Clay (KSF and K10)-supported heteropoly acids: Friendly, efficient, reusable and heterogeneous catalysts for high yield synthesis of 1,5-benzodiazepine derivatives both in solution and under solvent-free conditions Original Research Article

A simple and versatile method for the synthesis of 1,5-benzodiazepines via condensation of 1,2-phenylenediamines and ketones in the presence of catalytic amount of clay-supported polyoxometalates (POMs) was described. The method is applicable to both cyclic and acyclic ketones without significant differences. The reaction proceeds efficiently under ambient conditions with good to excellent yields.