Carbon tetrabromide → 3,4-Dimethoxyphenethyl bromide

HRID 2396125Notes

Reaction equation

HRID 2396125 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[CH2:6][CH2:7]O.C(Br)(Br)(Br)[Br:15].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[Br:15][CH2:7][CH2:6][C:5]1[CH:9]=[CH:10][C:11]([O:12][CH3:13])=[C:3]([O:2][CH3:1])[CH:4]=1

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 819113,4-Dimethoxyphenethyl alcohol

Product 1

HCID 114706023,4-Dimethoxyphenethyl bromide

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Part A. A solution of 3,4-dimethoxyphenethyl alcohol (7.30 g, 40.1 mmol) and carbon tetrabromide (17.3 g, 52.1 mmol) in methylene chloride (100 mL)was cooled to 0° C., and a solution of triphenylphosphine (13.7 g, 52.1 mmol) in methylene chloride (50 mL) was added dropwise with stirring.After 20 hours, the reaction mixture was evaporated, and separated by flashchromatography (1:9 ethyl acetate-hexane) to afford the product, 1-(2-bromoethyl)-3,4-dimethoxybenzene, as a waxy solid, mp 72°-73° C. (9.48 g, 38.7 mmol, 96%). 1H NMR (CDCl3): δ 6.82 (1H, d, J=8.1 Hz); 6.75 (1H, dd, J=8.1, 1.8 Hz); 6.73 (1H, d, J=1.8 Hz); 3.88 (3H, s); 3.87 (3H, s); 3.55 (2H, t, J=7.7 Hz); 3.11 (2H, t, J=7.7 Hz). Mass spectrum (NH3 -CI/DDIP): m/z 264 (93%); 262 (100%); 245 (9%); 165 (6%).

Workup

  1. customthe reaction mixture was evaporated
  2. customseparated by flashchromatography (1:9 ethyl acetate-hexane)

Sources & evidence

ORD record
ord-12862aa0906d44b193a0ec4048b311fc
Source dataset
uspto-grants-1996_02
Patent number
US05491152

Reaction notes

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