Dimethyl Sulfoxide → 1-[2-(2,2-Dimethylpropanoyl)-5-methoxy-1-benzofuran-3-yl]-3,3-dimethylbutan-2-one

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Reaction Steps

Cool 1.5 mL dichloromethane in dry ice bath under nitrogen. Add 38 mg oxalyl chloride followed by 47 mg DMSO. Stir for 30 minutes. Add a solution of 49.9 mg 1-[3-(2-hydroxy-3,3-dimethylbutyl)-5-methoxy-1-benzofuran-2-yl]-2,2-dimethylpropan-1-one from the Step A above in 2.5 mL dichloromethane. After another 25 minutes, 167 μL triethylamine were added. After stirring for additional 25 minutes, the reaction mixture was removed from the cooling bath and allowed to warm to room temperature. After 2 hours, solvents were removed under reduced pressure and the residue was purified directly on RP-HPLC using 70-100% MeCN gradient. The fractions containing pure product were pooled and lyophilized to give the title compound. 1H NMR (CDCl3, 500 MHz) 7.43 (d, J=8.9 Hz, 1H), 7.10 (dd, J=2.5 & 8.9 Hz, 1H), 6.90 (d, J=2.6 Hz, 1H), 4.39 (s, 2H), 3.87 (s, 3H), 1.42 (s, 9H), 1.34 (s, 9H). LC-MS: 4.17 min. (m/Z=247.2, 353.3, 331.4).

Provenance & Evidence