Dicyclohexylcarbodiimide → HCID 131710225, compound

Participants

Reaction Steps

667 mg of Z-Gly-Phe-Gly-Pro-OH are dissolved in 20 ml of acetonitrile together with 608 mg of H-Glu(OtBu)-Thr(tBu)-Pro-OtBu obtained under 4 and after the addition of 222 mg of N-hydroxysuccinimide and 269 mg of dicyclohexylcarbodiimide, stirred for 16 hours at room temperature. The precipitated dicyclohexyl urea is filtered off, the filtrate . evaporated, the residue dissolved in much ethyl acetate and the solution washed as described under 1, above. After drying and evaporation of the solution in vacuo, the crude product is purified by chromatography on a column of silica gel. It can be eluted with ethyl acetate an ethyl acetate×ethanol (4:1). It is then reprecipitated from ether. Melting point: 96° - 99°C. Thin-layer chromatogram on silica gel: RfCHCl3-MeOH(δ:1) = 0.40; Rf102A = 0.75; Rf52 = 0.80

Provenance & Evidence