2,5-Dimethylphenol → 4-Bromo-2,5-dimethylphenol

HRID 1170957Notes

Reaction equation

HRID 1170957 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][C:3]=1[OH:9].[Br-:10].[Br-].[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC>O.C(Cl)(Cl)Cl>[CH3:1][C:2]1[CH:7]=[C:6]([Br:10])[C:5]([CH3:8])=[CH:4][C:3]=1[OH:9]

Participants

5

Reactant 2

HCID 72672,5-DimethylphenolHCID 23500184Tetra-n-butylammonium tribromide

Product 1

HCID 139746574-Bromo-2,5-dimethylphenolYield 76%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent

Procedure

To a stirred suspension of 2,5-dimethyl phenol (5.0 g, 40.9 mmol) in H2O (150 mL), at room temperature was added tetrabutylammonium tribromide (19.9 g, 41.39 mmol) in CHCl3 (150 mL). The reaction mixture was stirred for 2 h at rt, the organic layer was separated and dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography on silica gel eluting with hexane-ethyl acetate (1:5) to afford 2,5-dimethyl-4-bromophenol as a brown solid (6.2 g, 76%); 1H NMR (300 MHz, DMSO-d6): δ 9.47 (s, 1 H), 7.24 (s, 1 H), 6.74 (s, 1 H), 2.21 (s, 3 H), 2.07 (s, 3 H); TLC conditions: Uniplate silica gel, 250 microns; Mobile phase=hexanes-ethyl acetate (9:1); Rf=0.52.

Workup

  1. customthe organic layer was separated
  2. dry with materialdried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified by column chromatography on silica gel eluting with hexane-ethyl acetate (1:5)

Sources & evidence

ORD record
ord-c0ad0ac1726a450d8a9f2786fe7811c4
Source dataset
uspto-grants-2010_11
Patent number
US07829552B2

Reaction notes

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