N,N-Diethylaniline → 2-Chloro-5-fluoro-1-methyl-1H-benzimidazole

Participants

Reaction Steps

3.9 g 5-fluoro-1-methyl-1,3-dihydro-benzimidazol-2-one are suspended in 80 ml phosphorus oxychloride and the reaction mixture is stirred for 2 hours at reflux temperature. 50 ml diethylaniline are added. The reaction mixture is stirred for a further 10 minutes at reflux temperature and ice water is slowly added thereto. The product is extracted with dichloromethane and purified by chromatography (silica gel, cyclohexane, methylene chloride/acetone 20/1). 1.4 g product are obtained in the form of a solid. M.p.=138-141° C.

Provenance & Evidence