Aminoacetaldehyde dimethyl acetal → 5-Bromo-2-fluorobenzylidene-2,2-dimethoxyethylamine

HRID 272777Notes

Reaction equation

HRID 272777 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:10])=[C:6]([CH:9]=1)[CH:7]=O.[CH3:11][O:12][CH:13]([O:16][CH3:17])[CH2:14][NH2:15]>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:10])=[C:6]([CH:9]=1)[CH:7]=[N:15][CH2:14][CH:13]([O:16][CH3:17])[O:12][CH3:11]

Participants

4

Reactant 2

HCID 89728Aminoacetaldehyde dimethyl acetalHCID 7363275-Bromo-2-fluorobenzaldehyde

Product 1

HCID 692158965-Bromo-2-fluorobenzylidene-2,2-dimethoxyethylamine

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 5-bromo-2-fluorobenzaldehyde (15 g, 74 mmol) and 2,2-dimethoxy-ethylamine (7.77 g, 74 mmol) in toluene (142 mL) was heated to reflux for 30 minutes using a Dean-Stark trap to remove water. The solution was then concentrated under vacuum to provide 5-bromo-2-fluorobenzylidene-2,2-dimethoxyethylamine. 5-Bromo-2-fluorobenzylidene-2,2-dimethoxyethylamine and cold concentrated sulfuric acid (28 mL) were added separately, dropwise, over a period of 20 minutes to concentrated sulfuric acid (83 mL) at 140° C. The mixture was stirred at 135° C. for 30 minutes, allowed to cool, and carefully poured onto ice. Filtered to remove solids and the mixture was washed with dichloromethane. The aqueous layer was made basic by cautious addition of 50% sodium hydroxide solution, and extracted with diethyl ether. Combined ether layers were dried (MgSO4), filtered and concentrated under vacuum to provide 310 mg (2%) of the desired product. MS (ESI) m/e 226 (M+H)+.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 30 minutes
  3. customto remove water
  4. concentrationThe solution was then concentrated under vacuum

Sources & evidence

ORD record
ord-ea9e706d576e4638bc718a6c87ecf8c6
Source dataset
uspto-grants-2008_11
Patent number
US07456169B2

Reaction notes

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