HCID 178455946, compound → HCID 178455945, compound

Participants

Reaction Steps

80 mg of Z-Phe-His-Leu-Val-Ile-His-Lys(BOC)-OMe (Example 55) are dissolved in 800 μl of 95% trifluoroacetic acid (duration approximately 1 minute) and left to stand for 2 minutes. The product is then precipitated by the addition of 8 ml of diisopropyl ether, left to stand for 15 minutes at 0°, filtered off, and the precipitate is washed with diisopropyl ether and dried over KOH in a high vacuum. The powder is then dissolved in 1 ml of 90trifluoroethanol, precipitated by the addition of 10 ml of 3% MaHCO3 solution, filtered off, washed with H2O and dried over potassium hydroxide and phosphorus pentoxide in a high vacuum. To convert the resulting acid-free title compound into the acetate, the product is dissolved in 2 ml of 90% acetic acid and lyophilised. The title compound is a chromatographically homogeneous amorphous powder; Rf (B17)=0.08, Rf (B21)=0.65.

Provenance & Evidence