反应详情

A mixture of 7.81 g (10.0 mmol) of dimethyl sulfoxide with 9.21 g (10.0 mmol) of toluene was placed in a 200 ml flask. Then 40 ml of a previously prepared phosphorus pentaoxide/metanesulfonic acid reagent (prepared by dissolving 36 g of phosphorus pentaoxide in 360 g of methanesulfonic acid) was added thereto while stirring with a magnetic stirrer. A slight exothermic reaction occurred. The system was stirred at room temperature for 6 hours. The reaction mixture was poured into 150 ml of water and 150 g of ice. The slightly suspended solution was filtered, followed by addition of 23.2 g (10.0 mmol) of 3,3,3,2,1,1-hexafluoropropane sulfonic acid to yield a colorless oil. The oil was stirred for 1 hour, and 200 ml of dichloromethane was added thereto. The mixture was extracted. The organic phase was washed several times with water, and then dried. The solvent was removed by distillation. The oily residue was recrystallized from isopropyl alcohol to give 6.5 g of the contemplated material. The structure was confirmed by 1H-NMR (CDCl3) with δ=2.41 (s, 3H), 3.46 (s, 6H), 5.32-5.56 (d[m], 1H), 7.42-7.45 (d, 2H), 7.50-7.53 (d, 2H) ppm.

1. customwas placed in a 200 ml flask
2. customA slight exothermic reaction
3. stirringThe system was stirred at room temperature for 6 hours
4. filtrationThe slightly suspended solution was filtered
5. customto yield a colorless oil
6. stirringThe oil was stirred for 1 hour
7. extractionThe mixture was extracted
8. washThe organic phase was washed several times with water
9. customdried
10. customThe solvent was removed by distillation
11. customThe oily residue was recrystallized from isopropyl alcohol