Molecular iodine: A highly efficient catalyst for the synthesis of 7-arylbenzopyrano[1,3]diazepines in non-protic solvents

A simple and facile synthesis of 7-arylbenzopyrano[1,3]diazepines has been accomplished by treatment of 4-hydroxycoumarin, cyanoguanidine with aromatic or heteroaromatic aldehydes using molecular iodine in non-protic solvent under reflux. This method not only provide an excellent complement for 7-arylbenzopyrano[1,3]diazepines but also avoids the multistep and harsh reaction conditions.

Graphical abstractA simple and facile synthesis of 7-arylbenzopyrano[1,3]diazepines has been accomplished by treatment of 4-hydroxycoumarin, cyanoguanidine with aromatic or heteroaromatic aldehydes using molecular iodine in non-protic solvent under reflux. Figure optionsDownload full-size imageDownload as PowerPoint slide