反应详情

1-(2-Nitrophenyl)-1-ethoxycarbonyl chloride (XIV; R3=H, R4=CH3; 1.4 g; 6 mmol) was dissolved in diisopropylamine (30 ml) under an inert atmosphere and the solution was refluxed for 48 hr. The resulting diisopropylammonium chloride was filtered off and excess of diisopropylamine was removed by evaporation under vacuum to give an oil, which was purified by flash chromatography on silica, eluting with dichloromethane to afford the required compound as a colourless solid. Recrystallization from toluene-petroleum ether (bp 60-80° C.) 2:1 gave colourless crystals (1.0 g; 57% yield), mp 40-41° C.

1. temperaturethe solution was refluxed for 48 hr
2. filtrationThe resulting diisopropylammonium chloride was filtered off and excess of diisopropylamine
3. customwas removed by evaporation under vacuum
4. customto give an oil, which
5. customwas purified by flash chromatography on silica
6. washeluting with dichloromethane