Hydrochloric Acid → 7-Fluoro-8-(1-piperazinyl)-5-oxo-1,2-dihydro-5H-thiazolo(3,2-a)quinoline-4-carboxylic acid

HRID 2295727Notes

Reaction equation

HRID 2295727 reaction equation
Cl[C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:18])[C:7]([C:15]([OH:17])=[O:16])=[C:8]3[S:14][CH2:13][CH2:12][N:9]32)=[CH:4][C:3]=1[F:19].[NH:20]1[CH2:25][CH2:24][NH:23][CH2:22][CH2:21]1.Cl>N1C=CC=CC=1>[F:19][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:2]=1[N:20]1[CH2:25][CH2:24][NH:23][CH2:22][CH2:21]1)[N:9]1[CH2:12][CH2:13][S:14][C:8]1=[C:7]([C:15]([OH:17])=[O:16])[C:6]2=[O:18]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 4837PiperazineHCID 104700458-chloro-7-fluoro-5-oxo-1,2-dihydro-5H-thiazolo(3,2-a)quinoline-4-carboxylic acid

Product 1

HCID 131164297-Fluoro-8-(1-piperazinyl)-5-oxo-1,2-dihydro-5H-thiazolo(3,2-a)quinoline-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To one gram of 8-chloro-7-fluoro-5-oxo-1,2-dihydro-5H-thiazolo(3,2-a)quinoline-4-carboxylic acid (33 mmol) were added 2.87 grams (33 mmol) of anhydrous piperazine and 30 ml of pyridine and the resulting suspension was heated to reflux for twelve hours in an oil bath. Pyridine was evaporated therefrom under reduced pressure, water was added to the residue, and the mixture was again concentrated under reduced pressure. Water was added to the resulting residue, then 4 ml of 2 N aqueous solution of sodium hydroxide was added thereto, and the mixture was warmed to prepared uniform solution. Then this was adjusted to pH nearly seven with 1 N hydrochloric acid. Crystals separated out therefrom were collected by filtration, washed with water, washed with acetone and ether, and air dried to give the title product as powdery crystals. Yield 997.8 mg (90.7 percent). Melting point 287° to 288° C. (decomposition). Elementary analysis calculated as C16H16FN3O3S.3H2O: C 47.64, H 5.50, N 10.41; Found: C 47.60, H 5.42, N 10.63.

Workup

  1. temperaturethe resulting suspension was heated
  2. temperatureto reflux for twelve hours in an oil bath
  3. customPyridine was evaporated
  4. additionunder reduced pressure, water was added to the residue
  5. concentrationthe mixture was again concentrated under reduced pressure
  6. additionWater was added to the resulting residue
  7. addition4 ml of 2 N aqueous solution of sodium hydroxide was added
  8. temperaturethe mixture was warmed
  9. customto prepared uniform solution
  10. customCrystals separated out
  11. filtrationtherefrom were collected by filtration
  12. washwashed with water
  13. washwashed with acetone and ether, and air
  14. customdried

Sources & evidence

ORD record
ord-8069201a98fa48bab1fa0d76b883a1a1
Source dataset
uspto-grants-1984_01
Patent number
US04426381

Reaction notes

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