反应详情

4.2 g of N-(4-[2-(1-oxo-isoindoline-2-carboxamido)-ethyl]-benzenesulfonyl)-carbamic acid methyl ester (melting point 215°-217° C., prepared from 4-(2-[1-oxo-isoindoline-2-carboxamido]-ethyl)-benzenesulfonamide and methyl chloroformate) are dissolved in 100 ml of dioxane at 50° C. and 1 g of cyclohexylamine is added. The cyclohexylamine salt of the urethane, which precipitates, dissolves slowly on boiling under reflux for one hour. The mixture is concentrated to 1/3 of its volume and the residual solution is poured onto dilute hydrochloric acid. N-(4-[2-(1-Oxo-isoindoline-2-carboxamido)-ethyl]-benzenesulfonyl)-N'-cyclohexyl-urea, which is obtained in good yield, is filtered off and recrystallized from aqueous acetone. It melts at 214°-216° C.

1. customThe cyclohexylamine salt of the urethane, which precipitates
2. dissolutiondissolves slowly
3. temperatureunder reflux for one hour
4. concentrationThe mixture is concentrated to 1/3 of its volume
5. additionthe residual solution is poured onto dilute hydrochloric acid