反应详情

温度

0 °C

7-(2,4-Dimethoxy-benzyl)-5,9-dihydroxy-pyrrolo[3,4-g]quinoline-6,8-dione 300 (1.1 g, 2.9 mmol) was dissolved in dioxane (14.5 ml) and H2O (9.7 ml) and cooled to 0° C. To this reaction mixture was added 1.0 M NaOH (5.8 ml, 5.8 mmol), followed by ethylchloroformate (347.3 mg, 3.2 mmol). After stirring at 0° C. for 30 minutes, dioxane (10 ml) and ethylchloroformate (51 mg, 0.5 mmol) were added and the reaction stirred for another 30 minutes at 0° C. The reaction mixture was quenched with the addition of acetic acid (0.6 ml) and concentrated in vacuo. The crude mixture was diluted with ethyl acetate and washed once with 5% citric Acid (aqueous), twice with water, once with brine, and dried over magnesium sulfate. The resulting residue was dissolved in 1,2-dichloroethane (30 ml) and diphenyl-methanediazonium 38 (diphenyldiazomethane, 1.1 g, 5.6 mmol) was added. The reaction mixture was then stirred overnight at room temperature. Following dilution with dichloromethane, the reaction mixture was washed with once with water, once with brine, dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by silica gel chromatography (1/1-Hexanes/Ethyl Acetate) to afford 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, 66%). 1H NMR (CDCl3) δ 9.10 (dd, 1H), 8.40 (dd, 1H), 7.95 (s, 1H), 7.68 (m, 1H), 7.60 (d, 4H), 7.15 (m, 6H), 7.0 (d, 1H), 6.40 (d, 1H), 6.36 (d, 1H), 4.80 (s, 2H), 4.35 (q, 2H), 3.75 (s, 3H), 3.73 (s, 3H), 1.31 (t, 3H). MS: 641.2 (M+23).

1. stirringthe reaction stirred for another 30 minutes at 0° C
2. customThe reaction mixture was quenched with the addition of acetic acid (0.6 ml)
3. concentrationconcentrated in vacuo
4. additionThe crude mixture was diluted with ethyl acetate
5. washwashed once with 5% citric Acid (aqueous), twice with water, once with brine
6. dry with materialdried over magnesium sulfate
7. dissolutionThe resulting residue was dissolved in 1,2-dichloroethane (30 ml)
8. stirringThe reaction mixture was then stirred overnight at room temperature
9. washthe reaction mixture was washed with once with water
10. dry with materialonce with brine, dried over magnesium sulfate
11. concentrationconcentrated in vacuo
12. customThe residue was purified by silica gel chromatography (1/1-Hexanes/Ethyl Acetate)