617706-15-7

57631-11-5

c) 5-bromo-3-(trifluoromethyl)-1H-indazole; Beilstein registry number: 914313; chemical formula: C8H4BrF3N2; exact mass: 263.95; molecular weight: 265.03.1-(5-bromo-2-fluorophenyl)-2,2,2-trifluoroethanone (1.49 g, 5.50 mmol) was dissolved in 1-butanol (25 mL) and hydrazine hydrate (5.0 mL, 100 mmol) was added. The reaction mixture was heated to reflux and stirred for 6 hours. Upon completion of the reaction, the mixture was cooled, diluted with deionized water (100 mL) and extracted with ethyl acetate (4 x 100 mL). The organic phases were combined, washed with saturated saline (100 mL), dried over anhydrous sodium sulfate, filtered and concentrated. Purification by fast column chromatography (silica gel, dichloromethane as eluent) afforded the title compound (0.64 g, 44% yield) as an off-white powder.1H NMR (500 MHz, CDCl3) δ 8.04 (s, 1H), 7.59 (dd, J = 9.0, 1.5 Hz, 1H), 7.46 (d, J = 9.0 Hz, 1H).