Sodium Hydroxide → 1-Cyclopropyl-6-fluoro-7-chloro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid
Reaktionsgleichung
[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([CH3:16])[C:10]([F:15])=[C:11](Br)[CH:12]=3)[C:7](=[O:17])[C:6]([C:18]([OH:20])=[O:19])=[CH:5]2)[CH2:3][CH2:2]1.S(Cl)([Cl:23])=O.[OH-].[Na+]>>[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([CH3:16])[C:10]([F:15])=[C:11]([Cl:23])[CH:12]=3)[C:7](=[O:17])[C:6]([C:18]([OH:20])=[O:19])=[CH:5]2)[CH2:3][CH2:2]1Komponenten
4
Versuchsvorschrift
To 1-cyclopropyl-6-fluoro-7-bromo-5-methyl-1,4- dihydro-4-oxoquinoline-3-carboxylic acid (0.2 g) is added thionyl chloride (2 ml) and the mixture is refluxed for 1 hour. After cooling, the reaction mixture is poured into ice-water and made alkaline with 10% aqueous sodium hydroxide solution. After stirring for 30 minutes, the resultant is extracted with dichloromethane. The aqueous layer is made acidic with 10% hydrochloric acid and then extracted with dichloroethane. The solvent is concentrated and the residue is recrystallized from acetic acid to give 1-cyclopropyl-6-fluoro-7-chloro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (80 mg), as white crystals, m.p. 258°-260° C.