Reacción #1388

Ecuación de reacción

ethyl 7-(1-piperazinyl)-1-cyclopropyl-6-fluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate

sodium hydroxide

ethanol

→

7-(1-piperazinyl)-1-cyclopropyl-6-fluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Rendimiento 56.4%

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe mixture is refluxed for 1 hour
2. 2
   TemperaturaAfter cooling
3. 3
   Lavadowashed with dichloromethane
4. 4
   ExtracciónThe resultant is extracted with dichloromethane
5. 5
   Otrothe extract is dried
6. 6
   workup.DISTILLATIONThe solvent is distilled off under reduced pressure and to the residue
7. 7
   workup.ADDITIONis added ethanol
8. 8
   FiltraciónThe precipitated crystals are filtered
9. 9
   Otrorecrystallized from dimethylformamide

Procedimiento

To ethyl 7-(1-piperazinyl)-1-cyclopropyl-6-fluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (23 mg) are added 10% aqueous solution of sodium hydroxide (3 ml) and ethanol (3 ml), and the mixture is refluxed for 1 hour. After cooling, the reaction mixture is diluted with water and washed with dichloromethane. After the aqueous layer is made acidic with acetic acid and then made weak alkaline with an aqueous sodium hydrogen carbonate. The resultant is extracted with dichloromethane and the extract is dried. The solvent is distilled off under reduced pressure and to the residue is added ethanol. The precipitated crystals are filtered and recrystallized from dimethylformamide to give 7-(1-piperazinyl)-1-cyclopropyl-6-fluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (12 mg), as white powder, m.p. 231°-233° C.

Fuente