Synthesis of tetrazolo-fused benzodiazepines and benzodiazepinones by a two-step protocol using an Ugi-azide reaction for initial diversity generation

A two-step strategy for the synthesis of arrays of tricyclic tetrazolo-fused benzodiazepines and benzodiazepinones has been investigated. The protocol uses ortho-N-Boc phenylisocyanides and phenylglyoxaldehydes or ethyl glyoxylate in the four-component Ugi-azide reaction to afford MCR (MultiComponent Reactions) derived adducts equipped with the desired diversity inputs. A subsequent acidic treatment (TFA/DCE) allows a simultaneous deprotection–cyclization leading to the final products.