Piperazine → Ciprofloxacin

HRID 637940Notes

Reaction equation

HRID 637940 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° to 140° C. for 2 hours. The solvent is distilled off under a fine 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 up with 100 ml of water, filtered off with suction at room temperature, washed with H2O and dried to constant weight over CaCl2 at 100° C. in a vacuum drying cabinet. 19.6 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid of decomposition point 255° to 257° C. are obtained.

Workup

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

Sources & evidence

ORD record
ord-c3953db46f374338af327b39bf2d60be
Source dataset
uspto-grants-1985_12
Patent number
US04559342

Reaction notes

Loading…