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

HRID 27635Notes

Reaction equation

[S:1](Cl)(Cl)=[O:2].[CH3:5][S:6]([O:9][C:10]1[CH:15]=[CH:14][C:13]([OH:16])=[C:12]([C:17]([CH3:21])([CH3:20])[CH2:18][OH:19])[CH:11]=1)(=[O:8])=[O:7]>C1(C)C=CC=CC=1>[CH3:5][S:6]([O:9][C:10]1[CH:15]=[CH:14][C:13]2[O:16][S:1](=[O:2])[O:19][CH2:18][C:17]([CH3:20])([CH3:21])[C:12]=2[CH:11]=1)(=[O:8])=[O:7]

Participants

Conditions

Temperature: 50 °C

Procedure

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.

Workup

customwhen reaction commenced
temperaturemaintained at this temperature for 15 minutes
temperatureThe temperature was then raised
temperatureunder reflux for 2 hours
customThe solvent was then evaporated off under reduced pressure

Sources & evidence

ORD record: ord-81db7735d30a476da296493743d7558e
Source dataset: uspto-grants-1980_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04222767

Reaction notes

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