Synthesis and biological evaluation of 1,2,4 triazole and 1,3,4-Oxa-and Thiadiazoles derivatives

ABSTRACT

The alkaline hydrolysis with dimethylsulfate and potassium hydroxide of coumarin-6-derivatives [Ia-d] yielded 3-propenoic acid derivatives [IIa-d] which in turn were reached with thionyl chloride in toluene to give carbonyl chloride derivatives [IIa-d]. The latter compounds condensed with thiosemicarbazide in dioxane to give carbonylthiosemicarbazide derivatives [IVa-d], respectively. Cyclization of IVa-d, using sodium hydroxide yielded 5-mercapto- 1,2,4-triazol-3-yl-derivatives [Va-d]. Cyclodehydration of IVa-d using ortho-phosphoric acid or dicyclohexylcarbodiimide [DCC] led to the formation of the corresponding 5-amino-1,3,4-thia and oxadiazol-2-derivatives [VIa-d] and [VIIa-d], respectively. The antimicrobial and antiaflatoxigenic activities of Va-d, VIa-d were also evaluated