Phenylhydrazine → 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5-amine

Participants

Reaction Conditions

Reaction Steps

A mixture of (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (2.93 g, 16 mmol) and phenylhydrazine (1.947 g, 18 mmol) in EtOH (15 mL) was heated at 95° C. for 8 hours. The reaction was quenched with water and extracted with CH2Cl2. Extracts were dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by silica gel chromatography with 5-25% EtOAc/hexane as eluants to afford 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5-amine as a yellow solid (2.23 g, 66%). 1H NMR (300 MHz, CDCl3) δ 7.51 (m, 5H), 5.87 (s, 1H), 3.93 (br, 2H); LC-MS (ESI) m/z 228 (M+H)+.

Provenance & Evidence