Dimethyl Sulfoxide → 4,4-Difluorocyclohexanone

Temperature

-78 °C

The inside of a reactor was sufficiently dried by vacuum heating, and the atmosphere inside the reactor was replaced with dry nitrogen. The reactor was charged with 2000 ml of dichloromethane and 128.4 ml (1.5 mol) of oxalyl chloride at −78° C. After the dropwise addition of 233 ml (3.0 mol) of DMSO, the mixture was stirred at −78° C. After 10 minutes had elapsed, a dichloromethane (300 ml) solution of 136.1 g (1.0 mol) of 4,4-difluorocyclohexanol was added dropwise to the mixture using a syringe over 10 minutes. After stirring the reaction mixture at −78° C. for 40 minutes and at −45° C. for 40 minutes, N,N-diisopropylethylamine (500 ml) was added to the reaction mixture. After stirring the mixture at 0° C. for 20 minutes, a saturated ammonium chloride aqueous solution (1000 ml) was added to the mixture to terminate the reaction. The mixture was then extracted three times with dichloromethane (3000 ml). The organic layer was washed with 1N hydrochloric acid and a saturated salt solution, and dried over magnesium sulfate. After removing anhydrous magnesium sulfate using a Buchner funnel, the solvent was evaporated. The residue was distilled under reduced pressure (30 mmHg) to obtain 4,4-difluorocyclohexanone (118.9 g (yield: 85%)).

1. customThe inside of a reactor was sufficiently dried by vacuum
2. temperatureheating
3. customover 10 minutes
4. stirringAfter stirring the reaction mixture at −78° C. for 40 minutes
5. waitat −45° C. for 40 minutes
6. stirringAfter stirring the mixture at 0° C. for 20 minutes
7. customto terminate
8. customthe reaction
9. extractionThe mixture was then extracted three times with dichloromethane (3000 ml)
10. washThe organic layer was washed with 1N hydrochloric acid
11. dry with materiala saturated salt solution, and dried over magnesium sulfate
12. customAfter removing anhydrous magnesium sulfate using a Buchner funnel
13. customthe solvent was evaporated
14. distillationThe residue was distilled under reduced pressure (30 mmHg)

ORD record

ord-8ddd63eebbf7424ca041fd36b7b79925

Source dataset

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08535871B2