Hydrazine hydrate (1:1) → HCID 178469276, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (E)-ethyl 2-cyano-3-ethoxybut-2-enoate (4.4 g, 24.02 mmol, 1.00 equiv) and hydrazine hydrate (3 mL) in acetic acid (40 mL) was stirred at 110° C. for 2 h. The resulting mixture was cooled to room temperature and concentrated under vacuum. Water (20 mL) was added to the residue and the resulting solution extracted with 2×20 mL of dichloromethane. The combined organic layers was washed with 2×40 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified on a silica gel column eluted with 0-50% of ethyl acetate in petroleum ether to give 2.1 g (52%) of ethyl 5-amino-3-methyl-1H-pyrazole-4-carboxylate as a yellow oil. 1H-NMR (300 MHz, CDCl3): δ 6.76 (br s, 2H), 4.30 (q, J=7.2 Hz, 2H), 2.41 (s, 3H), 1.35 (t, J=7.2 Hz, 3H) ppm. LCMS (method D, ESI): RT=0.98 min, m/z=170.0 [M+H]+.

Provenance & Evidence