Piperazine, hexahydrate → Norfloxacin

HRID 544228Notes

Reaction equation

HRID 544228 reaction equation
[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([F:14])=[C:10](Cl)[CH:11]=2)[C:6](=[O:15])[C:5]([C:16]([OH:18])=[O:17])=[CH:4]1)[CH3:2].O.O.O.O.O.O.[NH:25]1[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]1>O>[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([F:14])=[C:10]([N:25]3[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]3)[CH:11]=2)[C:6](=[O:15])[C:5]([C:16]([OH:18])=[O:17])=[CH:4]1)[CH3:2]

Participants

4

Reactant 2

HCID 120181Piperazine, hexahydrateHCID 4831697-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid

Product 1

HCID 4539Norfloxacin

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
170 °C

Procedure

A mixture of 1-ethyl-6-fluoro-7-chloro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (1.9 g), piperazine hexahydrate (15 g) and water (15 ml) was heated at 170° C. in a sealed tube for 16 hours. After evaporation of the solvent, the residue was acidified with diluted hydrochloric acid, heated at 100° C., and the hot solution was filtered. The filtrate was evaporated to dryness. The residue was dissolved in 10% sodium hydroxide and neutralized with acetic acid. The precipitate was collected, washed with water, dried, and recrystallized from ethanol to give 1-ethyl-6-fluoro-1,4-dihydro-7-(1-piperazinyl)-4-oxoquinoline-3-carboxylic acid as colorless powder.

Workup

  1. customAfter evaporation of the solvent
  2. temperatureheated at 100° C.
  3. filtrationthe hot solution was filtered
  4. customThe filtrate was evaporated to dryness
  5. dissolutionThe residue was dissolved in 10% sodium hydroxide and neutralized with acetic acid
  6. customThe precipitate was collected
  7. washwashed with water
  8. customdried
  9. customrecrystallized from ethanol

Sources & evidence

ORD record
ord-c0013df55c8e4acd86c4c9cfa3148f97
Source dataset
uspto-grants-1984_05
Patent number
US04448962

Reaction notes

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