Acetyl chloride → 2-Acetyl-3-bromo-benzothiophene

HRID 2036595Notes

Reaction equation

HRID 2036595 reaction equation
[CH:1]1[CH:6]=[C:5]2[C:7]([Br:10])=[CH:8][S:9][C:4]2=[CH:3][CH:2]=1.[Cl-].[Al+3].[Cl-].[Cl-].[C:15](Cl)(=[O:17])[CH3:16]>C(Cl)Cl>[Br:10][C:7]1[C:5]2[CH:6]=[CH:1][CH:2]=[CH:3][C:4]=2[S:9][C:8]=1[C:15](=[O:17])[CH3:16]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 123250Benzo(b)thiophene, 3-bromo-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 107061652-Acetyl-3-bromo-benzothiophene

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a mixture of 3-bromothianaphthene (Sigma-Aldrich Chemical Company, 2.000 mL, 9.39 mmol) and aluminum chloride (1.002 mL, 9.39 mmol) in DCM (50 mL) cooled with an ice bath was added acetyl chloride (0.667 mL, 9.39 mmol) via syringe, in one minute. The resulting intense orange reaction solution was stirred at rt for 1 h. The reaction was poured into ice and partitioned between water and DCM. The aqueous layer was extracted with DCM, and the combined extracts were washed with 50 mL 5% aqueous sodium hydroxide, 50 mL brine, and stirred over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give 1-(3-bromobenzo[b]thiophen-2-yl)ethanone as a pale yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 2.77 (s, 3H), 7.57-7.65 (m, 2H), 7.95 (dd, J=7.7, 1.1 Hz, 1H), 8.10 (dd, J=7.1, 1.3 Hz, 1H); LC-MS (ESI)] m/z 254.9 [M+H]+.

Workup

  1. temperaturecooled with an ice bath
  2. additionThe reaction was poured into ice
  3. custompartitioned between water and DCM
  4. extractionThe aqueous layer was extracted with DCM
  5. washthe combined extracts were washed with 50 mL 5% aqueous sodium hydroxide, 50 mL brine
  6. stirringstirred over anhydrous magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-d89f4ca5f2cf48d385baab2880447723
Source dataset
uspto-grants-2013_11
Patent number
US08575183B2

Reaction notes

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