To a suspension of 1.0 g (2.39 mmole) of 3-(6-fluoro-1-methyl-1H-indol-3-yl)-4-(1-methyl-6-nitro-1H-indol-3-yl)-pyrrole-2,5-dione in 20 ml of ethanol and 10 mL of tetrahydrofuran was added 0.55 g of 10% Pd/C and 0.54 mL of 5% hydrochloric acid. The mixture was cooled in an ice bath, and 0.54 mL (14.34 mmole) of hydrazine hydrate (85%) was added dropwise over 5 min. The reaction mixture was allowed to warm to room temp as it was stirred for two hours. The catalyst was removed by filtration over Celite. The filtrate was evaporated and the residue was crystallized from ethyl acetate/tetrahydrofuran/hexane to give 708 mg (76%) of )3-(6-amino-1-methyl-1H-indol-3-yl)-4-(6-fluoro-1-methyl-1H-indol-3-yl)-pyrrole-2,5-dione.
