Methanol → 2,6-Difluoro-beta-oxo-benzenepropanoic acid methyl ester

HRID 568748Notes

Reaction equation

HRID 568748 reaction equation
C[C:2]1(C)[O:9][C:7](=[O:8])[CH2:6][C:4](=[O:5])O1.[F:11][C:12]1[CH:20]=[CH:19][CH:18]=[C:17]([F:21])[C:13]=1C(Cl)=O.CO.S(=O)(=O)(O)O>CN(C)C1C=CN=CC=1.C(Cl)Cl>[F:11][C:12]1[CH:20]=[CH:19][CH:18]=[C:17]([F:21])[C:13]=1[C:4]([CH2:6][C:7]([O:9][CH3:2])=[O:8])=[O:5]

Participants

7

Reactant 4

HCID 887MethanolHCID 1118Sulfuric AcidHCID 162492,2-Dimethyl-1,3-dioxane-4,6-dioneHCID 874382,6-Difluorobenzoyl chloride

Product 1

HCID 201489942,6-Difluoro-beta-oxo-benzenepropanoic acid methyl ester

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

To 3.6 g (25 mmole, 1 eq) of Meldrum's acid and 6.1 g of 4-dimethylamino-pyridine in 60 ml of methylenechloride was added with stirring, 4.4 g (25 mmole) of 2,6-difluorobenzoylchloride. The temperature was maintained at 0° throughout the addition period and for three additional hours of stirring under argon atmosphere. Most of the methylene chloride was then removed by distillation at 25° or less using a water aspirator to maintain reduced pressure. There was then added 60 ml of anhydrous methanol containing 25 mmole of conc. sulfuric acid.

Workup

  1. temperatureThe temperature was maintained at 0° throughout the addition period and for three additional hours
  2. stirringof stirring under argon atmosphere
  3. customMost of the methylene chloride was then removed by distillation at 25° or less
  4. temperatureto maintain reduced pressure

Sources & evidence

ORD record
ord-2e41e3ecd2274b329cc2477bc76cc104
Source dataset
uspto-grants-1988_03
Patent number
US04729782

Reaction notes

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