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oai:ojs.www.eurjchem.com:article/767 2013-06-30T03:41:05Z eurjchem:ART driver

Ecofriendly regioselective one-pot synthesis of chromeno[4,3-d][1,2,4]triazolo[4,3-a]pyrimidine derivatives Gomha, Sobhi Mohamed Badrey, Mohamed Gomaa Chitosan Hydrazonoyl halides Ultrasound irradiation Active chloromethylene Benzopyranopyrimidine Chromeno[4 3-d][1 2 4]triazolo[4 3-a]pyrimidine The reaction between 2-mercapto-3H-chromeno[4,3-d]pyrimidine-4,5-dione (1) or its 2-methylthio derivative (7) with hydrazonoyl halides (2) in dioxane under ultrasound irradiation in the presence of chitosan yielded chromeno[4,3-d][1,2,4]triazolo[4,3-a]pyrimidine derivatives (5a-r). On the other hand, the reaction of compound 1 with the appropriate active chloromethylene compounds (9b, h and m) followed by coupling the products with benzenediazonium chloride afforded the azo coupling products which converted in situ to compound 5. The reaction mechanism was proposed and the structure of the newly synthesized compounds were established on the basis of spectral data (Mass, IR, 1H and 13C NMR) and elemental analyses. Atlanta Publishing House LLC 2013-06-30 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion application/pdf https://www.eurjchem.com/index.php/eurjchem/article/view/767 10.5155/eurjchem.4.2.180-184.767 European Journal of Chemistry; Vol. 4 No. 2 (2013): June 2013; 180-184 2153-2257 2153-2249 eng https://www.eurjchem.com/index.php/eurjchem/article/view/767/PDF