Cyclohexanecarboxylic acid → 1-(2-Propen-1-yl)cyclohexanecarboxylic acid

Temperature

-20 °C

300 cm3 of dry tetrahydrofuran (THF) and 40 g of diisopropylamine redistilled over calcium hydride were introduced into a 1 liter three-necked flask fitted with a condenser closed with a calcium chloride guard tube, a low-temperature thermometer, a mechanical stirrer and a nitrogen inlet tube. The solution was cooled to -20° C. and 220 cm3 of a 1.47 M solution of butyl-lithium in hexane were added. The addition was made in the course of 1 hour; the temperature of the mixture was kept at -10° C. 25.5 g (0.2 mole) of 1-cyclohexyl-carboxylic acid, dissolved in 50 cm3 of dry THF, were then introduced in the course of 20 minutes and the temperature of the whole was then raised gradually to 50° C. and this temperature was maintained for 2 hours. The yellow solution was cooled to -70° C. 15.3 g of dry allyl chloride were added and the mixture was stirred for a further 2 hours whilst allowing the temperature to return to ambient temperature, after which the whole was left to stand for 12 hours. The solution was concentrated in vacuo and then poured into 100 cm3 of ice-cold distilled water and 100 cm3 of hexane. The aqueous phase, which had been separated off, was acidified with dilute hydrochloric acid. The 1-allyl-1-cyclohexylcarboxylic acid obtained was extracted with ether. It was purified by distillation under reduced pressure and was in the form of a colourless liquid.

1. distillation300 cm3 of dry tetrahydrofuran (THF) and 40 g of diisopropylamine redistilled over calcium hydride
2. additionwere introduced into a 1 liter three-necked flask
3. customfitted with a condenser
4. customclosed with a calcium chloride guard tube
5. addition220 cm3 of a 1.47 M solution of butyl-lithium in hexane were added
6. additionThe addition
7. customwas made in the course of 1 hour
8. customwas kept at -10° C
9. additionwere then introduced in the course of 20 minutes
10. temperaturethe temperature of the whole was then raised gradually to 50° C.
11. temperaturethis temperature was maintained for 2 hours
12. temperatureThe yellow solution was cooled to -70° C
13. customto return to ambient temperature
14. waitafter which the whole was left
15. waitto stand for 12 hours
16. concentrationThe solution was concentrated in vacuo
17. additionpoured into 100 cm3 of ice-cold
18. distillationdistilled water and 100 cm3 of hexane
19. customThe aqueous phase, which had been separated off

ORD record

ord-3adef44be15d4351bda6855493c9957c

Source dataset

uspto-grants-1981_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04283420