Bromine → 8-Bromo-2,2,4,4-tetramethyl-6-chromanoic acid

HRID 1739097Notes

Reaction equation

HRID 1739097 reaction equation
[CH3:1][C:2]1([CH3:17])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][CH:6]=[C:7]([C:14]([OH:16])=[O:15])[CH:8]=2)[O:3]1.[Br:18]Br>CC(O)=O>[Br:18][C:5]1[CH:6]=[C:7]([C:14]([OH:16])=[O:15])[CH:8]=[C:9]2[C:4]=1[O:3][C:2]([CH3:17])([CH3:1])[CH2:11][C:10]2([CH3:12])[CH3:13]

Participants

4

Reactant 2

HCID 24408BromineHCID 157287092,2,4,4-Tetramethyl-3,4-dihydro-2H-1-benzopyran-6-carboxylic acid

Product 1

HCID 158405358-Bromo-2,2,4,4-tetramethyl-6-chromanoic acid

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a solution of 2,2,4,4-tetramethyl-6-chromanoic acid (200 mg, 0.85 mmol) in 0.5 ml of AcOH was added Br2 (0.07 ml, 1.28 mmol). The resulting dark-orange solution was stirred at room temperature for overnight. The excess bromine was removed under reduced pressure. Then the solution was poured into 5 ml of water and extracted with ethyl acetate (3×3 ml). The combined ethyl acetate layers were further washed with NaHCO3 (sat.), brine and dried over MgSO4. After concentration, the residue was purified by column chromatography (silica gel, ethyl acetate/hexane 1/3) to yield the desired product (170 mg, as white solids.

Workup

  1. customThe excess bromine was removed under reduced pressure
  2. additionThen the solution was poured into 5 ml of water
  3. extractionextracted with ethyl acetate (3×3 ml)
  4. washThe combined ethyl acetate layers were further washed with NaHCO3 (sat.), brine
  5. dry with materialdried over MgSO4
  6. concentrationAfter concentration
  7. customthe residue was purified by column chromatography (silica gel, ethyl acetate/hexane 1/3)

Sources & evidence

ORD record
ord-a17623b8d25e4954baf96d3f01d2c06a
Source dataset
uspto-grants-1999_10
Patent number
US05965606

Reaction notes

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