Gandotinib

Gandotinib (LY2784544) is a potent JAK2 inhibitor with IC50 of 3 nM. Gandotinib (LY2784544) also inhibits FLT3, FLT4, FGFR2, TYK2, and TRKB with IC50 of 4, 25, 32, 44, and 95 nM.

Prepare active catalyst by combining palladium chloride (160 mg, 0.90 mmol) and 4, 5-bis(diphenylphosphino)-9, 9-dimethylxanthene (1.10 g, 1.84 mmol) in DMF (25 mL) and warming to form a solution. Add the preformed catalyst to a solution of 3-methyl-1H-pyrazol-5-amine (3.0 g, 29.65 mmol), 4-((6-chloro-3-(4-chloro-2-fluorobenzyl)-2-methylimidazo[1, 2-b]pyridazin-8-yl)methyl)morpholine hydrochloride (9.0 g, 20.19 mmol), potassium bicarbonate (6.0 g, 59.93 mmol) in DMF (65 mL) and heat to 150° C. for 1 h. Cool the reaction to 60° C. and add mercaptopropyl functionalized silica (500 mg) and stir for 1 h then filter to remove the silica. Cool to ambient temperature, add 2-methyltetrahydrofuran (125 mL) and extract with water to remove DMF. Add HCl to the organic solution to form the 3-(4-chloro-2-fluorobenzyl)-2-methyl-N-(5-methyl-1H-pyrazol-3-yl)-8-(morpholinomethyl)imidazo[1, 2-b]pyridazin-6-amine hydrochloride salt. Add the HCl salt (1.1 g) to sodium hydroxide (10 mL, 1N) in n-butanol (10 mL) and stir. Filter the resulting mixture to obtain 0.22 g of the free base, imidazo[1, 2-b]pyridazin-6-amine, 3-[(4-chloro-2-fluorophenyl)methyl]-2-methyl-N-(5-methyl-1H-pyrazol-3-yl)-8-(4-morpholinylmethyl), (22percent yield, M+1.=470).Prepare active catalyst by combining palladium chloride (160 mg, 0.90 mmol) and 4, 5-bis(diphenylphosphino)-9, 9-dimethylxanthene (1.10 g, 1.84 mmol) in DMF (25 mL) and warming to form a solution. Add the preformed catalyst to a solution of 3-methyl-1H-pyrazol-5-amine (3.0 g, 29.65 mmol), 4-((6-chloro-3-(4-chloro-2-fluorobenzyl)-2-methylimidazo[1, 2-b]pyridazin-8-yl)methyl)morpholine hydrochloride (9.0 g, 20.19 mmol), potassium bicarbonate (6.0 g, 59.93 mmol) in DMF (65 mL) and heat to 150° C. for 1 h. Cool the reaction to 60° C. and add mercaptopropyl functionalized silica (500 mg) and stir for 1 h then filter to remove the silica. Cool to ambient temperature, add 2-methyltetrahydrofuran (125 mL) and extract with water to remove DMF. Add HCl to the organic solution to form the 3-(4-chloro-2-fluorobenzyl)-2-methyl-N-(5-methyl-1H-pyrazol-3-yl)-8-(morpholinomethyl)imidazo[1, 2-b]pyridazin-6-amine hydrochloride salt. Add the HCl salt (1.1 g) to sodium hydroxide (10 mL, 1N) in n-butanol (10 mL) and stir. Filter the resulting mixture to obtain 0.22 g of the free base, imidazo[1, 2-b]pyridazin-6-amine, 3-[(4-chloro-2-fluorophenyl)methyl]-2-methyl-N-(5-methyl-1H-pyrazol-3-yl)-8-(4-morpholinylmethyl), (22percent yield, M+1.=470).3-(4-Chloro-2-fluorobenzyl)-2-methyl-N-(5-methyl-1H-pyrazol-3-yl)-8-(morpholinomethyl)imidazo[1, 2-b]pyridazin-6-amine hydrochloride Combine Prepare active catalyst by combining palladium chloride (160 mg, 0.90 mmol) and 4, 5-bis(diphenylphosphino)-9, 9-dimethylxanthene (1.10 g, 1.84 mmol) in DMF (25 mL) and warming to form a solution. Add the preformed catalyst to a solution of 3-methyl-1H-pyrazol-5-amine (3.0 g, 29.65 mmol), 4-((6-chloro-3-(4-chloro-2-fluorobenzyl)-2-methylimidazo[1, 2-b]pyridazin-8-yl)methyl)morpholine hydrochloride (9.0 g, 20.19 mmol), potassium bicarbonate (6.0 g, 59.93 mmol) in DMF (65 mL) and heat to 150 C. for 1 h. Cool the reaction to 60 C. and add mercaptopropyl functionalized silica (500 mg) and stir for 1 h then filter to remove the silica. Cool to ambient temperature, add 2-methyltetrahydrofuran (125 mL) and extract with water to remove DMF. Add HCl to the organic solution to form the