A small screw cap test tube was charged with 2-Isopropyl-2H-pyrazole-3-carboxylic acid [3-(3-hydroxymethylene-2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide (prepared below, 138 mg, 0.3314 mmol) and THF (3.3 mL). To the resulting solution was added 4-(4-methyl-piperazin-1-yl)-phenylamine (63.3 mg, 0.331 mmol), and the mixture was stirred for 24 h at 65° C. Subsequently, the reaction mixture was cooled to room temperature and diluted with EtOAc (˜5 mL) and Hexane (˜40 mL). The precipitate that formed was collected by filtration and washed with 0° C. iPrOH (˜10 mL) to afford the title compound in 65% yield (0.127 g, 0.215 mmol).
