Available free online at www.medjchem.com Mediterranean Journal of Chemistry 2021, 11(3), 215-228 *Corresponding author: Achraf El Hallaoui; Abdelaziz Souizi Received August 22, 2021 Email address:adamsmcorg@gmail.com; souizi@yahoo.com Accepted October 2, 2021 DOI: http://dx.doi.org/10.13171/mjc02108091579elhallaoui Published December 11, 2021 Synthesis of new bimetallic phosphate (Al/Ag3PO4) and study for its Catalytic performance in the synthesis of 1,2-dihydro-l-phenyl- 3H-naphth [1,2-e]-[1,3] oxazin-3-one derivatives Achraf El Hallaoui 1,* , Tourya Ghailane, Soukaina Chehab 1 , Youssef Merroun 1 , Rachida Ghailane 1 , Said Boukhris 1 , Taoufik Guédira 1 and Abdelaziz Souizi 1,* 1 Organic, Inorganic Chemistry, Electrochemistry, and Environment Laboratory, University of Ibn Tofail, Faculty of Sciences, Po Box 133, 14000 Kenitra, Morocco Abstract: This work aims to prepare a new bimetallic phosphate catalyst using a new simple and effective method. This new catalyst was ready for the first time by a modification of Triple Super Phosphate (TSP) fertilizer with silver sulfate (AgSO4), followed by the impregnation of the aluminum atoms using aluminum nitrate (Al(NO3)3). The use of Al/Ag3PO4, for the first time as a heterogeneous catalyst in organic chemistry, offers a new, efficient, and green pathway for synthesizing 1,2-dihydro-l-phenyl-3H-naphth[1,2-e]-[1,3]oxazin-3-one derivatives by one- pot three-component cyclocondensation of -naphthol, aryl aldehyde, and urea. The structure and the morphology of the prepared catalyst were characterized by spectroscopic methods such as X-Ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), and dispersive X-ray spectrometry coupled with a scanning electron microscope (EDX-SEM). In addition, the optimization of the reaction parameters was carried out considering the effect of catalyst amount, the temperature, and the solvent. The procedure described herein allowed a comfortable preparation of oxazine derivatives with excellent yields, short reaction times, and in the absence of organic solvent. Keywords: One-pot reaction; heterogeneous catalyst; TSP fertilizer; Al/Ag3PO4; Oxazine derivatives. 1. Introduction Over the last few years, multicomponent reactions (MCRs) have incited great interest and were used to synthesize complex molecules and are highly functionalized in a single synthetic operation 1,2 . MCRs are considered an inventive strategy in organic chemistry 3,4 . Therefore, multicomponent reactions are part of sustainable chemistry and constitute a novel way of ideal organic synthesis. Complex structures are rapidly obtained from very simple substrates involving simple synthetic operations and safe processes in the environment. The use of eco- friendly solvents and reusable heterogeneous catalysts make these reactions ecological and environmentally benign 5-9 . In this context, organic chemists are headed towards applying different catalysts in multicomponent reactions. Among the used catalysts, one can find heterogeneous catalysts which are recoverable and reusable several times. The application of heterogeneous catalysts allows having advantages such as the simplicity of the procedure, high atomic economy, high selectivity, structural diversity, and environment protection 10-12 . These catalysts have become very popular for their ability to catalyze many cascading processes under mild conditions and, often, with high levels of regioselectivity. The oxazinone derivatives synthesis is one of the multicomponent reactions which have attracted widespread attention. These compounds have interesting pharmacological properties associated with their heterocyclic structure 13,14 . For example, in 1998, the Food and Drug Administration has approved naphthoxazinone derivatives as antibacterial agents and benzoxazinone as a non- nucleoside reverse transcriptase inhibitor 15 . Nowadays, these derivatives are used for the treatment of AIDS 16 . Therefore, numerous methods for the synthesis of oxazinone derivatives are reported in the literature 17,18 . Some strategies for the synthesis of 1,2-dihydro-1-arylnaphtho [1, 2-e]-[1,3]oxazine-3- ones synthesis were described by three-component condensation of urea, or thiourea, aldehyde, and - naphthol in the presence of the different catalysts such as phosphomolybdic acid 19 , Thiamine Hydrochloride 20 , iron(III) phosphate 21 , Chitosan 22 , wet cyanuric chloride 23 , Silica vanadic acid 18 , graphene oxide 24 , amberlite IRA-400 Cl Resin 25 , and TiCl4 26 , etc.