Acetic Acid → 1-Cyclopropyl-6,8-difluoro-7-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid

HRID 34576Notes

Reaction equation

HRID 34576 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:16])=[C:11]([CH3:15])[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]([CH3:15])[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 13657408Ethyl 1-cyclopropyl-6,8-difluoro-7-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylate

Product 1

HCID 136574231-Cyclopropyl-6,8-difluoro-7-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acidYield 95%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 30 g of ethyl 1-cyclopropyl-6,8-difluoro-7-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylate, 210 ml of glacial acetic acid, 160 ml of water and 23.5 ml of concentrated sulphuric acid is heated under reflux for 2 hours. The hot suspension is then poured onto ice and the precipitate is filtered off with suction, rinsed thoroughly with water and dried in vacuo at 100° C. 25.9 g of pure 1-cyclopropyl-6,8-difluoro-7-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid of melting point 227°-229° C. are obtained in this manner.

Workup

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

Sources & evidence

ORD record
ord-278dd9c5777f4bd4926a60756f704be2
Source dataset
uspto-grants-1988_08
Patent number
US04762844

Reaction notes

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