RP-HPLC LIPOPHILICITY STUDIES FOR SOME (HETERO)ARYLAMIDES DERIVED FROM 2-AMINO 4,6-DIMETHYL PYRIDINE: INTRODUCTION OF AN HYDROGEN-BOND DESCRIPTOR

Abstract

RP-HPLC measurements (in water + 60% v/v acetonitrile, on a porous polystyrene column) lead to a linear calibration between the retention factor logk and the lipophilicity logP for a series of 9 OECD standards. Introduction of a variable indicator D for hydrogen-bond donors enhances the goodness of fit. From experimental retention factors, estimated values of logP are given for 23 substituted (hetero)arylcarboxamides derived from 2-amino 4,6-dimethyl pyridine, whose anti-inflammatory behavior and anti-cholinesterase activity were previously characterized. From the logP versus logk relationship, a family-dependent indicator variable D is attributed to each compound.

Keywords:

• heteroarylamides
• hydrogen-bond descriptor
• lipophilicity
• RP-HPLC

Notes

*measured in 40% AN medium.

^(a) Klein et al.^{[ 23 ]}

^(b) Experimental values by isocratic chromatography in 60% (v/v) AN.

^(c) Hydrogen-bonding descriptor (see text).

^(d) Molecular volume, calculated according to Abraham^{[ 30 , 31 ]}(unit: 10⁻² cm³ mol⁻¹).