Ru(II)-Catalyzed Cyclization of 1-Aryl-5-aminopyrazoles and α-Diazolidinones for One-Pot Synthesis of Benzopyrazole[1,3]Diazepines in H2O/EtOH

An efficient Ru(II)-catalyzed protocol has been developed for the synthesis of benzopyrazole1, 3diazepines in H2O/EtOH with Zn(OAc)2 as an additive. The reaction proceeds without oxidizing agent from 1-aryl-5-aminopyrazoles and α-azolidinone to obtain benzopyrazole1, 3diazepines. This approach has the advantages of a wide range of substrates and high functional group compatibility. The gram-scale experiment demonstrated the potential applications of this reaction.