Hydrochloric Acid → 1-(2-Ethyl-butyl)-cyclohexanecarboxylic acid

A suspension of 60% sodium hydride (980 mg) in tetrahydrofuran (80 ml) was stirred at room temperature and a tetrahydrofuran solution (10 ml) containing cyclohexanecarboxylic acid (3.00 g) was added dropwise thereto. After completion of addition, a mixture was stirred for 1 hour and cooled to 0° C., followed by adding a cyclohexane solution (18.7 ml) containing 1.5 M lithium isopropylamide dropwise thereto. Then, after stirring at room temperature for 1.5 hours and cooling to 0° C., a tetrahydrofuran solution (10 ml) containing 1-bromo-2-ethylbutane (4.64 g) was added dropwise thereto. The solution was gradually warmed to room temperature and stirred overnight. Water and a 10% hydrochloride solution were added to this reaction solution and the solution was extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. After drying, the resulting solution was concentrated to obtain 1-(2-ethylbutyl)cyclohexanecarboxylic acid (3.17 g, yield: 64%).

1. additionwas added dropwise
2. additionAfter completion of addition
3. stirringa mixture was stirred for 1 hour
4. temperaturecooled to 0° C.
5. stirringThen, after stirring at room temperature for 1.5 hours
6. temperaturecooling to 0° C.
7. additionwas added dropwise
8. temperatureThe solution was gradually warmed to room temperature
9. stirringstirred overnight
10. extractionthe solution was extracted with ethyl acetate
11. washThe organic layer was washed with saturated brine
12. dry with materialdried over anhydrous sodium sulfate
13. customAfter drying
14. concentrationthe resulting solution was concentrated

ORD record

ord-ce1d467411124cf3b5a5d1ccaa53df3b

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06753346B2