Acetic Anhydride → N-[2-[6-fluoro-2-oxo-3-(1H-pyrrol-2-yl)-1,2-dihydro-benzo[cd]indol-5-ylamino]-ethyl]-acetamide

To a suspension of 5-(2-amino-ethylamino)-6-fluoro-3-(1H-pyrrol-2-yl)-1H-benzo[cd]indol-2-one hydrochloride salt (from Example 10 above) (35.5 mg, 0.1 mmol) in CH2Cl2 (2 mL) were added acetic anhydride (Fisher Scientific, 10.2 mg, 0.1 mmol) and triethylamine (Aldrich, 20.2 mg, 0.2 mmol) at room temperature. The reaction mixture was stirred for 2 hours at the same temperature and then quenched with a saturated aqueous ammonium chloride solution (5 mL) and extracted with ethyl acetate (3×10 mL). The combined organic extracts were successively washed with water (5 mL) and brine (5 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The crude product was triturated with ethyl acetate and hexanes, filtered, and dried to give N-[2-[6-fluoro-2-oxo-3-(1H-pyrrol-2-yl)-1,2-dihydro-benzo[cd]indol-5-ylamino]-ethyl]-acetamide as a brown solid. (Yield 13.5 mg, 38.4%).