5-Chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one → N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]ethyl}-4-fluoro-2-nitrobenzamide hydrochloride

Participants

Reaction Steps

A mixture of 16 parts of N-(2-bromoethyl)-4-fluoro-2-nitrobenzamide, 12.6 parts of 5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one and 216 parts of N,N-dimethylformamide is stirred and refluxed for 3 hours. The N,N-dimethylformamide is evaporated and 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. The residue is converted into the hydrochloride salt in 2-propanone and 2-propanol. The salt is filtered off and crystallized from methanol, yielding 1.5 parts of N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]ethyl}-4-fluoro-2-nitrobenzamide hydrochloride; mp. 276.8° C.

Provenance & Evidence