1240518-54-0

General procedure for the synthesis of 3-amino-1H-indazole-4-carbonitrile from 3-fluorophthalonitrile: 3-fluoro-1,2-benzenedicarbonitrile (5 g, 34.2 mmol) was dissolved in ethanol (80 mL), and hydrazine monohydrate (4.98 mL, 103 mmol) was subsequently added to the solution. The reaction mixture was heated at 70 °C for overnight reaction. After completion of the reaction, the mixture was concentrated under vacuum and the residue was partitioned with ethyl acetate (200 mL) and water (200 mL). The organic layer was washed with water (100 mL) and the aqueous layer was then extracted with ethyl acetate (200 mL). All organic layers were combined and dried over anhydrous magnesium sulfate, followed by evaporation of the solvent under vacuum to give the title compound 3-amino-1H-indazole-4-carbonitrile (4.7 g, 87% yield) as a yellow solid.LCMS (System A) retention time (RT) = 0.53 min, electrospray positive ion mode (ES+ve) m/z 159 ([M+H]+).

[1] Patent: US2010/216860, 2010, A1. Location in patent: Page/Page column 32
[2] Journal of Medicinal Chemistry, 2013, vol. 56, # 5, p. 1946 - 1960
[3] Patent: WO2015/67549, 2015, A1. Location in patent: Page/Page column 105
[4] Patent: US2015/126449, 2015, A1. Location in patent: Paragraph 0578 - 0580