Conversion of 2,4,6-Trimethylaniline to 3-(Mesitylthio)-1H-1,2,4-triazole Using a Continuous-Flow Reactor

An expeditious and highly efficient continuous-flow process was developed for the synthesis of 3-(mesitylthio)-1 H -1,2,4-triazole. The starting material 2,4,6-trimethylaniline was diazotized to give diazonium chloride, followed by azo-coupling with 1 H -1,2,4-triazole-3-thiol and dediazoniation to provide 3-(mesitylthio)-1 H -1,2,4-triazole in 85% yield with a productivity of 344 g/h. The side reactions such as hydrolysis, dimerization, and intramolecular coupling were significantly inhibited by the continuous-flow technology.