Eleven oxazolone derivatives were synthesized and characterized by 1H NMR, EI, IR and UV spectroscopic and CHN analysis. Three compounds, 4-[(E)-(4-nitrophenyl) methylidene]- 2-phenyl-1, 3-oxazol-5 (4H)-one (11), 4-[(E)-(4-methoxyphenyl) methylidene]-2-methyl-1, 3- oxazol-5-one (12) and 4-[(E)-(4-nitrophenyl) methylidene]-2-methyl-1, 3-oxazol-5 (4H)-one (13) were screened for phagocyte chemiluminescence, neutrophil chemotaxis, T-cell ...