Ethylene Glycol → 2-[(4-bromophenyl)methyl]-1,3-dioxolane

HRID 332671Notes

Reaction equation

HRID 332671 reaction equation
[Br:1][C:2]1[CH:10]=[CH:9][C:5]([CH2:6][CH2:7][OH:8])=[CH:4][CH:3]=1.[CH3:11][C:12](OI1(OC(C)=O)(OC(C)=O)OC(=O)C2C=CC=CC1=2)=[O:13].C(O)CO>C(Cl)Cl.C1(C)C=CC=CC=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Br:1][C:2]1[CH:10]=[CH:9][C:5]([CH2:6][CH:7]2[O:13][CH2:12][CH2:11][O:8]2)=[CH:4][CH:3]=1

Participants

7

Reactant 3

HCID 174Ethylene GlycolHCID 728512-(4-Bromophenyl)ethanolHCID 159087Triacetoxyperiodinane

Product 1

HCID 27569562-[(4-bromophenyl)methyl]-1,3-dioxolaneYield 49%

Reagents, catalysts & solvents 3

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Procedure

To a cooled (0° C.) solution of 4-bromophenethylalcohol (3.9 g, 19.4 mmol) in DCM (50 mL), was added the Dess-Martin reagent (8.22 g, 19.4 mmol). After 10 minutes, the coolant was removed, and the reaction mixture was stirred at ambient temperature for 2 hours. The reaction mixture was quenched with 10% aqueous potassium carbonate, and the mixture was separated. The aqueous phase was extracted with further DCM (×2), and the combined organic phases were dried with anhydrous magnesium sulphate, and the solvent evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 50% ethyl acetate in iso-hexane to afford a oil. The oil was dissolved in toluene (35 mL), para-toluenesulfonic acid—monohydrate (0.1 g, 0.52 mmol) and ethylene glycol (5.3 mL, 94.2 mmol) was added, and the mixture heated at reflux under Dean and Stark conditions for 2 hours. The solvent was evaporated at reduced pressure and the residue dissolved in ethyl acetate. The solution was washed with 10% aqueous potassium carbonate, dried with anhydrous magnesium sulfate, and the solvent evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 50% ethyl acetate in iso-hexane to afford an oil (2.3 g, 49%).

Workup

  1. customthe coolant was removed
  2. customThe reaction mixture was quenched with 10% aqueous potassium carbonate
  3. customthe mixture was separated
  4. extractionThe aqueous phase was extracted with further DCM (×2)
  5. dry with materialthe combined organic phases were dried with anhydrous magnesium sulphate
  6. customthe solvent evaporated at reduced pressure
  7. customThe crude material was purified by silica gel chromatography
  8. washeluting with 100% iso-hexane to 50% ethyl acetate in iso-hexane
  9. customto afford a oil
  10. temperaturethe mixture heated
  11. temperatureat reflux under Dean and Stark conditions for 2 hours
  12. customThe solvent was evaporated at reduced pressure
  13. dissolutionthe residue dissolved in ethyl acetate
  14. washThe solution was washed with 10% aqueous potassium carbonate
  15. dry with materialdried with anhydrous magnesium sulfate
  16. customthe solvent evaporated at reduced pressure
  17. customThe crude material was purified by silica gel chromatography
  18. washeluting with 100% iso-hexane to 50% ethyl acetate in iso-hexane

Sources & evidence

ORD record
ord-3f5e3b8403c240768de8ddb0149bb833
Source dataset
uspto-grants-2014_11
Patent number
US08877774B2

Reaction notes

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