Methyl iodide → (+/-)-4-Dimethylamino-2-methyl-4-phenylcyclohexanone

Temperature

-78 °C

Diisopropylamine (2.1 ml, 15 mmol) was provided in dry THF in argon and mixed with n-butyl lithium in hexane (2.5M, 6 ml, 15 mmol) at 30° C. The reaction mixture was cooled to −78° C. 4-(dimethylamino)-4-phenylcyclohexanone (2.17 g, 10 mmol), dissolved in 10 ml of dry THF, was added in drops to this solution within 10 min. The batch was stirred for 30 min at −78° C. and then mixed with methyl iodide (1.86 ml, 30 mmol). It was heated to RT and stirred for a further 18 h. The solvent was removed at the rotary evaporator and the residue taken up in DCM. Extraction was conducted with 1N HCl (3×30 ml). The aqueous phase was basified with 5N NaOH (20 ml) and extracted with DCM (3×30 ml). The combined organic phases were washed with H2O (2×10 ml) and dried over Na2SO4. The semisolid residue (1.2 g) obtained after removal of the solvent was recrystallised from ethyl acetate (1 ml).

1. additionwas added in drops to this solution within 10 min
2. temperatureIt was heated to RT
3. stirringstirred for a further 18 h
4. customThe solvent was removed at the rotary evaporator
5. extractionExtraction
6. extractionextracted with DCM (3×30 ml)
7. washThe combined organic phases were washed with H2O (2×10 ml)
8. dry with materialdried over Na2SO4

ORD record

ord-0d735cbbb9c2411a9a3f0da231d40022

Source dataset

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08293758B2