反应详情

56.8 g (0.08 mol) of tris-(4-butoxyphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (Synthesis Example 110) and 1.86 g (0.008 mol) of 3,3,3,2,1,1-hexafluoropropane sulfonic acid were dissolved in 200 ml of ethanol. The solution was heated under ref lux for 8 hours with stirring. After removal of the solvent by distillation, the obtained crude product of tris-(4-hydroxyphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (yield about 100%) was dissolved in 160 g of N,N-dimethylformamide and reacted with 55.4 g (0.40 mol) of anhydrous potassium carbonate and 60.3 g (0.40 mol) of di-t-butyl dicarbonate at 20° C. for 3 hours. The reaction solution was poured into 700 ml of water and extracted with dichloromethane. The organic phase was washed with water and dried. The solvent was removed by distillation. The oily residue was purified by column chromatography on silica gel using a dichloromethane and methanol as the developing solvent. The white product was collected to yield 31.8 g (yield 45%) of analytically pure tris-(4-t-butoxycarbonylmethoxyphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate. The melting point of the product was 78° C. The 1H-NMR spectrum gave the following signals (CDCl3): δ=1.45 (s, 27H), 5.30-5.56 (d[m], 1H), 7.10-7.13 (d, 6H), 7.55-7.60 (d, 6H).

1. temperatureThe solution was heated under ref lux for 8 hours
2. customAfter removal of the solvent
3. distillationby distillation