ammonium formate; palladium on activated charcoal in methanol T=20°C; Hydrogenolysis; 0.166667 h;

1: BOC-glycine; C14H14NPol With benzotriazol-1-ol; diisopropyl-carbodiimide in N,N-dimethyl-formamide solid phase reaction; 2: With trifluoroacetic acid in dichloromethane 0.5 h; solid phase reaction; 3: BOC-glycine; 1-(tert-butoxycarbonyl)-L-proline; N-tert-butoxycarbonyl-L-leucine; boc-Ng-tosyl-L-arginine; N-tert-butoxycarbonyl-O-benzyl-L-serine; Boc-L-tyrosine(2-Br-Z)-OH; boc-Trp(CHO)-OH; Boc-pGlu-OH; N-Boc-L-His(Tos)-OH Further stages;

1: C21H31N2O5Pol With trifluoroacetic acid in dichloromethane 0.5 h; solid phase reaction; 2: N-Boc-L-His(Tos)-OH With benzotriazol-1-ol; O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; N-ethyl-N,N-diisopropylamine in 1-methyl-pyrrolidin-2-one; dimethyl sulfoxide 3 h; solid phase reaction; 3: 1-(tert-butoxycarbonyl)-L-proline; t-Boc-L-valine; (2S,3S)-2-(tert-butoxycarbonylamino)-3-methylpentanoic acid; N-tert-butoxycarbonyl-L-phenylalanine; boc-Ng-tosyl-L-arginine; (2S)-3-cyclohexyloxycarbonyl-2-t-butoxycarbonylaminopropanoic acid; Boc-L-tyrosine(2-Br-Z)-OH; N-Boc-L-His(Tos)-OH Further stages;

1: C24H29N2O5Pol With trifluoroacetic acid in dichloromethane 0.5 h; solid phase reaction; 2: 1-(tert-butoxycarbonyl)-L-proline With benzotriazol-1-ol; O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; N-ethyl-N,N-diisopropylamine in 1-methyl-pyrrolidin-2-one; dimethyl sulfoxide 3 h; solid phase reaction; 3: t-Boc-L-valine; (2S,3S)-2-(tert-butoxycarbonylamino)-3-methylpentanoic acid; boc-Ng-tosyl-L-arginine; (2S)-3-cyclohexyloxycarbonyl-2-t-butoxycarbonylaminopropanoic acid; Boc-L-tyrosine(2-Br-Z)-OH; N-Boc-L-His(Tos)-OH Further stages;

2: H2, AcOH / Pd/C View Scheme

Yield given. Multistep reaction;

2: aq. NaOH / dimethylformamide View Scheme