PREPARATION OF PEPTIDE DERIVATIVE

摘要

PURPOSE: Provided is a preparation method of a peptide derivative in high yields. The prepared peptide derivative acts as an antagonist of motilin, and is useful as a therapeutic drug for enteric and gastric diseases. CONSTITUTION: The peptide derivative is represented by the formula(I), wherein R1 is a hydrogen atom or a C1-C4 linear or branched alkyl group; R2 is a hydrogen atom or a methyl group; and R3 s a halogen atom. It is manufactured by the steps of: reaction of a compound of the formula(II) and a compound of the formula(III) to obtain a compound of the formula(IV); demethylating the compound of the formula(IV) to obtain a compound of the formula(V); reaction of a compound of the formula(V) and a compound of the formula(VI) to obtain a compound of the formula(VII); and deprotecting an amino group of the compound of the formula(VII).