Lipophilicity of Some N‐ and O‐Substituted Alkanoic Acids of 1,2‐Benzisothiazol‐3(2H)‐one Determined by Reversed‐Phase Thin Layer Chromatography

Abstract

The relative lipophilicity (R _Mo) and specific hydrophobic surface area of four N‐substituted and seven O‐substituted alkanoic acids of chloro‐ and fluoro‐ derivatives of 1,2‐benzisothiazol‐3(2H)‐one was studied by reversed‐phase thin layer chromatography (RP‐TLC) on silica C‐18 plates with mixtures of methanol–water, methanol–glycine buffer pH 1.95, and methanol–glycine buffer pH 10.0 as mobile phases. The linear correlations between the volume fraction of methanol and R _M values over a limited range were established for each solute with high values of correlation coefficients (r > 0.98). The lipophilicity and specific hydrophobic surface area of the investigated acids were significantly intercorrelated, although the chemical structures of the acids were different. The linear correlation was found between R _Mo values for mobile phase methanol–glycine buffer pH 1.95 and theoretically calculated log P values.

Keywords:

• Lipophilicity
• R _M values
• N‐ and O‐Substituted alkanoic acids
• 1,2‐Benzisothiazol‐3(2H)‐one

Acknowledgment

The authors gratefully thank Dr. Hab. Dariusz Matosiuk (Department of Synthesis and Technology of Drugs, Medical University of Lublin) for calculations of log P.