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

HRID 1636542Notes

Reaction equation

HRID 1636542 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-91b5fe00b7d44e3f88cb4d5b5671aef6
Source dataset
uspto-grants-2000_03
Patent number
US06034244

Reaction notes

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