Boron tribromide → 4H-1-Benzopyran-4-one, 3-(2,4-dihydroxyphenyl)-7-hydroxy-

HRID 1357062Notes

Reaction equation

HRID 1357062 reaction equation
C[O:2][C:3]1[CH:8]=[C:7]([O:9]C)[CH:6]=[CH:5][C:4]=1[C:11]1[C:20](=[O:21])[C:19]2[C:14](=[CH:15][C:16]([O:22]C)=[CH:17][CH:18]=2)[O:13][CH:12]=1.B(Br)(Br)Br>C(Cl)Cl>[OH:2][C:3]1[CH:8]=[C:7]([OH:9])[CH:6]=[CH:5][C:4]=1[C:11]1[C:20](=[O:21])[C:19]2[C:14](=[CH:15][C:16]([OH:22])=[CH:17][CH:18]=2)[O:13][CH:12]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 140183653-(2,4-Dimethoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one

Product 1

HCID 52805204H-1-Benzopyran-4-one, 3-(2,4-dihydroxyphenyl)-7-hydroxy-Yield 57.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

At 0° C., a solution of 14 (1.0 g, 3.2 mmol) in CH2Cl2 was treated with BBr3 (16 mL, 16 mmol, 1 M in CH2Cl2) and the reaction mixture was allowed to stir at rt for 18 h. The reaction was quenched slowly with MeOH, concentrated and taken up in EtOAc. The EtOAc layer was washed with 2N HCl aq. And the EtOAc was dried over MgSO4, filtered, concentrated and chromatographed on silica gel (EtOAC/hexanes; 1:1) to yield 15 as a white solid (0.5 g).

Workup

  1. customThe reaction was quenched slowly with MeOH
  2. concentrationconcentrated
  3. washThe EtOAc layer was washed with 2N HCl aq.
  4. dry with materialthe EtOAc was dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customchromatographed on silica gel (EtOAC/hexanes; 1:1)

Sources & evidence

ORD record
ord-e58ff85d164f434ab31246de31256286
Source dataset
uspto-grants-2003_07
Patent number
US06589980B2

Reaction notes

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