Synthesis of perimidine and 1,5-benzodiazepine derivatives using tamed Brønsted acid, BF3-H2O

Synthesis of dihydroperimidines and their fluorinated derivatives has been achieved from the correspondiing naphthalene diamines and acetone, butanone and mono and difluoroacetones using BF3-H2O, an efficient Brønsted acid catalyst as well as the solvent. 1,5-Benzodiazepines were also prepared by similar strategy from phenylene diamines. Non-oxidising conjugate Brønsted acid system, BF3-H2O is a good substitute for other expensive acid catalysts and make the method efficient and more economical.