Ethoxalyl chloride → Ethyl 3,5-dibromo-alpha-oxo-2-thiopheneacetate

HRID 590984

Reaction equation

HRID 590984 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[Br:5][C:6]1[S:7][CH:8]=[C:9]([Br:11])[CH:10]=1.Cl[C:13](=[O:19])[C:14]([O:16][CH2:17][CH3:18])=[O:15]>ClCCl>[Br:11][C:9]1[CH:10]=[C:6]([Br:5])[S:7][C:8]=1[C:13](=[O:19])[C:14]([O:16][CH2:17][CH3:18])=[O:15]

Participants

5

Reactant 3

HCID 20884Ethoxalyl chlorideHCID 2724560Thiophene, 2,4-dibromo-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 14113379Ethyl 3,5-dibromo-alpha-oxo-2-thiopheneacetateYield 100%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Aluminium chloride (0.26 g, 1.98 mmol) was added to a solution of 2,4-dibromothiophene (0.30 g, 1.24 mmol) and ethyl chlorooxoacetate (0.19 g, 1.36 mmol) in dichloromethane (10 mL) previously cooled with an ice bath. The reaction mixture was stirred at room temperature 45 minutes, poured into ice water and extracted with dichloromethane (2×20 mL). The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to provide the desired keto-ester (10a) (0.42 g, 1.24 mmol, 100%) as a yellow oil.

Workup

  1. temperaturepreviously cooled with an ice bath
  2. extractionextracted with dichloromethane (2×20 mL)
  3. dry with materialThe organic layer was dried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d74ffaa69872415e9aebab0a935931fd
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Linked notes

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