AbstractA number of aminoketones with prospective local anaesthetic activity were prepared. The structure of the synthesized compounds was confirmed by spectroscopic and elemental analyses. The physicochemical parameters (pka and logP) were also investigated. The local anaesthetic activity was determinedin vitroon sciatic frog's nerve by the compound action potential technique: the phthalimide derivatives possess considerable local anaesthetic activity equal to that of lidocaine and higher than that of procaine.