Methyl iodide → 6,7,8-Trifluoro-1,4-dihydro-1-methyl-4-oxoquinoline-3-carboxylic acid

HRID 434564Notes

Reaction equation

HRID 434564 reaction equation
C([O:3][C:4]([C:6]1[C:15](=[O:16])[C:14]2[C:9](=[C:10]([F:19])[C:11]([F:18])=[C:12]([F:17])[CH:13]=2)[NH:8][CH:7]=1)=[O:5])C.[C:20](=O)([O-])[O-].[K+].[K+].CI>CN(C)C=O>[F:17][C:12]1[CH:13]=[C:14]2[C:9](=[C:10]([F:19])[C:11]=1[F:18])[N:8]([CH3:20])[CH:7]=[C:6]([C:4]([OH:3])=[O:5])[C:15]2=[O:16]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 27339723-Quinolinecarboxylic acid, 1,4-dihydro-4-oxo-6,7,8-trifluoro-, ethyl ester

Product 1

HCID 127708996,7,8-Trifluoro-1,4-dihydro-1-methyl-4-oxoquinoline-3-carboxylic acidYield 77.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of 6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid ethyl ester (0.3 g), anhydrous potassium carbonate (0.8 g), methyl iodide (1.6 g), and N,N-dimethyl-formamide (DMF) (10 ml) was heated with stirring at 90°-100° C. for 10 hours. The mixture was evaporated to dryness. The residue was treated with water, extracted with dichloromethane. The organic layer was washed with water, dried over anhydrous sodium sulfate, and evaporated. The residue was added to a mixture of 18% hydrochloric acid (5 ml) and ethanol (2.5 ml) and the mixture was refluxed for 2.5 hours. After water (5 ml) and ethanol (5 ml) added and cooled, the resulting precipitate was filtered off and recrystallized from a mixture of DMF and ethanol to give 6,7,8-trifluoro-1,4-dihydro-1-methyl-4-oxoquinoline-3-carboxylic acid (0.22 g), mp 255°-258° C.

Workup

  1. temperaturewas heated
  2. customThe mixture was evaporated to dryness
  3. additionThe residue was treated with water
  4. extractionextracted with dichloromethane
  5. washThe organic layer was washed with water
  6. dry with materialdried over anhydrous sodium sulfate
  7. customevaporated
  8. additionThe residue was added to a mixture of 18% hydrochloric acid (5 ml) and ethanol (2.5 ml)
  9. temperaturethe mixture was refluxed for 2.5 hours
  10. additionAfter water (5 ml) and ethanol (5 ml) added
  11. temperaturecooled
  12. filtrationthe resulting precipitate was filtered off
  13. customrecrystallized from a mixture of DMF and ethanol

Sources & evidence

ORD record
ord-f30dea91d8904733aefa6b2dd8cc6106
Source dataset
uspto-grants-1983_08
Patent number
US04398029

Reaction notes

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