To a solution of methyl[6-(acetyloxy)-5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1-yl](oxo)acetate (632 mg, 2.09 mmol) and indole-3-acetamide (328 mg, 1.88 mmol) in anhydrous tetrahyrofuran (25 mL) at 0° C. was added a solution of potassium tert-butoxide (9.3 mL, 9.3 mmol, 1M in THF) dropwise over 30 min. The mixture was stirred at 0° C., allowed to warm to room temperature and stirred for 2 h. Concentrated hydrochloric acid (1 mL) was added and the mixture stirred for 1 hour at room temperature. The mixture was diluted with water (25 mL), and extracted with ethyl acetate (2×25 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (50 mL) and dried over anhydrous sodium sulfate. The residue was purified by silica gel chromatography, eluting with a methanol/dichloromethane (1-5%) to afford 3-(6-hydroxy-5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1-yl)-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione as a bright red solid (293 mg, 36%). Mp: 165-168° C.; 1H NMR (DMSO-d6) 400 MHz δ: 11.62 (brs, 1H), 10.89 (brs, 1H), 7.85 (s, 1H), 7.65 (s, 1H), 7.38 (d, J=8.2 Hz, 1H), 6.96-6.94 (m, 3H), 6.71 (t, J=7.4 Hz, 1H), 6.59 (d, J=7.4 Hz, 1H), 6.49 (d, J=8.2 Hz, 1H), 5.41 (d, J=5.0 Hz, 1H), 4.89 (brs, 1H), 4.26 (s, 2H), 3.33 (s, 2H); LCMS [M+H]: 384.
