Synthesis and Thermodynamic Parameters of Phase Transitions of 3-(1-R-5-Phenyl-1H-Pyrrol-2-yl)propanoic Acid Derivatives

A series of 3-(1-R-5-phenyl-1H-pyrrol-2-yl)propanoic acids (R = H, Ar, Alk, Hetaryl) was obtained via the reaction of 4,7-dioxo-7-phenylheptanoic acid with amines. The enthalpies of vaporization and fusion of eight compounds were experimentally determined using differential thermal and thermogravimetric methods of analysis for the first time. Based on the experimentally determined thermodynamic parameters of the melting process, an analytical method for calculating the enthalpy of fusion from the specific value of the entropy of fusion for substances with an arylpyrrole fragment is proposed. Calculating methods for the enthalpies of sublimation using the data of derivatographic studies are analyzed. Recalculation of the enthalpies of phase transitions to 298.15 K was performed.