反应详情

9.0 g of N-ethyl-carbamic acid-2-(4-phenoxyphenoxy)ethyl ester are dissolved in 90 ml of ethylene chloride. To this solution are added 9.6 g of oxalic acid monoethyl ester chloride, and stirring is maintained for 10 hours under mild refluxing conditions. The cooled reaction mixture is then poured into 200 ml of ice-water, and the organic phase is separated. This is washed with cold water, dried over sodium sulfate, concentrated by evaporation and taken up in dichloromethane. Chromatography on silica gel with dichloromethane as the eluant thus yields the compound of the formula ##STR6## in the form of white crystals having a m.p. of 56°-58° C.

1. temperatureis maintained for 10 hours
2. temperatureunder mild refluxing conditions
3. customThe cooled reaction mixture
4. customthe organic phase is separated
5. washThis is washed with cold water
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated by evaporation
8. customChromatography on silica gel with dichloromethane as the eluant thus yields the compound of the formula ##STR6## in the form of white crystals