of compound (xiii) in Example 34. 1 H NMR (600 MHz, CDCl 3 ) δ 9.49 (s, 1H), 7.94 (d, J = 5.3 Hz, 1H), 7.58 (d, J = 5.3 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 150.89, 146.07, 139.51, 138.28, 134.53, 123.26. HRMS (ESI): cal. mass C 6 H 3 ClN 2 S [M+1] + 170.9778, found [M+1] + 170.9781, cal. mass C 6 H 3 ClN 2 SNa [M+Na] + 192.9598, found [M+Na] + 192.9596.

[0146] 3-Methylthieno[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 36 Compound 36 was prepared from compound (xvi) according to compound 34. 1 H NMR (600 MHz, CDCl 3 ) δ 8.69 (s, 1H), 7.73 (d, J = 5.2 Hz, 1H), 7.55 (d, J = 5.2 Hz, 1H), 2.85 (s, 3H). 13 C NMR (126 MHz, CDCl 3) δ 147.76, 142.17, 141.23, 132.51, 130.76, 129.98, 124.00, 10.31. HRMS (ESI): cal. mass C 8 H 6 N 4 S [M+1] + 191.0386, found [M+1] + 191.0388, cal. mass C 8 H 6 N 4 SNa [M+Na] + 213.0205, found [M+Na] + 213.0207.

[0147] Example 37 Tetrazolo[1,5-b]thieno[2,3-d]pyridazine 37 Compound 37 was prepared from compound (xvi) according to compound 35. 1 H NMR (500 MHz, DMSO) δ 9.43 (s, 1H), 8.43 (d, J = 5.1 Hz, 1H), 7.99 (d, J = 5.1 Hz, 1H). 13 C NMR (126 MHz, DMSO) δ 144.02, 141.33, 134.94, 134.78, 130.73, 125.22. HRMS (ESI): cal. mass C 6 H 3 N 5 S [M+1] + 178.0182, found [M+1] + 178.0183, cal. mass C 6 H 3 N 5 SNa [M+Na] + 200.0001, found [M+Na] + 200.0003.

[0148] Example 38 6-Chloro-3-methylthieno[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 38 Dimethylthiophene-3,4-dicarboxylate (xvii) A round-bottom flask was equipped with a stir bar and a reflux condenser. The flask was charged with commercially available diacid (2.5 g, 14.52 mmol, 1.0 equiv.) and a catalytic amount of H 2 SO 4 (~2.5 mL) in MeOH (65 mL). The reaction was heated to reflux and stirred for 24 h. The reaction was cooled to room temperature and concentrated by rotary evaporation. The residue was purified on a silica gel chromatography column eluted with DCM to give dimethylthiophene-3,4-dicarboxylate (xvii) as a solid (2.42 g, 83%). 1 H NMR (400 MHz, CDCl 3 ) δ 7.85 (s, 2H), 3.88 (s, 6H). 13 C NMR (101 MHz, CDCl 3 ) δ 163.62, 133.37, 131.97, 52.49. HRMS (ESI): cal. mass C 8 H 8 O 4 S [M+1] + 201.0216, found [M+1] + 201.0216, cal. mass C 8 H 8 O 4 SNa [M+Na] + 223.0036, found [M+Na] + 223.0040.

[0149] 2,3-Dihydrothieno[3,4-d]pyridazine-1,4-dione (xviii) Compound (xvii) (2.0 g, 0.9.99 mmol, 1.0 equiv.) was placed in a round bottom flask in ethanol (15 mL) and reacted with hydrazine hydrate (1.35 g, 26.97 mmol, 2.7 equiv.). The reaction mixture was refluxed for 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and concentrated under vacuum. The crude solid compound was purified by 1% by volume NH 4The compound was dissolved in a minimum amount of water containing OH, and concentrated hydrochloric acid was added to the solution to precipitate it. Finally, the solid compound was washed with cold water, MeOH, and dried at room temperature to give (xviii) as a solid (1.3 g, 78%). 1 H NMR (400 MHz, DMSO) δ 11.20 (broad singlet, 2H), 8.36 (s, 2H). 13 C NMR (101 MHz, DMSO) δ 153.12, 130.42, 128.41. HRMS (ESI): cal. mass C 6 H 4 N 2 O 2 S [M+1] + 169.0066, found [M+1] + 169.0069, cal. mass C 6 H 4 N 2 O 2 SNa [M+Na] + 190.9886, found [M+Na] + 190.9891.

[0150] 1,4-Dichlorothieno[3,4-d]pyridazine (xix) A round bottom flask was fitted with a stir bar and a reflux condenser. The flask was charged with product (xviii) (1.3 g, 7.73 mmol, 1.0 equiv.), phosphorus oxychloride (4 mL), and pyridine (1 mL) and refluxed under argon for 16 h. The reaction was cooled to room temperature and poured onto ice. The mixture was separated and the aqueous layer was extracted with chloroform (4×75 mL). The organic layers were combined and dried (Na 2 SO 4 ) and concentrated by rotary evaporation. The residue was purified by silica gel chromatography column eluted with DCM to give (xix) as a yellow solid (0.72 g, 46%). 1 H NMR (400 MHz, CDCl 3 ) δ 8.31 (s, 2H). 13 C NMR (126 MHz, CDCl 3) δ 150.37, 131.24, 126.40. HRMS (ESI): cal. mass C 6 H 2 N 2 SCl 2 [M+1] + 204.9389, found [M+1] + 204.9389, cal. mass C 6 H 2 N 2 SCl 2 Na [M+Na] + 226.9208, found [M+Na] + 226.9209.

[0151] 6-Chloro-3-methylthieno[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 38 Compound (xix) (0.204 g, 1.0 mmol, 1.0 equiv.) and acetohydrazine (0.222 g, 3.0 mmol, 2.0 equiv.) were refluxed in dioxane (3 mL) for 16 h. The reaction mixture was extracted with chloroform (4×30 mL). The organic phase was diluted with Na 2 SO 4 The mixture was dried at 40° C. and evaporated to dryness. The crude product was purified by column chromatography using dichloromethane to give amorphous solid 38 (0.192 g, 86%). 1 H NMR (600 MHz, CDCl 3 ) δ 8.42 (d, J = 3.0 Hz, 2H), 8.28 (d, J = 3.1 Hz, 2H), 2.75 (s, 6H). 13 C NMR (126 MHz, CDCl 3 ) δ 147.78, 145.11, 141.19, 129.60, 127.87, 124.31, 122.63, 10.20. HRMS (ESI): cal. mass C 8 H 5 N 4 SCl [M+1] + 224.9996, found [M+1] + 224.9997, cal. mass C8 H 5 N 4 SClNa [M+Na] + 246.9816, found [M+Na] + 246.9822.

[0152] Example 39 3-Methylthieno[3,4-d][1,2,4]triazolo[4,3-b]pyridazine 39 Compound 38 (40 mg, 0.17 mmol, 1.0 equiv.) was dissolved in ethanol (3 mL), hydrazine hydride (55%) (17.8 mg, 0.35 mmol, 2.0 equiv.) was slowly added, and the reaction mixture was refluxed for 2 h to give a precipitate. The product was collected by suction filtration and dried. A solution of 0.15 M TMSOK (22 mg, 0.17 mmol, 1.0 equiv.) in water (1.6 mL) was then added, and the slurry was stirred at room temperature for 48 h. The resulting mixture was extracted with chloroform (4 x 20 mL). The organic phase was washed with Na 2 SO 4 Drying at rt and evaporation gave amorphous solid 39 (12 mg, 35%). 1 H NMR (600 MHz, CDCl 3 ) δ 8.49 (d, J = 0.9 Hz, 1H), 8.39 (dd, J = 2.9, 0.9 Hz, 1H), 8.15 (d, J = 2.9 Hz, 1H), 2.76 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.18, 142.27, 141.73, 128.44, 128.31, 124.58, 121.39, 10.26. HRMS (ESI): cal. mass C 8 H 6 N 4 S [M+1] + 191.0386, found [M+1] + 191.0387, cal. mass C 8 H 6 N 4 SNa [M+Na] + 213.0205, found [M+Na] + 213.0199.

[0153] Example 40 6-Chlorotetrazolo[1,5-b]thieno[3,4-d]pyridazine 40 1,4-Dichlorothieno[3,4-d]pyridazine (xix) (0.100 g, 0.49 mmol, 1.0 equiv.) was dissolved in methanol (8 mL), hydrazine hydride (55%) (0.049 g, 0.98 mmol, 2.0 equiv.) was slowly added, and the reaction mixture was refluxed for 1 h. After completion of the reaction, the reaction mixture was cooled to room temperature and concentrated under vacuum to obtain a crude yellow precipitate. The precipitate was dissolved in acetic acid (5 mL, 2N) and the ice-cold solution was stirred with NaNO 2 (50 mg, 0.73 mmol, 1.5 equiv. in 2 mL water). The reaction mixture was stirred at room temperature for 1 h. The compound was extracted with chloroform (3×25 mL). The organic phase was washed with Na 2 SO 4 Drying at rt and evaporation gave amorphous solid 40 (48 mg, 46%). 1 H NMR (500 MHz, DMSO) δ 8.99 (d, J = 2.8 Hz, 1H), 8.80 (d, J = 2.8 Hz, 1H). 13 C NMR (126 MHz, DMSO) δ 150.35, 140.43, 130.79, 126.37, 124.04, 121.94.

