Selective Synthesis of Functionally Substituted 1,2,3-Triazoles

Different conditions were used to achieve selective formation of 4.5-disubstituted 1-aryl(hetaryl)-1,2,3-triazoles via cycloaddition of the corresponding enolates and aryl or hetaryl azides. Optimal conditions were found for the bromination of 1-(5-methyl-1-phenyl-1,2,3-triazol-4-yl)ethanone to obtain 2-bromo-1-(5-methyl-1-phenyl-1,2,3-triazol-4-yl)ethanone.