The effect of pressurized carbon dioxide on the cyclocondensation reaction between 4-alkoxy-1,1,1-trifluoro-3-alken-2-ones and hydrazines

Abstract

The synthesis of 1-unsubstituted and 1-phenyl-5-trifluoromethylpyrazoles from the reaction of 4- alkoxy-1,1,1-trifluoro-3-alken-2-ones [CF3C(O)CH=C(R1)OR, where R = Me, Et and R1 = H, Me, Ph] with hydrazines [NH2NHR2, where R2 = H, Ph] in pressurized carbon dioxide is reported for the first time. Reaction conditions such as pressure, temperature and time were evaluated. The methodology developed herein was suitable to synthesize products in moderate to excellent yields (60 % - 96 %) and short reaction times (15 - 45 min). © ARKAT-USA, Inc.