Diisopropylethylamine → H-Val-Gln-Pro-Gly-OH

Temperature

25 °C

H-Gln-Pro-Gly-OH (1 eq.) was added to H2O containing DIPEA (2.00 eq.). The slurry was stirred at 25° C. until a clear solution was observed and was then cooled to 0° C. Z-Val-OSu (1.1 eq.) was dissolved in MeCN at 25° C. until a clear solution was obtained and was then cooled to 0° C. The Z-Val-OSu solution was added to the solution of H-Gln-Pro-Gly-OH in such way that the temperature did not rise above 5° C. Then the mixture was stirred for at least 2 h. The peptide solution was concentrated and then diluted with a KHSO4 solution and stirred for a few minutes. This aqueous solution was washed twice with a mixture of IPE and AcOEt. The organic phases were discarded and the aqueous phase was extracted 2 times with a 20% i-BuOH in DCM solution. The organic phases were collected and concentrated under reduced pressure until water content in the evaporates was ≦1% weight. The solution of the protected tetrapetide was then precipitated in IPE at 25° C. Z-Val-Gln-Pro-Gly-OH (SEQ ID NO 16) was collected by filtration washed with IPE and dried under vacuum until IPE content in the peptide was <5% weight. The protected fragment was dissolved in methanol at 30° C. and Pd/C (0.02 eq.) was added to the peptide solution. The solution was stirred at 20° C. followed by the introduction of hydrogen under pressure (0.3 bar). After stirring for 3 hours the solution was filtered to remove the catalyst which was washed with methanol. After evaporation, the free tetrapeptide was then precipitated by transferring the solution into MeCN at 10° C. The solid was filtered and washed with MeCN. After drying under vacuum, 60% of H-Val-Gln-Pro-Gly-OH (SEQ ID NO 4) was recovered.

1. temperaturewas then cooled to 0° C
2. customwas obtained
3. temperaturewas then cooled to 0° C
4. customdid not rise above 5° C
5. stirringThen the mixture was stirred for at least 2 h
6. concentrationThe peptide solution was concentrated
7. additiondiluted with a KHSO4 solution
8. stirringstirred for a few minutes
9. washThis aqueous solution was washed twice with a mixture of IPE and AcOEt
10. extractionthe aqueous phase was extracted 2 times with a 20% i-BuOH in DCM solution
11. customThe organic phases were collected
12. concentrationconcentrated under reduced pressure until water content in the evaporates
13. customThe solution of the protected tetrapetide was then precipitated in IPE at 25° C
14. filtrationZ-Val-Gln-Pro-Gly-OH (SEQ ID NO 16) was collected by filtration
15. washwashed with IPE
16. dry with materialdried under vacuum until IPE content in the peptide
17. dissolutionThe protected fragment was dissolved in methanol at 30° C.
18. stirringThe solution was stirred at 20° C.
19. stirringAfter stirring for 3 hours the solution
20. filtrationwas filtered
21. customto remove the catalyst which
22. washwas washed with methanol
23. customAfter evaporation
24. customthe free tetrapeptide was then precipitated
25. customat 10° C
26. filtrationThe solid was filtered
27. washwashed with MeCN
28. dry with materialAfter drying under vacuum, 60% of H-Val-Gln-Pro-Gly-OH (SEQ ID NO 4)
29. customwas recovered

ORD record

ord-2c3ab0cc23fc4f68a61fdf717db5d9e5

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09051349B2