Potassium Carbonate → Methyl 4-bromo-3-(2-methylallyloxy)benzoate

HRID 1409250Notes

Reaction equation

HRID 1409250 reaction equation
[Br:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[OH:12].C(=O)([O-])[O-].[K+].[K+].Br[CH2:20][C:21]([CH3:23])=[CH2:22]>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.CN(C=O)C>[Br:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[O:12][CH2:22][C:21]([CH3:23])=[CH2:20]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 3577853-Bromo-2-methyl-1-propeneHCID 6425184Methyl 4-Bromo-3-hydroxybenzoate

Product 1

HCID 57662790Methyl 4-bromo-3-(2-methylallyloxy)benzoateYield 100.5%

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 6228DimethylformamideSolvent

Procedure

In a 200 ml pear flask were added methyl 4-bromo-3-hydroxybenzoate (3.5 g, 15 mmol), potassium carbonate (4.2 g, 30 mmol) and tetrabutylammonium iodide (0.084 g, 0.23 mmol) in DMF (35 ml) to give a suspension. At 0° C. was added 3-bromo-2-methylprop-1-ene (1.7 ml, 17 mmol) to this mixture, which was then stirred at room temperature for ˜16 h. The reaction mixture was partitioned between brine and ether, and the aqueous layer was extracted one more time with ethyl acetate. Combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated to give the crude product methyl 4-bromo-3-(2-methylallyloxy)benzoate (4.3 g, 99% yield) as a light yellow oil. 1H NMR (CHLOROFORM-d) δ: 7.61 (d, J=8.1 Hz, 7H), 7.53 (d, J=1.5 Hz, 7H), 7.50 (dd, J=8.1, 1.8 Hz, 7H), 5.20 (d, J=1.0 Hz, 7H), 5.02-5.07 (m, 7H), 4.56 (s, 2H), 3.92 (s, 3H), 1.87 (s, 3H); ESI-MS: m/z 242.3 (M+H)+.

Workup

  1. customto give a suspension
  2. customThe reaction mixture was partitioned between brine and ether
  3. extractionthe aqueous layer was extracted one more time with ethyl acetate
  4. washCombined organic layers were washed with brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-0e8c2b8897de4bd1889489382f5e89b4
Source dataset
uspto-grants-2014_12
Patent number
US08921358B2

Reaction notes

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