Ethylene Glycol → 2-(5-Bromo-2,4-dimethoxyphenyl)-1,3-dioxolane

HRID 10662Notes

Reaction equation

HRID 10662 reaction equation
[Br:1][C:2]1[C:3]([O:12][CH3:13])=[CH:4][C:5]([O:10][CH3:11])=[C:6]([CH:9]=1)[CH:7]=[O:8].[CH2:14](O)[CH2:15][OH:16]>C1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Br:1][C:2]1[C:3]([O:12][CH3:13])=[CH:4][C:5]([O:10][CH3:11])=[C:6]([CH:7]2[O:16][CH2:15][CH2:14][O:8]2)[CH:9]=1

Participants

5

Reactant 2

HCID 174Ethylene GlycolHCID 6683465-Bromo-2,4-dimethoxybenzaldehyde

Product 1

HCID 161160542-(5-Bromo-2,4-dimethoxyphenyl)-1,3-dioxolaneYield 92%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 241BenzeneSolvent

Procedure

Ex-46A: 5-Bromo-2,4-dimethoxybenzaldehyde (4.92 g, 20.1 mmol) was dissolved in benzene (41 mL). Ethylene glycol (3 mL, 54 mmol) and p-toluenesulfonic acid (25 mg, 0.13 mmol) were added and the solution was refluxed with a Dean-Stark trap attached. After 6 h, the reaction was cooled and washed with water (1×20 mL), saturated, aqueous NaHCO3 (1×20 mL), and water (1×20 mL). The organic phase was dried over sodium sulfate, filtered, concentrated, and dried to provide 5.32 g of 2-(5-bromo-2,4-dimethoxy-phenyl)-[1,3]dioxolane as a faint yellow oil which solidified upon standing (92% yield). 1H-NMR (CDCl3) δ 7.67 (s, 1H), 6.47 (s, 1H), 6.06 (s, 1H), 4.11–4.13 (m, 2H), 3.98–4.03 (m, 2H), 3.91 (s, 3H), 3.87 (s, 3H). HRMS (ES+) Calcd. for C11H13BrO4: 289.0075. Found: 289.0077.

Workup

  1. temperaturethe solution was refluxed with a Dean-Stark trap
  2. temperaturethe reaction was cooled
  3. washwashed with water (1×20 mL)
  4. dry with materialThe organic phase was dried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customdried

Sources & evidence

ORD record
ord-6e624bf1f72147079f9c2ca4a68268e2
Source dataset
uspto-grants-2006_08
Patent number
US07094801B2

Reaction notes

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