Reaktion #511513

Reaktionsgleichung

sodium hydroxide

triphenylsulfonium 2-(pivaloyloxy)-1,1-difluoroethane-sulfonate

hydrochloric acid

→

triphenylsulfonium 1,1-difluoro-2-hydroxy-ethanesulfonate

Ausbeute 78.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat a temperature below 10° C. to quench
2. 2
   Sonstigethe reaction
3. 3
   workup.DISTILLATIONThe methanol was distilled off in vacuum
4. 4
   workup.ADDITIONTo the residue was added 1,000 g of dichloromethane
5. 5
   WaschenThe organic layer was washed three times with 30 g of saturated saline
6. 6
   Einengenconcentrated
7. 7
   workup.ADDITIONDiisopropyl ether, 1 L, was added to the
8. 8
   Einengenconcentrate for crystallization
9. 9
   FiltrationThe crystals were filtered
10. 10
    Sonstigedried
11. 11
    Sonstigeobtaining the target compound (PAG1), 187 g (purity 78%, net yield 78%)

Vorschrift

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.

Quelle