Microwave-Assisted Synthesis of Unsymmetrical 5-Phenyl-1,3,4-oxadiazoles Containing Bis(carboxymethyl)amino Group

Abstract

New derivatives of 5-phenyl-1,3,4-oxadiazole substituted at position 2 with (bromomethyl)phenyl or bromoalkyl groups were obtained via microwave-assisted cyclodehydration of unsymmetrical N,N′-diacylhydrazines. Then, bromine-containing oxadiazoles were substituted with diisopropyl iminodiacetate, yielding the corresponding ester derivatives, which were subsequently hydrolyzed in an aqueous methanol solution. The cleavage of the ester group resulted in the formation of the appropriate 5-phenyl-1,3,4-oxadiazoles bearing bis(carboxymethyl)amino groups in satisfactory yields. The structures of all products were confirmed by typical spectroscopic methods including 1H and 13C NMR, and HRMS.