反应详情

温度

-78 °C

To a solution of 4-bromobenzoic acid (3.00 g, 14.9 mmol) in tetrahydrofuran (54 mL) at −78° C. was added n-butyllithium (19.1 mL of 1.6 M in hexanes, 30.6 mmol) dropwise while maintaining the internal temperature below −65° C. The mixture was stirred at −78° C. for 30 min. Cyclohexanone (1.55 mL, 14.9 mmol) was added dropwise while maintaining the reaction temperature below −65° C. The mixture was stirred at −78° C. for 10 min then allowed to warm to room temperature and stirred for 2 h. The reaction mixture was quenched with saturated NH4Cl (50 mL) and 1N HCl (25 mL). The mixture was extracted with ethyl acetate (3×100 mL). The combined organics were dried over Na2SO4, filtered and concentrated in vacuo. The residue was stirred with 1:1 dichloromethane/hexane (20 mL) to provide a white solid, which was filtered and discarded. The filtrate was concentrated in vacuo and purified by silica gel chromatography (0-5% methanol/dichloromethane) to provide an off-white solid. The solid was stirred with hexane, filtered, and dried to provide 4-(1-hydroxycyclohexyl)benzoic acid (375 mg, 11%). ESI-MS m/z calc. 220.1. found 221.3 (M+1)+; Retention time: 1.18 minutes (3 min run). 1H NMR (400 MHz, DMSO-d6) δ 12.77 (s, 1H), 7.88 (d, J=8.3 Hz, 2H), 7.60 (d, J=8.5 Hz, 2H), 4.84 (s, 1H), 1.81-1.46 (m, 9H), 1.35-1.17 (m, 1H).

1. temperaturewhile maintaining the internal temperature below −65° C
2. temperaturewhile maintaining the reaction temperature below −65° C
3. stirringThe mixture was stirred at −78° C. for 10 min
4. temperatureto warm to room temperature
5. stirringstirred for 2 h
6. customThe reaction mixture was quenched with saturated NH4Cl (50 mL) and 1N HCl (25 mL)
7. extractionThe mixture was extracted with ethyl acetate (3×100 mL)
8. dry with materialThe combined organics were dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. stirringThe residue was stirred with 1:1 dichloromethane/hexane (20 mL)
12. customto provide a white solid, which
13. filtrationwas filtered
14. concentrationThe filtrate was concentrated in vacuo
15. custompurified by silica gel chromatography (0-5% methanol/dichloromethane)
16. customto provide an off-white solid
17. filtrationfiltered
18. customdried