Comparison of synthetic routes for fully substituted (1H-1,2,3-triazol-4-yl)acetic acids

Abstract

The new fully substituted (1H-1,2,3-triazol-4-yl)acetic acids were synthesized from available precursors (1H-1,2,3-triazol-4-yl)ethanones and 1Н-1,2,3-triazole-4-carboxylic acids, which are easily prepared by the Dimroth reaction from azides and 1,3-dicarbonyl compounds. The practical methods of homologization (the Arndt–Eistert reaction and homologization as a result of nucleophilic substitution by cyanide anion) and the Willgerodt-Kindler reaction were compared. The Willgerodt-Kindler method starting from (5-methyl-1H-1,2,3-triazol-4-yl)ethanones was selected as the most convenient method for the synthesis of 2-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)acetic acids, which are promising building blocks for drug discovery. Additionally, (1H-1,2,3-triazol-4-yl)ethanones were studied for the synthesis of alcohols, amines and in the Johnson–Corey–Chaykovsky reaction.