Acetic Acid → 1-Cyclopropyl-6,7,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid

HRID 1710181Notes

Reaction equation

HRID 1710181 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:16])=[C:11]([F:15])[C:12]=3[F:14])[C:7](=[O:17])[C:6]([C:18]([O:20]CC)=[O:19])=[CH:5]2)[CH2:3][CH2:2]1.C(O)(=O)C.S(=O)(=O)(O)O>O>[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:16])=[C:11]([F:15])[C:12]=3[F:14])[C:7](=[O:17])[C:6]([C:18]([OH:20])=[O:19])=[CH:5]2)[CH2:2][CH2:3]1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 1118Sulfuric AcidHCID 5354151-Cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic Acid Ethyl Ester

Product 1

HCID 5354141-Cyclopropyl-6,7,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acidYield 103.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 94 g of ethyl 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate (7), 600 ml of glacial acetic acid, 450 ml of water and 70 ml of concentrated sulphuric acid is heated under reflux for 1.5 hours. Thereafter, the hot suspension is poured onto ice, and the precipitate is filtered off under suction, rinsed thoroughly with water and dried in vacuo at 100° C. In this manner, 88.9 g of pure 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid II of melting point 228°-230° C. (decomposition) are obtained.

Workup

  1. temperatureis heated
  2. temperatureunder reflux for 1.5 hours
  3. additionThereafter, the hot suspension is poured onto ice
  4. filtrationthe precipitate is filtered off under suction
  5. washrinsed thoroughly with water
  6. customdried in vacuo at 100° C

Sources & evidence

ORD record
ord-d00ada769a884ad2b6646100beb7bf55
Source dataset
uspto-grants-1990_08
Patent number
US04952695

Reaction notes

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