Piperazine → Ciprofloxacin

HRID 542701Notes

Reaction equation

HRID 542701 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 h. The solvent is removed by distillation 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, washed with H2O and dried to constant weight in a vacuum drying oven over CaCl2 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.

Workup

  1. temperatureis heated at 135°-140° C. for 2 h
  2. customThe solvent is removed by distillation under high vacuum
  3. filtrationfiltered off with suction
  4. washwashed with water
  5. customFor further purification
  6. filtrationfiltered with suction at room temperature
  7. washwashed with H2O
  8. customdried to constant weight in a vacuum
  9. dry with materialdrying oven over CaCl2 at 100° C

Sources & evidence

ORD record
ord-052b6e563d524accb7ba40df4e9f6267
Source dataset
uspto-grants-1987_04
Patent number
US04659603

Reaction notes

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