A novel series of pyrido[3’,2’:4,5]selenolo[3,2- d]pyrimidine, 7,9-dimethylpyrido [3’,2’:4,5]selenolo[3,2- d]pyrimidine-2,4-( 1H,3H)-dithione, 7,9-dimethylpyrido[3’,2’:4,5]selenolo[2,3- e]tetrazolo[1,5- c]pyrimidine-6( 5H)-thione, 9,11-dimethyl-pyrido[3’,2’:4,5]selenolo[2,3- e][1,2,4]triazolo[1,5- c]pyrimidine, 7,9-dimethylpyrido[3’,2’:4,5]selenolo[2,3- e]imidazo[1,2- c] pyrimidine and 10,12-dimethylpyrido[3″,2″:4’,5']selenolo[3’,2’:4,5]pyrimido[1,6- a]pyrimidine derivatives were prepared from 3-amino-4,6-dimethylselenolo[2,3- b]pyridine-2-carbonitrile.