Piperazine → Methyl 1-ethyl-6-fluoro-4-oxo-7-piperazin-1-ylquinoline-3-carboxylate

Participants

Reaction Steps

A mixture of 1.7 g of anhydrous piperazine and 1.4 g of 1-ethyl-6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid methyl ester in 3 ml of pyridine was refluxed with stirring for 5 hrs. The reaction mixture was cooled to give crude crystals. The crude crystals were recrystallized from a mixture of methylene chloride and methanol to give 1.55 g (77.5% yield) of 1-ethyl-6-fluoro-7-(1-piperazinyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid methyl ester. mp: 179°-181° C.

Provenance & Evidence