Vicarious nucleophilic substitution of 1-benzyl-5-nitroimidazole, application to the synthesis of 6,7-dihydroimidazo[4,5-d][1,3]diazepin-8(3H)-one

Reaction of 1-benzyl-5-nitroimidazole with carbanion generated from chloroform and potassium tert-butoxide afforded 1-benzyl-4-dichloromethyl-5-nitroimidazole in 72% yield. This vicarious nucleophilic substitution reaction was successfully applied to the synthesis of 6,7-dihydroimidazo[4,5-d][1,3]diazepin-8(3H)-one, an important intermediate in the synthesis of natural and biologically active compounds.