Abstract: The ¹³C NMR spectra of 33 mono-, di- and tri-substituted pyridine derivatives were recorded and the spectral lines were assigned. 16 of the derivatives are novel compounds.On the basis of the variation of the ¹³C NMR spectral data the empirical parameters for the calculation of both pyridine ring and alkyl chemical shifts in α-, β and γ-mono substituted pyridines with the number of alkyl carbon atoms greater than 2 were obtained. The empirical additivity rules of mono-and multi-alkyl substituted pyridines are discussed.

Key words: Substituted pyr.idines, ¹³C-NMR spectra, empirical parameters, substituent effect, additivity rules