Multi-gram scale mercury-free synthesis of optically pure 3,4,5-trisubstituted 1,2,4-triazoles using silver benzoate

We report a new method using silver benzoate instead of mercury salts as a key reagent for the synthesis of 3,4,5-trisubstituted 1,2,4-triazoles. This method allows the introduction of a large variety of substituents in the three positions. We demonstrated that we could introduce one chiral center without any loss of the optical purity. This method is compatible with at least multi-gram scale-up. (C) 2010 Elsevier Ltd. All rights reserved.