反应详情

The (E)-trans-4-(2-(trans-4-pentylcyclohexyl)vinyl)cyclohexanecarboxylic acid, which was prepared by the same manner as in the first step of Example 1 with the exception that ethyl trans-4-formylcyclohexanecarboxylate was used in place of 4-cyanobenzaldehyde, in an amount of 1.1 g (3.6 mmol) was mixed with 0.8 g (3.9 mmol) of 3-fluoro-4-trifluromethoxyphenol, 0.1 g (1.1 mmol) of DMAP, and 20 ml of dichloromethane. To this mixture was added dropwise 4 ml of solution of 1.0 g (4.7 mmol) of DCC in dichloromethane while being cooled with ice in 5 min, and stirred as it was for 12 hours. Separated crystals were filtered off, 70 ml of toluene was added to the filtrate, and the filtrate was washed with 2N-NaOH five times and with water thrice, and then dried over anhydrous magnesium sulfate. The solvent was distilled off under a reduced pressure. The residue thus obtained was subjected to silica gel column chromatography (eluent:toluene) to obtain 1.7 g of a crude (E)-3-fluoro-4-trifluoromethoxyphenyl trans-4-(2-(trans-4-pentylcyclohexyl)vinyl)cyclohexanecarboxylate. This crude product was recrystallized from a mixed solvent of heptane/diethyl ether to obtain 0.7 g of the subjective compound (yield 38.7%).

1. temperaturewhile being cooled with ice in 5 min
2. customSeparated crystals
3. filtrationwere filtered off
4. addition70 ml of toluene was added to the filtrate
5. washthe filtrate was washed with 2N-NaOH five times and with water thrice
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationThe solvent was distilled off under a reduced pressure
8. customThe residue thus obtained