4-(1H-imidazol-1-ylcarbonyl)-3,5-dimethyl-1H-pyrrole-2-carbaldehyde (14.0 g), N,N-diethylethylenediamine (15.0 g), 5-fluorooxindole (9.86 g), triethylamine (27 ml), and acetonitrile (250 ml) were mixed and heated to 60° C. The black slurry was stirred for 18 h at 60° C. (needs mechanical stirrer). The resulting yellow slurry was cooled to room temperature, diluted with 100 ml acetonitrile, and filtered. The cake was washed with 3×100 ml acetonitrile and dried overnight at 50° C. under house vacuum. N-[2-(diethylamino)ethyl]-5-[(Z)-(5-fluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide (21.7 g) was obtained with 85% yield.
