73105-48-3

GENERAL METHOD: A mixture of 2-fluoro-5-nitrobenzonitrile (10.0 mmol) and methylhydrazine (2.8 mL, 50.0 mmol) in ethanol (10.0 mL) was heated to reflux and reacted overnight. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently concentrated under reduced pressure. Water (10.0 mL) and ethyl acetate (20.0 mL) were added to the residue and extracted. After separation of the organic layer, it was washed sequentially with water (10.0 mL) and brine (10.0 mL), dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. Finally, the residue was purified by silica gel column chromatography using ethyl acetate/hexane (1:1) as eluent to afford the target product 1-methyl-5-nitro-1H-indazol-3-amine.

[1] Tetrahedron, 2013, vol. 69, # 19, p. 3907 - 3912
[2] Patent: WO2013/55984, 2013, A1. Location in patent: Paragraph 00338
[3] Patent: US2009/76275, 2009, A1. Location in patent: Page/Page column 10