Ethyl Acetate → 6-Bromo-8-hydroxy-2,2,4,4-tetramethyl chroman

HRID 1869852Notes

Reaction equation

HRID 1869852 reaction equation
C([O:4][C:5]1[CH:6]=[C:7]([Br:19])[CH:8]=[C:9]2[C:14]=1[O:13][C:12]([CH3:16])([CH3:15])[CH2:11][C:10]2([CH3:18])[CH3:17])(=O)C.C(=O)([O-])[O-].[Na+].[Na+].C(OCC)(=O)C>CO.CCCCCC>[Br:19][C:7]1[CH:8]=[C:9]2[C:14](=[C:5]([OH:4])[CH:6]=1)[O:13][C:12]([CH3:16])([CH3:15])[CH2:11][C:10]2([CH3:18])[CH3:17]

Participants

6

Reactant 3

HCID 8857Ethyl AcetateHCID 10340Sodium CarbonateHCID 574242158-Acetoxy-6-bromo-2,2,4,4-tetramethyl chroman2×

Product 1

HCID 574242146-Bromo-8-hydroxy-2,2,4,4-tetramethyl chromanYield 84%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8058HexaneSolvent

Procedure

A solution of 8-acetoxy-6-bromo-2,2,4,4-tetramethyl chroman (Intermediate 16, 1.3 g, 3.98 mmol) in methanol was treated with sodium carbonate (0.8 g, 7.95 mmol) and the resulting reaction mixture was stirred at ambient temperature overnight. The volatiles were evaporated in vacuo, the residue was diluted with water and extracted with ethyl acetate. The organic phase was dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo to afford a residue that on flash column chromatography over silica gel (230-400 mesh) using 10% ethyl acetate in hexane as the eluent afforded the title product as an oil (0.95 g, 84%).

Workup

  1. customthe resulting reaction mixture
  2. customThe volatiles were evaporated in vacuo
  3. additionthe residue was diluted with water
  4. extractionextracted with ethyl acetate
  5. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customto afford a residue that on flash column chromatography over silica gel (230-400 mesh)

Sources & evidence

ORD record
ord-debb86021c1f472bac4313f683c04d4d
Source dataset
uspto-grants-2009_12
Patent number
US07638648B2

Reaction notes

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