Piperazine → Ciprofloxacin

HRID 1284507Notes

Reaction equation

HRID 1284507 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-oxo-3-quinolinecarboxylic acid, 30.1 g of anhydrous piperazine and 100 ml of dimethylsulphoxide is heated at 135°-140° C. for 2 hours. The solvent is distilled off under a fine vacuum, the residue is suspended in water and the solid is filtered off with suction and washed with water. For further purification, the moist crude product is boiled up with 100 ml of water and the solid is filtered off with suction at room temperature, washed with water and dried to constant weight over calcium chloride in a vacuum drying cabinet at 100° C. 19.6 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid of decomposition point 255°-257° C. are obtained.

Workup

  1. temperatureis heated at 135°-140° C. for 2 hours
  2. distillationThe solvent is distilled off under a fine vacuum
  3. filtrationthe solid is filtered off with suction
  4. washwashed with water
  5. customFor further purification
  6. filtrationthe solid is filtered off with suction at room temperature
  7. washwashed with water
  8. dry with materialdried to constant weight over calcium chloride in a vacuum
  9. customdrying cabinet at 100° C

Sources & evidence

ORD record
ord-858f212571b9423182205b535ebdf8bd
Source dataset
uspto-grants-1986_01
Patent number
US04563459

Reaction notes

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