series of pyridine‐, pyridazine‐, and pyrazine‐derived carboxamides bearing at the ring N‐atom an alkyl side‐chain with a terminal carboxylic group (7–11) or with a terminal acetylamino malonic ester moiety (13–17, 19–23) is described. Two desaza‐pyridazomycin derivatives (24, 26) and homologs thereof (25, 27) were synthesised. The novel compounds which are structurallyrelated to the antifungal antibiotic