[0154] Example 41 Tetrazolo[1,5-b]thieno[3,4-d]pyridazine 41 Compound 40 (40 mg, 0.18 mmol, 1.0 equiv.) was dissolved in ethanol (3 mL), hydrazine hydride (55%) (18.9 mg, 0.37 mmol, 2.0 equiv.) was slowly added, and the reaction mixture was refluxed for 2 h to give a precipitate. The product was collected by suction filtration and dried. A solution of 0.15 M TMSOK (24 mg, 0.18 mmol, 1.0 equiv.) in water (1.7 mL) was then added, and the slurry was stirred at room temperature for 48 h. The resulting mixture was extracted with chloroform (4 × 20 mL). The organic phase was diluted with Na 2 SO 4Drying at rt and evaporation gave amorphous solid 41 (8 mg, 23%). 1 H NMR (600 MHz, CDCl 3 ) δ 9.34 (s, 1H), 8.48 (d, J = 3.2 Hz, 1H), 7.96 (d, J = 3.2 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 157.22, 135.32, 132.41, 131.03, 130.35, 126.09. HRMS (ESI): cal. mass C 6 H 3 N 5 S [M+1] + 178.0182, found [M+1] + 178.0192.

[0155] Example 42 3-Methylfuro[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 42 2-Formylfuran-3-carboxylic acid (xx) n-BuLi (17.84 mL, 44.61 mmol, 2.5 mol / L, 2.5 equiv.) was added dropwise to a stirred solution of commercially available furan-2-carboxylic acid (2.0 g, 17.84 mmol, 1.0 equiv.) in dry THF (60 mL) at -78 °C. After 2 h, DMF (2.7 mL, 35.68 mmol, 2.0 equiv.) was added. After an additional h, the cooling bath was removed and the mixture was stirred at ambient temperature for 16 h. Then, HCl (aq, 1 M, 60 mL) was added. The mixture was extracted with ethyl acetate (3 x 40 mL), dried (Na 2 SO 4 ) and concentrated in vacuo The resulting yellow solid (xx) (yield 2.36 g, 94%) was used without further purification.

[0156] 7-Chlorofuro[2,3-d]pyridazine (xxi) A round bottom flask was fitted with a stir bar and reflux condenser. The flask was charged with the product 2-formylfuran-3-carboxylic acid (xx) (0.500 g, 3.57 mmol, 1.0 equiv.), hydrazine hydrate (55%) (0.446 g, 8.92 mmol, 2.5 equiv.), and MeOH (10 mL) and refluxed for 4 h. The reaction was cooled to room temperature, concentrated by rotary evaporation, and dried under high vacuum to give crude furo[2,3-d]pyridazin-7(6H)-one. Phosphorus oxychloride (5.46 g, 3.3 mL, 35.71 mmol, 10.0 equiv.) and pyridine (0.56 g, 0.57 mL, 7.14 mmol, 2.0 equiv.) were then added and refluxed for 24 h. The reaction was cooled to room temperature, poured onto ice, and diluted with NaHCO 3 The mixture was separated and the aqueous layer was extracted with chloroform (4×50 mL). The organic layers were combined and dried (Na 2 SO 4 The residue was purified by silica gel chromatography column eluted with DCM to give 7-chlorofuro[2,3-d]pyridazine (xxi) as a yellow solid (yield 0.135 g, 25%). 1 H NMR (400 MHz, CDCl 3 ) δ 9.47 (s, 1H), 7.94 (d, J = 2.1 Hz, 1H), 7.00 (d, J = 2.1 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 149.84, 149.15, 146.51, 141.89, 105.74. HRMS (EI): cal. mass C 6 H 3 ClN 2 O [M] + 153.9928, found [M] + 153.9927.

[0157] 3-Methylfuro[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 42 7-Chlorofuro[2,3-d]pyridazine (xxi) (25 mg, 0.16 mmol, 1.0 equiv.) and acetohydrazine (24 mg, 0.32 mmol, 2.0 equiv.) were refluxed in dioxane (2 mL) for 24 h. The reaction mixture was extracted with chloroform (4 × 20 mL). The organic phase was diluted with Na 2 SO 4 The mixture was dried at 40° C. and evaporated to dryness. The crude product was purified by column chromatography with dichloromethane to give 3-methylfuro[2,3-d][1,2,4]triazolo[4,3-b]pyridazine 42 (17 mg, 60%) as an amorphous solid. 1 H NMR (400 MHz, CDCl 3 ) δ 8.66 (s, 1H), 7.90 (d, J = 2.1 Hz, 1H), 7.00 (d, J = 2.1 Hz, 1H), 2.85 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 147.96, 147.31, 145.54, 140.93, 138.11, 117.60, 106.72, 10.39. HRMS (ESI): cal. mass C 8 H 6 N 4 O [M+1] + 175.0614, found [M+1] + 175.0617, cal. mass C 8 H 6 N 4 ONa [M+Na] + 197.0434, found [M+Na] + 197.0434.

[0158] Example 43 Furo[2,3-d]tetrazolo[1,5-b]pyridazine 43 7-Chlorofuro[2,3-d]pyridazine (xxi) (50 mg, 0.32 mmol, 1.0 equiv.) was dissolved in DMF (1 mL) and sodium azide (31 mg, 0.48 mmol, 1.5 equiv.) was added. The reaction mixture was heated at 120° C. for 24 h. The reaction was cooled to room temperature and poured into water. The mixture was separated and the aqueous layer was extracted with chloroform (4×25 mL). The organic layers were combined, dried (Na 2 SO 4 ) and concentrated by rotary evaporation to give furo[2,3-d]tetrazolo[1,5-b]pyridazine 43 as a yellow amorphous solid (yield 40 mg, 76%). 1 H NMR (400 MHz, CDCl 3 ) δ 9.01 (s, 1H), 8.14 (d, J = 2.1 Hz, 1H), 7.23 (d, J = 2.1 Hz, 1H). 13 C NMR (101 MHz, CDCl 3 ) δ 149.91, 144.73, 142.13, 137.04, 122.11, 107.26. HRMS (ESI): cal. mass C 6 H 3 N 5 O [M+1] + 162.0410, found [M+1] + 162.0409, cal. mass C 6 H 3 N 5 ONa [M+Na] + 184.0230, found [M+Na] + 184.0235.

[0159] Example 44 6,10-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44a (major isomer) and 6,7-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44b (Minor isomer) 5-Chloro-2,3-dihydrophthalazine-1,4-dione 4-Chloroisobenzofuran-1,3-dione (10 g, 54.76 mmol, 1.0 equiv.) was dissolved in 10% hydrochloric acid (50 mL), hydrazine hydrate (55%) (2.63 g, 82.14 mmol, 1.5 equiv.) was added, and the mixture was refluxed with stirring for 16 h. The product was collected by suction filtration, washed with water, and dried to give an amorphous solid (10.1 g, 93%). 1 H NMR (300 MHz, DMSO) δ 11.60 (s, 2H), 8.00 (d, J = 7.6 Hz, 1H), 7.84 (m, 2H). HRMS (ESI): cal. mass C 8 H 5 ClN 2 O 2 [M+1] + 197.0112, found [M+1] + 197.0110, cal. mass C 8 H 5 ClN 2 O 2 [M+Na] + 218.9932, found [M+Na] + 218.9938.

[0160] 1,4,5-Trichlorophthalazine A round bottom flask was fitted with a stir bar and a reflux condenser. The flask was charged with 5-chloro-2,3-dihydrophthalazine-1,4-dione (10 g, 50.86 mmol, 1.0 equiv.), phosphorus oxychloride (23.65 mL, 508.64 mmol, 5.0 equiv.) and refluxed for 24 h. The reaction was cooled to room temperature and poured onto ice. The mixture was separated and the aqueous layer was extracted with chloroform (4×60 mL). The organic layers were combined and dried (Na 2 SO 4 ) and concentrated by rotary evaporation. The crude product was purified by column chromatography using dichloromethane to give an amorphous solid (2.1 g, 26%). 1 H NMR (400 MHz, CDCl 3) δ 8.34 (dd, J = 8.3, 1.2 Hz, 1H), 8.11 (dd, J = 7.8, 1.2 Hz, 1H), 7.94 (dd, J = 8.3, 7.8 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 155.28, 152.45, 137.79, 134.17, 132.06, 129.45, 125.83, 124.59. HRMS (ESI): cal. mass C 8 H 3 Cl 3 N 2 [M+1] + 232.9435, found [M+1] + 232.9441, cal. mass C 8 H 3 Cl 3 N 2 [M+Na] + 254.9254, found [M+Na] + 254.9263.

[0161] 6,10-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44a (major isomer) and 6,7-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44b (Minor isomer) 1,4,5-Trichlorophthalazine (500 mg, 2.15 mmol, 1.0 equiv.) and acetic hydrazide (318 mg, 4.31 mmol, 2.0 equiv.) were refluxed in dioxane (6 mL) for 4 h. The reaction mixture was extracted with dichloromethane (4×40 mL). The organic phase was washed with Na 2 SO 4 It was dried at 47° C. and concentrated by rotary evaporation to give a solid (421 mg, 77%). 1 H NMR (300 MHz, CDCl 3) δ 8.67 (dd, J = 7.4, 2.0 Hz, 0.17H), 8.23 ​​(dd, J = 8.1, 1.1 Hz, 1H), 8.03 (dd, J = 8.0, 1.2 Hz, 1H), 7.88 - 7.80 (m, 0.36H), 7.77 (t, J = 8.1 Hz, 1H), 2.83 (s, 3H), 2.81 (s, 0.60H). HRMS (ESI): cal. Mass C 10 H 6 Cl 2 N 4 [M+1] + 253.0042, found [M+1] + 253.0042, cal. Mass C 10 H 6 Cl 2 N 4 [M+Na] + 274.9862, found [M+Na] + 274.9868.

