1-Methylpiperazine → Ethyl 7-fluoro-1-methylamino-8-(4-methylpiperazin-1-yl)-4H-quinolizin-4-one-3-carboxylate

Ethyl 8-chloro-7-fluoro-1-methylamino-4H-quinolizin-4-one-3-carboxylate (899 mg, 3.0 mmol), the product of Step 6, is suspended in 12 mL of dry pyridine under a nitrogen atmosphere. To the resultant solution is added 6.0 mL (6.0 mmol) of N-methylpiperazine and the reaction mixture is heated at 70° C. for 8 hours. The reaction mixture is then concentrated in vacuo in order to remove all of the pyridine. The dry residue is dissolved in 125 mL of methylene chloride and the methylene chloride solution is washed with 125 mL of brine. The aqueous layer is extracted with 125 mL of methylene chloride and the combined methylene chloride solutions are dried over anhydrous sodium sulfate, filtered and concentrated and dried in vacuo to afford the title compound.