3-Methyl-but-2-enoic acid 4-bromo-phenyl ester → 2H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-

HRID 1608935Notes

Reaction equation

HRID 1608935 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[CH3:5][C:6]([CH3:18])=[CH:7][C:8]([O:10][C:11]1[CH:16]=[CH:15][C:14]([Br:17])=[CH:13][CH:12]=1)=[O:9]>C(Cl)Cl>[CH3:5][C:6]1([CH3:18])[C:12]2[C:11](=[CH:16][CH:15]=[C:14]([Br:17])[CH:13]=2)[O:10][C:8](=[O:9])[CH2:7]1

Participants

4

Reactant 2

HCID 7337973-Methyl-but-2-enoic acid 4-bromo-phenyl esterHCID 6451240Aluminum(III) Chloride

Product 1

HCID 225689232H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred, ice cooled suspension of 11.5 g (86.3 mmol) of aluminum chloride in 200 ml of methylene chloride was added a solution of 11.0 g (43.1 mmol) of (4-bromophenyl) 3,3-dimethyl-acrylate in 100 ml of methylene chloride. The mixture was then stirred at room temperature for 20 hours and then poured into ice/brine mixture. The mixture was extracted with methylene chloride and the combined orgainc extracts were washed with water, brine and dried (MgSO4). The solvent was removed in-vacuo and the resulting residue purified using flash chromatography (SiO2 ; 4% ethyl acetate in hexanes) to give the title compound as a yellow oil.

Workup

  1. temperatureTo a stirred, ice cooled
  2. extractionThe mixture was extracted with methylene chloride
  3. washthe combined orgainc extracts were washed with water, brine
  4. dry with materialdried (MgSO4)
  5. customThe solvent was removed in-vacuo
  6. customthe resulting residue purified

Sources & evidence

ORD record
ord-dbacf84528094e8eaea9bbd63fe943ff
Source dataset
uspto-grants-1995_03
Patent number
US05399561

Reaction notes

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