反应详情

0.5 g N-(4-[2-(4-methyl-2-oxo-piperidine-1-carboxamide)-ethyl]-benzenesulfonyl)-N'-cyclohexyl-isourea methyl ether (m.p. 138°-140° C., prepared by desulfurization of N-(4-[2-(4-methyl-2-oxo-piperidine-1-carboxamido)-ethyl]-benzenesulfonyl)-N'-cyclohexyl-thiourea with mercury oxide in the presence of methanol) is dissolved in 5 ml of dioxan, and heated for a short time on a steam bath with 2 ml of concentrated hydrochloric acid. Subsequently, the water is added to the reaction mixture, the product is suction-filtered, reprecipitated from dilute ammonia and recrystallized from dilute acetone. The N-(4-[2-(4-methyl-2-oxo-piperidine-1-carboxamido)-ethyl]-benzenesulfonyl)-N'-cyclohexyl urea obtained has a melting point of 176°-178° C. and, with the substance obtained according to Example 8, shows no depression.

1. filtrationthe product is suction-filtered
2. customreprecipitated from dilute ammonia
3. customrecrystallized from dilute acetone