Dicyclohexylcarbodiimide → HCID 131717720, compound

Participants

Reaction Conditions

Reaction Steps

14 g of H-D-Tyr(Bzl)-OBzl (38.7 mmoles) and 12.53 g of Boc-Asp(OBzl)-OH (38.7 mmoles) are dissolved in 145 ml of CH2Cl2. In the ice-cooled solution 8.78 g of DCC (42.5 mmoles) dissolved in 35 ml of CH2Cl2 are dropped. The mixture is left under stirring for 1 h at room temperature and for one night at 4° C. The resulting precipitate (dicyclohexylurea) is filtered off and the filtrate is evaporated to dryness under vacuum. The semi-solid residue is taken up with 170 ml of 70/30 ethanol/H2O, the mixture is refluxed while two immiscible phases are formed, and left to cool under vigorous stirring. The resulting white solid is filtered and treated again with 70/30 ethanol/H2O to reflux. Thus 20 g of Boc-Asp(OBzl)-D-Tyr(Bzl)-OBzl are obtained.

Provenance & Evidence