4-Nitrophenol → N,N'-Dicyclohexylurea

Participants

Reaction Conditions

Reaction Steps

The above product (0.75 g, 0.0024 mole) is dissolved in 50 ml ethyl acetate. This is cooled to -5° C. and p-nitrophenol is added followed by the portionwise addition of dicyclohexylcarbodiimide. The reaction mixture is stirred at -5° C. for 2 hours. The formed dicyclohexylurea is filtered off. After concentrating to a 10 ml volume, the reaction mixture is cooled overnight. More dicyclohexylurea is formed. This is filtered and the filtrate is concentrated in vacuo to yield 0.95 g of active ester, (the p-nitrophenyl ester of N-[N-[2-(mercaptomethyl)-4-methyl-1-oxopentyl]glycyl]glycine).

Provenance & Evidence