反应详情

Using the procedure described in Example 161A Step 3, (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (2.34 g, 12.78 mmol) and methylhydrazine (0.645 g, 14 mmol) were reacted in EtOH (10 mL) at 95° C. for 8 hours, and purified by silica gel chromatography with 30-40% EtOAc/hexane as eluants to afford 1-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amine as solid (1.733 g, 68.3%). MP: 100-101° C.; 1H NMR (300 MHz, CDCl3) δ 5.80 (s, 1H), 3.71 (s, 3H), 3.62 (br, 2H); LC-MS (ESI) m/z 166 (M+H)+.

1. custompurified by silica gel chromatography with 30-40% EtOAc/hexane as eluants