Morpholinium glycolate as an efficient and reusable catalyst for the synthesis of bis(pyrazol-5-ol) derivatives under solvent-free conditions

Abstract

In this paper, an environmentally benign access to synthesize Bis(pyrazol-5-ol) derivatives was developed through the one pot pseudo five component condensation reaction of phenyl hydrazine with ethyl acetoacetate, and different aryl/heteroaryl aldehydes using morpholinium glycolate as the homogeneous reusable catalyst under solvent-free conditions at 80 °C. Further, the ionic liquid was prepared and characterized by FT-IR, ¹HNMR, ¹³CNMR and TG-DTG techniques. The present synthetic protocol offers excellent yields of the products, short reaction times, clean and simple work up, reusability of catalyst up to five runs, a significant reduction in cost, and eco-efficient alternative to the existing methods.