Abstract Reaction of 2-, 3-and 4-pyridyl isothiocyanates with diazomethane or diazoethane afforded the corresponding 5-(pyridyl substituted) amino-1, 2, 3-thiadiazoles or 5-(pyridyl substituted)-amino-4-methyl-1, 2, 3-thiadiazoles; reaction with azoimide gave 5-(pyridyl substituted) amino-1, 2, 3, 4-thiatriazoles and 5-(2-pyridylamino) tetrazole, which underwent a thermal rearrangement to yield 1-(2-pyridyl)-5-aminotetrazole. The synthesized ...