Fabrication of HPA-ZSM-5 and their successful application to the recyclable heterogeneous catalyst for the smooth synthesis of spiro-pyrido-pyrimidine indoline derivatives

Abstract

A beneficial and efficient one-pot three-component approach for the synthesis of spiro cyclic 2-oxindole derivatives has been described by the reaction of isatins, cyclic-1,3-diketones and 6-amino-1,3-dimethyluracil in the presence of highly active HPA-ZSM-5 microporous catalyst. The zeolite catalyst has been synthesized and the catalyst has been thoroughly characterized by X-ray diffraction (XRD), field emission scanning electronic microscopy (FE-SEM), Fourier transform infrared (FT-IR), energy dispersive spectroscopy (EDS) and N2-adsorption analysis. HPA-ZSM-5 catalyst exhibited exceptional recyclability at least for 6 times and the surface acidity was not significantly changed. The best results were gained in H2O and we found the convincing results in the synthesis of spiro-pyridopyrimidine in the presence of HPA-ZSM-5 (10 mg) under ultrasound irradiation (40W). Experimental simplicity, wide range of products, excellent yields in short reaction times and low catalyst loading are some of the substantial features of this procedure. The present catalytic method is extensible to a wide diversity of substrates for the synthesis of a variety-oriented library of spiro-pyrido-pyrimidine indoline derivatives.