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

HRID 2185255Notes

Reaction equation

HRID 2185255 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[C:5](Cl)(=[O:7])[CH3:6].[Br:9][C:10]1[CH:11]=[C:12]2[C:17](=[CH:18][CH:19]=1)[O:16][C:15]([CH3:21])([CH3:20])[CH2:14][C:13]2([CH3:23])[CH3:22]>ClCCl>[C:5]([C:18]1[CH:19]=[C:10]([Br:9])[CH:11]=[C:12]2[C:17]=1[O:16][C:15]([CH3:20])([CH3:21])[CH2:14][C:13]2([CH3:23])[CH3:22])(=[O:7])[CH3:6]

Participants

5

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 83%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A stirred, cooled (ice bath) suspension of aluminum chloride (0.99 g, 7.46 mmol) in anhydrous dichloromethane (20 mL) was treated with acetyl chloride (0.58 g, 7.46 mmol). After 5 minutes, a solution of 6-bromo-2,2,4,4-tetramethyl chroman (1 g, 3.73 mmol)in dichloromethane was added. The reaction was allowed to warn to ambient temperature and stirred for 2 h. The reaction mixture was then poured into ice containing 10% hydrochloric acid and extracted with diethyl ether (×2). The combined organic phase was washed with saturated aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to a residue which was subjected to flash column chromatography over silica gel (230-400 mesh) using 5% ethyl acetate in hexane as the eluent to afford the title compound as a pale yellow oil (0.95 g, 83%). It was used as such for the next step without any characterization.

Workup

  1. temperatureA stirred, cooled
  2. customto warn to ambient temperature
  3. extractionextracted with diethyl ether (×2)
  4. washThe combined organic phase was washed with saturated aqueous sodium bicarbonate solution
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. customevaporated in vacuo to a residue which

Sources & evidence

ORD record
ord-c957787f0cbb46ff919aa9c5bfe1fefd
Source dataset
uspto-grants-2002_06
Patent number
US06399774B1

Reaction notes

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