1-(2-CHLORO-6-FLUORO-BENZYL)-5-METHYL-1 H-PYRAZOL-3-YLAMINE synthesis

Yield:925200-31-3 73%

Reaction Conditions:

with hydrazine hydrate in ethanol at 20; for 50 h;

Steps:

36

Intermediate 36: 1-[(2-chloro-6-fluorophenyl)methyl]-5-methyl-1H-pyrazol-3-amine In a 100 mL round-bottom flask Intermediate 32 (314 mg, 0.849 mmol) was dissolved in EtOH (40 mL) and hydrazine monohydrate (Aldrich, 0.095 mL, 1.953 mmol) was added. Mixture was stirred at room temperature for 50 hours. The white precipitate was filtered and washed with EtOH. Filtrate was evaporated to dryness to afford 330 mg of crude that was purified in silica chromatography with gradient DCM/MeOH (0%-6%-20%). 148 mg (yield 73%) of 1-[(2-chloro-6-fluorophenyl)methyl]-5-methyl-1H-pyrazol-3-amine were obtained. ¹H NMR (300 MHz, DMSO-d₆) δ ppm: 7.18-7.42 (m, 3H), 5.18 (s, 1H), 5.01-5.02 (m, 2H), 4.41 (br s, 2H), 2.23 (s, 3H). [ES+MS] m/z 240 (MH⁴).

References:

US2012/95064,2012,A1 Location in patent:Page/Page column 23