S-ethyl 3-[3-chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propionate 以66%的产率得到S-3-[3-chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propanoic acid