Sulfuric Acid → 2-(4-Chlorophenyl)pyrazolidin-3-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 4.2 grams (0.05 mole) of sodium bicarbonate in 25 ml of water, 8.9 grams (0.05 mole) of (4-chlorophenyl)hydrazine hydrochloride was added portionwise. After complete addition the mixture was stirred until gas evolution ceased. To this mixture was added 5.5 grams (0.1 mole) of acrylonitrile and the total heated at 80° C. for 4.5 hours. The mixture was cooled and added to a solution of 9.8 grams of concentrated sulfuric acid in 29 ml of water at room temperature. The resultant mixture was heated for one hour at 40° C. and then at reflux for 2.5 hours. This mixture was cooled and added dropwise to a solution of 7.8 grams of sodium hydroxide in 11 ml of water, cooled by an ice bath and stirred for one hour after complete addition. A precipitate formed which was collected by filtration. The filter cake was washed with water, dried under reduced pressure and purified by recrystallization from ethanol to yield 2.78 grams of 2-(4-chlorophenyl)-3-pyrazolidinone (mp 120°-122° C.).

Provenance & Evidence