(rac)-6-[1-(6-Chloro-imidazo[1,2-b]pyridazin-3-yl)-ethyl]-5,7-difluoro-quinoline (Intermediate C, 50 mg, 0.145 mmol), KF (42.1 mg, 0.725 mmol), 6-methylpiperazin-2-one (49.7 mg, 0.435 mmol) were suspended in NMP (483 μL). The RM was stirred at 180° C. for 16 h. The mixture was purified by preparative UPLC with acetonitrile and water (+0.1% TFA) The fractions were collected and acetonitrile was removed. It was taken up with MeOH and passed through an SPE cartridge of PL-HCO3 MP from polymer lab. The solvent was removed and a brown solid was obtained (tR 0.9 min (conditions 4), MH+=423).
