An efficient method for the synthesis of 1,5-benzodiazepine derivatives under microwave irradiation without solvent

2,3-Dihydro-1H-1,5-benzodiazepines have been synthesized in solvent-free conditions from o-phenylenediamines and ketones in the presence of a catalytic amount of acetic acid, under microwave irradiation. This method is a very easy, rapid and high yielding reaction for the synthesis of 1,5-benzodiazepine derivatives.