Potassium Carbonate → Ethyl 5-amino-1-isopropyl-1H-pyrazole-4-carboxylate

Participants

Reaction Steps

A mixture of ethyl 2-cyano-3-ethoxyacrylate (84.4 g, 0.50 mol), isopropyl hydrazine hydrochloride (55.2 g, 0.50 mol) and potassium carbonate (68.8 g, 0.50 mol) in 90% ethanol/methanol (1.5 L) was heated under reflux for 16 hours. The solvent was then removed in vacuo and water and ethyl acetate were added. The mixture was separated and the organic layer was dried over magnesium sulfate, filtered and the solvent was removed in vacuo to yield ethyl 5-amino-1-isopropyl-1H-pyrazole-4-carboxylate (92.4 g, 94%). +ESI (M+H) 198.1; 1H NMR (400 MHz, CDCl3, δ): 7.63 (s, 1H), 4.97 (br. s., 2H), 4.28 (q, 2H), 4.18 (m, 1H), 1.45 (d, 6H), 1.31 (t, 3H).

Provenance & Evidence