4-Nitrobenzaldehyde (0.3 g, 2.0 mmol) was added to a stirred mixture of 5-(5,6-difluoro-1H-indol-2-yl)-2-methoxy-phenylamine (0.548 g, 2.0 mmol) in methylene chloride (125 mL), followed by acetic acid (0.2 g). The resulting mixture was stirred at room temperature for 1 hour. Sodium triacetoxyborohydride (0.46 g, 2.2 mmol) was added in one portion, and the resulting homogeneous solution was stirred at room temperature for 6 days. Saturated aqueous sodium bicarbonate solution (100 mL) was added, and the mixture was stirred for 2 hours. The mixture was shaken; the organic layer was separated and dried over Na2SO4. The solvent was evaporated to give a red solid. Recrystallization from methanol gave the product (450 mg), mp 181-182° C.
