PROTECTED DERIVATIVES OF OCTREOTIDE Russian patent published in 2003 - IPC

FIELD: organic chemistry, biochemistry, peptides. SUBSTANCE: invention describes derivatives of octreotide of the general formula (I) where (D)A means residue D-(N_indole-formyl)-tryptophane; R¹ means hydrogen atom or tert. -butoxycarbonyl group either group of species CO-OX¹ where X¹ can mean the following values: 2-alkylsulfonylethyl, 2-phenyl-sulfonylethyl, 2-(4-substituted aryl)-sulfonylethyl; R² means CO-OX² where X² can mean the following values: 2-alkylsulfonylethyl, 2-phenylsulfonylethyl, 2-(4- substituted aryl)-sulfonylethyl; R³ and R⁴ mean simultaneously values -CH₂-NH-CO-Y where Y means methyl, C₁-C₅-alkyl, phenyl, substituted phenyl or in common they form disulfide bond; R⁵ means hydrogen atom or group of species CO-OX³ where X³ can mean the following values: 2- alkylsulfonylethyl, 2-phenyl-sufonylethyl, 2-(4-substituted aryl)-sulfonylethyl. New protected derivatives of octreotide are parent compounds for the more effective and simple synthesis of octreotide with the enhanced yield. EFFECT: improved method of synthesis. 2 tbl