Dicyclohexylcarbodiimide → N-lysyl-5'-O-palmitoyl-deoxycytidine

Participants

Reaction Conditions

Reaction Steps

14 grams of 5′-O-palmitoyl-deoxycytidine is dissolved in 100 ml dimethylacetamide, 1 molar equivalent of di-tert-butoxycarbonyl-lysine is added, and the mixture is cooled in an ice bath. 1.2 molar equivalents (7.4 g) of dicyclohexylcarbodiimide are added and the mixture is stirred at 4° C. for 90 hours. The precipitate (dicyclohexylurea) is removed by filtration. 100 ml of water is added to the filtrate, followed by 1 liter of ethyl acetate. N4-(di-N-tert-butoxycarbonyl-lysyl)-5′-O-palmitoyl-deoxycytidine is separated from unreacted reagents by chromatography over silica gel. The t-butoxycarbonyl protecting groups are removed by the standard methods of treatment with an acid, such as trifluoroacetic acid.

Provenance & Evidence