Eighteen new 3-[2-(2-/4-pyridyl)ethyl]benzoxazolinone (benzothiazolinone) derivatives were synthesized by reacting 2-/4-vinylpyridine and appropriate benzoxazolinones and benzothiazolinones. The analgesic activities of these compounds were investigated by modified Koster and hot-plate tests. Test results revealed that most of the compounds at 100 mg/kg dose levels have higher analgesic activities than acetylsalicylic acid. Compounds with bromo substituents on the phenyl ring in the 6-position of the main ring seemed to show less activity than those with fluorinated ones. Compound 6b showed remarkably high activity in the hot-plate test, although it was inactive in the Koster test. However compound 3a had statistically significant high peripheral analgesic activity at all doses compared to other compounds, although it was inactive in the hot-plate test.

Eighteen new 3-[2-(2-/4-pyridyl)ethyl]benzoxazolinone (benzothiazolinone) derivatives were synthesized by reacting 2-/4-vinylpyridine and appropriate benzoxazolinones and benzothiazolinones. The analgesic activities of these compounds were investigated by modified Koster and hot-plate tests. Test results revealed that most of the compounds at 100 mg/kg dose levels have higher analgesic activities than acetylsalicylic acid. Compounds with bromo substituents on the phenyl ring in the 6-position of the main ring seemed to show less activity than those with fluorinated ones. Compound 6b showed remarkably high activity in the hot-plate test, although it was inactive in the Koster test. However compound 3a had statistically significant high peripheral analgesic activity at all doses compared to other compounds, although it was inactive in the hot-plate test.