4-Nitrophenol → N,N'-Dicyclohexylurea

Participants

Reaction Conditions

Reaction Steps

The above compound (8.2 g) and p-nitrophenol (3.3 g) are dissolved in 200 ml of ethyl acetate and cooled to 5° C. N,N'-Dicyclohexylcarbodiimide (5.0 g) is added portionwise and the reaction mixture is stirred at 5° C. for about 16 hours. The dicyclohexylurea is filtered off and the ethyl acetate filtrate is concentrated in vacuo for 1 hour. Diisopropyl ether (4 ml) and ethyl acetate (4 ml) are added to the pot residue. A second crop of dicyclohexylurea is obtained. The filtrate is concentrated in vacuo to yield 8.7 g of crude active ester.

Provenance & Evidence