Simultaneous sonication assistance for the synthesis of tetrahydropyridines and its efficient catalyst ZrP2O7 nanoparticles.

In this research, a general synthetic method for the synthesis of tetrahydropyridines were developed using ZrP2O7 nanoparticles under ultrasonic irradiations. Firstly by a simple and green process, nano zirconium pyrophosphate was prepared via sonication. Subsequently, this nanoparticle was used as an efficient catalyst for the synthesis of highly functionalized tetrahydropyridines via five-component reaction of aromatic aldehyde, amine and ethyl acetoacetate in ethanol under ultrasound irradiation. The present approach offers several advantages such as high yields, environmentally benign, simple work-up, excellent yield of products, short reaction times as well as recoverability and reusability of the catalyst.