Vol. 14 | No. 2 |1415-1422| April - June | 2021 ISSN: 0974-1496 | e-ISSN: 0976-0083 | CODEN: RJCABP http://www.rasayanjournal.com http://www.rasayanjournal.co.in Rasayan J. Chem., 14(2), 1415-1422(2021) http://dx.doi.org/10.31788/ RJC.2021.1426069 This work is licensed under a CC BY 4.0 license. A NOVEL, GREEN AND HETEROGENEOUS CERIA-BASED SOLID LEWIS ACID CATALYST ASSISTED ONE-POT MULTI- COMPONENT SYNTHESIS OF DIHYDRO- PYRANO[2,3‐C]PYRAZOLES Nilam D. Bansode, Vaishali N. Rathod, Sachin P. Gadekar and M. K. Lande  Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431 004, India  Corresponding Author: mkl_chem@yahoo.com ABSTRACT A green and easy protocol for Dihydro-pyrano[2,3‐c]pyrazoles, were synthesized in the presence of Ceria- Molybdenum mix metal oxides (Ce-Mo MMO) as a recyclable solid heterogeneous Lewis acid catalyst and one-pot four-component synthesis from the reaction between 3-nitro benzaldehydes, malononitrile ethyl acetoacetate and hydrazine hydrate Here, the Ce-Mo MMO catalyst was designed ,prepared and utilized as a catalyst in a various organic reaction. The present protocol offers several superiorities like short reaction time, high percent yield, clean reaction, simple separation technique and recoverable catalyst and it also shows the same catalytic activity when it was reused in consecutive reaction. Keywords: Catalyst, Synthesis, Dihydropyrano[2,3‐c]pyrazoles, Lewis Acid, Heterogeneous Mix Metal Oxide, Cerium Molybdenum (Ce-Mo). RASĀYAN J. Chem., Vol. 14, No.2, 2021 INTRODUCTION According to the green chemistry approach, catalyst and organic compound synthesis procedures must be eco-friendly and alternative. Green chemistry focus on using environmental friendly synthetic mixtures and simple reaction conditions. In the progress of our research work that synthesis of a heterogeneous catalyst, we have designed and synthesized Ce-Mo MMO catalyst. It was synthesized by the co- precipitation method. 1-4 Recently, from 2-4 decades, mixed metal oxides increase demand in catalysis, because of their versatile properties, it is stable in different organic-inorganic acids, as well as stable in high reaction temperature for a long time with reusable ability. In the Lanthanide series, especially ceria with other metal-containing oxides such mixed metal oxides have been rewarded much interest. Materials of ceria can promptly form redox sites Ce 4+/3+ and assisting enhance catalytic application. 5-7 In the last few years, ceria with other metal-containing oxides are synthesized by various methods and used in a different fields such as cosmetics, gas sensors, fuel cells; solid-state electrolytes and acts as a promoter of catalysts. 8 Catalytic or oxidation/ reduction, stability of Ce 4+/3+ can be significantly improved by the insertion of a transition metal such as Zr 2+/4+ ,Ti 3+/4+ , Pt 2+/4+ , Pd 2+/4+ , Rh 2+/4+ , Cu 2+ /Al 3+ , Si 4+ , Hf 4+ , Au 2+ etc. 9-12 Ceria based metal oxides used as a catalyst in organic transformations. 13-15 Subsequently, there is an impressive interest in the synthesis and development of novel catalyst with higher reaction quotient, low cost, great reusability, eco-friendly catalyst. Literature survey reveals that many organic reactions are accelerated in presence of a catalyst. Ceria metal-containing mixed metal oxides have been sustainable alternatives due to the presence of Lewis acidity 12-16 and used as a catalyst in organic synthesis such as 1,3-Diols, Polyhydroquinolines, 13-15 this component containing pharmaceutical product and are in great demand in drug synthesis because of the biological significance. 17 Early 2-3 decades, researchers have shown more interest in the preparation of dihydro-pyrano[2,3‐c]pyrazole derivatives due to their different therapeutic and pharmacological properties, it has bioactive and