Acetyl chloride → 8-Acetyl-6-bromo-2,2,4,4-tetramethyl chroman

HRID 1869850Notes

Reaction equation

HRID 1869850 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:13])([CH3:12])[CH2:6][C:5]2([CH3:15])[CH3:14].[Cl-].[Al+3].[Cl-].[Cl-].[C:20](Cl)(=[O:22])[CH3:21]>ClCCl.O>[C:20]([C:10]1[CH:11]=[C:2]([Br:1])[CH:3]=[C:4]2[C:9]=1[O:8][C:7]([CH3:13])([CH3:12])[CH2:6][C:5]2([CH3:15])[CH3:14])(=[O:22])[CH3:21]

Participants

6

Reactant 3

HCID 6367Acetyl chlorideHCID 6451240Aluminum(III) ChlorideHCID 121370056-Bromo-2,2,4,4-tetramethylchroman

Product 1

HCID 211072398-Acetyl-6-bromo-2,2,4,4-tetramethyl chromanYield 67.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

A stirred, cooled (−78° C.) solution of 6-bromo-2,2,4,4-tetramethyl chroman (1 g, 3.72 mmol) in anhydrous dichloromethane (10 mL) was treated with aluminum chloride (0.8 g, 6.8 mmol) followed by acetyl chloride (0.4 mL, 6.08 mmol). After 10 minutes, the reaction mixture was diluted with water and extracted with diethyl ether. The organic phase was washed with water, and dried over anhydrous sodium sulfate, filtered and evaporated to a residue that was subjected to flash column chromatography on silica gel (230-400 mesh) using 10% ethyl acetate in hexane as the eluent to afford the title compound as a solid (0.78 g, 67%).

Workup

  1. extractionextracted with diethyl ether
  2. washThe organic phase was washed with water
  3. dry with materialdried over anhydrous sodium sulfate
  4. filtrationfiltered
  5. customevaporated to a residue that

Sources & evidence

ORD record
ord-99d6d9b0715a44bdbcac0f9f7c8b0926
Source dataset
uspto-grants-2009_12
Patent number
US07638648B2

Reaction notes

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