An efficient protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via multi-component coupling reaction of aromatic aldehydes, β-ketoester and urea or thiourea under solvent-free conditions using Silica Supported Barium Chloride as a catalyst is described. All prepared compounds with melting points, IR,1H NMR and 13C NMR were identified. High yields, mild conditi...

A novel method for oxazine derivatives formation is established using the reaction of ammonium thiocyanate and acid chlorides with 1-naphthol in the presence of Nanoparticle of ZnO to afford [1,3]oxazine-4-thione derivatives under solvent-free conditions at room temperature in excellent yields. 

4-amino-6-methyl- 1,2,4-triazine-3(2h)-thione-5-0ne (1) was condensed with propargyl bromidein the presence of sodium rnethoxide to afford 3-propargylmercapto- 4-arnino-6-rnethyl-1,2,4-triazin-5-one(2) . transformation of the latter to 8-dihydro- 3-methyl-7-methylene-4-oxo-6h-[1,2,4]triazino [3,4-b] [1,3,4] thiadiazine (3) was performed under the condition of palladium (ii) salt. ring closure o...