Buchowski Ksiazaczak Λh Equation Research Articles

Solubility measurement, correlation and mixing properties of thioacetamide in fifteen pure solvents

The solubility of thioacetamide in fifteen pure solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, ethyl acetate, 2-butanone, 2-pentanone, acetone, acetonitrile, ethyl formate and methyl acetate) was determined by a gravimetric method from 272.85 K to 323.95 K under ambient pressure. Four thermodynamic models, including the modified Apelblat equation, Buchowski-Ksiazaczak λh equation, non-random two-liquid (NRTL) model and the Wilson model were used to correlate the solubility data. And the NRTL model provides the best data fitting results among the four models. To elucidate the dissolution behavior of thioacetamide, the KAT-LSER model was introduced to analyze the solvent effect. The results revealed that hydrogen bond basicity and bipolarity/polarizability had a similar and significant favorable effect to the dissolution of thioacetamide. The mixing thermodynamic properties such as enthalpy, entropy and Gibbs free energy were calculated and the results indicated that the dissolution process of thioacetamide was spontaneous and favorable.

Experiment and Computation of Solubility and Dissolution Properties for Enalapril Maleate and Its Intermediate in Pure Solvents

The object is to research the solid–liquid phase of enalapril maleate and its intermediate enalapril hydride in pure solvent. Within the investigated temperature range, the mole fraction solubility data in the selected solvents increase with the increasing temperature. The solubility of enalapril hydride in different solvents decreases according to the order ethyl acetate > acetone > ethanol > n-octanol > isopropanol > acetonitrile, while enalapril maleate obeys the order ethyl acetate > acetone > ethanol > acetonitrile > n-octanol > isopropanol. The experimental solubility data of enalapril hydride and enalapril maleate in those solvents were correlated by the modified Apelblat equation, Buchowski–Ksiazaczak λh equation, and Wilson equation. The maximum values of root-mean-square deviation (RMSD) and relative average deviation (RAD) obtained by the three equations were 1.48 × 10–4, 3.32% (enalapril hydride) and 2.82 × 10–4, 4.36% (enalapril maleate), respectively. It was found from the RMSD value that th...

Experimental Determination and Thermodynamic Models for Solid–Liquid Equilibrium of 4-(4-Aminophenoxy)-N-methylpyridine-2-carboxamide in Pure and Binary Solvent Mixtures for T = (278.15–328.15) K

In this study, the solubility of 4-(4-aminophenoxy)-N-methylpyridine-2-carboxamide (APMC) in pure tetrahydrofuran, ethyl acetate, acetonitrile, n-butanol, n-propanol, ethanol, methanol, and three binary solvent mixtures (ethyl acetate + methanol, ethyl acetate + ethanol, and ethyl acetate + n-butanol) was first experimentally determined within the temperature range from (278.15 to 328.15) K under atmosphere pressure by the gravimetric method. The results reveal that the solubility of APMC increases with an increase in temperature in all of the solvents selected. The modified Apelblat equation and the Buchowski–Ksiazaczak λh equation were used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model, and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. All of the models could be well applied, and the modified Apelblat equation stood out to be more suitable with a higher accuracy compared to that of the ot...

Solid–Liquid Phase Equilibrium and Thermodynamic Properties of Olaparib in Selected Organic Solvents and (Tetrahydrofuran + MTBE, Acetonitrile + Isopropyl Alcohol) Binary Solvent Mixtures

We focused on the solubility of olaparib under atmospheric pressure in isopropyl alcohol, MTBE, acetonitrile, and tetrahydrofuran as well as in the (tetrahydrofuran + MTBE, acetonitrile + isopropyl alcohol) mixtures from 280.35–319.35 K. It is found that the solubility of olaparib and temperature were positively correlated in the range of our study. We chose the modified Apelblat equation, the Buchowski–Ksiazaczak λh equation, CNIBS/R-K equation, and the Jouyban–Acree equation to verify the thermodynamic properties of olaparib. Computational results showed that all selected equations agreed well with the experimental data, and the modified Apelblat equation gives the best correlation. We also selected two binary solvent dissolution systems, and the test found that (tetrahydrofuran + MTBE) mixtures may be a good recrystallization system. This study provides valuable data for olaparib’s production process purification.

