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

HRID 1081432Notes

Reaction equation

HRID 1081432 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 3 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), and the resulting solution was filtered and neutralized to pH 6.8. The precipitate which formed 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 3 hours
  5. temperatureThe suspension was cooled
  6. concentrationconcentrated by half
  7. filtrationfiltered
  8. washthe solids were washed with water
  9. filtrationthe resulting solution was filtered
  10. customThe precipitate which formed
  11. filtrationwas filtered
  12. washwashed with water
  13. customdried

Sources & evidence

ORD record
ord-52bf604a28f44bbe815f6dd4ca564c0e
Source dataset
uspto-grants-1996_12
Patent number
US05585491

Reaction notes

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