Hydrochloric Acid → Triphenylsulfonium 1,1-difluoro-2-hydroxyethanesulfonate

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Reaction Steps

Triphenylsulfonium 2-(pivaloyloxy)-1,1-difluoroethane-sulfonate, 243.5 g (0.48 mole), was dissolved in 760 g of methanol and ice cooled. An aqueous sodium hydroxide solution (40 g of sodium hydroxide in 120 g of water) was added dropwise at a temperature below 5° C. The solution was allowed to mature for 8 hours at room temperature. At a temperature below 10° C., dilute hydrochloric acid (99.8 g of 12N hydrochloric acid in 200 g of water) was added to quench the reaction. The methanol was distilled off in vacuum. To the residue was added 1,000 g of dichloromethane. The organic layer was washed three times with 30 g of saturated sodium chloride aqueous solution and concentrated. Diisopropyl ether, 1 L, was added to the concentrate for crystallization. The crystals were filtered and dried, obtaining the target compound. Amount 187 g (purity 78%, reduced yield 78%).

Provenance & Evidence