Polyvinylpolypyrrolidone supported antimony(III) chloride (PVPP-SbCl3): An efficient catalyst for the synthesis of chromenylphenylpropanones

An efficient synthesis of chromenylphenylpropanone derivatives as warfarine-like analogues was developed by the Michael addition of 4-hydroxycoumarin to α,β-unsaturated compounds in the presence of polyvinylpolypyrrolidone supported antimony(III) chloride (PVPP-SbCl3) as a new polymeric Lewis acid catalyst in chloroform at reflux conditions without formation of 2,4-diarylpyrano[3,2-c]chromen-5(4H)-ones. The synthesized compounds were identified by FT-IR, 1HNMR and 13CNMR spectroscopic techniques and elemental analysis. Polyvinylpolypyrrolidone supported antimony(III) chloride was characterized via Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Clean methodologies, simple preparation of the catalyst, good yields, environmentally friendly and reusable catalyst are some advantages of this work.