| abstract |
A process for the preparation of a pentapeptide derivative of the general formula (I) wherein A is OH or NR.sup.1 wherein R @ 2 is independently R.sup.1. and R.sup.2.n. H, C.sub.1-7.n.alkyl, phenyl having up to 3 substituents from C.sub.1-6n.alkyl, CF.sub.3, NO.sub.2-. and halogen, furthermore benzyl having up to 3 substituents from C.sub.1-6n.alkyl, CF.sub.3, NO.sub.2. and halogen, R.sup.3, R.sup.4. and R 5 is methyl, isopropyl, isobutyl, tert-butyl or 1-methylpropyl, starting with the proline amide of formula II and optionally recovering the -NR.sub.1.nRsub group from the resulting peptide. 2.n. where the individual symbols are as defined above, cleaves hydrolytically |