Novel triethylsilane mediated reductive N-alkylation of amines: improved synthesis of 1-(4-imidazolyl)methyl-4-sulfonylbenzodiazepines, new farnesyltransferase inhibitors

An improved synthesis of 1-(imidazolyl)methyl-4-sulfonylbenzodiazapines, new farnesyltransferase inhibitors, was achieved using a novel reductive N-alkylation method. The new method involves reaction of a secondary amine with an aldehyde using triethylsilane in the presence of trifluoroacetic acid, giving a tertiary amine in 90–95% isolated yields.