A simple and versatile method for the synthesis of 1,5-benzodiazepines is via condensation of o-phenylenediamines (OPDA) and ketones in the presence of Samarium trifled Sm(OTf)3 catalytic using acetonitrile as solvent at room temperature. In all the cases, the reactions are highly selective and are completed within 1 h. 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
