The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance by Correlation Gas Chromatography

Abstract

Vapor pressures, vaporization, and sublimation enthalpies of several pharmaceuticals have been evaluated by a combination of correlation chromatography experiments, differential calorimetry measurements with existing literature values. The compounds investigated and their properties include 1-adamantylamine [ΔcrlHm(Tfus)/kJ·mol–1 = (7.3 ± 0.2); Tfus/K = (477.4 ± 0.9); ΔlgHm(298.15 K)/kJ·mol–1 = (59.9 ± 2.5); ΔcrgHm(298.15 K)/kJ·mol–1 = (∼59.9 ± 3.5); p(l)/Pa = (21 ± 1); p(cr)/Pa = (11.5 ± 2.1)]; 1-adamantyl-ethanamine, [ΔlgHm(298.15 K)/kJ·mol–1 = (68.7 ± 3.7); p(l)/Pa = (3 ± 1)]; α,α-dimethylphenethylamine [ΔlgHm(298.15 K)/kJ·mol–1 = (60.2 ± 2.6); p(l)/Pa = (35 ± 4)]; trans 2-phenylcyclopropylamine [ΔlgHm(298.15 K)/kJ·mol–1 = (60.3 ± 2.1), p(l)/Pa = (28 ± 5)]; 1-dodecanamine [ΔcrgHm(298.15 K)/kJ·mol–1 = (118.3 ± 1.8); p(cr)/Pa = 1.6 ± 0.1]; and 1-tetradecanamine [ΔcrgHm(298.15 K)/kJ·mol–1 = (134.5 ± 2.1); p(cr)/Pa = 0.12 ± 0.04]. Vapor pressure equations also derived from vapor pressure—retention time correlations as a function of temperature are reported for both standards and targets. The equations appear applicable from T/K = 298.15 to each compound’s respective boiling temperature.