Water → Cyclohexylurea

Participants

Reaction Conditions

Reaction Steps

6.0 g of 4-(β-<1-ethyl-1,2-dihydro-2-oxo-nicotinamido>-ethyl)-benzenesulfonamide (melting point 215 - 216° C, prepared from 4-(β-aminoethyl)-benzenesulfonamide and 1-ethyl-1,2-dihydro-2-oxo-nicotinic acid chloride) were suspended in 60 ml acetone. After the addition of 8.55 ml 2N sodium hydroxide solution, the reaction mixture was cooled to 0° C, 2.35 g of cyclohexyl isocyanate in 5 ml acetone were added dropwise while stirring and stirring was continued for 1 hour at 0° C and for 4 hours at room temperature. The volume of the reaction mixture was then doubled by adding water, the mixture was filtered and the filtrate acidified with 2N hydrochloric acid. The precipitate was dissolved in dilute ammonia solution and precipitated again with dilute hydrochloric acid, stirred with sodium bicarbonate solution and recrystallized from methanol. The N-[4-(β-<1-ethyl-1,2-dihydro-2-oxo-nicotinamido>-ethyl)-benzenesulfonyl]-N'-cyclohexyl urea obtained in this manner melted at 189 - 190° C.

Provenance & Evidence