Piperazine → 6-Fluoro-1-(2,4-difluorophenyl)-1,4-dihydro-5-methyl-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid

HRID 2073855Notes

Reaction equation

HRID 2073855 reaction equation
[F:1][C:2]1[C:3]([CH3:27])=[C:4]2[C:9](=[CH:10][C:11]=1F)[N:8]([C:13]1[CH:18]=[CH:17][C:16]([F:19])=[CH:15][C:14]=1[F:20])[CH:7]=[C:6]([C:21]([O:23]CC)=[O:22])[C:5]2=[O:26].[NH:28]1[CH2:33][CH2:32][NH:31][CH2:30][CH2:29]1>C(#N)C>[F:1][C:2]1[C:3]([CH3:27])=[C:4]2[C:9](=[CH:10][C:11]=1[N:28]1[CH2:33][CH2:32][NH:31][CH2:30][CH2:29]1)[N:8]([C:13]1[CH:18]=[CH:17][C:16]([F:19])=[CH:15][C:14]=1[F:20])[CH:7]=[C:6]([C:21]([OH:23])=[O:22])[C:5]2=[O:26]

Participants

4

Reactant 2

HCID 4837PiperazineHCID 14774107Ethyl 1-(2,4-difluorophenyl)-5-methyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate

Product 1

HCID 146512396-Fluoro-1-(2,4-difluorophenyl)-1,4-dihydro-5-methyl-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acidYield 69.5%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution of 0.76 g (2.00 mmol) of ethyl 6,7-difluoro-1-(2,4-difluorophenyl)-1,4-dihydro-5-methyl-4-oxo-3-quinolinecarboxylate, 0.69 g (8.00 mmol) of anhydrous piperazine, and 30 ml of acetonitrile was refluxed for 18 hours, cooled, and concentrated. The residue was dissolved in 20 ml 6N hydrochloric acid and refluxed for three hours. The suspension was cooled, concentrated by half and filtered, and the solids were washed with water. The crude product was suspended in water which was made basic (pH 12), filtered, and neutralized to pH 6.8. The precipitate was filtered and neutralized to pH 6.8. The precipitate was filtered, washed with water, and dried to give 0.58 g of the title compound, mp 198°-200° C.

Workup

  1. temperaturecooled
  2. concentrationconcentrated
  3. dissolutionThe residue was dissolved in 20 ml 6N hydrochloric acid
  4. temperaturerefluxed for three hours
  5. temperatureThe suspension was cooled
  6. concentrationconcentrated by half
  7. filtrationfiltered
  8. washthe solids were washed with water
  9. filtrationfiltered
  10. filtrationThe precipitate was filtered
  11. filtrationThe precipitate was filtered
  12. washwashed with water
  13. customdried

Sources & evidence

ORD record
ord-690c95b8a0964bb9ab1cafdd98ecfa8b
Source dataset
uspto-grants-1990_04
Patent number
US04920120

Reaction notes

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