Trifluoroacetic acid → 1-Bromomethyl-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepin

HRID 223229Notes

Reaction equation

HRID 223229 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH2:11][CH2:12][CH2:13][OH:14])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].C(O[CH:18](OCC)[CH2:19][Br:20])C.FC(F)(F)C(O)=O>[N+](C)([O-])=O>[CH3:1][O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][C:6]2[CH:18]([CH2:19][Br:20])[O:14][CH2:13][CH2:12][CH2:11][C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 74852Ethane, 2-bromo-1,1-diethoxy-HCID 775283-(3',4'-Dimethoxyphenyl)-1-propanol

Product 1

HCID 126693281-Bromomethyl-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepin

Reagents, catalysts & solvents 1

HCID 6375NitromethaneSolvent

Procedure

A solution of 5.00 g. of 3-(3,4-dimethoxyphenyl)-1-propanol, 9.76 ml of bromoacetaldehyde diethyl acetal, 2.0 ml of trifluoroacetic acid, and 125 ml of nitromethane is heated at 65° under a nitrogen atmosphere for 2 hours. After cooling, the reaction mixture is extracted with methylene chloride and aqueous sodium bicarbonate. The organic layer is taken to dryness in vacuo and the residue is chromatographed first with 100% CH2Cl2 and a second time with 10% ethyl acetate:SSB to give 300 g of 7,8-dimethoxy-1-bromomethyl-1,3,4,5-tetrahydro-2-benzoxepin, m.p., 44°-45°.

Workup

  1. temperatureAfter cooling
  2. extractionthe reaction mixture is extracted with methylene chloride and aqueous sodium bicarbonate
  3. customthe residue is chromatographed first with 100% CH2Cl2

Sources & evidence

ORD record
ord-4900289832124373b07d33a01bfd37eb
Source dataset
uspto-grants-1982_10
Patent number
US04352805

Reaction notes

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