The present invention relates to a process for preparing 4-{[(2S)-2-{4-[5-chloro-2-(4-chloro-1H-1,2,3-triazol-1-yl)phenyl]-5-methoxy-2-oxopyridin-1(2H)-yl}butanoyl]amino}-2-fluorobenzamide (I) or 4-({(2S)-2-[4-{5-chloro-2-[4-(trifluoromethyl)-1H-1,2,3-triazol-1-yl]phenyl}-5-methoxy-2-oxopyridin-1(2H)-yl]butanoyl}amino)-2-fluorobenzamide (II) from 2,5-dimethoxypyridine (III), 1-(2-bromo-4-chlorophenyl)-4-chloro-1H-1,2,3-triazole (X-Cl) or 1-(2-bromo-4-chlorophenyl)-4-(trifluoromethyl)-1H-1,2,3-triazole (X-CF3), 4-amino-2-fluorbenzamide (XIII) and (2R)-2-aminobutanoic acid (XVII).