A facile one pot CC and CN bond formation for the synthesis of spiro-benzodiazepines and their cytotoxicity

An efficient, multicomponent and environmentally benign protocol has been developed for the synthesis of spiro-benzodiazepines through CC and CN bond formations in a single step. This one-pot protocol proceeds via three component reaction of o-phenylenediamines, tetronic acid and isatins by using mild and inexpensive catalyst like sulphamic acid in water. A variety of spiro-benzodiazepine derivatives has been synthesized in excellent yields by using this protocol in a shorter reaction time. All the synthesized compounds were evaluated for their cytotoxic potential on different human cancer cell lines and most of the compounds exhibited moderate to good cytotoxic activity, while some of them like 4f, 4h, 4i, 4j and 4q showed promising cytotoxicity with IC50 values ranging between 1.14 and 1.69 μM.