Trifluoroacetic acid → HCID 131711084, compound

Participants

Reaction Steps

BOC-Ala-Gly-Thr(Bzl)-Pro-NH2 (10.5 g.) was added to TFA (35 ml.) at -5° C., and, after stirring for 30 minutes, concentrated in vacuo. The residue was treated with ethyl ether, and the precipitated material was filtered and dried in vacuo over sodium hydroxide to obtain H-Ala-Gly-Thr(Bzl)-Pro-NH2.TFA. THF (100 ml.) was added thereto, and triethylamine was added at -5° C. to adjust the pH to 5.0. BOC-Val-Gly-OH (5.49 g.) and HOBT (2.66 g.) were added thereto. To this mixture WSC (3.61 ml.) was added dropwise at -5° C., and the mixture stirred at -5° C. for 1 hour and at room temperature overnight. The reaction mixture was concentrated in vacuo, and the residue was dissolved in chloroform (300 ml.). The solution was washed twice with NaCl-saturated 1 N HCl (200 ml.), twice with NaCl saturated 5% sodium bicarbonate solution (200 ml.) and saturated NaCl solution (75 ml.) in this order. After the solution was dried with anhydrous sodium sulfate, the organic layer was concentrated in vacuo. Recrystallization from methanol - ethyl ether gave BOC-Val-Gly-Ala-Gly-Thr(Bzl)-Pro-NH2 (12.0 g., Yield: 88.3%). m.p.: 121° - 135° C. (decomp.). TLC: one spot. (solvent system 6).

Provenance & Evidence