<p>Alumina (Al₂O₃)-supported 10-molybdo-2-tungstosilicic green acid catalysts were developed by a novel, cheap, environment-friendly approach and utilized in the synthesis of 2,3-dihydroquinazolin-4(1<i>H</i>)-one derivatives. The structure and morphology of the prepared heteropoly acid catalyst were studied by FT-IR, XRD, BET, FE-SEM, HR-TEM, EDX and TG–DTA techniques. The present catalyst shows maximum conversion efficiency in 2,3-dihydroquinazolin-4(1<i>H</i>)-one’s derivatives synthesis. The activity of H₄SiMo₁₀W₂O₄₀/Al₂O₃ catalysts was tested for the synthesis of 2,3-dihydroquinazolin-4(1<i>H</i>)-ones by the reaction of 2-aminobenzamide and aromatic aldehydes. However, among different catalysts, 20% H₄SiMo₁₀W₂O₄₀/Al₂O₃ has shown better catalytic activity. Besides, the catalyst was recyclable and reused several times without loss of its catalytic activity. Highest yields of products, mild reaction conditions, short reaction times, non-toxicity, economically affordable catalyst, easy separation of products are some of the advantages of this protocol.</p> Graphical abstract <p>An economic, sustainable, and straightforward environmentally friendly synthesis of 2,3 dihydroquinazolin-4(1H)-ones derivatives from benzaldehyde (1) and 2-aminobenzamide (2) in presence of catalytic amount of H₄SiMo₁₀W₂O₄₀/Al₂O₃. Excellent yields, reusability of catalyst, green metrics and environmentally sustainability are the main advantages of the present method.</p>