BF3•Et2O promoted one-pot expeditious and convenient synthesis of 2-substituted benzimidazoles and 3,1,5-benzoxadiazepines

2-substituted benzimidazoles and 3,1.5-benzoxadiazepines have been synthesized in excellent yields in a single pot by cyclodehydration of N-acryl-1,2-phenylenediamines and N,N'-diacyl-1,2-phenylenediamines prepared in situ from the corresponding 1.2-phenylenediamines and an acid chloride, respectively. (C) 2004 Elsevier Ltd. All rights reserved.