Hydrogen Peroxide → 2-(Methanesulfonyl)-5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

A mixture of 5,7-dimethyl-2-(methylsulfanyl)-[1,2,4]triazolo[1,5-a]pyrimidine (9.9 g, 51.0 mmol), sodium tungstate dihydrate (505 mg, 1.53 mmol), and glacial acetic acid (95 mL) was added to a 200 mL RBF with a magnetic stirring bar. The flask was cooled to =10° C. using ice and water bath. A solution of 35% hydrogen peroxide in water (13.1 mL, 153.1 mmol) was slowly added via syringe. The mixture was stirred at room temperature for 10 minutes, then at 60° C. for 60 minutes. Progress of the reaction was monitored by analytical HPLC with UV detection at 215 nm. The starting material elutes with retention time of 3.8 min, and the product elutes with retention time of 1.3 min. The reaction was cooled to room temperature and a solution of sodium sulfite (3.0 g Na2SO3 in 20 mL water) (=5 mL) was added to the mixture until negative to peroxide test strip, and allowed to stir 30 minutes at room temperature. The reaction was concentrated to ˜20 mL and water was added to precipitate product. The solid was collected by filtration, rinsed with cold water (=30 mL) and dried under vacuum to afford the title compound as a white powder (7.78 g, 67% yield).

Provenance & Evidence