[0162] The isomeric mixture was separated by column chromatography. First eluent isomer: 6,10-dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44a (major isomer). 1 H NMR (300 MHz, CDCl 3 ) δ 8.23 ​​(dd, J = 8.1, 1.3 Hz, 1H), 8.04 (dd, J = 8.1, 1.3 Hz, 1H), 7.77 (t, J = 8.1Hz, 1H), 2.83 (s, 3H). Second eluent isomer: 6,7-dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 44b (minor isomer) 1 H NMR (300 MHz, CDCl 3 ) δ 8.68 (dd, J = 7.3, 1.9 Hz, 1H), 7.91 - 7.80 (m, 2H), 2.81 (s, 3H).

[0163] Example 45 10-Chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 45 Compound 44a (major isomer) (250 mg, 0.98 mmol, 1.0 equiv.) was dissolved in ethanol (5 mL), hydrazine hydride (55%) (63.24 mg, 1.97 mmol, 2.0 equiv.) was slowly added, and the reaction mixture was refluxed for 3 h to give a precipitate. The product was collected by suction filtration and dried. Then, an aqueous solution of 0.15 M TMSOK (126 mg, 0.98 mmol, 1.0 equiv.) was added, and the slurry was stirred at room temperature for 48 h. The resulting mixture was extracted with chloroform (4 × 30 mL). The organic phase was diluted with Na 2 SO 4 The mixture was dried at 40° C. and evaporated. The crude product was purified by column chromatography using dichloromethane to give an amorphous solid (45 mg, 21%). 1 H NMR (300 MHz, CDCl 3 ) δ 8.59 (s, 1H), 7.98 (dd, J = 7.9, 1.2 Hz, 1H), 7.84 (dd, J = 7.8, 1.2 Hz, 1H), 7.71 (t, J = 7.9 Hz, 1H), 2.84 (s, 3H). HRMS (ESI): cal. mass C 10 H 7 ClN 4 [M+1] + 219.0432, found [M+1] + 219.0435, cal. mass C 10 H 7 ClN 4 [M+Na] + 241.0251, found [M+Na] + 241.0259.

[0164] Example 46 6,10-Dichlorotetrazolo[5,1-a]phthalazine 46 1,4,5-Trichlorophthalazine (800 mg, 3.44 mmol, 1.0 equiv.) was dissolved in ethanol (10 mL), hydrazine hydride (55%) (221 mg, 6.89 mmol, 2.0 equiv.) was slowly added, and the reaction mixture was refluxed for 1 h. After completion of the reaction, the reaction mixture was cooled to room temperature and concentrated under vacuum to obtain a crude yellow precipitate. The precipitate was dissolved in acetic acid (15 mL, 2N), and the ice-cold solution was stirred with NaNO 2 (356 mg, 5.17 mmol, 1.5 equiv. in 2 mL water). The reaction mixture was stirred at room temperature for 1 h. The compound was extracted with chloroform (3×35 mL). The organic phase was diluted with Na 2 SO 4 Drying at rt and evaporation gave an amorphous solid (452 ​​mg, 55%). 1 H NMR (300 MHz, CDCl 3 ) δ 8.43 (dd, J = 8.3, 1.1 Hz, 1H), 8.21 (dd, J = 8.0, 1.1 Hz, 1H), 8.01 (t, J = 8.1 Hz, 1H). HRMS (ESI): cal. mass C 8 H 3 Cl 2 N 5 [M+1] + 239.9838, found [M+1] + 239.9842, cal. mass C 8 H 3 Cl 2 N 5 [M+Na] + 261.9658, found [M+Na] + 261.9664.

[0165] Example 47 10-Chlorotetrazolo[5,1-a]phthalazine (47a) and 7-chlorotetrazolo[5,1-a]phthalazine (47b) The above compound was prepared from compound 46 according to the procedure described in Example 45. The yield was 22%. The mixture of isomers was separated by column chromatography on silica gel with DCM as solvent. First isomer: 10-chlorotetrazolo[5,1-a]phthalazine (47a). 1H NMR (600 MHz, CDCl 3 ) δ 8.95 (s, 1H), 8.16 (dd, J = 7.9, 1.1 Hz, 1H), 8.07 (dd, J = 7.9, 1.1 Hz, 1H), 7.95 (t, J = 7.9 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.91, 140.92, 136.18, 132.89, 132.77, 127.09, 126.44, 121.19. Second isomer: 7-chlorotetrazolo[5,1-a]phthalazine (47b). 1 H NMR (600 MHz, DMSO) δ 9.56 (s, 1H), 8.64 (d, J = 7.8 Hz, 1H), 8.24 (dd, J = 7.9, 1.1 Hz, 1H), 8.19 (t, J = 7.9 Hz, 1H). 13 C NMR (126 MHz, DMSO) δ 147.01, 142.05, 136.46, 133.70, 133.43, 124.28, 123.42, 122.98. HRMS (ESI): cal. mass C 8 H 4 N 5 Cl [M+1] + 206.0228, [M+2] + 208.0199 found [M+1] + 206.0234, [M+2] + 208.0230 cal. mass C 8 H 4 N 5 ClNa [M+1] + 228.0047, [M+2] + 230.0018 found [M+1] + 228.0045, [M+2] + 230.0018.

[0166] Example 48 6,9-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (48a) and 6,8-dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (48b) 6-Chloro-2,3-dihydrophthalazine-1,4-dione (xxiv) Prepared from 5-chloroisobenzofuran-1,3-dione in the same manner as compound (xxii) in Example 44. The yield was 98%. 1 H NMR (300 MHz, DMSO) δ 8.07 (d, J = 8.6 Hz, 1H), 8.00 (d, J = 2.1 Hz, 1H), 7.90 (dd, J = 8.5, 2.2 Hz, 1H). 13 C NMR (75 MHz, DMSO) δ 138.07, 136.13, 133.32, 131.08, 130.99, 128.40, 128.16, 124.90.

[0167] 1,4,6-Trichlorophthalazine(XXV) Prepared from (xxiv) in analogy with compound (xxiii) of Example 44. Yield 51%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.31 - 8.26 (m, 2H), 8.01 (ddd, J = 8.9, 2.0, 0.9 Hz, 1H). 13 C NMR (75 MHz, CDCl3) δ 154.80, 154.07, 141.39, 135.55, 128.25, 127.94, 125.71, 125.28.

[0168] 6,9-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (48a) and 6,8-dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (48b) Prepared from compound (xxv) in the same manner as in Example 44. The yield was 91%. 1 H NMR (300 MHz, CDCl 3) δ 8.64 (d, J = 2.1 Hz, 1H), 8.62 (d, J = 8.6 Hz, 1H), 8.23 ​​(d, J = 2.0 Hz, 1H), 8.19 (d, J = 8.8 Hz, 1H), 7.97 - 7.91 (m, 1H), 7.82 - 7.76 (m, 1H), 2.81 (s, 6H). 13 C NMR (75 MHz, CDCl 3 ) δ 149.30, 148.69, 148.53, 148.03, 141.85, 137.78, 135.43, 131.88, 129.21, 127.18, 125.33, 125.29, 123.39, 123.31, 122.52, 120.42, 9.93 (2 x CH 3 ).

[0169] Example 49 9-Chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (49a) and 8-chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (49b) Prepared from (48a / 48b) analogously to Example 45. The mixture of isomers was separated by column chromatography on silica gel with DCM and methanol (100 to 98:2). First isomer: 9-chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (49a). 1 H NMR (600 MHz, CDCl 3 ) δ 8.64 (d, J = 2.0 Hz, 1H), 8.60 (s, 1H), 7.87 (d, J = 8.5 Hz, 1H), 7.75 (dd, J = 8.4, 2.0 Hz, 1H), 2.83 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.57, 146.73, 141.77, 140.76, 131.52, 129.63, 124.86, 123.17, 121.27, 10.03. Second isomer: 8-chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (49b). 1 H NMR (600 MHz, CDCl 3) δ 8.68 (d, J = 8.4 Hz, 1H), 8.60 (s, 1H), 7.95 - 7.91 (m, 2H), 2.85 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.47, 146.48, 142.10, 137.20, 134.72, 127.62, 125.18, 124.17, 121.93, 10.05.

[0170] Example 50 6,9-Dichlorotetrazolo[5,1-a]phthalazine (50a) and 6,8-Dichlorotetrazolo[5,1-a]phthalazine (50b) Prepared from compound (xxv) in the same manner as in Example 46. The yield was 71%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.78 - 8.71 (m, 1.4H), 8.46 - 8.37 (m, 1.4H), 8.13 (dt, J = 8.6, 1.7 Hz, 1H), 8.03 (dt, J = 8.9, 1.8 Hz, 0.4H). 13 C NMR (75 MHz, CDCl 3 ) δ 151.82, 151.79, 151.11, 143.01, 141.55, 140.36, 136.39, 134.15, 129.72, 127.74, 126.80, 125.45, 124.90, 123.61, 122.57, 120.84.

