[OH:1][C:2]1[C:3]([CH3:13])=[C:4]([CH:10]=[CH:11][CH:12]=1)[C:5]([O:7][CH2:8][CH3:9])=[O:6].C(N(CC)C(C)C)(C)C.[CH3:23][S:24](Cl)(=[O:26])=[O:25]>ClCCl.O>[CH3:13][C:3]1[C:2]([O:1][S:24]([CH3:23])(=[O:26])=[O:25])=[CH:12][CH:11]=[CH:10][C:4]=1[C:5]([O:7][CH2:8][CH3:9])=[O:6]To a cooled (0° C.) solution of ethyl 3-hydroxy-2-methylbenzoate (116a, 2.4 g, 13 mmol) and N,N-diisopropylethylamine (5.8 mL, 33 mmol) in dichloromethane (50 mL) was added drop wise methanesulfonyl chloride (1.4 mL, 17 mmol). The reaction mixture was stirred at 0° C. for 30 minutes then diluted with water (20 mL) and extracted with dichloromethane (2×25 mL). The combined organic extracts were dried over magnesium sulfate, concentrated under vacuum, and purified by column chromatography (30% EtOAc/Heptane) to give ethyl 2-methyl-3-[(methylsulfonyl)oxy]benzoate (116b, 3.0 g, 88% yield) as a yellow oil.
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