Reaktion #1384

Reaktionsgleichung

sodium hydroxide

1-cyclopropyl-6-fluoro-7-bromo-5-methyl-1,4- dihydro-4-oxoquinoline-3-carboxylic acid

thionyl chloride

→

1-cyclopropyl-6-fluoro-7-chloro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture is refluxed for 1 hour
2. 2
   TemperaturAfter cooling
3. 3
   Extraktionthe resultant is extracted with dichloromethane
4. 4
   Extraktionextracted with dichloroethane
5. 5
   EinengenThe solvent is concentrated
6. 6
   Sonstigethe residue is recrystallized from acetic acid

Vorschrift

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.

Quelle