[0171] Example 51 9-Chlorotetrazolo[5,1-a]phthalazine (51a) and 8-chlorotetrazolo[5,1-a]phthalazine (51b) Prepared from (50a / 50b) analogously to example 45. Yield 21%. The mixture of isomers was separated by column chromatography on silica gel with DCM. First isomer: 9-chlorotetrazolo[5,1-a]phthalazine (51a). 1 H NMR (600 MHz, CDCl 3) δ 8.94 (d, J = 0.7 Hz, 1H), 8.74 (dd, J = 2.0, 0.6 Hz, 1H), 8.11 (dd, J = 8.5, 0.5 Hz, 1H), 7.97 (dd, J = 8.5, 2.0 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.50, 141.94, 141.42, 133.62, 130.11, 124.52, 123.63, 123.14. Second isomer: 8-chlorotetrazolo[5,1-a]phthalazine (51b). 1 H NMR (600 MHz, CDCl 3 ) δ 8.90 (s, 1H), 8.72 (d, J = 8.5 Hz, 1H), 8.14 (d, J = 2.0 Hz, 1H), 8.08 (dd, J = 8.6, 2.0 Hz, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 148.07, 141.82, 139.45, 135.60, 128.08, 126.39, 125.98, 120.82.

[0172] Example 52 6,8,9-Trichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 6,7-Dichloro-2,3-dihydrophthalazine-1,4-dione (xxvi) A solution of 4,5-dichlorophthalic acid (10 g, 42.55 mmol) in AcCl (60 mL) was refluxed for 2 h and then concentrated in vacuo to give 5,6-dichloroisobenzofuran-1,3-dione (9.21 g, 99%) as a light brown solid. The crude product was then used directly in the next step without further purification. 1 H NMR (300 MHz, CDCl 3 ) δ 8.11 (s, 2H). 13 C NMR (75 MHz, CDCl3) δ 160.82, 141.87, 130.42, 127.57.

[0173] To a stirred solution of 5,6-dichloroisobenzofuran-1,3-dione (9.2 g, 42.39 mmol) in 10% hydrochloric acid (60 mL) was added hydrazine (55%) (2.71 g, 84.79 mmol) and the mixture was refluxed for 24 h, forming a precipitate. The product was collected by suction filtration, washed with water and dried to give compound (xxvi) (9.51 g, 94%) as an amorphous solid.

[0174] 1,4,6,7-Tetrachlorophthalazine(xxvii) Prepared from compound (xxvi) in the same manner as compound (xxiii) in example 44. Yield: 29%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.41 (s, 2H). 13 C NMR (75 MHz, CDCl 3 ) δ 153.59, 140.40, 127.53, 126.21.

[0175] 6,8,9-Trichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 52 Prepared from compound (xxvii) in the same manner as in Example 44. The yield was 74%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.75 (s, 1H), 8.33 (s, 1H), 2.81 (s, 3H). 13 C NMR (75 MHz, CDCl3) δ 148.41, 148.08, 141.53, 140.50, 136.37, 129.19, 125.34, 123.18, 121.32, 9.94.

[0176] Example 53 8,9-Dichloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine Prepared from 52 as in example 45. Yield 19%. 1 H NMR (300 MHz, CDCl 3) δ 8.76 (s, 1H), 8.56 (s, 1H), 8.04 (d, J = 1.1 Hz, 1H), 2.84 (d, J = 1.1 Hz, 3H).

[0177] Example 54 6,8,9-Trichlorotetrazolo[5,1-a]phthalazine Prepared from compound (xxvii) in analogy to Example 46. Yield: 51%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.87 (s, 1H), 8.53 (s, 1H). 13 C NMR (75 MHz, CDCl 3 ) δ 141.79, 140.80, 140.78, 139.14, 129.66, 126.78, 123.36, 121.40.

[0178] Example 55 8,9-Dichlorotetrazolo[5,1-a]phthalazine Prepared from 54 as in example 45. Yield 26%. 1 H NMR (600 MHz, CDCl 3 ) δ 8.89 (s, 1H), 8.86 (s, 1H), 8.26 (s, 1H). 13 C NMR (126 MHz, CDCl 3 ) δ 147.48, 140.98, 140.71, 138.31, 129.96, 126.48, 123.89, 121.52.

[0179] Example 56 6-Chloro-10-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (56a) and 6-chloro-7-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (56b) 5-Fluoro-2,3-dihydrophthalazine-1,4-dione (xxviii) Prepared from commercially available 4-fluoroisobenzofuran-1,3-dione in analogy to compound (xxii) in Example 44. Yield 95%. 1H NMR (300 MHz, DMSO) δ 11.58 (s, 2H), 7.95 - 7.81 (m, 2H), 7.73 - 7.58 (m, 1H). 19 F NMR (282 MHz, DMSO) δ -111.42. HRMS (ESI): cal. mass C 8 H 5 N 2 O 2 F [M+1] + 181.0408, found [M+1] + 181.0404, cal. mass C 8 H 5 N 2 O 2 F [M+Na] + 203.0227, found [M+Na] + 203.0237.

[0180] 1,4-Dichloro-5-fluorophthalazine(xxix) Prepared from compound (xxviii) in the same manner as compound (xxiii) in example 44. Yield: 38%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.18 (dd, J = 8.4, 1.0 Hz, 1H), 8.11 - 7.97 (m, 1H), 7.80 - 7.67 (m, 1H). HRMS (ESI): cal. mass C 8 H 3 N 2 Cl 2 F [M+1] + 216.9730, found [M+1] + 216.9724, cal. mass C 8 H 3 N 2 Cl 2 F [M+Na] + 238.9550, found [M+Na] + 240.9520.

[0181] 6-Chloro-10-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (56a) and 6-chloro-7-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (56b) Prepared from compound (xxix) similarly to Example 44. Yield: 82%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.52 - 8.47 (m, 0.5H), 8.10 (dd, J = 8.1, 1.1 Hz, 1H), 7.95 (td, J = 8.1, 4.6 Hz, 0.5H), 7.84 (td, J = 8.2, 5.0 Hz, 1H), 7.75 (td, J = 8.7, 8.1, 1.1 Hz, 1H), 7.57 - 7.46 (m, 0.5H), 2.82 (s, 3H), 2.81 (s, 1.5H).

[0182] Example 57 10-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (57a) and 7-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (57b) Prepared from 56a / 56b as in example 45. Yield 31%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.91 (s, 1H), 8.63 (d, J = 2.1 Hz, 1H), 8.44 (d, J = 8.0 Hz, 1H), 7.91 (td, J = 8.1, 5.3 Hz, 1H), 7.81 - 7.65 (m, 3H), 7.51 - 7.43 (m, 1H), 2.84 (s, 6H). 19 F NMR (282 MHz, CDCl 3 ) δ -107.77, -118.06.

[0183] After recrystallization from hexane, 10-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (57a) was obtained as a crystalline solid. 1H NMR (600 MHz, DMSO) δ 9.02 (s, 1H), 8.11 - 8.07 (m, 1H), 7.83 - 7.78 (m, 2H), 2.62 (s, 3H). 13 C NMR (126 MHz, DMSO) δ 158.57, 156.53, 152.55, 146.03, 138.39, 131.23, 119.78, 119.31, 112.62, 9.40.

[0184] Example 58 6-Chloro-10-fluorotetrazolo[5,1-a]phthalazine (58a) and 6-chloro-7-fluorotetrazolo[5,1-a]phthalazine (58b) Prepared from compound (xxix) similarly to example 46. Yield: 69%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.62 (d, J = 8.0 Hz, 0.5 H), 8.31 (d, J = 8.0 Hz, 1H), 8.19 - 8.07 (m, 1.5H), 7.92 (td, J = 8.5, 0.9 Hz, 1H), 7.75 (ddd, J = 11.6, 8.3, 1.1 Hz, 0.5H).

[0185] Example 59 10-Fluorotetrazolo[5,1-a]phthalazine (59a) and 7-Fluorotetrazolo[5,1-a]phthalazine (59b) Prepared from 58a / 58b as in example 45. Yield 37%. 1 H NMR (300 MHz, CDCl 3 ) δ 9.23 (s, 0.3H), 8.98 (s, 1H), 8.56 (d, J = 8.1 Hz, 0.3H), 8.15 - 8.07 (m, 0 .3H), 8.05 - 7.94 (m, 2H), 7.86 (td, J = 8.3, 7.4, 1.6 Hz, 1H), 7.69 (t, J = 8.9 Hz, 0.3H). 19 F NMR (282 MHz, CDCl 3) δ -106.33, -115.77. The mixture of isomers was separated by column chromatography on silica gel with dichloromethane. First isomer: 7-fluorotetrazolo[5,1-a]phthalazine (59b). 1 H NMR (400 MHz, CDCl 3 ) δ 9.24 (d, J = 0.8 Hz, 1H), 8.56 (d, J = 8.0 Hz, 1H), 8.11 (td, J = 8.1, 5.2 Hz, 1H), 7.69 (ddd, J = 9.3, 8.3, 0.9 Hz, 1H). Second isomer: 10-fluorotetrazolo[5,1-a]phthalazine (59a). 1 H NMR (400 MHz, CDCl 3 ) δ 8.98 (d, J = 2.0 Hz, 1H), 8.08 - 7.96 (m, 2H), 7.86 (ddd, J = 9.2, 7.8, 1.3 Hz, 1H).

