Ethanol → 4,4'-dibromobenzoin

HRID 1739360Notes

Reaction equation

HRID 1739360 reaction equation
[Br:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[CH:4][CH:3]=1.C(N([CH2:15][CH3:16])CC)C.[CH2:17]([OH:19])[CH3:18]>[Br-].C([N+]1C(C)=C(CCO)SC=1)C>[Br:1][C:2]1[CH:9]=[CH:8][C:5]([C:6]([CH:17]([C:18]2[CH:16]=[CH:15][C:2]([Br:1])=[CH:3][CH:4]=2)[OH:19])=[O:7])=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 702EthanolHCID 8471TriethylamineHCID 707414-Bromobenzaldehyde

Product 1

HCID 39382434,4'-dibromobenzoinYield 100%

Reagents, catalysts & solvents 1

HCID 99649233-Ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromideCatalyst

Procedure

A solution of 4-bromobenzaldehyde (25.0 g, 0.135 mol), 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide (1.70 g, 0.0068 mol) and triethylamine (4.10 g, 0.0405 mol) in ethanol (125 mL) is stirred at room temperature for 60 hours. The reaction mixture is concentrated to dryness, then taken up in CH2Cl2 (150 mL), washed with 1 M HCl and saturated aqueous NaHCO3 and dried (Na2SO4), then concentrated, giving 25.2 g (100 percent) of a viscous yellow oil which solidifies upon standing at room temperature. 1H NMR (CDCl3) δ 7.73 (d, J=8.5 Hz, 2H), δ7.52 (d, J=8.5 Hz, 2H), 7.44 (d, J=8.2 Hz, 2H), 7.17 (d, J=8.2 Hz, 2H) 13C NMR (CDCl3) δ 197.33, 137.56, 132.33, 132.13, 131.90, 130.43, 129.46, 129.31, 122.93, 75.68.

Workup

  1. concentrationThe reaction mixture is concentrated to dryness
  2. washwashed with 1 M HCl and saturated aqueous NaHCO3
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-7cf0864fef8e4d3999f77b965635226a
Source dataset
uspto-grants-1999_10
Patent number
US05965679

Reaction notes

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