Ultrasound-assisted PSA catalyzed one-pot green synthesis of pyrazolyl pyrrole derivatives

A fast, efficient and environmentally benign synthesis of pyrazolyl pyrrole derivatives has been developed by the one-pot multicomponent reaction of an aldehyde, nitroalkane, amine, and enolizable reactant with active C-H group, using Phosphosulfonic acid (PSA) as reusable solid acid catalyst under mild, solvent-free, ultra-sonication conditions. In comparison to the existing conventional methods, this green and efficient protocol provides remarkable advantages such as good to excellent yields, lower reaction time, less cost, easy work-up and solvent-free.