ported to have analgetic properties1 (Haffner tail-pinch method2), Sufficient biological activity was exhibited by several members in the series to warrant further investigation of a number of related compounds (Table I). Mannich Bases. From prior studies which investigated@-dimethylaminopropiophenones, ArCOCH2CH2NMe2, for analgetic activity, there emerged the lead compound 5 (Table I). In this particular structure, the active ...