1,2-Dibromoethane → Methyl 2,3-dihydro-1,4-benzodioxine-5-carboxylate

HRID 2426978Notes

Reaction equation

HRID 2426978 reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][CH:7]=[C:6]([OH:10])[C:5]=1[OH:11].C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH2:20][CH2:21]Br>CN(C=O)C.C(OCC)(=O)C>[CH3:1][O:2][C:3]([C:4]1[C:5]2[O:11][CH2:21][CH2:20][O:10][C:6]=2[CH:7]=[CH:8][CH:9]=1)=[O:12]

Participants

6

Reactant 3

HCID 78391,2-DibromoethaneHCID 10796Cesium carbonateHCID 75484Methyl 2,3-Dihydroxybenzoate

Product 1

HCID 15380892Methyl 2,3-dihydro-1,4-benzodioxine-5-carboxylateYield 57.4%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A suspension of 2,3-Dihydroxy-benzoic acid methyl ester (336 mg, 2 mmol) and cesium carbonate (1.56 g, 4.8 mmol) in DMF was stirred at room temperature for 0.5 h. 1,2-Dibromoethane (0.224 ml, 2.6 mmol) was added to the DMF solution. The mixture was stirred at 80 C for 4 h, and then diluted with ethyl acetate. The organic layer was washed with water and brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo to give the crude product. It was chromatographed on silica gel with EtOAc/hexane (20%-40%) as eluent to afford 2,3-dihydro-benzo[1,4]dioxine-5-carboxylic acid methyl ester as a white solid. (223 mg, 1.14 mmol, 57.4% yield).

Workup

  1. stirringThe mixture was stirred at 80 C for 4 h
  2. washThe organic layer was washed with water and brine
  3. dry with materialdried over anhydrous MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customto give the crude product
  7. customIt was chromatographed on silica gel with EtOAc/hexane (20%-40%) as eluent

Sources & evidence

ORD record
ord-749256454fa24a6eb27b89b4c97800e4
Source dataset
uspto-grants-2011_06
Patent number
US07968577B2

Reaction notes

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