Bromine → 1-Bromo-2,5-dimethoxy-3,4,6-trimethylbenzene

HRID 1528124Notes

Reaction equation

HRID 1528124 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[C:7]([CH3:9])[C:6]([O:10][CH3:11])=[C:5]([CH3:12])[C:4]=1[CH3:13].[Br:14]Br>C(O)(=O)C>[Br:14][C:8]1[C:7]([CH3:9])=[C:6]([O:10][CH3:11])[C:5]([CH3:12])=[C:4]([CH3:13])[C:3]=1[O:2][CH3:1]

Participants

4

Reactant 2

HCID 24408BromineHCID 109240691,4-Dimethoxy-2,3,5-trimethyl-benzene

Product 1

HCID 2973651-Bromo-2,5-dimethoxy-3,4,6-trimethylbenzeneYield 83.6%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A stirred solution of 1,4-dimethoxy-2,3,5-trimethylbenzene (61.2 g) was dissolved into 350 mL acetic acid (1.0 M) and treated with a solution of Br2 (17.7 mL, 55.1 g) in 115 mL acetic acid over 1 h. The reaction was stirred for an additional hour and poured over 1.5 l ice. The cloudy solution was filtered and the solids washed 2×200 mL H2O and dried under high vacuum. The product was azeotroped twice from toluene to remove residual acetic acid to give 73.6 g of 1-bromo-2,5-dimethoxy-3,4,6-trimethylbenzene as a red-brown solid; Mp 57.2-62.8° C.; 1H NMR (400 MHz, CDCl3) δ=3.75 (s, 3H), 3.66 (s, 3H), 2.35 (s, 3H), 2.22 (s, 3H), 2.17 (s, 3H) ppm.

Workup

  1. filtrationThe cloudy solution was filtered
  2. washthe solids washed 2×200 mL H2O
  3. customdried under high vacuum
  4. customThe product was azeotroped twice from toluene
  5. customto remove residual acetic acid

Sources & evidence

ORD record
ord-b97c4ab44b584af48d58bb49eff3d5b3
Source dataset
uspto-grants-2015_07
Patent number
US09090576B2

Reaction notes

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