反应详情

To a suspension of methyl 1-ethyl-6,7-bis((4-methoxybenzyl)oxy)-4-oxo-1,4-dihydrocinnoline-3-carboxylate (3 g, 5.95 mmol) in a mixed solvent of water (25.00 mL) and methanol (75 mL) was added potassium hydtoxide (1.668 g, 29.7 mmol). The mixture was stirred at room temperature for 0.5 h and then heated to reflux for 1 h when the yellow suspension turned into a clear yellow solution. LCMS indicated completion of the reaction. The mixture was cooled to room temperature and concentrated. The residue was dissolved in water (100 mL), and was then acidified to ˜pH 1 using aq. 6N hydrochloric acid. The white precipitates were collected by filtration, and the filtrate was extracted with ethyl acetate (2×100 mL). The combined organic layers were concentrated to provide more white solids that were combined with previous white precipitates and dried under high vacuum to afford 1-ethyl-6,7-bis((4-methoxybenzyl)oxy)-4-oxo-1,4-dihydrocinnoline-3-carboxylic acid (2.8 g, 5.71 mmol, 96% yield). LCMS: (M+H)+: 491.4.

1. temperatureheated
2. temperatureto reflux for 1 h when the yellow suspension
3. customcompletion of the reaction
4. temperatureThe mixture was cooled to room temperature
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in water (100 mL)
7. customThe white precipitates
8. filtrationwere collected by filtration
9. extractionthe filtrate was extracted with ethyl acetate (2×100 mL)
10. concentrationThe combined organic layers were concentrated
11. customto provide more white solids that
12. customwhite precipitates
13. customdried under high vacuum