Potassium Hydroxide → Fluoroquinolonic acid

HRID 652056Notes

Reaction equation

HRID 652056 reaction equation
[H-].[Na+].Cl[C:4]1[CH:22]=[C:21]([Cl:23])[C:20]([F:24])=[CH:19][C:5]=1[C:6]([C:8](=[CH:14][NH:15][CH:16]1[CH2:18][CH2:17]1)[C:9]([O:11]CC)=[O:10])=[O:7].[OH-].[K+]>O1CCOCC1.O>[Cl:23][C:21]1[CH:22]=[C:4]2[C:5]([C:6](=[O:7])[C:8]([C:9]([OH:11])=[O:10])=[CH:14][N:15]2[CH:16]2[CH2:18][CH2:17]2)=[CH:19][C:20]=1[F:24]

Participants

6

Reactant 3

HCID 14797Potassium HydroxideHCID 24758Sodium hydrideHCID 178471868HCID 178471868, compound

Product 1

HCID 483180Fluoroquinolonic acidYield 106.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent2×

Procedure

3.44 g of 80 percent sodium hydride were added in portions to a solution of 31.9 g of ethyl 2-(2,4-dichloro-5-fluoro-benzoyl)-3-cyclopropylamino-acrylate (R1 =C2H5) in 100 ml of anhydrous dioxane while cooling with ice and stirring. The mixture was then stirred at room temperature for 30 minutes and under reflux for 2 hours, and the dioxane was stripped off in vacuo. The residue (40.3 g) was suspended in 150 ml of water, 6.65 g of caustic potash were added, and the mixture was refluxed for 1.5 hours. The warm solution was filtered and the residue was rinsed with H2O. The filtrate was then acidified to pH=1 to 2 with semiconcentrated hydrochloric acid, while cooling with ice, and the precipitate was filtered off under suction, washed with water and dried in vacuo at 100° C. 27.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid (R1 =H) of melting point 234° to 237° C. were obtained in this manner.

Workup

  1. temperaturewhile cooling with ice
  2. stirringThe mixture was then stirred at room temperature for 30 minutes
  3. temperatureunder reflux for 2 hours
  4. temperaturethe mixture was refluxed for 1.5 hours
  5. filtrationThe warm solution was filtered
  6. washthe residue was rinsed with H2O
  7. temperaturewhile cooling with ice
  8. filtrationthe precipitate was filtered off under suction
  9. washwashed with water
  10. customdried in vacuo at 100° C

Sources & evidence

ORD record
ord-e1363c3fa6cf45c5b4b4926e35119518
Source dataset
uspto-grants-1987_06
Patent number
US04670444

Reaction notes

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