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© 2016 American Pharmacists Association®.Benzoic acid is a model compound for drug substances in pharmaceutical research. Process design requires information about thermodynamic phase behavior of benzoic acid and its mixtures with water and organic solvents. This work addresses phase equilibria that determine stability and solubility. In this work, Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the phase behavior of aqueous and organic solutions containing benzoic acid and chlorobenzoic acids. Absolute vapor pressures of benzoic acid and 2-, 3-, and 4-chlorobenzoic acid from literature and from our own measurements were used to determine pure-component PC-SAFT parameters. Two binary interaction parameters between water and/or benzoic acid were used to model vapor-liquid and liquid-liquid equilibria of water and/or benzoic acid between 280 and 413 K. The PC-SAFT parameters and 1 binary interaction parameter were used to model aqueous solubility of the chlorobenzoic acids. Additionally, solubility of benzoic acid in organic solvents was predicted without using binary parameters. All results showed that pure-component parameters for benzoic acid and for the chlorobenzoic acids allowed for satisfying modeling phase equilibria. The modeling approach established in this work is a further step to screen solubility and to predict the whole phase region of mixtures containing pharmaceuticals

Structure–property relationships in halogenbenzoic acids: Thermodynamics of sublimation, fusion, vaporization and solubility

© 2016 Elsevier LtdTemperature dependences of vapor pressures for 2-, 3-, and 4-bromobenzoic acid, as well as for five isomeric bromo-methylbenzoic acids were studied by the transpiration method. Melting temperatures and enthalpies of fusion for all isomeric bromo-methylbenzoic acids and 4-bromobenzoic acid were measured with a DSC. The molar enthalpies of sublimation and vaporization were derived. These data together with results available in the literature were collected and checked for internal consistency using a group-additivity procedure and results from X-ray structural diffraction studies. Specific (hydrogen bonding) interactions in the liquid and in the crystal phase of halogenbenzoic acids were quantified based on experimental values of vaporization and sublimation enthalpies. Structure-property correlations of solubilities of halogenobenzoic acids with sublimation pressures and sublimation enthalpies were developed and solubilities of bromo-benzoic acids were estimated. These new results resolve much of the ambiguity in the available thermochemical and solubility data on bromobenzoic acids. The approach based on structure property correlations can be applied for the assessment of water solubility of sparingly soluble drugs

Benzoic Acid and Chlorobenzoic Acids: Thermodynamic Study of the Pure Compounds and Binary Mixtures with Water

© 2016 American Pharmacists Association®.Benzoic acid is a model compound for drug substances in pharmaceutical research. Process design requires information about thermodynamic phase behavior of benzoic acid and its mixtures with water and organic solvents. This work addresses phase equilibria that determine stability and solubility. In this work, Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the phase behavior of aqueous and organic solutions containing benzoic acid and chlorobenzoic acids. Absolute vapor pressures of benzoic acid and 2-, 3-, and 4-chlorobenzoic acid from literature and from our own measurements were used to determine pure-component PC-SAFT parameters. Two binary interaction parameters between water and/or benzoic acid were used to model vapor-liquid and liquid-liquid equilibria of water and/or benzoic acid between 280 and 413 K. The PC-SAFT parameters and 1 binary interaction parameter were used to model aqueous solubility of the chlorobenzoic acids. Additionally, solubility of benzoic acid in organic solvents was predicted without using binary parameters. All results showed that pure-component parameters for benzoic acid and for the chlorobenzoic acids allowed for satisfying modeling phase equilibria. The modeling approach established in this work is a further step to screen solubility and to predict the whole phase region of mixtures containing pharmaceuticals

Vaporization enthalpies of a series of the fluoro- and chloro-substituted methylbenzenes

Vapor pressures of fluorobenzene, chlorobenzene, 2-chloro-, 3-chloro-, and 4-chloro-methylbenzenes, 2-chloro-1,3-dimethylbenzene, 2,6-dichloro-1-methylbenzene were measured by the transpiration method. Molar standard enthalpies of vaporization at the reference temperature were calculated from temperature dependences of vapor pressures. Available literature data on halogenobenzenes were collected and evaluated by using correlation gas-chromatographic method. Simple group-additivity procedure was developed for estimation vaporization enthalpies of mono- and di-halogen-substituted benzenes. © 2014

Thermochemistry of halogenobenzoic acids as an access to PC-SAFT solubility modeling

© 2015 Elsevier B.V. Absolute vapor pressures and molar sublimation enthalpies of 2-, 3-, and 4-monohalogenobenzoic acids (halogen = fluorine and iodine) were derived from transpiration measurements. Molar enthalpies of fusion were measured by DSC. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results in order to recommend sets of sublimation and fusion enthalpies. Further, the recommended data were used to estimate PC-SAFT pure-component parameters. These parameters were applied to predict the solubility of the monohalogenobenzoic acids in water at 298.15 K, yielding satisfying prediction results. This approach proved the capability of PC-SAFT to predict solid-liquid phase equilibria if precise data on sublimation pressures and fusion properties is available

