Thionyl Chloride → 4,5-Dihydro-5,5-dimethyl-2-oxido-1,3,2-benzodioxathiepin-7-yl methanesulphonate

Participants

Reaction Conditions

Reaction Steps

Thionyl chloride (12 parts) was added dropwise at room temperature to a suspension of 4-hydroxy-3-(2-hydroxy-1,1-dimethylethyl)phenyl methanesulphonate (5 parts) (from Example 1) in toluene (50 parts). The mixture was gently warmed to 50° C. when reaction commenced, then maintained at this temperature for 15 minutes. The temperature was then raised to boiling point and the mixture boiled under reflux for 2 hours. The solvent was then evaporated off under reduced pressure to give crude 4,5-dihydro-5,5-dimethyl-2-oxido-1,3,2-benzodioxathiepin-7-yl methanesulphonate (5.2 parts, 90% yield). Recrystallisation from ethanol gave the pure product (2.4 parts), melting point 96°-98° C.

Provenance & Evidence