Benzyl Bromide → 1-Benzylazepan-2-one

HRID 988795Notes

Reaction equation

HRID 988795 reaction equation
[H-].[Na+].[NH:3]1[CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][C:4]1=[O:10].[CH2:11](Br)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>C1COCC1>[CH2:11]([N:3]1[CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][C:4]1=[O:10])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

5

Procedure

To a stirring 0° C. suspension of NaH (18.3 g, 763 mmol) in THF (195 mL) was added by addition funnel azepan-2-one (75.0 g, 667 mmol) in THF. An additional 2 L of solvent was added as the reaction progressed in order to maintain agitation of the very viscous reaction suspension. Following addition, the reaction was allowed to warm to room temperature, and when the evolution of H2 ceased after stirring overnight, benzyl bromide was added dropwise by addition funnel and the reaction was stirred overnight. The crude product was filtered through Celite and concentrated in vacuo. Recrystallization from hexanes and ethyl acetate provided pure 1-benzyl-azepan-2-one (142) as a white fluffy solid. 1H NMR (CDCl3) 7.38-7.24 (5H, m), 4.61 (2H, s), 3.33-3.29 (2H, m), 2.65-2.61 (2H, m), 1.77-1.66 (4H, m), 1.56-1.46 (2H, m) ppm. 13C NMR (CDCl3, 75 MHz) 176.13, 138.06, 128.67, 128.31, 127.43, 51.20, 49.04, 37.33, 30.12, 28.26, 23.58 ppm.

Workup

  1. temperatureto maintain agitation of the very viscous reaction suspension
  2. additionaddition
  3. stirringthe reaction was stirred overnight
  4. filtrationThe crude product was filtered through Celite
  5. concentrationconcentrated in vacuo
  6. customRecrystallization from hexanes and ethyl acetate provided pure 1-benzyl-azepan-2-one (142) as a white fluffy solid

Sources & evidence

ORD record
ord-3b86390c531f4465a28de735ef760cf5
Source dataset
uspto-grants-2003_10
Patent number
US06635661B2

Reaction notes

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