Water → Ethyl (4-bromo-2,5-dimethyl-thiophen-3-yl)-oxo-acetate

HRID 591052Notes

Reaction equation

HRID 591052 reaction equation
Cl[C:2](=[O:8])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[Cl-].[Al+3].[Cl-].[Cl-].[Br:13][C:14]1[CH:18]=[C:17]([CH3:19])[S:16][C:15]=1[CH3:20].O>ClCCl>[Br:13][C:14]1[C:18]([C:2](=[O:8])[C:3]([O:5][CH2:6][CH3:7])=[O:4])=[C:17]([CH3:19])[S:16][C:15]=1[CH3:20]

Participants

6

Reactant 4

HCID 962WaterHCID 20884Ethoxalyl chlorideHCID 6385853-Bromo-2,5-dimethylthiopheneHCID 6451240Aluminum(III) Chloride

Product 1

HCID 70818387Ethyl (4-bromo-2,5-dimethyl-thiophen-3-yl)-oxo-acetateYield 53.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Under a nitrogen atmosphere, ethyl chlorooxoacetate (1.04 mL, 9.27 mmol) and aluminum chloride (per 3 portions) (2.47 g, 18.54 mmol) was added successively at −5° C. to a solution of 3-bromo-2,5-dimethylthiophene (28b) (886 mg, 4.64 mmol) in dichloromethane (20 mL). After 3 hours at −5° C., the reaction mixture was slowly hydrolyzed at 0° C. with water. The organic layer was separated, washed with water, brine, dried over sodium sulfate, filtered, and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 95/5) to give the desired keto-ester (28c) (725 mg, 2.50 mmol, 50%).

Workup

  1. customThe organic layer was separated
  2. washwashed with water, brine
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. customevaporated under reduced pressure
  6. customThe residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 95/5)

Sources & evidence

ORD record
ord-6331ce2500664e8f851c411d6d42fd3f
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Reaction notes

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