Piperazine, hexahydrate → 1-Ethyl-6-fluoro-1,4-dihydro-7-(1-piperazinyl)-4-oxoquinoline-3-carboxylic acid pentahydrate

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-ethyl-6-fluoro-7-chloro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (1.9g), piperazine hexahydrate (15g) and water (15 ml) was heated at 170° C. in a sealed tube for 16 hr. After evaporation of the solvent, the residue was acidified with diluted hydrochloric acid, heated at 100° C., and the hot solution was filtered. The filtrate was evaporated to dryness. The residue was dissolved in 10% sodium hydroxide and neutralized with acetic acid. The precipitate was collected, washed with water, dried, and recrystallized from ethanol to give 1-ethyl-6-fluoro-1,4-dihydro-7-(1-piperazinyl)-4-oxoquinoline-3-carboxylic acid pentahydrate (I) as colorless powder, m.p.: 226°-227° C. Mass spectrum m/e: 319 (M+).

Provenance & Evidence