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

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Reaction Steps

Triphenylsulfonium 2-(pivaloyloxy)-1,1-difluoroethanesulfonate, 243.5 g (0.48 mole), was dissolved in 760 g of methanol and ice cooled. An aqueous solution of 40 g sodium hydroxide in 120 g water was added dropwise to the solution at a temperature below 5° C. It was aged at room temperature for 8 hours. 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, after which 1,000 g of dichloromethane was added to the residue. The organic layer was washed with 30 g of a saturated sodium chloride solution three times. The organic layer was concentrated, after which 1 L of diisopropyl ether was added to the residue for crystallization. The crystals were filtered and dried, obtaining the target compound. 187 g (purity 78%, net yield 78%).

Provenance & Evidence