Acetic Acid → DCCI HOBt

Participants

Reaction Conditions

Reaction Steps

Z-Tyr-Gly-Gly-Phe-Met-Thr(Bzl)-Ser(Bzl)-Glu(OBzl)-Lys(Z)-OH (VI) (0.311g, 0.2 mmol) was dissolved in DMF (2 ml) and the solution was cooled to 0° C. HOBt (0.065g, 0.4 mmol) was added, followed by DCC (0.045g, 0.22 mmol). The mixture was stirred for 1 hour at 0° C and for 1 hour at room temperature. It was then added to a solution of the above docosapeptide amine dissolved in molten phenol. The mixture was stirred for 3 days at room temperature. It was poured slowly to a stirred, cold (0° C), solution of 0.5% AcOH (200 ml). The precipitated solid was filtered and washed with H2O and EtOH. The crude product was triturated three times with boiling MeOH, centrifuged, and dried. Precipitation from DMF/MeOH provided 0.20g (50%); mp 275°-279° C dec. The material was without further characterization subjected to complete protecting group removal with liquid HF.

Provenance & Evidence