[0186] Example 60 6-Chloro-9-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (60a) and 6-chloro-8-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (60b) 6-Fluoro-2,3-dihydrophthalazine-1,4-dione(xxx) Prepared from commercially available 5-fluoroisobenzofuran-1,3-dione in analogy to compound (xxii) in Example 44. Yield 96%. 1 H NMR (300 MHz, DMSO) δ 11.67 (s, 2H), 8.15 (dd, J = 9.6, 5.3 Hz, 1H), 8.17 - 7.69 (m, 2H). 19 F NMR (282 MHz, DMSO) δ -105.04.

[0187] 1,4-Dichloro-6-fluorophthalazine (xxxi) Prepared from compound (xxx) in the same manner as compound (xxiii) in Example 44. Yield: 53%. 1 H NMR (300 MHz, CDCl 3) δ 8.39 (dd, J = 9.1, 5.0 Hz, 1H), 7.94 (dd, J = 8.1, 2.5 Hz, 1H), 7.80 (ddd, J = 9.1, 8.1, 2.5 Hz, 1H). HRMS (ESI): cal. mass C 8 H 3 N 2 Cl 2 F [M+1] + 216.9730, found [M+1] + 216.9742, cal. mass C 8 H 3 N 2 Cl 2 F [M+Na] + 238.9550, found [M+Na] + 240.9560.

[0188] 6-Chloro-9-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (60a) and 6-chloro-8-fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (60b) Preparation was carried out from 1,4-dichloro-6-fluorophthalazine (xxxi) analogously to Example 44. The yield was 80%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.68 (dd, J = 8.8, 5.1 Hz, 1H), 8.33 - 8.24 (m, 2H), 7.91 (dd, J = 8.8, 2.5 Hz, 1H), 7.72 (td, J = 8.4, 2.5 Hz, 1H), 7.54 (ddd, J = 9.1, 8.1, 2.6 Hz, 1H), 2.81 (s, 3H), 2.80 (s, 3H). HRMS (ESI): cal. mass C 10 H 6 N 4 ClF [M+1] + 237.0338, found [M+1] + 237.0346, cal. mass C 10 H 6 N 4ClF [M+Na] + 259.0157, found [M+Na] + 259.0167.

[0189] Example 61 9-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (61a) and 8-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (61b) Prepared from 60a / 60b as in Example 45. Yield 24%. The mixture of isomers was separated by column chromatography on silica gel with DCM. HRMS (ESI): cal. mass C 10 H 7 N 4 F [M+1] + 203.0728, found [M+1] + 203.0722, cal. mass C 10 H 7 N 4 F [M+Na] + 225.0547, found [M+Na] + 225.0542. First isomer: 9-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (61a). 1 H NMR (500 MHz, CDCl 3 ) δ 8.61 (s, 1H), 8.32 (dd, J = 8.5, 2.5 Hz, 1H), 7.98 (dd, J = 8.7, 5.0 Hz, 1H), 7.52 (td, J = 8.5, 2.5 Hz, 1H), 2.85 (s, 3H). Second isomer: 8-Fluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (61b). 1 H NMR (500 MHz, CDCl 3 ) δ 8.68 (dd, J = 8.7, 5.0 Hz, 1H), 8.58 (s, 1H), 7.69 (td, J = 8.5, 2.5 Hz, 1H), 7.59 (dd, J = 8.1, 2.5 Hz, 1H), 2.82 (s, 3H).

[0190] Example 62 6-Chloro-9-fluorotetrazolo[5,1-a]phthalazine (62a) and 6-chloro-8-fluorotetrazolo[5,1-a]phthalazine (62b) Preparation was carried out from 1,4-dichloro-6-fluorophthalazine (xxxi) analogously to Example 46. The yield was 77%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.82 (dd, J = 8.8, 5.0 Hz, 1H), 8.52 (dd, J = 9.1, 4.9 Hz, 1H), 8.41 (dd, J = 7.6, 2.6 Hz, 1H), 8.11 (dd, J = 8.5, 2.5 Hz, 1H), 7.91 (td, J = 8.4, 2.5 Hz, 1H), 7.80 (td, J = 8.5, 2.5 Hz, 1H). HRMS (ESI): cal. mass C 8 H 3 N 5 FCl [M+1] + 224.0134, found [M+1] + 224.0145, cal. mass C 8 H 3 N 5 FCl [M+Na] + 245.9953, found [M+Na] + 245.9961.

[0191] Example 63 9-Fluorotetrazolo[5,1-a]phthalazine (63a) and 8-Fluorotetrazolo[5,1-a]phthalazine (63b) Prepared from 62a / 62b as in example 45. Yield 25%. 1 H NMR (300 MHz, CDCl 3) δ 8.94 (s, 0.3H), 8.93 (s, 1H), 8.80 (dd, J = 8.8, 4.9 Hz, 1H), 8.40 (dd, J = 7.8, 2.5 Hz, 0.3H), 8.21 (dd, J = 8.8, 4.9 Hz, 0.3H), 7.89 - 7.80 (m, 2H), 7.74 (td, J = 8.5, 2.4 Hz, 0.3H). HRMS (ESI): cal. mass C 8 H 4 N 5 F [M+1] + 190.0523, found [M+1] + 190.0519, cal. mass C 8 H 4 N 5 F [M+Na] + 212.0343, found [M+Na] + The mixture of isomers was separated by column chromatography on silica gel with DCM as solvent. First isomer: 9-fluorotetrazolo[5,1-a]phthalazine (63a). 1 H NMR (500 MHz, CDCl 3 ) δ 8.94 (s, 1H), 8.40 (dd, J = 7.8, 2.5 Hz, 1H), 8.21 (dd, J = 8.8, 4.9 Hz, 1H), 7.74 (ddd, J = 8.8, 8.2, 2.5 Hz, 1H). 19 F NMR (282 MHz, CDCl 3 ) δ -97.05 (td, J = 8.1, 4.8 Hz). Second isomer: 8-fluorotetrazolo[5,1-a]phthalazine (63b). 1 H NMR (500 MHz, CDCl 3 ) δ 8.92 (s, 1H), 8.80 (dd, J = 8.8, 4.9 Hz, 1H), 7.90 - 7.79 (m, 2H). 19 F NMR (282 MHz, CDCl 3 ) δ -102.02 (td, J = 7.9, 4.8 Hz).

[0192] Example 64 6-Chloro-8,9-difluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine 64 6,7-Difluoro-2,3-dihydrophthalazine-1,4-dione (xxxii) Ac of 4,5-difluorophthalic acid (5 g, 24.74 mmol) 2 The O (30 mL) solution was refluxed for 2 h and then concentrated in vacuo to give 5,6-difluoroisobenzofuran-1,3-dione (yield 4.51 g, 99%) as a light brown solid, which was used directly in the next reaction without further purification. 1 H NMR (300 MHz, CDCl3) δ 7.83 (t, J = 7.0 Hz, 2H).

[0193] To a stirred solution of 5,6-difluoroisobenzofuran-1,3-dione (4.5 g, 24.59 mmol) in ethanol (50 mL) was added hydrazine (55%) (1.57 g, 49.18 mmol, 2.0 equiv.) and the mixture was heated under reflux for 24 hours, forming a precipitate. The product was collected by suction filtration, washed with water and dried to give compound (xxxii) as an amorphous solid (4.62 g, 95%). 1 H NMR (300 MHz, DMSO) δ 11.76 (s, 2H), 7.98 (t, J = 9.0 Hz, 2H).

[0194] 1,4-Dichloro-6,7-difluorophthalazine (xxxiii) Prepared from compound (xxxii) in the same manner as compound (xxiii) in Example 44. Yield: 52%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.11 (t, J = 8.3 Hz, 2H). HRMS (ESI): cal. mass C 8 H 2 N 2 F 2 Cl 2 [M+1] + 234.9636, [M+2] +236.9607 found [M+1] + 234.9643, [M+2] + 236.9615 cal. mass C 8 H 2 N 2 F 2 Cl 2 Na [M+1] + 256.9455, [M+2] + 258.9426 found [M+Na] + 256.9461, [M+2] + 258.9430.

[0195] 6-Chloro-8,9-difluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine Prepared from compound (xxxiii) in the same manner as in Example 44. The yield was 81%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.45 (dd, J = 9.4, 7.3 Hz, 1H), 8.07 (dd, J = 9.4, 7.3 Hz, 1H), 2.81 (s, 3H). HRMS (ESI): cal. mass C 10 H 5 N 4 F 2 Cl [M+1] + 255.0244, [M+2] + 257.0214 found [M+1] + 255.0246, [M+2] + 257.0225 cal. mass C 10 H 5 N 4 F 2 ClNa [M+1] + 277.0063, [M+2] + 279.0034 found [M+1] + 277.0064, [M+2] + 279.0034.

