反应详情

温度

-10 °C

0.515 ml Diisopropyl-aethylamine, 0.674 g (3.00 mmol) 4-trifluoromethylphenyl chloroformate [Org. Lett. (2000), 2(8), 1049-1051] and 0.828 mg potassium carbonate (dissolved in the minimal amount of water) were added to a suspension of 0.625 g (2.00 mmol) trans-[4-(5-bromo-pentyl)-cyclohexylmethyl]-methyl-amine hydrochloride in 20.0 ml of tetrahydrofuran kept at −10° C. The reaction mixture was then intensively stirred for 1 hour at −10° C. and for 3 hour at room temperature. 0.200 g 4-trifluoromethylphenyl chloroformate were added and stirring at room temperature continued for additional 2 hours. The reaction mixture was subsequently acidified with dilute hydrogen chloride solution. It was then evaporated, poured into 50 ml of an ice/water mixture and extracted 3 times with 50 ml of dichloromethane. The combined dichloromethane phases were dried over magnesium sulfate and evaporated under reduced pressure. The residue formed was chromatographed on silica gel with a 1:1 v/v mixture of hexane and dichloromethane as the eluent giving 0.90 g (96.9%) trans-[4-(5-bromo-pentyl)-cyclohexylmethyl]-methyl-carbamic acid 4-trifluoromethyl-phenyl ester as colorless viscous oil, MS: 464 (MH+, 1Br).

1. customkept at −10° C
2. stirringstirring at room temperature
3. waitcontinued for additional 2 hours
4. customIt was then evaporated
5. additionpoured into 50 ml of an ice/water mixture
6. extractionextracted 3 times with 50 ml of dichloromethane
7. dry with materialThe combined dichloromethane phases were dried over magnesium sulfate
8. customevaporated under reduced pressure
9. customThe residue formed
10. customwas chromatographed on silica gel with a 1:1 v/v mixture of hexane and dichloromethane as the eluent