Dimethyl Sulfoxide → 3-methyl-6-(methylsulfonyl)-3,4-dihydronaphthalen-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-bromo-3-methyl-3,4-dihydronaphthalen-1(2H)-one (10 g, 41.8 mmol) methanesulfinic acid, sodium salt (16.7 g, 163.1 mmol), copper(I) iodide (3.18 g, 16.7 mmol), cesium carbonate (6.81 g, 20.9 mmol) and L-proline (3.85 g, 33.4 mmol) in DMSO (200 mL) was heated at 100° C., protected from light. After 3.5 hours, copper(I) iodide (1.59 g) and L-proline (1.9 g) were added and the reaction continued for 5 hours, and then stirred overnight at room temperature. The mixture was diluted with ice/water (200 mL) and extracted with ethyl ether (3×), ethyl acetate (3×). The combined organic layer was washed with brine, dried (MgSO4), filtered, and purified by flash column chromatography (silica gel, 30 to 60% ethyl acetate/hexanes) to give the desired product. 1H NMR (400 MHz, CDCl3) δ 8.20 (d, J=8.1 Hz, 1H), 7.87 (s, 1H), 7.86 (d, J=7.7 Hz, 1H), 3.10-3.00 (m, 1H), 3.08 (s, 3H), 2.86-2.71 (m, 2H), 2.48-2.31 (m, 2H), 1.19 (d, J=6.0 Hz, 3H).

Provenance & Evidence