Synthesis of 5-alkyl-2-amino-1,3,4-thiadiazoles and α,ω-bis(2-amino-1,3,4-thiadiazol-5-yl)alkanes in ionic liquids

Reaction of thiosemicarbazide with carboxylic acids, including N-substituted amino acids, in ionic liquids with H₂SO₄ as a catalyst affords 5-R-2-amino-1,3,4-thiadiazoles. On using alkanedicarboxylic acids, α,ω-bis(2-amino-1,3,4,-thiadiazol-5-yl)alkanes were obtained.