Ethyl Acetate → HCID 178455937, compound

Participants

Reaction Steps

The tripeptide, from part C, Pyr-Trp-Pro (23.3 mmoles) is dissolved in DMF (85 ml) and 3.27 ml (23.3 mmoles) TEA, the solution cooled to -20° (inside the flask, or -35° to -40° in the cooling bath) and kept at this temperature for 15-20 minutes. To this cold solution 3.19 ml of isobutyloxycarbonyl chloride is added and then a time of 30 minutes is allowed for the mixed anhydride to be formed at the same temperature. A solution of Arg-Pro-Gln-Ile-Pro-Pro (16.5 g) in DMF (100 ml) is precooled to about 0° and then added into the solution of the mixed anhydride. At this moment, the pH value is adjusted to 8 with TEA (8.5 ml) while the temperature of 0° is maintained. After 20 to 24 hours at room temperature, the volume of the solvents is reduced to 1/3-1/4 and poured into 20-25 volumes of EtOAc containing 3 % of AcOH. The precipitate is washed thoroughly with EtOAc and then dried in vacuo over KOH overnight to yield the title compound. This material is dissolved in water, sterilized by filtration, and the sterile aqueous solution freeze-dried to a free flowing powder. The powder is reconstituted for injection with water for injection or saline.

Provenance & Evidence