[0196] Example 65 8,9-Difluoro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine Prepared from 64 as in example 45. Yield 22%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.56 (s, 1H), 8.44 (dd, J = 9.7, 7.3 Hz, 1H), 7.75 (dd, J = 9.2, 7.2 Hz, 1H). HRMS (ESI): cal. mass C 10 H 6 N 4 F 2 [M+1] + 221.0633, found [M+1] + 221.0638, cal. mass C 10 H 6 N 4 F 2 [M+Na] + 243.0453, found [M+Na] + 243.0463.

[0197] Example 66 6-Chloro-8,9-difluorotetrazolo[5,1-a]phthalazine Prepared from compound (xxxiii) in the same manner as in Example 46. The yield was 49%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.00 - 7.90 (m, 2H).

[0198] Example 67 8,9-Difluorotetrazolo[5,1-a]phthalazine Prepared from 66 as in example 45. Yield 15%. 1 H NMR (300 MHz, CDCl 3 ) δ 9.18 (s, 1H), 7.84 (d, J = 8.2 Hz, 1H), 7.13 (d, J = 8.2 Hz, 1H).

[0199] Example 68 6-Chloro-9-methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (68a) and 6-chloro-8-methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (68b) 6-Methoxy-2,3-dihydrophthalazine-1,4-dione (xxxiv) Ac of 4,5-dichlorophthalic acid (5g, 25.48mmol, 1.0equiv.) 2 The 2H2O (40 mL) solution was refluxed for 2 h and then concentrated in vacuo to give 5-methoxyisobenzofuran-1,3-dione as a light brown solid. The crude product was directly used in the next step without further purification. To a stirred solution of 5-methoxyisobenzofuran-1,3-dione in ethanol (40 mL) was added hydrazine (55%) (1.63 g, 50.97 mmol, 2.0 equiv.) and the mixture was refluxed for 24 h to form a precipitate. The product was collected by suction filtration, washed with water and dried to give compound (xxxiv) as an amorphous solid (4.1 g, 85%).

[0200] 1,4-Dichloro-6-methoxyphthalazine (xxxv) A mixture of 6-methoxy-2,3-dihydrophthalazine-1,4-dione (xxxiv) (4.0 g, 20.82 mmol, 1.0 equiv.) and phosphorus oxychloride (15.92 g, 104.11 mmol, 5.0 equiv.) was refluxed for 4 h. The reaction mixture was cooled to room temperature and poured onto crushed ice. The phases were separated and the aqueous phase was extracted with chloroform (4 x 70 mL). The combined organic phase was dried (Na 2 SO 4 ) and concentrated in vacuo. The crude product was purified by column chromatography on silica gel using dichloromethane to give compound (xxxv) (1.35 g, 28%) as an amorphous solid. 1 H NMR (300 MHz, CDCl 3 ) δ 8.20 (d, J = 9.1 Hz, 1H), 7.60 (dd, J = 9.1, 2.5 Hz, 1H), 7.49 (d, J = 2.5 Hz, 1H), 4.06 (s, 3H). 13 C NMR (75 MHz, CDCl 3 ) δ 164.03, 154.21, 129.49, 127.99, 126.18, 122.17, 121.10, 104.18, 56.29. HRMS (ESI): cal. mass C 9 H 6 N2 OCl 2 [M+1] + 228.9930, [M+2] + 230.9901 found [M+1] + 228.9933, [M+2] + 230.9908 cal. mass C 9 H 6 N 2 OCl 2 Na [M+1] + 250.9749, [M+2] + 252.9720 found [M+1] + 250.9757, [M+2] + 252.9730.

[0201] 6-Chloro-9-methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (68a) and 6-chloro-8-methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (68b) Preparation was carried out from 1,4-dichloro-6-methoxyphthalazine (xxxv) analogously to Example 44. The yield was 86%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.58 (d, J = 8.7 Hz, 0.7H), 8.14 (d, J = 9.1 Hz, 1H), 8.02 (d, J = 2.6 Hz, 1H), 7.61 - 7.52 (m, 1.5 H), 7.35 (dd, J = 9.1, 2.6 Hz, 1H), 4.05 (s, 3H), 4.01 (s, 2H), 2.81 (s, 3H), 2.79 (s, 2H).

[0202] Example 69 9-Methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (69a) and 8-Methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (69b) Prepared from 68a / 68b analogously to example 45. Yield 21%. The mixture of isomers was separated by column chromatography on silica gel with DCM / MeOH (98 / 2). First isomer: 9-methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (69a)1 H NMR (600 MHz, CDCl 3 ) δ 8.53 (s, 1H), 8.06 (d, J = 2.5 Hz, 1H), 7.83 (d, J = 8.7 Hz, 1H), 7.33 (dd, J = 8.7, 2.4 Hz, 1H), 4.04 (s, 3H), 2.83 (s, 3H). 13 C NMR (126 MHz, CDCl3) δ 164.11, 148.24, 146.92, 143.02, 130.03, 125.75, 121.21, 117.26, 104.03, 56.43, 10.09. Second isomer: 8-Methoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (69b) 1 H NMR (600 MHz, CDCl 3 ) δ 8.57 (d, J = 8.8 Hz, 1H), 8.55 (s, 1H), 7.52 (dd, J = 8.8, 2.5 Hz, 1H), 7.28 (d, J = 2.5 Hz, 1H), 3.98 (s, 3H), 2.81 (s, 3H). 13 C NMR (126 MHz, CDCl 3 ) δ 161.31, 147.65, 146.92, 142.74, 125.01, 124.63, 122.98, 117.27, 109.38, 55.80, 9.90.

[0203] Example 70 9-Chloro-6-isopropoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (70a) and 8-chloro-6-isopropoxy-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine (70b) 48 (100 mg, 0.39 mmol, 1.0 equiv) and K 2 CO 3 A mixture of (109 mg, 0.79 mmol, 2.0 equiv) in isopropanol (5 mL) was heated under reflux for 36 h and then concentrated in vacuo. The residue was extracted with dichloromethane (4×40 mL) and the combined organic phase was washed with Na 2 SO 4The mixture was dried at rt and concentrated in vacuo. The crude product was purified by column chromatography on silica gel using dichloromethane to give compounds 70a and 70b as a mixture of isomers in 89% yield as an amorphous solid. 1 H NMR (300 MHz, CDCl 3 ) δ 8.53 (d, J = 2.1 Hz, 1H), 8.50 (d, J = 8.5 Hz, 1H), 8.12 (d, J = 2.1 Hz, 1H), 8.08 (d, J = 8.7 Hz, 1H), 7.82 (dd, J = 8.5, 2.1 Hz, HRMS (ESI): cal. mass C 13 H 13 N 4 OCl [M+1] + 277.0851, [M+2] + 279.0822 found [M+1] + 277.0850, [M+2] + 279.0824 cal. mass C 13 H 13 N 4 OCl Na [M+1] + 299.0670, [M+2] + 301.0641 found [M+1] + 299.0670, [M+2] + 301.0639.

[0204] Example 71 9-Chloro-6-isopropoxytetrazolo[5,1-a]phthalazine (71a) and 8-chloro-6-isopropoxytetrazolo[5,1-a]phthalazine (71b) Prepared from 50 as in Example 70. Yield 81%. 1 H NMR (300 MHz, CDCl 3) δ 8.62 (d, J = 2.1 Hz, 0.5H), 8.58 (d, J = 8.5 Hz, 1H), 8.28 (d, J = 2.1 Hz, 1H), 8.25 (d, J = 8.8 Hz, 0.5H), 7.98 (dd, J = 8.5, 2.1 Hz, HRMS (ESI): cal. mass C 11 H 10 N 5 OCl [M+1] + 264.0647, [M+2] + 266.0618 found [M+1] + 264.0647, [M+2] + 266.0613 cal. mass C 11 H 10 N 5 OCl Na [M+1] + 286.0466, [M+2] + 288.0437 found [M+1] + 286.0465, [M+2] + 288.0438.

[0205] The mixture of isomers was separated by column chromatography on silica gel eluted with DCM. First isomer: 9-chloro-6-isopropoxytetrazolo[5,1-a]phthalazine (71a). 1 H NMR (300 MHz, CDCl 3 ) δ 8.62 (d, J = 2.1 Hz, 1H), 8.25 (d, J = 8.7 Hz, 1H), 7.86 (dd, J = 8.7, 2.1 Hz, 1H), 5.62 (hept, J = 6.2 Hz, 1H), 1.57 (d, J = 6.2 Hz, 6H). 13 C NMR (75 MHz, CDCl 3) δ 157.59, 141.07, 140.36, 132.74, 127.41, 124.13, 123.96, 118.90, 73.59, 21.70. Second isomer: 8-chloro-6-isopropoxytetrazolo[5,1-a]phthalazine (71b). 1 H NMR (300 MHz, CDCl 3 ) δ 8.58 (d, J = 8.5 Hz, 1H), 8.27 (d, J = 2.1 Hz, 1H), 7.98 (dd, J = 8.5, 2.1 Hz, 1H), 5.62 (hept, J = 6.2 Hz, 1H), 1.57 (d, J = 6.1 Hz, 6H). 13 C NMR (75 MHz, CDCl 3 ) δ 157.73, 140.46, 138.85, 134.79, 126.57, 125.53, 121.87, 121.10, 72.67, 22.59.

