New Heterocycles derived from 2-Amino-1,3,4-Thiadiazoles,-Pyrimidines and -Thiazolo [5,4-b] Pyridines
New Heterocycles derived from 2-amino-1,3, 4-Thiadiazoles, 2-Aminobenzimidazole, 3-Aminoisoxazole and 3-Isoxazole -Carbonyl Azides