2,2-Dimethoxypropane → Ethanone, 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-

HRID 369359Notes

Reaction equation

HRID 369359 reaction equation
[Br:1][CH2:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]([OH:11])=[C:7]([CH2:12][OH:13])[CH:6]=1)=[O:4].O.[C:15]1(C)[CH:20]=CC(S(O)(=O)=O)=C[CH:16]=1.COC(OC)(C)C.C(=O)(O)[O-].[Na+]>CC(C)=O>[Br:1][CH2:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]2[O:11][C:15]([CH3:20])([CH3:16])[O:13][CH2:12][C:7]=2[CH:6]=1)=[O:4]

Participants

6

Reactant 4

HCID 64952,2-DimethoxypropaneHCID 516892Sodium BicarbonateHCID 521998p-Toluenesulfonic acid monohydrateHCID 113340552-Bromo-1-(4-hydroxy-3-(hydroxymethyl)phenyl)ethan-1-one

Product 1

HCID 11150315Ethanone, 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-Yield 6,402.1%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

2-Bromo-4'-hydroxy-3'-hydroxymethylacetophenone (17.7 g), p-toluenesulfonic acid monohydrate (124 mg) and acetone dimethyl acetal (256 ml) were dissolved in acetone (256 ml), and the solution was heated under reflux for 30 minutes. After cooling, a saturated aqueous sodium bicarbonate solution was added to the reaction mixture, and the resulting mixture was extracted with ethyl acetate. The extract was washed with water and brine, and dried over anhydrous magnesium sulfate, then the solvent was removed in vacuo. Purification of the residue by medium pressure liquid column chromatography on silica gel (eluent: hexane/ethyl acetate=7/1) gave 2-bromo-1-(2,2-dimethylbenzo[1,2-d]-1,3-dioxan-6-yl)-1-ethanone (11.9 g) having a melting point of 52-54° C.

Workup

  1. temperaturethe solution was heated
  2. temperatureunder reflux for 30 minutes
  3. temperatureAfter cooling
  4. extractionthe resulting mixture was extracted with ethyl acetate
  5. washThe extract was washed with water and brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. customthe solvent was removed in vacuo
  8. customPurification of the residue by medium pressure liquid column chromatography on silica gel (eluent: hexane/ethyl acetate=7/1)

Sources & evidence

ORD record
ord-03727dccfb3b4a319e6c94680c47cce2
Source dataset
uspto-grants-2000_10
Patent number
US06136852

Reaction notes

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