a design for convenient and greener root towards one-pot multi-component synthesis of substituted pyrano-dichromeneo-dione and chromeno-pyrido-pyrimidinone derivatives using rice husk based heterogeneous catalyst

in this work, a convenient and greener procedure for synthesizing substituted pyrano-dichromeno-dione and substituted chromeno-pyrido-pyrimidinone derivatives were explored using sulphonated rice husk (srh) as a novel bio-degradable, greener, heterogeneous catalyst. we designed an efficient pseudo three-component synthetic method for 7-aryl/heteroaryl substituted pyranodichromene-6, 8-dione and 7-aryl/heteroaryl substituted chromeno[4, 3-d]pyrido[1, 2-a]pyrimidinone derivatives using this greener catalyst (srh) under reasonable reaction condition. the fundamental features of this procedure are the operational simplicity, hassle-free recovery of product, and reusability of the catalyst with excellent product yield (up to 98%). the toxic metal-free catalyst was prepared conveniently, and characterized using different spectroscopic techniques, including fourier-transform infrared spectroscopy (ftir), x-ray diffraction analysis (xrd), scanning electron microscopy (sem), energy dispersive x-ray spectroscopy (edx). then the synthesized material was used for the greener synthetic target.