Piperazin-2-one → Cebaracetam

Participants

Reaction Steps

4.46 g (44.6 mmol) of piperazin-2-one (ketopiperazine) and 300 ml of dimethylformamide are added to 22.4 g (44.6 mmol) of 2-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-yl]-acetic acid pentachlorophenyl ester and the whole is stirred for 5 hours at room temperature. The whole is concentrated to dryness by evaporation under reduced pressure at 70°, stirred with 150 ml of ethyl acetate for 1 hour and then 150 ml of diethyl ether are added; the whole is filtered with suction, washed with 50 ml of diethyl ether and allowed to dry. 1-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-ylacetyl]-3-oxopiperazine having a melting point of 205°-207° is obtained and can be purified further by recrystallisation from 300 ml of butanol, washing with 50 ml of diethyl ether and drying, and then melts at 208°-210°.

Provenance & Evidence