Diethyl Ether → 1-[4-(p-Chlorophenyl)-2-oxopyrrolidin-1-ylacetyl]-4-(2-oxopyrrolidin1-ylacetyl)-piperazine

Participants

Reaction Steps

To a suspension of 6.0 g (23.3 mmol) of 1-[2-(2-oxopyrrolidin-1-yl)-acetyl]-piperazine hydrochloride in 80 ml of methylene chloride there are added firstly 2.6 g (3.6 ml; 25.5 mmol) of triethylamine and then, dropwise, a solution of 13.7 g (23.3 mmol) of 2-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-yl]-acetic acid pentachlorophenyl ester in 30 ml of methylene chloride. After being stirred at 20° for 16 hours, the suspension is filtered with suction. 6.16 g of a white crystalline mass are obtained. 110 ml of ethyl ether are stirred into the filtrate, whereby a further 6.51 g of precipitate can be formed and collected. The two portions are combined, triturated under 200 ml of ethyl ether and filtered with suction, and the resulting product is dissolved in 150 ml of hot glacial acetic acid, and warm water (50°) is added until the solution becomes cloudy. The whole is cooled to 20 °; after 3 hours, the resulting crystalline product is filtered off with suction and dried on a water bath. 1-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-ylacetyl]-4-(2-oxopyrrolidin1-ylacetyl)-piperazine having a melting point of 224°-226° is obtained.

Provenance & Evidence