Methylhydrazine sulfate → 1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-amine

Participants

Reaction Steps

Using the procedure described in Example 161A Step 3, (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (1.83 g, 10 mmol) and methylhydrazine sulfate (1.586 g, 11 mmol) were reacted and the crude product purified by silica gel chromatography (with 0-10% EtOAc/CH2Cl2 as eluants) to afford 1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-amine as solid (0.381 g, 23%). 1H NMR (300 MHz, CDCl3) δ 5.94 (s, 1H), 3.78 (s, 3H), 3.67 (br, 2H); LC-MS (ESI) m/z 166 (M+H)+.

Provenance & Evidence