7-Amino-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic Acid is the 2-(triazolylthio)methyl analogue of 7-Aminocephalosporanic Acid (A603415). 7-Amino-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic Acid is used in the preparation of triazole-based semi-synthetic cephalosporins.