p-Toluenesulfonic acid → Ethyl 3-(2-chloro-4,5-difluorophenyl)-3-oxopropanoate

HRID 982206Notes

Reaction equation

HRID 982206 reaction equation
[Cl:1][C:2]1[CH:20]=[C:19]([F:21])[C:18]([F:22])=[CH:17][C:3]=1[C:4]([CH:6](C(OCC)=O)[C:7]([O:9][CH2:10][CH3:11])=[O:8])=[O:5].C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[Cl:1][C:2]1[CH:20]=[C:19]([F:21])[C:18]([F:22])=[CH:17][C:3]=1[C:4]([CH2:6][C:7]([O:9][CH2:10][CH3:11])=[O:8])=[O:5]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 14425827Diethyl (2-chloro-4,5-difluorobenzoyl)propanedioate

Product 1

HCID 14423850Ethyl 3-(2-chloro-4,5-difluorophenyl)-3-oxopropanoateYield 58.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 70 g of diethyl 2-chloro-4,5-difluorobenzoylmalonate, 90 cc of water was added for emulsification. Then, 0.2 g of p-toluenesulfonic acid was added thereto, and the mixture was refluxed for three hours under vigorous stirring. After cooling, the reaction mixture was extracted three times with 150 cc of methylene chloride, and the extract was washed with a saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, concentrated and then recrystallized from methylene chloride/n-hexane to obtain 32 g of the desired compound. The physical properties of obtained ethyl 2-chloro-4,5-difluorobenzoylacetate were as follows. From the results of the NMR analysis in chloroform-d1, this compound was found to be a mixture of a keto form and an enol-form. ##STR26##

Workup

  1. temperaturethe mixture was refluxed for three hours under vigorous stirring
  2. temperatureAfter cooling
  3. extractionthe reaction mixture was extracted three times with 150 cc of methylene chloride
  4. washthe extract was washed with a saturated sodium chloride aqueous solution
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated
  7. customrecrystallized from methylene chloride/n-hexane

Sources & evidence

ORD record
ord-e6e3c87926074279ac7a7078d5610024
Source dataset
uspto-grants-1991_02
Patent number
US04994610

Reaction notes

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