Cesium carbonate → 5-Bromo-2-methylbenzo[d][1,3]dioxole

HRID 879319Notes

Reaction equation

HRID 879319 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([OH:9])[C:5]([OH:8])=[CH:6][CH:7]=1.C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH:17](Br)[CH3:18]>CC(C)=O.CCOC(C)=O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]2[O:8][CH:17]([CH3:18])[O:9][C:4]=2[CH:3]=1

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 112011,1-DibromoethaneHCID 284874-Bromocatechol

Product 1

HCID 217125925-Bromo-2-methylbenzo[d][1,3]dioxole

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 4-bromobenzene-1,2-diol (500 mg, 2.65 mmol) in acetone (4 mL) was added cesium carbonate (1.90 g, 5.82 mmol) and 1,1-dibromoethane (1.09 g, 5.82 mmol). The mixture was microwaved to 120° C. for 3 h. After cooling, the reaction mixture was diluted with EtOAc, extracted with H2O, brine, dried over Na2SO4, filtered and concentrated and purified by flash column chromatography (silica gel, 0 to 10% ethyl acetate/hexanes) to give the product. 1H-NMR: 400 MHz, (CDCl3) δ 6.93-6.89 (m, 2H), 6.63 (d, J=8 Hz, 1H), 6.27 (q, J=9.6 Hz, 1H), 1.67 (d, J=4.4 Hz, 3H).

Workup

  1. customThe mixture was microwaved to 120° C. for 3 h
  2. temperatureAfter cooling
  3. extractionextracted with H2O, brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. custompurified by flash column chromatography (silica gel, 0 to 10% ethyl acetate/hexanes)
  8. customto give the product

Sources & evidence

ORD record
ord-604b8c287dcc4178a9404e11ca55c6c6
Source dataset
uspto-grants-2015_03
Patent number
US08987250B2

Reaction notes

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