2-Methylpiperazine → 9-chloro-5-methyl-8-(3-methyl-1-piperazinyl)-6,7-dihydro-1,7-dioxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid ethyl ester

Participants

Reaction Steps

14.17 g (0.04 mole) of 8,9-dichloro-5-methyl-6,7-dihydro-1,7-dioxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid ethyl ester was suspended in 250 ml of acetonitrile, 12.02 g (0.12 mole) of 2-methylpiperazine was added thereto, and this mixture was stirred at 50°-60° C. for 3 hours. The resulting reaction solution was concentrated under reduced pressure and the residue thus obtained was purified by silica gel column chromatography [using a chloroform-methanol mixture (with a volume ratio of 10:1) as the developing solvent]. The fraction containing the desired product was evaporated to dryness under reduced pressure and the resulting residue was recrystallized from benzene to obtain 12.75 g (76.3% yield) of 9-chloro-5-methyl-8-(3-methyl-1-piperazinyl)-6,7-dihydro-1,7-dioxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid ethyl ester in the form of yellow crystals.

Provenance & Evidence