TBAF Controlled Access to 1,4,5-Trisubstituted and 1,5-Disubstituted Pyrido-triazoles from Tetrazolopyridine with β-Keto Ester and Their Anti-leishmanial Efficacy Studies

The synthesis of 1,4,5-trisubstituted pyrido-triazole and 1,5-disubstituted pyrido-triazole, from tetrazolopyridine and 1,3-dicarbonyl compounds using tetrabutyl ammonium fluoride (TBAF) salt, is reported here. The concentration of TBAF in the reaction medium dictates the selectivity of formation of two pyrido-triazoles. The gram-scale synthesis and late-stage modification of the ester substituent further enhance the synthetic utility of this methodology. Anti-leishmanial screening of selected 15 trisubstituted pyrido-triazoles revealed moderate activity against promastigotes and axenic amastigotes.