Hydrochloric Acid → 4-Fluorophenyldiphenylsulfonium 1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate

Participants

Reaction Steps

In 139 g of methanol was dissolved 59.4 g (0.1 mole) of 4-fluorophenyldiphenylsulfonium 1,1,3,3,3-pentafluoro-2-pivaloyloxypropane-1-sulfonate in Comparative Synthesis Example 1. The solution was stirred under ice cooling, to which a solution of 8.0 g (0.2 mole) of sodium hydroxide in 24 g of water was added dropwise at a temperature below 20° C. The solution was stirred overnight at room temperature, after which 21 g of conc. hydrochloric acid and 60 g of water were added to quench the reaction. Methanol was removed in vacuum from the reaction solution, dichloromethane and water were added to the residue, and the organic layer was separated and concentrated again. Diisopropyl ether was added to the residue for crystallization. Filtration and drying gave white crystals. On 19F-NMR analysis of the crystal, however, the peak assigned to fluorine in 4-fluorophenyldiphenylsulfonium cation and observed near −104 ppm extinguished. The product was identified as 4-methoxyphenyldiphenylsulfonium 1,1,3,3,3-pentafluoro-2-hydroxypropane-1-sulfonate (PAG-3). The 1H-NMR and 19F-NMR spectra of PAG-3 are shown in FIGS. 5 and 6, respectively.

Provenance & Evidence