Modulation of pharmacological profile of diphenylethane (lefetamine-type) derivatives.

With the aim to split the pharmacological properties of lefetamine (CAS 14148-99-3), some structural modifications of this compound have been studied. The basic group of lefetamine has been shifted from the alkyl chain to the vicinal phenyl ring and the N-substitution has been changed. The dimethylaminomethyl derivatives and chiefly the o-morpholinometyhl exhibited a strong anti-visceral chemical antinociception activity stripped of thermal antinociception properties and physical dependence liability. Furthermore, through the introduction of a diethylaminomethyl group in the lefetamine structure some derivatives were selected exhibiting besided a significant increase in the anti-visceral chemical antinociception activity, remarkable local anesthetic properties.