反应详情

To a stirred solution of 4-cyclohexyl-3-(trifluoromethyl)benzoic acid (Preparation 118B, 0.5 g, 1.836 mmol) in dichloromethane (2 mL) and MeOH (2 mL) was added 2M diethyl ether solution of TMS-diazomethane (1.836 mL, 3.67 mmol) dropwise at 0° C. till no gas evolved. The mixture was stirred at room temperature for 1 hr before AcOH (0.210 mL, 3.67 mmol) was added at 0° C. to quench the reaction. The mixture was concentrated. To the residue was added saturated aqueous sodium bicarbonate solution (5 mL) and extracted with dichloromethane (3×3 mL). The combined dichloromethane extracts were dried (sodium sulfate) and concentrated under reduced pressure to give a liquid. Flash chromatography purification (silica gel column, 10→40% dichloromethane in n-heptane) afforded methyl 4-cyclohexyl-3-(trifluoromethyl)benzoate (0.5 g, 1.746 mmol, 95% yield) as a colorless liquid. The compound had an HPLC retention time=4.03 min. (condition C); LC/MS M+1=287.2.

1. additionwas added at 0° C.
2. customto quench
3. customthe reaction
4. concentrationThe mixture was concentrated
5. additionTo the residue was added saturated aqueous sodium bicarbonate solution (5 mL)
6. extractionextracted with dichloromethane (3×3 mL)
7. dry with materialThe combined dichloromethane extracts were dried (sodium sulfate)
8. concentrationconcentrated under reduced pressure
9. customto give a liquid
10. customFlash chromatography purification (silica gel column, 10→40% dichloromethane in n-heptane)