Abstract The alkylation of 3-R′-thio-5-amino-1H-1, 2, 4-triazoles 1 or their sodium salt with alkyl and aralkyl halides 2, respectively, to yield all the four possible monoalkylated derivatives 3, 4, 5 and 6 was studied. The comparison of the spectral data of different type isomers 3, 4, 5 and 6 isolated and their Schiff bases 8, 9 and 10, respectively, was unequivocal evidence in support of their structure which was then further supported by ...