Within the framework of a systematic study of phenylcarbamic acid derivatives with local anaes- thetic effects, a series of 1-methyl-2-piperidinoethylesters of 2-, 3- and 4-alkoxy(methoxy to decylo- xy)phenylcarbamic acids and an unsubstituted derivative, i.e. 1-methyl-2-piperidinoethylester of phenylcarbamic acid, were prepared. In the prepared series of compounds, the mutual relationship of the surface local anaesthetic activity and some physical and physico-chemical parameters (g, pKa, pH of turbidity, log P, p, RMr, log k’) was studied and quantified by the method of QSAR analysis. The steric constants L and B4, molar refraction (MR), valence indices of molecular connectivity ( 1 c v ), the number of carbons of the alkoxysubstituent (Cx) and molecular mass (Mr) were also correlated. The study has revealed that there exists a linear relation between the number of the carbons of the alkoxysubstituent (Cx), tabulated or calculated values (Mr, L, B4, MR, 1 c v ) and experimentally obtained physico-chemical parameters (RMr, log P, p, log k’, pH of turbidity, pKa).

        Key words: 1-methyl-2-piperidinoethylester of alkoxyphenylcarbamic acids – local anaesthetic activity – structure–activity relationship