Reaction #40765

Reaction equation

cyclohexanone

formaldehyde

dimethylamine hydrochloride

→

light-yellow liquid

2-Dimethylaminomethyl-cyclohexanone

Solvents

H2O

Conditions

Workup

1. 1
   TemperatureThe stirred mixture was slowly heated
2. 2
   Temperaturerefluxed for 1 h
3. 3
   workup.ADDITIONwas added
4. 4
   Extractionthe mixture was extracted twice with Et2O
5. 5
   workup.ADDITIONThe aqueous layer was made basic by addition of 50% aqueous NaOH (27.5 mL)
6. 6
   Extractionsubsequently extracted twice with DCM
7. 7
   DryingThe combined organic phases were dried over Na2SO4
8. 8
   Otherevaporated under reduced pressure

Procedure

To cyclohexanone (259 mL) was added formaldehyde (37.2 mL of a 37% aqueous solution) and dimethylamine hydrochloride (40.8 g). The stirred mixture was slowly heated and refluxed for 1 h. After cooling to ambient temperature H2O was added, and the mixture was extracted twice with Et2O. The aqueous layer was made basic by addition of 50% aqueous NaOH (27.5 mL), and subsequently extracted twice with DCM. The combined organic phases were dried over Na2SO4 and evaporated under reduced pressure to give 66.6 g of a light-yellow liquid. 1H NMR (400 MHz, CDCl3) δ 1.34-1.47 (m, 1H), 1.60-1.78 (m, 2H), 1.81-1.92 (m, 1H), 1.98-2.09 (m, 1H), 2.16-2.55 (m, 5H), 2.21 (s, 6H), 2.69 (dd, J=13 and 6 Hz, 1H).

Source