Piperazine, hexahydrate → Norfloxacin

HRID 614908Notes

Reaction equation

HRID 614908 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>>[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

3

Reactant 2

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

Product 1

HCID 4539Norfloxacin

Procedure

A mixture of 1-ethyl-6-fluoro-7-chloro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (22g) and piperazine hexahydrate (160g) was heated at 135°-145° C. in an autoclave for 18.5 hr. The mixture was evaporated to dryness and dissolved in 10% sodium hydroxide. The solution was neutralized with acetic acid. The precipitate was collected, washed with water, dissolved in 30% acetic acid, and filtered. The filtrate was neutralized with 10% sodium hydroxide. The resulting precipitate was collected, washed with water and ethanol, and dried at 140°-145° C. in vacuo for 1.5 hr. to give 14g (54%) of 1-ethyl-6-fluoro-1,4-dihydro-7-(1-piperazinyl)-4-oxoquinoline-3-carboxylic acid (II) as colorless powder, m.p. 227°-228° C.

Workup

  1. temperaturewas heated at 135°-145° C. in an autoclave for 18.5 hr
  2. customThe mixture was evaporated to dryness
  3. dissolutiondissolved in 10% sodium hydroxide
  4. customThe precipitate was collected
  5. washwashed with water
  6. dissolutiondissolved in 30% acetic acid
  7. filtrationfiltered
  8. customThe resulting precipitate was collected
  9. washwashed with water and ethanol
  10. customdried at 140°-145° C. in vacuo for 1.5 hr

Sources & evidence

ORD record
ord-c5a7194b63064ce6804b8b7f1db8bd0e
Source dataset
uspto-grants-1979_03
Patent number
US04146719

Reaction notes

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