Water → 9-Benzhydryloxy-7-(2,4-dimethoxy-benzyl)-5-methoxy-pyrrolo[3,4-g]quinoline-6,8-dione

Participants

Reaction Steps

Potassium carbonate (2.6 g, 19.0 mmol) and N,N-dimethyl-aminopyridine (DMAP, 0.464 g, 3.8 mmol) were added to carbonic acid 9-benzhydryloxy-7-(2,4-dimethoxy-benzyl)-6,8-dioxo-7,8-dihydro-6H-pyrrolo[3,4-g]quinolin-5-yl ester ethyl ester 301 (1.2 g, 1.9 mmol) dissolved in tetrahydrofuran (40 ml) and water (20 ml) was added. After stirring overnight at room temperature, the reaction mixture was concentrated in vacuo and diluted with ethyl acetate. It was washed twice with 5% citric Acid (aqueous), twice with water, once with brine, dried over magnesium sulfate, and concentrated in vacuo. The resulting residue was dissolved in dimethylformamide (10 ml). To this reaction mixture was added potassium carbonate (1.24 g, 9.0 mmol) and iodomethane (methyl iodide, MeI, 2.55 g, 18.0 mmol). After stirring overnight at room temperature, the reaction mixture was diluted with ethyl acetate, washed twice with 5% citric acid, twice with water, once with brine, and concentrated in vacuo to afford 9-benzhydryloxy-7-(2,4-dimethoxy-benzyl)-5-methoxy-pyrrolo[3,4-g]quinoline-6,8-dione 302 (1.1 g, 1.9 mmol, 100%). 1H NMR (d-DMSO) δ 9.16 (dd, 1H), 8.60 (dd, 1H), 7.82 (s, 1H), 7.75 (m, 1H), 7.54 (d, 4H), 7.16 (m, 6H), 6.82 (d, 1H), 6.56 (d, 1H), 6.44 (dd, 1H), 4.66 (s, 2H), 4.10 (s, 3H), 3.76 (s, 3H), 3.70 (s, 3H). MS: 583.2 (M+23).

Provenance & Evidence