Diethyl Ether → PD 135042

HRID 358860

Reaction equation

HRID 358860 reaction equation
[B](F)F.[CH:4]1([N:7]2[C:16]3[C:11](=[CH:12][C:13]([F:20])=[C:14](F)[C:15]=3[O:17][CH3:18])[C:10](=[O:21])[C:9]([C:22]([OH:24])=[O:23])=[CH:8]2)[CH2:6][CH2:5]1.[NH:25]1[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]1.C(OCC)C>CS(C)=O>[CH:4]1([N:7]2[C:16]3[C:11](=[CH:12][C:13]([F:20])=[C:14]([N:25]4[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]4)[C:15]=3[O:17][CH3:18])[C:10](=[O:21])[C:9]([C:22]([OH:24])=[O:23])=[CH:8]2)[CH2:6][CH2:5]1

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 4837PiperazineHCID 86585298Difluoroborane 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxo-3-quinolinecarboxylate

Product 1

HCID 465562PD 135042Yield 60.5%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

0.11 g (0.00032 mole) of 1-cyclopropyl-6,7-difluoro-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylic acid boron difluoride chelate (IV) (prepared as described in Preparation 7) was dissolved in 0.5 ml of dimethyl sulfoxide, and 0.11 g (0.0012 mole) of anhydrous piperazine was added to the resulting solution. The mixture was then allowed to stand at room temperature overnight, after which it was poured into 50 ml of diethyl ether. The yellow crystals which precipitated were collected by filtration and dissolved in 30 ml of 80% aqueous ethanol and 5 ml of triethylamine, and the resulting solution was heated under reflux for 4 hours. The reaction mixture was then filtered while hot to remove insoluble material, and the filtrate was concentrated by evaporation under reduced pressure to give a crystalline substance, which was washed with ethanol to afford 0.07 g of 1-cyclopropyl-6-fluoro-8-methoxy-7-(1-piperazinyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid as colorless powdery crystals, melting at 177°-178° C.

Workup

  1. customThe yellow crystals which precipitated
  2. filtrationwere collected by filtration
  3. dissolutiondissolved in 30 ml of 80% aqueous ethanol
  4. temperature5 ml of triethylamine, and the resulting solution was heated
  5. temperatureunder reflux for 4 hours
  6. filtrationThe reaction mixture was then filtered while hot
  7. customto remove insoluble material
  8. concentrationthe filtrate was concentrated by evaporation under reduced pressure
  9. customto give a crystalline substance, which
  10. washwas washed with ethanol

Sources & evidence

ORD record
ord-9fea01a665bb4c21ad93924085579c09
Source dataset
uspto-grants-1991_03
Patent number
US04997943

Linked notes

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