Department of Chemistry,Shri Durga Ji P.G. College, Chandeswhar Azamgarh, and R. P.G. College, Jamuhai, Jaunpur, U.P. (INDIA)

3-Aryl-4-amino-5-mercapto-s-triazoles (Ia-g) were prepared in excellent yield. These compounds further treating with equimolar mixture of cyanogen bromide in ethanol yielded 6-amino-3-aryl-s-triazolo- [3,4-b]-1,3,4-thiadizoles (IIa-g) which on further treating with 2,3-dichloroquinoxaline in the presence of anhydrous sodium acetate gives the title compound 3-aryl-s-triazolo [3,4-b]-1,3,4-thiadiazolo [3,2- b] imidazo [4,5-b] quinoxalines (IIIa-g). All the synthesize compounds were well characterized by their elemental and spectral studies. Fungitoxicity of the synthesized compounds were evaluated against Phytophthora infestans and Aspergillus niger.