METHOD FOR SYNTHESIS NONAPEPTIDE ETHYLAMIDE AND INTEMEDIATE COMPOUNDS FOR SYNTHESIS THEREOF Russian patent published in 2012 - IPC C07K1/06 C07K7/06 C07K5/06 C07K5/08 A61K38/08 A61P5/06 

FIELD: chemistry.

SUBSTANCE: invention relates to methods for synthesis of nonapeptide ethylamide, having strong LH-RH/FSH-RH activity, of formula pGlu-His-Trp-Ser-Tyr-D-Ser(Bu^t)-Leu-Arg-Pro-NH-C₂H₅·2AcOH (I), and intermediate compounds for synthesis thereof. The nonapeptide ethylamide is obtained via condensation of a C-terminal tetrapeptide of formula H-D-Ser(Bu^t)-Leu-Arg-Pro-NH-C₂H₅·HCl (II) with a dipeptide of formula: X-Ser-Tyr-OH (IV), where X is a protective group. The obtained N-substituted hexapeptide ethylamide of formula X-Ser-Tyr-D-Ser(Bu^t)-Leu-Arg-Pro-NH-C₂H₅·HCl (III) is treated with an unblocking agent to remove the N-protective group, and then condensed with a tripeptide of formula pGlu-His-Trp-OH·HCl (V) and the end product is purified through chromatography and extracted in form of a monoacetate salt.

EFFECT: high output.

4 cl, 1 ex