Tripeptide

Abstract

The new blocked tripeptide Y-(N w -R')Arg-Pro-Gly-R wherein R is .[.hydroxy, methoxy or.]. amino, R' is a suitable blocking group and Y is hydrogen or an easily removable protective group has been found to be a valuable intermediate for the preparation of large peptide chains, such as for instance, the decapeptide Gn-RH.

I claim: 
     
       1. The optically active L-form of the tripeptide Y-(N.sup.ω -R')Arg-Pro-Gly-R wherein R is .[.hydroxy, methoxy or.].  amino, R' is nitro, p-nitrobenzyloxycarbonyl, tetrachloroisopropyloxyphthaloyl or p-tolylsulfonyl, and wherein Y is hydrogen, tert.-butoxycarbonyl, o-nitrophenylsulfenyl, 2-(diphenyl)isopropyloxycarbonyl, benzyloxycarbonyl or phthalyl. 
     
     
       2. The compounds of claim 1 wherein R is .[.hydroxy, methoxy or.]. amino, R' is p-toluenesulfonyl, p-nitrobenzyloxycarbonyl, tetrachloroisopropoxyphthaloyl, or nitro and Y is hydrogen, tert.-butoxycarbonyl, o-nitrophenylsulfenyl, phthalyl, benzoyloxycarbonyl or 2-(diphenyl)isopropyloxycarbonyl. 
     
     
       3. The compound of claim 2 wherein R is amino, R' is nitro and Y is hydrogen. 
     
     
       4. The compound of claim 2 wherein R is amino, R' is p-toluenesulfonyl and Y is hydrogen. 
     
     
       5. The compound of claim 2 wherein R is amino, R' is p-toluenesulfonyl and Y is benzyloxycarbonyl. 
     
     
       6. The compound of claim 2 wherein R is amino, R' is toluenesulfonyl and Y is tert.-butoxycarbonyl. 
     
     
       7. The compound of claim 2 wherein R is amino, R' is nitro and Y is benzyloxycarbonyl. .[.8. The compound of claim 2 wherein R is amino, R' is nitro and Y is trert.-butoxycarbonyl. .].