Sodium Hydroxide → N-(1-((6-isopropylpyridin-2-yl)methyl)-1H-indazol-4-yl)-7-(2-(4-methylpiperazin-1-yl)ethoxy)imidazo[1,2-a]pyridine-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

To lithium 7-(2-(4-methylpiperazin-1-yl)ethoxy)imidazo[1,2-a]pyridine-3-carboxylate (188 mg, 0.595 mmol) was added NMP (5 mL, distilled over oven dried MgSO4 directly into the 25 mL flask charged with the lithium salt). A heat gun was used to dissolve the starting material. The flask was cooled to 0° C. and 2,4,6-trichlorobenzoyl chloride (94.2 μL, 0.590 mmol) was added drop-wise. The cold bath was removed after addition was complete, and the reaction mixture was stirred for another hour. The reaction mixture turned from a clear solution to slightly cloudy. 1-((6-Isopropylpyridin-2-yl)methyl)-1H-indazol-4-amine (120 mg, 0.451 mmol) was added in one portion to the reaction mixture and the reaction was heated to 88° C. for 5 hours. NMP was removed by a vacuum distillation (at the same bath temperature) until the reaction mixture became a thick oil. NaOH (1.8 mmol) in H2O (10 mL) was added to the thick oil and the solution was stirred at 80° C. for 30 minutes. The solution was cooled to ambient temperature and the pH of the dark solution was adjusted to pH 12 to 13 with saturated NH4Cl. The solution was cooled to 0° C. and H2O (20 mL) was added. Stirring was continued for 30 minutes, during which time solids precipitated out of solution. The mixture was filtered and the filtrate was washed with saturated NaHCO3 and H2O. The resulting solid was dissolved in DCM, dried (Na2SO4), filtered and concentrated. The residue was triturated with MTBE give final product (15%). MS (ES+APCI) m/z=553.1 (M+H).

Provenance & Evidence