Acetic Anhydride → HCID 21428813, compound

Participants

Reaction Steps

A mixture of 0.8 parts of 2-amino-N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1yl)-1-piperidinyl]ethyl}-4-fluorobenzamide, 1 part of acetic acid anhydride and 10 parts of water is stirred for 30 minutes in a water-bath at 80°-90° C. The reaction mixture is cooled, alkalized with ammonium hydroxide and the product is extracted with trichloromethane. The extract is dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions are collected and the eluent is evaporated, yielding 0.5 parts of 2-(acetylamino)-N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]ethyl}-4-fluorobenzamide; mp. 196.5° C.

Provenance & Evidence