3,4-Dimethylphenol → 2-Bromo-4,5-dimethylphenol

HRID 1482026Notes

Reaction equation

HRID 1482026 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([OH:9])[CH:5]=[CH:6][C:7]=1[CH3:8].CC(O)C.C(=O)=O.[Br:17]Br.[O-]S([O-])=O.[Na+].[Na+]>C(Cl)Cl>[Br:17][C:5]1[CH:6]=[C:7]([CH3:8])[C:2]([CH3:1])=[CH:3][C:4]=1[OH:9]

Participants

6

Reactant 4

HCID 72493,4-DimethylphenolHCID 24408BromineHCID 24437Sodium SulfiteHCID 86586944Isopropanol carbon dioxide

Product 1

HCID 1409612-Bromo-4,5-dimethylphenolYield 100.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 3,4-dimethylphenol (2.48 g, 20.3 mmol, 1 equiv) in DCM (200 mL) at −78° C. (IPA/dry ice) was added dropwise bromine (1.05 mL, 20.3 mmol, 1 equiv). After 1 h, 1 N Na2SO3 was added and the cold bath was removed. After warming to ambient temperature, the DCM layer was separated, dried (Na2SO4), and concentrated in vacuo to provide the product (4.09 g, 100%) as a yellow solid. Regioselectivity>10:1, use as is. 1H NMR (400 MHz, CDCl3) δ 7.21 (s, 1H), 6.83 (s, 1H), 5.26 (s, 1H), 2.20 (s, 3H), 2.18 (s, 3H).

Workup

  1. customthe cold bath was removed
  2. customthe DCM layer was separated
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d588833ae2e440f2b31daa8307482aa8
Source dataset
uspto-grants-2016_08
Patent number
US09409922B2

Reaction notes

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