反应详情

温度

200 °C

A mixture of 2-benzyl-4-ethoxy-7-allyloxysaccharin (0.25 g) and triglyme was heated at 200° C. for 20 minutes, examined for extent of reaction by thin layer chromatography, heated at 200° C. for 20 minutes more, stirred overnight and poured into ice-water. The resulting tacky, brown solid was dissolved in dichloromethane. The dichloromethane solution was washed with saturated aqueous sodium chloride solution, dried over sodium sulfate and stripped of dichloromethane. Column chromatography of the residue (0.29 g) on silica using dichloromethane and dichloromethane-acetone (up to 99:1) as eluants afforded 2-benzyl-4-ethoxy-6-allyl-7-hydroxysaccharin (90 mg, 36% yield) whose mass spectrogram showed a molecular ion at mass 373.

1. customexamined for extent of reaction by thin layer chromatography
2. temperatureheated at 200° C. for 20 minutes more
3. washThe dichloromethane solution was washed with saturated aqueous sodium chloride solution
4. dry with materialdried over sodium sulfate