Boron tribromide → Methyl 4-hydroxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-6-carboxylate

HRID 1177384Notes

Reaction equation

HRID 1177384 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:15]=[C:14]([O:16]C)[C:8]2[CH2:9][C:10]([CH3:13])([CH3:12])[O:11][C:7]=2[CH:6]=1)=[O:4].COC(C1C=C(OC)C=C2OC(C)(C)CC=12)=O.B(Br)(Br)Br>C(Cl)Cl>[CH3:1][O:2][C:3]([C:5]1[CH:15]=[C:14]([OH:16])[C:8]2[CH2:9][C:10]([CH3:13])([CH3:12])[O:11][C:7]=2[CH:6]=1)=[O:4]

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 59559907HCID 59559907, compoundHCID 59560109HCID 59560109, compound

Product 1

HCID 25067323Methyl 4-hydroxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-6-carboxylateYield 10%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To the mixture of 4-methoxy-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid methyl ester and 6-methoxy-2,2-dimethyl-2,3-dihydro-benzofuran-4-carboxylic acid methyl ester (3d) (1.74 g, 7.36 mmol) in CH2Cl2 (10 mL) at 0° C. was added BBr3 (22.0 mL, 22 mmol, 1.0 M solution in CH2Cl2). The reaction mixture was stirred at 0° C. for 6 hr, quenched with H2O (100 mL), extracted with CH2Cl2(2×100 mL), dried over MgSO4, and concentrated in vacuo. The residue was purified by flash column chromatography eluting with 10% EtOAc in hexanes to give a pale yellow solid (171 mg, 10% yield). 1H NMR (400 MHz, CDCl3) δ 7.15 (s, 1 H) 6.99 (s, 1 H) 5.87 (s, 1 H) 3.89 (s, 3 H) 3.00 (s, 2 H) 1.50 (s, 6 H); LCMS for C12H14O4 m/z 223.0 (M+H)+.

Workup

  1. customquenched with H2O (100 mL)
  2. extractionextracted with CH2Cl2(2×100 mL)
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated in vacuo
  5. customThe residue was purified by flash column chromatography
  6. washeluting with 10% EtOAc in hexanes

Sources & evidence

ORD record
ord-c753209724e34dd9bb820fa299708bb8
Source dataset
uspto-grants-2010_11
Patent number
US07842713B2

Reaction notes

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