[0206] Example 72 10-Chloro-6-isopropoxytetrazolo[5,1-a]phthalazine 72 Prepared from 46a as in example 70. Yield 86%. 1 H NMR (300 MHz, CDCl 3 ) δ 8.27 (d, J = 8.1Hz, 1H), 8.05 (d, J = 8.1 Hz, 1H), 7.84 (t, J = 8.1 Hz, 1H), 5.63 (hept, J = 6.1 Hz, 1H), 1.57 (d, J = 6.1 Hz, 6H). 13 C NMR (126 MHz, CDCl3) δ 158.36, 139.91, 135.85, 132.66, 132.37, 124.38, 122.56, 121.70, 73.84, 21.83. HRMS (ESI): cal. mass C 11 H 10 N 5 OCl [M+1] + 264.0647, [M+2] + 266.0618 found [M+1]+ 264.0645, [M+2] + 266.0616 cal. mass C 11 H 10 N 5 OCl Na [M+1] + 286.0466, [M+2] + 288.0437 found [M+1] + 286.0464, [M+2] + 288.0438.

[0207] Example 73 6-Isopropoxytetrazolo[5,1-a]phthalazine 73 To a stirred solution of l-chloro-4-hydrazinylphthalazine (400 mg, 2.405 mmol, 1.0 equiv.) in acetic acid (20 mL, 2 N) was added NaNO 2 A cold aqueous solution of (212 mg, 3.08 mmol, 1.5 equiv. in 2 mL of water) was added dropwise and stirring was continued at room temperature for 1 h. The mixture was extracted with chloroform (3×40 mL) and the combined organic phases were dried (Na 2 SO 4 ), which was evaporated in vacuo to give 6-chlorotetrazolo[5,1-a]phthalazine (335 mg, 80%) as an amorphous solid. 1 H NMR (300 MHz, CDCl 3 ) δ 8.78 (dd, J = 7.8, 1.4 Hz, 1H), 8.45 (dd, J = 7.8, 1.4 Hz, 1H), 8.18 (td, J = 7.8, 1.4 Hz, 1H), 8.09 (td, J = 7.8, 1.4 Hz, 1H). 13 C NMR (75 MHz, CDCl 3 ) δ 152.25, 141.89, 135.67, 133.37, 128.04, 125.11, 124.17, 122.37.

[0208] 6-Chlorotetrazolo[5,1-a]phthalazine (200 mg, 0.97 mmol, 1.0 equiv.) in isopropanol (8 mL) and K 2 CO 3(268 mg, 1.94 mmol, 2.0 equiv.) was refluxed for 36 h and then concentrated in vacuo. After extraction with dichloromethane (4×40 mL), the combined organic phase was washed with Na 2 SO 4 The mixture was dried at rt and concentrated in vacuo The crude product was purified by column chromatography on silica gel eluted with dichloromethane to give 190 mg (86%) of 73 as an amorphous solid. 1 H NMR (300 MHz, CDCl 3 ) δ 8.62 (dd, J = 8.1, 1.3 Hz, 1H), 8.31 (dd, J = 8.1, 1.3 Hz, 1H), 8.01 (td, J = 7.7, 1.3 Hz, 1H), 7.92 (td, J = 7.7, 1.3 Hz, 1H), 5.62 (hept, J = 6.1 Hz, 1H), 1.56 (d, J = 6.1 Hz, 6H). 13 C NMR (126 MHz, CDCl3) δ 158.87, 141.07, 134.31, 132.26, 125.86, 124.56, 122.86, 120.82, 73.30, 21.86. HRMS (ESI): cal. mass C 11 H 11 N 5 O [M+1] + 230.1036, found [M+1] + 230.1038, cal. mass C 11 H 11 N 5 O [M+Na] + 252.0856, found [M+Na] + 252.0857.

[0209] biological results Example 74 cell culture Compound reconstitution Prior to treatment, each compound was used from a stock solution of 10 mg / ml in DMSO, the final concentration of DMSO in the cell cultures was kept below 0.1%.

[0210] Cell culture and treatments The human renal fibroblast cell line TK173 was derived from a normal human kidney (laboratory stock; GA Mueller et al., Exp. Nephrol. 1995, 3, 127). Stabilization of the cell line for research purposes was approved by the ethical committee of Georg-August University. TK173 cells were cultured in Dulbecco's modified Eagle's medium (DMEM, Gibco, USA) supplemented with 10% fetal bovine serum (FBS, Gibco, Germany) and 1% penicillin-streptomycin (PS, Gibco, USA) at 37°C and 5% CO. 2 The cells were cultured at 3 × 10 in a humidified atmosphere. The cell lines were periodically tested for mycoplasma contamination. To examine the effect of the compounds after treatment with profibrotic agents, 3 × 10 4 TK173 cells were seeded in one well of a 6-well culture plate in normal culture medium. After 24 h, the culture medium was removed and the cells were cultured in culture medium without FBS (starvation medium) for another 24 h. Then, 10 ng / ml TGFβ1 (R&D Systems, USA) was added to the starvation medium and replaced with fresh TGFβ1 culture medium every other day. After 5 days of TGFβ1 treatment, the cell culture medium was replaced with starvation medium containing different concentrations of the compounds and cultured for 48 h.

[0211] Example 75 Detection of secreted type I collagen by enzyme-linked immunosorbent assay (ELISA) Conditioned medium containing the secretome of TK173 fibroblasts was collected 48 hours after compound treatment. Secretion of type I procollagen was assessed using Human Pro-Collagen I alpha 1 DuoSet ELISA (R&D Systems, USA). To prepare the ELISA plate, Human Pro-Collagen alpha 1 capture antibody was diluted in ELISA plate coating buffer to a working concentration of 4 μg / ml. 100 μl of the diluted capture antibody was added to a 96-well microplate and incubated overnight at room temperature. After washing three times with wash buffer, the microplate was blocked for 1 hour at room temperature by adding 300 μl of reagent diluent. To proceed with the ELISA, Human Pro-Collagen alpha 1 standard samples were diluted in reagent diluent (range 31.3 pg / ml-200 g / ml) and 100 μl of standard samples or conditioned medium were added to the designated wells. The microplate was incubated at room temperature for 2 hours. Human type I procollagen α1 detection antibody was prepared to a working concentration of 100ng / ml in reagent diluent, and 100μl of diluted detection antibody was applied for 2h at room temperature after extensive washing. Then, a working solution of streptavidin-HRP was prepared by diluting 1:40 in reagent diluent and added to each well. After 20min incubation at room temperature, the microplate was washed and 100μl of substrate solution was applied for 20min, followed by addition of stop solution after washing. Finally, the signal was measured at 450nm absorbance using a PHOmo Microplate Reader (Autobio, China). The amount of type I procollagen antibody fusion was quantified by extrapolating the signal to the linear range of the standard curve of type I procollagen. Screening compounds were usually tested at concentrations ranging from 5 to 200μg / ml. IC by dose-response curve for each compound (n=4-6, bivariate test) 50 Values ​​were obtained by nonlinear regression analysis using Prism9 software (GraphPad, La Jolla, USA) and represent the concentration at which TGFβ-stimulated collagen secretion was attenuated by 50%.

[0212] Compound data extract (μg / ml): 1:157; 2:58; 3:96; 5:39; 6:61; 7:32; 9:10; 10:93; 13:87; 15:105; 23:21; 35:30; 38: <80; 39: <80; 41: <60; 45:20; 47a: <5; 49a: <30; 49b:30; 59a: <20; 59b: <5; 53: <20; 55: <10; 59b: <10; 61a: ≦30; 61b: <30; 63a: <30; 63b: <50; 69a: <30; 69b: <30; 72: <5.

[0213] Example 76 PCR assay for type I collagen mRNA RNA isolation Total RNA was extracted with TRIzol reagent (Life technologies, USA) and purified with PureLink RNA Mini Kit (Ambion, USA) according to the instructions available from the manufacturer with minor modifications. Samples were stored at -80°C before use. RNA concentration was measured with a NanoDrop Spectrophotometer (ThermoFisher Scientific, USA) and equilibrated to 100ng for complementary DNA (cDNA) synthesis.

[0214] Quantitative real-time PCR (qPCR) For SYBR Green-based qPCR, residual genomic DNA was removed using a DNAseI (Sigma-Aldrich, USA) digestion set, cDNA was synthesized using the SuperScript II Reverse Transcriptase kit (Invitrogen, USA), and cDNA preparation was performed according to the manufacturer's detailed instructions. All qPCR reactions were performed using the StepOne Plus Real-Time System (Applied Biosystems, USA), and amplification was performed using SYBR Green PCR Master Mix (Applied Biosystems, USA). Thermal cycling conditions were initiated at 95°C for 20 s, followed by 40 amplification cycles of 95°C for 3 s and 60°C for 30 s, and one dissociation cycle of 95°C for 15 s, 60°C for 60 s, and 95°C for 15 s. Triplicates were performed for each sample, with duplicate measurements performed for each. Cycle threshold values ​​(Ct) of the experiments were normalized to those obtained for GAPDH, and relative gene expression levels were determined using the 2_ddCT method. Primer sequences are shown in Table 1.

