A new direct synthetic access to 4-amino-2-N-(glycosyl/propyl)-1,2,4-triazole-3-thiones via hydrazinolysis of 3-N-((acylated glycosyl)/allyl)-1,3,4-oxadiazole-2-thiones

Hydrazinolysis of 3-N-alkyl-1,3,4-oxadiazole-2-thiones yielded 2-N-alkyl-4-amino-1,2,4-triazole-2-thiones in a straightforward new direct procedure. Whereas, hydrazinolysis of alkylsulfanyl-1,3,4-oxadiazole derivatives resulted in the opening of the oxadiazole ring and loss of the alkyl moiety, instead of a nucleophilic substitution at the electrophilic carbon or triazole formation. Thio-aza-Claisen rearrangement of the allyl moiety in 4-amino-1,2,4-triazole was successfully achieved by fusion at atmospheric pressure in the absence of solvents and catalysts.