Structure and activity of stereoisomers of fenaridine

We established that optimal analgesia peaks are obtained in the case of chemical structures where the radicals COC2H s and COC4H30 are contained on the nitrogen amide atom. However, only compound l-(2-phenethyl)-2,5-dimethyl-4-Npropionylanilinopiperidine IVc has a greater action and broader spectrum of pharmacological activity than the control analgesic fentanyl from among the same class of chemical compounds [i].