Study Of The Design And Synthesis Of2-amino-5-mercapto-1,3,4-Thiadiazolepyrimidine Derivatives

1,3,4-thiadiazole derivatives play an important role in the Heterocyclic Chemistry.During the past decades, such derivatives are widely used in agriculture, medicine, industry and other fields of study gradually, in particular, it has been achieved a breakthrough in the field of agriculture and medicine,for which to be the focus and hot spots.We used a multi-component condensation reaction (MCRs),Ethyl-2-(mercapto-benzyl)-7-methyl-5-phenyl-5H-[1,3,4]thiadiazol[3,2-a]pyrimidine-6-carboxylate was synthesised in the shortest time and the maximum efficiency,this method provides a mild condition, simple operation and avoids high boiling point solvent,besides the reaction time was shorten;and the same time avoids the tedious operation which from multi-steps.Starting from2-amino-5-mercapto-1,3,4-thiadiazole (AMT), after mercap’s protective,the other side of amino takes part in the one-pot three-component reaction.1,3,4-thiadiazole [3,2-a]pyrimidine was successfully attained by cyclization with aromatic aldehydes and the ethyl acetoacetate in the condition of acid-catalyzator.The optimum reaction conditions was obtained:5-benzyl-mercapto-1,3,4-thiadiazol-2-amino,benzaldehyde and ethyl acetoacetate molar ratio was1:1:1.5and catalyst sulfamate with1,3,4-thiadiazol molar ratio was3:1,the reaction refluxing in absolute ethanol for30hours.After Column chromatography the product yield is64%and the purity of HPLC more than98%.All the compounds were characterized by’H-NMR,IRand MS.