反应详情

5.0 g (21 mmol) of N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)benzene-1,2-diamine and 3.9 g (22 mmol) of diethyl ketomalonate were dissolved in toluene (60 ml), and the solution was heated to reflux for 12 hours while removing water using a Dean-Stark apparatus. The reaction solution was washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue thus obtained was purified by silica gel chromatography (developing solvent: ethyl acetate:hexane=2:3) to obtain 4.6 g (yield: 63%) of ethyl 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-oxo-1,2-dihydroquinoxaline-3-carboxylate as a milky yellow powder.

1. temperaturethe solution was heated
2. temperatureto reflux for 12 hours
3. customwhile removing water using a Dean-Stark apparatus
4. washThe reaction solution was washed with water
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue thus obtained
8. customwas purified by silica gel chromatography (developing solvent: ethyl acetate:hexane=2:3)