Oxalyl chloride → HCID 67624562, compound

Participants

Reaction Conditions

Reaction Steps

To a mixture of 0.78 g of the title compound of Step A in 35 mL of methylene chloride was added 0.66 mL of oxalyl chloride (purchased from Aldrich Chemical Co.) and 2 drops of N,N-dimethylformamide. The mixture was refluxed for 2 h and was then concentrated under reduced pressure to dryness. The resulting residue was redissolved in 30 mL of methylene chloride and the solution was evaporated to dryness again. Another 30 mL of methylene chloride was added to the residue and the solution was cooled to about 0° C. To this solution was added 0.31 g of 1,3-cyclohexanedione (purchased from Aldrich Chemical Co.) followed by addition of 1.0 mL of triethylamine. The mixture was stirred overnight while warming to room temperature. Saturated aqueous sodium bicarbonate was then added to the reaction mixture and the mixture was extracted with methylene chloride. The combined organic extracts were dried over MgSO4, filtered, and concentrated under reduced pressure to dryness. Chromatography of the crude product on silica gel eluting with a mixture of hexanes:ethyl acetate (8:1 and then 4:1) yielded 0.58 g of the title compound of Step B as a yellow solid melting at 120°-126° C. 1H NMR (CDCl3): δ 2.15 (m, 2H), 2.36 (s, 3H), 2.46 (t, 2H), 2.66 (t, 2H), 2.67 (s, 3H), 3.07 (m, 2H), 3.24 (br s, 2H), 3.41 (m, 2H), 6.00 (s, 1H), 7.60 (s, 1H).

Provenance & Evidence