1: fmoc-O-tert-butyl-L-tyrosine With benzotriazol-1-ol; N-ethyl-N,N-diisopropylamine; diisopropyl-carbodiimide in N,N-dimethyl-formamide 0.25 h; 2: in N,N-dimethyl-formamide 3: Fmoc-Arg (Boc)2-OH; N-(fluoren-9-ylmethoxycarbonyl)-L-Val; N-(9-fluorenylmethoxycarbonyl)-L-aspartic acid-β-(tert-butyl)ester; N-(fluoren-9-ylmethoxycarbonyl)-L-Lys(Nε-Boc) Further stages;