Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

Participants

Reaction Steps

NHS ester of 3-butenoic acid was synthesized based following literature procedure.32 3-butenoic acid (1.0 g, 1.2 mmol) and NHS (1.47 g, 1.28 mmol) were dissolved in THF (30 ml). The solution was cooled in an ice bath and N,N′-dicyclohyxylcarbodiimide (DCC, 2.4 g, 1.2 mmol) was added under stirring. A white precipitate, dicyclohexylurea (DCU), formed after ˜5 min and the mixture was stirred for 1 hour at 0° C. The reaction proceeded at 4° C. overnight without any agitation. DCU was then removed by filtration. The filtrate was concentrated to give a viscous oil containing some residual DCU. The crude product was re-dissolved in a small volume of THF and then filtered. This procedure was repeated until a clear THF solution was obtained. The solvent was removed and the product was then washed with hexane. Residual solvents were removed under vacuum until a constant weight was obtained. 1H-NMR (500 MHz, CDCl3, δ ppm): 2.64, 2.90, 5.21, 5.24, 5.94.

Provenance & Evidence