Hydrochloric Acid → 4-[5,5-Bis(4-fluorophenyl)-4-pentenyl]-2-piperazinecarboxamide monohydrate

Participants

Reaction Steps

A mixture of 60 parts of 7-[5,5-bis(4-fluorophenyl)-4-pentenyl]hexahydro-3,3-dimethylimidazo[1,5-a]pyrazin-1(5H)-one and 850 parts of a hydrochloric acid solution 0.5N was stirred for 2 hours at reflux temperature. After cooling, the reaction mixture was treated with potassium carbonate. The product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from 1,1'-oxybisethane. The product was filtered off and dried, yielding 29.5 parts (50%) of 4-[5,5-bis(4-fluorophenyl)-4-pentenyl]-2-piperazinecarboxamide monohydrate; mp. 51.3° C. (int. 25).

Provenance & Evidence