Piperazine → HCID 70487249, compound

Participants

Reaction Conditions

Reaction Steps

One hundred milliliter of hexamethylphosphoramide is added to a mixture of 5 g of 1-ethyl-7-chloro-8-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid and 8.5 g of anhydrous piperazine, and the mixture is heated at 140° C. for 8 hours. After heating, the solvent is removed under reduced pressure and, after 500 ml of water is added to the resultant residue, the mixture is adjusted to pH 4 with glacial acetic acid and the insolubles are filtered out. The filtrate is concentrated under reduced pressure, resulting in a light yellow, solid substance. Recrystallization from isopropanol-water (2:1) mixture yields 3.2 g of 1-ethyl-7-(1-piperazinyl)-8-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride as the white, needle-like crystals. m.p. not less than 300° C.

Provenance & Evidence