反应详情

To a cold (-76° C. dry ice, isopropanol bath) solution of (2-benzyl-benzofuran-3-yl)-(2,4-dimethoxy-phenyl)-methanone (6.13 g, 16.5 mmol) in anhydrous methylene chloride (60 mL) was added a 1 M solution of boron tribromide in methylene chloride (100 mL, 100 mmol, 6.06 eq) dropwise over a period of 20 minutes under a dry nitrogen atmosphere. The dry ice bath was removed and the reaction mixture was stirred at ambient temperature for 45 hours. After cooling in an ice bath water was carefully added and after quenching the reaction mixture was further diluted with water (300 mL). The organics were extracted with diethyl ether and methylene chloride. The extracts were combined, washed with water and brine, and combined with silica gel. The solvents were removed and the adsorbate was flash chromatographed (80/20 petroleum ether/ethyl acetate) to provide the title compound as a white solid (2.07 g, 38%): mp 201 -202° C.; NMR (CDCl3); δ8.03 (ddd, J=8, 7, 1 1 H), 8.01 (s, 1 H), 7.82 - 7.79 (m, 1 H), 7.58 - 7.54 (m, 2 H), 7.48 - 7.43 (m, 2 H), 7.20 (d, J=8 Hz, 1 H), 7.18 - 7.15 (m, 2 H), 6.70 (m, 2 H), 5.00 (s, 1 H), 4.70 (s, 1 H); Hi Res MS, Calc. Sample Mass for C22H14O3, 326.0942951, Measured Mass 326.09019, mas deviation 4 mmu. Anal. Calc. for C22H14O3: C, 80.97, H, 4.32, N, 0.00. Found: C, 79.80, H, 4.10, N, 0.07.

1. customThe dry ice bath was removed
2. temperatureAfter cooling in an ice bath water
3. additionwas carefully added
4. customafter quenching the reaction mixture
5. additionwas further diluted with water (300 mL)
6. extractionThe organics were extracted with diethyl ether and methylene chloride
7. washwashed with water and brine
8. customThe solvents were removed
9. customchromatographed (80/20 petroleum ether/ethyl acetate)