反应详情

A solution of 28.4 g of 3-(4'-fluoro-4-biphenylyl)-2-butenoic acid ethyl ester [obtainable by dehydrating 3-(4'-fluoro-4-biphenylyl)-3-hydroxybutyric acid ethyl ester employing p-toluenesulfonic acid] and 25 g of hydrazine hydrate (100% strength) in 400 ml of ethanol is boiled for 18 hours. The mixture is cooled, poured onto ice water and worked up in the usual manner to give 3-(4'-fluoro-4-biphenylyl)-3-methyl-pyrazolidin-5-one, m.p. 194°-196°.

1. temperatureThe mixture is cooled
2. additionpoured onto ice water