PROCESS FOR PREPARING A NONAPEPTIDE HAVING LH- AND FSH-RELEASING ACTIVITY AND INTERMEDIATES THEREFOR

摘要

AHP-6497 PROCESS FOR PREPARING A NONAPEPTIDE HAVING LH- AND FSH-RELEASING ACTIVITY AND INTERMEDIATES THEREFOR A process for preparing the nonapeptide of the formula I H-Pyr-His-Trp-Ser-Tyr-D-Ala-Leu-Arg-Pro-NHEt having LH- and FSHreleasing activity which comprises the following steps: condensing 5-oxoprolyl-histidyl-tryptophane hydrazide by means of the azide method with a protected hydrazide of seryi-tyrosyl-D-alanine, preferably seryl-tyrosyl-D-alanine carboxyhydrazide t-butyl ester (II), followed by treatment of the reaction product with an acid to obtain 5-oxoprolyl-histidyl-tryptophyl-seryl-tyrosyl-D-allanine hydrazide (IV), condensing the latter compound by means of the azide method with leucyl-arginyl-proline ethylamide (V)to obtain the nonapeptide of formula I isolated as an acid addition salt which is converted to the free base or other pharmaceutically acceptable acid additions salts.