Benzoic acid derivatives: Evaluation of thermochemical properties with complementary experimental and computational methods

© 2015 Elsevier B.V. Molar sublimation enthalpies of the methyl- and methoxybenzoic acids were derived from the transpiration method, static method, and TGA. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpy data and to recommend sets of sublimation and formation enthalpies for the benzoic acid derivatives. Gas-phase enthalpies of formation calculated with the G4 quantum-chemical method were in agreement with the experiment. Pairwise interactions of the methyl, methoxy, and carboxyl substituents on the benzene ring were derived and used for the development of simple group-additivity procedures for estimation of the vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of substituted benzenes

Thermochemistry of dihalogen-substituted benzenes: Data evaluation using experimental and quantum chemical methods

© 2014 American Chemical Society. Temperature dependence of vapor pressures for 12 dihalogen-substituted benzenes (halogen = F, Cl, Br, I) was studied by the transpiration method, and molar vaporization or sublimation enthalpies were derived. These data together with results available in the literature were collected and checked for internal consistency using structure-property correlations. Gas-phase enthalpies of formation of dihalogen-substituted benzenes were calculated by using quantum-chemical methods. Evaluated vaporization enthalpies in combination with gas-phase enthalpies of formation were used for estimation liquid-phase enthalpies of formation of dihalogen-substituted benzenes. Pairwise interactions of halogens on the benzene ring were derived and used for development of simple group additivity procedures for estimation of vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of dihalogen-substituted benzenes

Vaporization enthalpies of a series of the halogen-substituted fluorobenzenes

© 2014 Elsevier B.V. Vapor pressures of 2-, 3-, and 4-halogen-substituted fluorobenzenes (halogen. =. Cl, Br, and I) were measured by the transpiration method. Molar standard enthalpies of vaporization were calculated from temperature dependences of vapor pressures. New enthalpies of vaporization at 298. K and those available from literature were tested for consistency by correlation gas-chromatography and evaluated by group-additivity method. Contributions to vaporization due to mutual interactions of halogens on the benzene ring were derived and recommended for prediction vaporization enthalpies of halogen-substituted aromatics

Energetic structure–property relationships in thermochemistry of halogenosubstituted benzoic acids

© 2019, Akadémiai Kiadó, Budapest, Hungary. Abstract: Experimental thermodynamic properties of halogenosubstituted benzoic acids have been evaluated with the help of complementary in silico methods. The study encompassed benzoic acids with fluoro, chloro-, bromo-, and iodo-substituents in the 2-, 3-, and 4-position in the benzene ring, as well as a series of methyl-substituted bromobenzoic acids and dibromobenzoic acids. The high-level quantum-chemical composite method G4 was additionally used for mutual validation of the theoretical and experimental gaseous standard molar enthalpies of formation. A simple group contribution procedure has been developed for a quick appraisal of the gas-phase and liquid-phase enthalpies of formation as well as of vaporization enthalpies of halogenosubstituted benzoic acids and their poly-methyl or poly-halogen-substituted derivatives. The system of group-additivity parameters developed in this work can help in the evaluation of new experimental results or for validation of already available data compiled in comprehensive databases. Moreover, the reliable additive estimates are essential for material sciences or for assessment of chemicals fate in environment and in atmosphere. Graphical abstract: [Figure not available: see fulltext.]

Energetic structure–property relationships in thermochemistry of halogenosubstituted benzoic acids

© 2019, Akadémiai Kiadó, Budapest, Hungary. Abstract: Experimental thermodynamic properties of halogenosubstituted benzoic acids have been evaluated with the help of complementary in silico methods. The study encompassed benzoic acids with fluoro, chloro-, bromo-, and iodo-substituents in the 2-, 3-, and 4-position in the benzene ring, as well as a series of methyl-substituted bromobenzoic acids and dibromobenzoic acids. The high-level quantum-chemical composite method G4 was additionally used for mutual validation of the theoretical and experimental gaseous standard molar enthalpies of formation. A simple group contribution procedure has been developed for a quick appraisal of the gas-phase and liquid-phase enthalpies of formation as well as of vaporization enthalpies of halogenosubstituted benzoic acids and their poly-methyl or poly-halogen-substituted derivatives. The system of group-additivity parameters developed in this work can help in the evaluation of new experimental results or for validation of already available data compiled in comprehensive databases. Moreover, the reliable additive estimates are essential for material sciences or for assessment of chemicals fate in environment and in atmosphere. Graphical abstract: [Figure not available: see fulltext.]