Ultrasound assisted one-pot, three-components synthesis of pyrimido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines: A new access via phenylsulfone synthon

A simple, facile, efficient and three-components procedure for the synthesis of pyrimido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines utilizing phenylsulfone synthon, under ultrasonic irradiation was developed.

► Ultrasound assisted three-components condensation reaction of an aldehyde, amino azoles and β-ketosulfone.
► The obtained products are pyrimido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines.
► p-TsOH catalyze synthesis of pyrazolo[3,4-b]pyridines.
► Improvements in rates and yield of reactions are observed when reactions were carried out under sonication compared with classical condition.