反应详情

温度

-78 °C

To 3,4-difluoro-1,2-dibromo-benzene (0.75 g, 2.78 mmol) and furan (1 mL, 14.7 mmol) in Et2O (15 mL) at −78° C. was added BuLi (1.1 mL, 2.5M in hexanes, 2.75 mmol) dropwise. The reaction was stirred for two hours at −78° C. and then was allowed to warm to room temperature. After 2 hours, the reaction mixture was quenched with water dropwise and then was poured into water. The organic layer was separated and the aqueous layer was extracted three times with Et2O. The combined organic layers were washed with brine, dried over MgSO4, concentrated and chromatographed (25% ethyl acetate:hexanes) on silica gel to give 24 (350 mg, 70%) as a colourless oil. Rf=0.21 on silica gel (20% ethyl acetate:hexanes); bp 40° C. @ 0.5 mmHg]; IR (neat, cm−1), 3017 (M), 1624 (s), 1465 (s), 1365 (s), 1253 (s), 1190 (m), 1040 (s), 857 (s). 1H NMR (400Mz, CDCl3) δ 7.06 (2H, dd, JH-F=7.7, 7.7 Hz), 7.01 (2H, s), 5.67 (2H, s); 13C NMR (400 MHz, CDCl3) δ 147.2 (dd, JC-F=247.9, 14.5 Hz), 145.1 (dd, JC-F=4.3, 4.3 Hz), 143.1, 110.8 (m), 82.1.HRMS calcd for C10H6O (M+): 180.0387. Found: 180.0394.

1. temperatureto warm to room temperature
2. waitAfter 2 hours
3. customthe reaction mixture was quenched with water dropwise
4. additionwas poured into water
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted three times with Et2O
7. washThe combined organic layers were washed with brine
8. dry with materialdried over MgSO4
9. concentrationconcentrated
10. customchromatographed (25% ethyl acetate:hexanes) on silica gel