Acetone → 6-bromo-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

HRID 1978619Notes

Reaction equation

HRID 1978619 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[C:8]([Br:10])[CH:7]=[CH:6][C:5]=1[OH:11])=[O:3].[CH3:12][C:13]([CH3:15])=O.N1CCCC1.Cl>C1(C)C=CC=CC=1>[Br:10][C:8]1[CH:7]=[CH:6][C:5]2[O:11][C:13]([CH3:15])([CH3:12])[CH2:1][C:2](=[O:3])[C:4]=2[CH:9]=1

Participants

6

Reactant 4

HCID 180Acetone2×HCID 313Hydrochloric AcidHCID 31268PyrrolidineHCID 959915'-Bromo-2'-hydroxyacetophenone

Product 1

HCID 147553646-bromo-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 5-bromo-2-hydroxyacetophenone 10.0 g (46.5 milli mole), acetone (17 ml) and pyrrolidine (3.9 ml) in toluene (100 ml) was refluxed for 4 hours. To the mixture was added acetone (17 ml), and the mixture was refluxed for 15 hours. To the mixture was added 1N hydrochloric acid (100 ml), and the mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated brined, dried with magnesium sulfate and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (ethyl acetate/hexane=1:7) to give yellow oil of 6-bromo-2,2-dimethyl-2,3-dihydro-4H-1-benzopyran-4-one (7.57 g).

Workup

  1. temperaturethe mixture was refluxed for 15 hours
  2. extractionthe mixture was extracted with ethyl acetate
  3. washThe organic layer was washed with water
  4. dry with materialdried with magnesium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was purified with silica gel column chromatography (ethyl acetate/hexane=1:7)

Sources & evidence

ORD record
ord-1dd2314828ba4ae38b0481e96a89d6ad
Source dataset
uspto-grants-2001_05
Patent number
US06235771B1

Reaction notes

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