Selenium Dioxide → HCID 9795803, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-(3-(2,6-Dimethylbenzyloxy)-phenyl)-ethanone (WO 02/100341, 5 g, 20 mmol) in pyridine (20 ml) was added selenium dioxide (3.492 g, 31 mmol) diluted in pyridine (20 ml). The reaction mixture was heated at 100° C. for 3 hours, decanted from selenium metal and concentrated in vacuo to give orange oil, which solidified at room temperature. The solid was dissolved in saturated NaHCO3 (40 ml) and stirred with decolorizing carbon (0.5 g) for an hour at room temperature. The reaction mixture was filtered through celite and aqueous filtrate was acidified using 6N HCl (6 ml). A gray precipitant (6.3 g) was filtered and dried in vacuo at 40° C. for 2 hours. The acidified filtrate was washed with ether (2×75 ml), dried over Na2SO4, filtered, and concentrated to yield a white solid (0.5 g). Recrystallization using carbon tetrachloride afforded 4.9 g of the title compound with pyridine as an impurity. The semipure material (4.2 g) was dissolved in ethyl acetate (150 ml) and washed with 5% HCl (2×50 ml). The organic layer was dried over Na2SO4, filtered and concentrated to yield a yellow solid (3.9 g). The solid was recrystallized with carbon tetrachloride (30 ml) to afford the title compound (3.03 g) as a light yellow solid.

Provenance & Evidence