Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

Participants

Reaction Steps

To a solution consisting of 0.3 g (0.67 mmol) N-(2-aminoethyl) trans-1,2-diaminocyclohexane-N,N',N',N",N"pentaacetic acid in 20 ml dimethylsulfoxide was added 0.62 g (5.4 mmol) N-hydroxysuccinimide and 0.41 g (2.0 mmol) dicyclohexylcarbodiimide. This was stirred at room temperature for 24 hr. A white fluffy solid of dicyclohexyl urea formed in the reaction and was filtered. The filtrate was concentrated to a thick oil under reduced pressure. A solid precipitated from the oil upon the addition of acetonitrile. This solid was collected, washed with acetonitrile and dried under vacuum to give 0.25 g of the final product. NMR showed an average of 2 NHS esters so the yield is 58%. No further purification was attempted; mp 100°-130° C.

Provenance & Evidence