Boron tribromide → HCID 15064033, compound

HRID 1195920Notes

Reaction equation

HRID 1195920 reaction equation
B(Br)(Br)Br.C[O:6][C:7]1[CH:8]=[C:9]([C:15]2([C:21]3[CH:26]=[CH:25][C:24]([O:27]C)=[C:23]([O:29]C)[CH:22]=3)[O:20][C:18](=O)[CH2:17][CH2:16]2)[CH:10]=[CH:11][C:12]=1[O:13]C>C(Cl)Cl>[OH:6][C:7]1[CH:8]=[C:9]([C:15]2[C:21]3[C:26](=[CH:25][C:24]([OH:27])=[C:23]([OH:29])[CH:22]=3)[C:18]([OH:20])=[CH:17][CH:16]=2)[CH:10]=[CH:11][C:12]=1[OH:13]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 15064029HCID 15064029, compound

Product 1

HCID 15064033HCID 15064033, compoundYield 56.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of boron tribromide (20 g. 80 mmol) in methylene chloride (20 mL) is added dropwise to a vigorously stirred solution of 4,4-bis(3,4-dimethoxyphenyl)butyrolactone (10.0 g. 27.9 mmol) in methylene chloride (200 mL) at -78° C. Stirring is continued for 3 hours at 78° C., and then at room temperature overnight. Ice (100 g) is added to the mixture, and organic layer is separated. The aqueous layer is extracted with ethyl acetate (3×100 mL). The combined organic solutions are dried over sodium sulfate, and concentrated in vacuo. The residue is chromatographed over a silica gel colum using a mixture of chloroform and ethanol (98:2 v/v) as the eluent to give 1-(3,4-di-hydroxyphenyl)-4,6,7-trihydroxynaphthalene (4.5 g. 53%), mp 224°-226° C. 1H NMR (Me2SO-d6) δ9.6-8.8 (5H, m, OH, exchangeable), 7.4-6.5 (7H, m, aromatic H).

Workup

  1. customat room temperature
  2. customovernight
  3. customis separated
  4. extractionThe aqueous layer is extracted with ethyl acetate (3×100 mL)
  5. dry with materialThe combined organic solutions are dried over sodium sulfate
  6. concentrationconcentrated in vacuo
  7. customThe residue is chromatographed over a silica gel colum
  8. additiona mixture of chloroform and ethanol (98:2 v/v) as the eluent

Sources & evidence

ORD record
ord-b76fd7f7d8ae464ca89d1dc123925c2e
Source dataset
uspto-grants-1992_05
Patent number
US05112869

Reaction notes

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