反应详情

4-Ethylthio-3-p-nitrobenzyloxycarbonyloxyethyl-2-oxo-azetidine (9.0 g), p-nitrobenzyl glyoxylate ethyl hemiacetal (8.15 g) and benzene (350 ml) were heated at reflux for 20 hours under a nitrogen atmosphere using a Dean-Stark water separator. The solution was then concentrated in vacuo and the residue was dissolved in 700 ml of dichloromethane. The dichloromethane solution was washed two times with water, dried over anhydrous sodium sulfate and concentrated in vacuo to a yellowish semi-solid (15.0 g) of the title compound. The NMR spectrum in deuterochloroform showed peaks at 1.02-1.52 (c, 8H); 2.6 (m, 2H); 3.3 (m, 1H); 4.1 (b, 1H); 4.78-5.56 (c, 5H); 7.48 (d, 4H); and 8.18 (d, 4H) ppm. The IR spectrum in dichloromethane showed absorptions at 5.62 and 5.7 microns.

1. temperatureat reflux for 20 hours under a nitrogen atmosphere
2. concentrationThe solution was then concentrated in vacuo
3. dissolutionthe residue was dissolved in 700 ml of dichloromethane
4. washThe dichloromethane solution was washed two times with water
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated in vacuo to a yellowish semi-solid (15.0 g) of the title compound