反应详情

The sulfonamido benzoic acid obtained from Example IV is stirred in toluene under argon atmosphere in a flask equipped with a Dean-Strark trap. Toluenesulfonic acid monohydrate (5 mol%) is added and the reaction mixture is warmed to reflux. When no further co-distillation of water is observed, the reaction mixture is cooled to room temperature and concentrated using a rotary evaporator. The resulting crude semi-solid oil is dissolved in a minimum amount of ethyl acetate at the boiling point and the resulting solution then is made cloudy by the addition of hexane. The desired cyclohexyl saccharin compound crystallizes on cooling. The dissolution and crystallization procedure may be repeated if higher purity material is desired. Spectral data for the crystallized product (IR, C=O 1720 cm-1 ; nmr delta=1-2.2 m cyclohexyl, delta=6.2 s broad N--H, delta=7-8 m aromatic) are consistent with the anticipated structure of 5-cyclohexyl saccharin.

1. customequipped with a Dean-Strark trap
2. temperaturethe reaction mixture is warmed to reflux
3. concentrationconcentrated
4. customa rotary evaporator
5. dissolutionThe resulting crude semi-solid oil is dissolved in a minimum amount of ethyl acetate at the boiling point
6. additionby the addition of hexane
7. customThe desired cyclohexyl saccharin compound crystallizes
8. temperatureon cooling
9. dissolutionThe dissolution and crystallization procedure
10. customnmr delta=1-2.2 m cyclohexyl, delta=6.2 s broad N--H, delta=7-8 m