A simple and convenient method has been developed for the synthesis of a series of 2‐(4‐substituted phenyl)‐4‐(substituted arylidene)‐1,3‐oxazol‐5‐ones (5a–j) via reactions of hippuric acid with differently substituted aromatic aldehydes (4a–j) in sodium acetate, potassium acetate, calcium acetate, and ammonium acetate, respectively, which were tested for their efficiency as catalysts in both conventional and microwave‐assisted synthetic methods in presence of 4 Å zeolites. The title compounds were evaluated for their antimicrobial properties against selected human pathogens (bacterial and fungal) and phytopathogens (fungal) and were compared with standard drugs. The results of the study are reported.