反应详情

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).

1. temperaturewas heated
2. temperatureunder reflux for 16 hours
3. customThe solvent was then removed in vacuo and water and ethyl acetate
4. additionwere added
5. customThe mixture was separated
6. dry with materialthe organic layer was dried over magnesium sulfate
7. filtrationfiltered
8. customthe solvent was removed in vacuo