RGD-CONTAINING PEPTIDES Russian patent published in 2003 - IPC

FIELD: organic synthesis. SUBSTANCE: invention provides a group of novel protected linear peptides, which can be used as intermediates in synthesis of GRD-containing cyclopeptides and which are depicted by a general formula: , in which R¹ is benzyl or tert-butyl; R² is other than R¹ and is selected from group including tert-butyl, benzyl, 4-methoxybenzyl, 4-nitrobenzyl, diphenylmethyl, 2,2,2- trichloroethyl, 2,2,2-trichloro-1,1-dimethylethyl, allyl, 9-fluorenylmethyl, carboxamidomethyl, substituted 2- sulfonylethyl wherein A denotes optionally substituted phenyl or benzyl; R³ is hydrogen atom or (i) urethane protection group wherein B¹ is different from R¹ and selected from tert-butyl, benzyl, 4-methoxybenzyl, 9- fluorenylmethyl, 2-(4- nitrophenylsulfonyl)ethyl, or (ii) peptidyl containing one to three amino acid residues; as well as peptides of the above-indicated formula, in which R³ is peptidyl E-Z-Y-X- wherein E is hydrogen atom or urethane protection group wherein B² is different from R¹ and can be tert-butyl, benzyl, 4-methoxybenzyl, 9-fluorenylmethyl, or 2-(4-nitrophenylsulfonyl)ethyl; X is nil or Gly; Y is Gly, Ala, Val, Ile, Pro, Lys(G), or Orn(G), in which G denotes urethane protection group wherein connected to omega-amino group; and Z can be Phe or D-Phe. EFFECT: widened synthetic possibilities in the peptide synthesis area. 2 cl, 8 ex