Acetic Anhydride → 3-Acetoxy-5,5-difluoro-6-oxo-5,6-dihydro-quinoline-4-carboxylic acid methyl ester

HRID 2273199Notes

Reaction equation

HRID 2273199 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:14]2[C:13]([F:16])([F:15])[C:12](=[O:17])[CH:11]=[CH:10][C:9]=2[N:8]=[CH:7][C:6]=1[OH:18])=[O:4].[C:19](OC(=O)C)(=[O:21])[CH3:20].C(OCC)(=O)C>CC(C)=O>[CH3:1][O:2][C:3]([C:5]1[C:14]2[C:13]([F:16])([F:15])[C:12](=[O:17])[CH:11]=[CH:10][C:9]=2[N:8]=[CH:7][C:6]=1[O:18][C:19](=[O:21])[CH3:20])=[O:4]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 8857Ethyl AcetateHCID 672486575,5-Difluoro-3-hydroxy-6-oxo-5,6-dihydro-quinoline-4-carboxylic acid methyl ester

Product 1

HCID 672472263-Acetoxy-5,5-difluoro-6-oxo-5,6-dihydro-quinoline-4-carboxylic acid methyl esterYield 40.2%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A solution of 5,5-difluoro-3-hydroxy-6-oxo-5,6-dihydro-quinoline-4-carboxylic acid methyl ester (11.1 g, 43.50 mmol, 1.0 eq) in acetone (100 mL) is cooled to 0° C. before the addition of acetic anhydride (8.2 mL, 87.0 mmol, 2.0 eq). After 3 hours stirring at room temperature, solvent is evaporated and the crude product is purified by column chromatography (silica gel, eluent: petroleum ether:ethyl acetate, 5:1, v/v) to afford 3-acetoxy-5,5-difluoro-6-oxo-5,6-dihydro-quinoline-4-carboxylic acid methyl ester as a white solid (5.2 g, 40% yield).

Workup

  1. customsolvent is evaporated
  2. customthe crude product is purified by column chromatography (silica gel, eluent

Sources & evidence

ORD record
ord-b7096bee831b407bb8d3c14ba4a5ca85
Source dataset
uspto-grants-2015_09
Patent number
US09120822B2

Reaction notes

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