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

Beteiligte Stoffe

Reaktionsschritte

In 760 g of methanol was dissolved 243.5 g (0.48 mole) of triphenylsulfonium 2-(pivaloyloxy)-1,1-difluoroethane-sulfonate. To this solution under ice cooling, an aqueous sodium hydroxide solution (40 g sodium hydroxide in 120 g water) was added dropwise at a temperature below 5° C. The reaction solution was allowed to mature at room temperature for 8 hours, and dilute hydrochloric acid (99.8 g 12N hydrochloric acid in 200 g water) was added thereto at a temperature below 10° C. 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 saline and concentrated. Diisopropyl ether, 1 L, was added to the concentrate for crystallization. The crystals were filtered and dried, obtaining the target compound (PAG1), 187 g (purity 78%, net yield 78%). PAG1 has the following structure.

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