A direct preparation of 2-aryl-4-ethoxycarbonyl-3- pyrazolin-5-ones from aryl hydrazines

Article abstract of DOI:10.1016/S0040-4020(01)89994-4

Aryl hydrazines (1) possessing an electron-withdrawing substituent on the phenyl ring, on treatment with diethyl (ethoxymethylene)malonate in ethanolic sodium ethoxide solution, have directly afforded 2-aryl-4-ethoxy-carbonyl-3-pyrazolin-5-ones (4). Spect