Acetic Acid → HCID 15571789, compound

Participants

Reaction Steps

A mixture of 3 g of 9-fluoro-8-bromo-5-methyl-6,7-dihydro-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid, 3.8 g of anhydrous piperazine and 30 ml of hexamethylphosphoric triamide was heated at 150° to 160° C. on a water bath for 5 hours in an argon stream. After completion of the reaction the solvent was removed under reduced pressure and 20 ml of ethyl acetate was added to the residue. The crystals precipitated were collected by filtration. The crystals thus-obtained were dissolved in 300 ml of water and the solution was adjusted to a pH of 4 with acetic acid. After adding activated carbon to the solution and filtering, the filtrate was concentrated under reduced pressure. Recrystallization of the crude crystals precipitated from isopropanol-water (2:1 by volume) gave 2.7 g of 8-(1-piperazinyl)-9-fluoro-5-methyl-6,7-dihydro-1-oxo-benzo[ij]quinolizine-2-carboxylic acid hydrobromide as rhombic crystals having a melting point of 300° C. or more.

Provenance & Evidence