Potassium carbonate (60.1 mg, 0.435 mmol), 4-methoxybenzylchloride (41 mg, 0.26 mmol), and sodium iodide (6.3 mg, 0.043 mmol) were added to 9-hydroxy-5-methoxy-6,7-dihydro-pyrrolo[3,4-g]quinolin-8-one 303 (20 mg, 0.087 mmol) dissolved in dimethylformamide 8 (0.4 ml). The reaction mixture was warmed to 60° C. and stirred at 60° C. for one hour. After cooling the reaction mixture to 0° C., acetic acid (0.06 ml) was added and the mixture was concentrated in vacuo. The residue was diluted with ethyl acetate and washed once with 5% Citric Acid, twice with water, once with brine, and concentrated in vacuo. The residue was purified by silica gel chromatography (9/1-dichloromethane/methanol) to afford 5-methoxy-9-(4-methoxy-benzyloxy)-6,7-dihydro-pyrrolo[3,4-g]quinolin-8-one 304 (16 mg, 0.046 mmol, 53%). 1H NMR (CDCl3) δ 9.0 (dd, 1H), 8.64 (dd, 1H), 7.51 (d, 2H), 7.46 (m, 1H), 6.80 (d, 2H), 6.50 (broad, 1H), 5.60 (s, 2H), 3.98 (s, 3H), 3.72 (s, 3H). MS: 351.1 (M+1).
