Hydrochloric Acid → 4-Bromo-2-(4-hydroxy-phenyl)-benzofuran-5-ol

HRID 1836048Notes

Reaction equation

HRID 1836048 reaction equation
[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[O:9][C:10]3[CH:16]=[CH:15][C:14]([OH:17])=[CH:13][C:11]=3[CH:12]=2)=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].C1C(=O)N([Br:31])C(=O)C1.Cl>CC#N>[Br:31][C:13]1[C:11]2[CH:12]=[C:8]([C:5]3[CH:6]=[CH:7][C:2]([OH:1])=[CH:3][CH:4]=3)[O:9][C:10]=2[CH:16]=[CH:15][C:14]=1[OH:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 11430Potassium CarbonateHCID 67184N-bromobutanimideHCID 6569362-(4-Hydroxy-phenyl)benzofuran-5-OL2×

Product 1

HCID 222215874-Bromo-2-(4-hydroxy-phenyl)-benzofuran-5-ol

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent2×

Procedure

A solution of 75 2-(4-Hydroxy-phenyl)-benzofuran-5-ol (0.65 g, 2.9 mmol) in CH3CN (40 mL) was treated with K2CO3 (1 g, 7.1 mmol) followed by portionwise addition of NBS (0.36 g, 2.0 mmol). After stirring for approximately 30 minutes, the reaction was worked up by addition of 2 N HCl followed by 10% Na2SO3aq. and then the CH3CN was stripped off. The aqueous layer was extracted with EtOAc and washed with brine and dried over MgSO4. The reaction mixture was concentrated and chromatographed on silica gel (EtOAc/hexanes; 1:4): Mp 196-198° C.; 1H NMR (DMSO-d6) δ 9.93 (br s, 2 H), 7.76 (d, 2H, J=8.5 Hz), 7.40 (d, 1 H, J=8.7 Hz), 7.04 (s, 1 H), 6.87 (dd, 2 H, J=9.0 Hz, 3.1 Hz); MS 305/307 (M+H)+.

Workup

  1. extractionThe aqueous layer was extracted with EtOAc
  2. washwashed with brine
  3. dry with materialdried over MgSO4
  4. concentrationThe reaction mixture was concentrated
  5. customchromatographed on silica gel (EtOAc/hexanes; 1:4)

Sources & evidence

ORD record
ord-ea23d9bba5db4d22b1cfee2002d53ebe
Source dataset
uspto-grants-2004_08
Patent number
US06774248B2

Reaction notes

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