Piperazine → Ciprofloxacin

HRID 464307Notes

Reaction equation

HRID 464307 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])=[CH:8][N:9]2[CH:12]2[CH2:14][CH2:13]2)=[CH:4][C:3]=1[F:19].[NH:20]1[CH2:25][CH2:24][NH:23][CH2:22][CH2:21]1>CS(C)=O>[CH:12]1([N:9]2[C:10]3[C:5](=[CH:4][C:3]([F:19])=[C:2]([N:20]4[CH2:25][CH2:24][NH:23][CH2:22][CH2:21]4)[CH:11]=3)[C:6](=[O:18])[C:7]([C:15]([OH:17])=[O:16])=[CH:8]2)[CH2:14][CH2:13]1

Participants

4

Reactant 2

HCID 4837PiperazineHCID 483180Fluoroquinolonic acid

Product 1

HCID 2764CiprofloxacinYield 84.6%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

A mixture of 19.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, 30.1 g of anhydrous piperazine and 100 ml of dimethyl sulphoxide is heated at 135°-140° C. for 2 hours. The solvent is distilled out under high vacuum, and the residue is suspended in H2O, filtered off with suction and washed with water. For further purification, the moist crude product is boiled with 100 ml of water, filtered with suction at room temperature, the solid is washed with H2O and dried to constant weight over CaCl2 in a vacuum oven at 100° C. 19.6 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)quinoline-3-carboxylic acid, of decomposition point 255°-257° C., are obtained; RF value: 0.07.

Workup

  1. temperatureis heated at 135°-140° C. for 2 hours
  2. distillationThe solvent is distilled out under high vacuum
  3. filtrationfiltered off with suction
  4. washwashed with water
  5. customFor further purification
  6. filtrationfiltered with suction at room temperature
  7. washthe solid is washed with H2O
  8. dry with materialdried to constant weight over CaCl2 in a vacuum oven at 100° C

Sources & evidence

ORD record
ord-a44e77e3fe6b4197b805ca7494468061
Source dataset
uspto-grants-1985_10
Patent number
US04547503

Reaction notes

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