[0215] [Table 1]

[0216] Compound data extract (IC 50 , μg / ml): 1: <80; 3: <20; 5: <20; 12: <50; 51b: <5;

[0217] Example 77 Western Blot of Type I Collagen Protein extraction Total proteins were extracted from cultured cells using NP40 Cell Lysis Buffer (Invitrogen, USA) containing phosphatase (Sigma-Aldrich, USA) and protease inhibitors (Roche, Switzerland), followed by sonication and centrifugation at 12,000 × g for 20 min at 4 °C to clarify the lysate. The supernatant was collected and assayed on a PHOmo Microplate Reader (Autobio, China) using the Pierce BCA Protein Assay Kit (ThermoFisher Scientific). Samples were stored at -80 °C before use.

[0218] Immunoblotting For Western blot analysis, 10 μg of extracted protein was diluted in NuPAGE LDS Samples Buffer (Novex Life technologies, USA) containing 5% 2-mercaptoethanol (Sigma-Aldrich, Germany) and denatured at 95°C for 5 min. The resulting proteins were separated by 4-12% NuPAGE SDS-PAGE (Novex Life technologies, USA). Blots were stripped multiple times for reprobing using Thermo Scientific Restore PLUS Western Blot Stripping Buffer (Thermo Fisher Scientific, Germany). The following antibodies were used for immunoblotting: type I collagen (1:1000; ab233080, Abcam, USA), α-smooth muscle actin (1:1000; ab124964, Abcam, USA), and GAPDH (1:8000; sc-32233, SantaCruz, USA). Proteins were detected using appropriate secondary antibodies: anti-mouse HRP (1:2500; Dako, Denmark) and anti-rabbit HRP (1:2500; 7074, Cell Signaling Technology, USA) with the LumiGLO chemiluminescence system (Cell Signaling Technology, USA) using the ChemiDoc MP Imaging System (Bio-Rad, USA).

[0219] Compound data extract (IC 50 , μg / ml): 1: <40; 3: <5; 6: <5; 9: <1; 12: <5; 14: <30; 15: <40; 27: < 30; 35: < 40; 49a: < 50; 51a: ≤ 40; 51b: < 5; 53: < 60; 55: < 20; 61a: < 60; 61b: < 80; 63a: < 70; 63b: < 30; 65: < 50; 69a: < 30; 69b: < 80; 72: < 5

Claims

1. Azolo Compounds (I) for Use in a Method for Treating or Preventing Fibrosis 【Chemistry 1】 And, During the ceremony, R is H, D, CN, NHR ５ , N.D.R. ５ , Cl, OR ３ , S.R. ３ and C １－４ - alkyl, in particular selected from the group consisting of H, D, methyl, X is N or CR １ (wherein the nitrogen atom or the carbon atom is an aromatic atom), W is a covalent bond, CR ４ (wherein the carbon atom is an aromatic ring atom), CH ２ , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR ２ is selected from the group consisting of X １ is a covalent bond, CR ４ (wherein the carbon atom is an aromatic ring atom), CH ２ , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR ２ is selected from the group consisting of Y is a covalent bond, CR ４ (wherein the carbon atom is an aromatic ring atom), CH ２ , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR ２ is selected from the group consisting of Z is a covalent bond, CR ４ (wherein the carbon atom is an aromatic ring atom), CH ２ , S, O, N (wherein the nitrogen atom is an aromatic ring atom), NH and NR ２ is selected from the group consisting of In the formula, the dashed line represents a single or double bond. W, X １ Y and Z are selected to form the same ring, said ring being 5- or 6-membered; W, X １ , Y and Z are selected so that the ring does not contain more than two nitrogen atoms; W, X １ , Y and Z are selected such that the ring does not contain acetal, thioacetal, aminal or hydrazine groups; The compound does not contain a peroxide group or a disulfide group; R １ is OH, halogen, OR ３ H, D, CD ３ , C.H.D. ２ , C.H. ２ D, C.F. ３ , C.H.F. ２ , C.H. ２ F, C.D.F. ２ , C.D. ２ F, and C １―４ - alkyl, R ２ CHO, COCH ３ , C.O.C. ２ H ５ , C.O.C. ３ H ７ , COCH(CH ３ ) ２ , C.O.C. ４ H ９ , COC(CH ３ ) ３ is selected from the group consisting of R ３ is C １－４ - alkyl, R ４ is H, D, F, Cl, methyl, CH ２ F, C.H.F. ２ , C.F. ３ , O.C.H. ３ , O.C.D. ３ is selected from the group consisting of R ５ is C which may be substituted with OH １－４ -alkyl.

2. R is H, CN, or NHR ５ , Cl, OR ３ , methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl and SR ３ The azolo compound (I) for use according to claim 1, selected from the group consisting of:

3. R １ is OH, halogen or OR ３ may be substituted with H, D, CD ３ , C.H.D. ２ , C.H. ２ D, C.F. ３ , C.H.F. ２ , C.H. ２ F, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl and cyclopropyl, or optionally, R １ is H, methyl, CD ３ , C.F. ３ , C.H. ２ OH, ethyl, CH ２ OCH ３ and cyclopropyl, And / or R ３ is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl, optionally substituted with OH; And / or R ５ The azolo compound (I) for use according to claim 1 or 2, wherein is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl, each of which may be substituted with OH.

4. W, X １ 4. The azolo compound (I) for use according to any one of claims 1 to 3, wherein Y and Z are selected such that the compound does not contain a peroxide group and / or such that the compound does not contain a disulfide group.

5. X is N and CR １ R is selected from the group consisting of １ is H, methyl, CH ２ F, C.D. ２ F, C.H.F. ２ , C.D.F. ２ and C.F. ３ and preferably, X is selected from the group consisting of CR １ and R is H or D.

6. W, X １ Y and Z are selected such that the ring consists of carbon atoms or such that the ring consists of carbon atoms and one heteroatom; and / or W, X １ 6. The azolo compound (I) for use according to any one of claims 1 to 5, wherein Y and Z are selected such that the ring is aromatic or non-aromatic.

7. W, X １ , Y and Z are selected to form a moiety according to one of the following ring atom sequences: C...C...C...C, N...C...C...C, C...N...C...C, C...C...N...C, C...C...C...N, S...C...C...C, C...S...C...C, C...C...S...C, C...C...C...S, O...C...C...C, C...O...C...C, C...C...O...C, C...C...C...O, C...C...C, N...C...C, C...N...C, C...C...N, S...C...C, C...S...C, C...C...S, O...C...C, C...O...C, C...C...O (where "..." represents a single or double bond), and / or W, X １ 7. The azolo compound (I) for use according to any one of claims 1 to 6, wherein Y and Z are independently selected such that the ring forms a pyrrolidine, dihydrofuran, dihydrothiophene, pyrrole, furan, thiophene, oxazole, thiazole, tetrahydrobenzene, oxane, thiane, benzene, pyridine, pyran, thiopyran, preferably a benzene, pyridine, dihydropyridine, thiophene or furan structure.

8. W, X １ , Y and Z are independently CH=CH-CH=CH, CH=N-CH=CH, N=CH-CH=CH, CH=CH-CH=N, NH-CH ２ -CH ２ -CH ２ , C.H. ２ -NH-CH ２ =CH ２ , C.H. ２ -NCOCH ３ -CH ２ -CH ２ 8. The azolo compound (I) for use according to any one of claims 1 to 7, wherein the azolo compound (I) is selected to form a moiety selected from the group consisting of S-CH=CH, CH=CH-S, CH-S-CH, CH=CH-O, preferably CH=CH-CH=CH or CH-S-CH.

9. W, X １ , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H, and X is N; or W, X １ , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H, and X is C-CH ３ or W, X １ , Y and Z are selected to form the moiety CH=CH-CH=CH, R=H, and X is C-H, or W, X １ , Y and Z are selected to form the moiety CH-S-CH, R=H, and X is C-CH ３ or W, X １ 9. The azolo compound (I) for use according to any one of claims 1 to 8, wherein Y and Z are selected to form the moiety CH-S-CH, R=H and X is N.

10. X is C-CH ３ R is H, W, X １ , Y and Z are groups CR ４ =CR ４ -CR ４ =CR ４ (In the formula, R ４ One of the groups is F, Cl and OCH ３ The remaining three R are selected from the group consisting of ４ 10. The azolo compound (I) for use according to any one of claims 1 to 9, wherein the azolo compound (I) is a substituted or unsubstituted azolo group ...

11. X is C-CH ３ R is H, W, X １ , Y and Z are groups CR ４ =CR ４ -CR ４ =CR ４ (In the formula, R ４ Two of the groups are independently selected from F, Cl and OCH ３ The remaining two R ４ 11. The azolo compound (I) for use according to any one of claims 1 to 10, wherein the azolo compound (I) is a substituted or unsubstituted azolo group.

12. The azolo compound (I) is selected from the group consisting of: 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 or optionally, the azolo compound (I) is selected from the following group: 【Chemistry 5】 The azolo compound (I) for use according to any one of claims 1 to 11, selected from:

13. 13. The azolo compound (I) for use according to any of claims 1 to 12, wherein the fibrosis is selected from the group consisting of renal fibrosis, hepatic fibrosis, pulmonary fibrosis and cardiac fibrosis, optionally cardiac fibrosis.

14. The structure (I) of claim 1: 【Chemistry 6】 23. A pharmaceutical composition for treating fibrosis comprising an azolo compound or a mixture of azolo compounds having the formula:

15. 15. The pharmaceutical composition of claim 14, which is an oral solid formulation and / or wherein the azolo compound is present in an amount of 5 to 500 mg, preferably 10 to 200 mg.

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