Solubility determination and thermodynamic functions of 2-chlorophenothiazine in nine organic solvents from T = 283.15 K to T = 318.15 K and mixing properties of solutions

Solubility of 2-chlorophenothiazine in nine organic solvents including methanol, ethanol, isopropanol, n-propanol, ethyl acetate, acetone, acetonitrile, 1-butanol and 2-butanone was determined experimentally by the isothermal saturation method over a temperature range from T=283.15K to T=318.15K under 101.1kPa. Within the studied temperature range, the mole fraction solubility of 2-chlorophenothiazine in these solvents increased with a rise of temperature. Except for the solvent of acetonitrile, they follow the order of 2-butanone>(acetone, ethyl acetate)>methanol>ethanol>n-propanol>isopropanol>1-butanol. The solubility in ethyl acetate and acetonitrile had the strongest positive dependency on temperature. The determined solubility of 2-chlorophenothiazine in the solvents studied was correlated by using the modified Apelblat equation, Buchowski–Ksiazaczak λh equation, Wilson model and NRTL model. The maximum values of root-mean-square deviation (RMSD) and relative average deviation (RAD) were 2.77×10−4 and 0.59%, respectively. In general, the four thermodynamic models were all satisfactory for describing the solubility of 2-chlorophenothiazine, and the Wilson model can correlate the experimental solubility best based on the result of Akaike Information Criterion analysis. Furthermore, the mixing properties including the mixing Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration (γ1∞) and reduced excess enthalpy (H1E,∞) were computed. The findings will be very useful in optimizing the purification process of 2-chlorophenothiazine.

Solubility determination and thermodynamic modelling of 3-amino-1,2,4-triazole in ten organic solvents from T = 283.15 K to T = 318.15 K and mixing properties of solutions

The solubility of 3-amino-1,2,4-triazole in ten organic solvents including ethanol, isopropanol, n-propanol, methanol, ethyl acetate, acetone, acetonitrile, 1,4-dioxane, N-methyl-2-pyrrolidone and 2-butanone was determined experimentally by the isothermal saturation method over a temperature range from T=283.15K to T=318.15K under 101.1kPa. For the studied temperature range, the solubility of 3-amino-1,2,4-triazole in mole fraction in the solvents increased with a rise of temperature. On the whole, they obeyed the following order from high to low in different solvents: N-methyl-2-pyrrolidone>methanol>ethanol>n-propanol>(isopropanol, acetone)>1,4-dioxane>2-butanone>(ethyl acetate, acetonitrile). The determined solubility results of 3-amino-1,2,4-triazole in the solvents studied were correlated using the modified Apelblat equation, Buchowski–Ksiazaczak λh equation, Wilson model and NRTL model. The maximum values of root-mean-square deviation (RMSD) and relative average deviation (RAD) were 9.45×10−4 and 2.16%, respectively. In general, the four thermodynamic models were all acceptable for describing the solubility behaviour of 3-amino-1,2,4-triazole in these solvents. Furthermore, the mixing properties including the mixing Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration (γ1∞) and reduced excess enthalpy (H1E,∞) were acquired. The solution process of 3-amino-1,2,4-triazole was spontaneous and favourable in the selected solvents. The solubility values obtained and the thermodynamic studies would be very useful for optimizing the purification process of 3-amino-1,2,4-triazole.

Thermodynamic Models for Determination of the Solubility of Boc-(R)-3-Amino-4-(2, 4, 5-trifluorophenyl)butanoic acid in Different Pure Solvents and (Tetrahydrofuran + n-Butanol) Binary Mixtures with Temperatures from 280.15 to 330.15 K

A gravimetric method was taken to measure the solubility of the Boc-(R)-3-amino-4-(2,4,5-trifluorophenyl)butanoic acid under atmospheric pressure in methanol, ethanol, propanol, n-butanol, ethyl acetate, and tetrahydrofuran as well as in the (tetrahydrofuran + n-butanol) mixtures from 280.15 to 330.15 K.The experiment results have proved that the rising temperature leads to increased solubility of the Boc-(R)-3-amino-4- (2,4,5-trifluorophenyl)butanoic acid in all selected solvents. The solid–liquid equilibrium data in pure and mixed solvents is correlated with a series of equations, including the modified Apelblat equation, the Buchowski–Ksiazaczak λh equation, CNIBS/R–K equation and the Jouyban–Acree equation. During the study, the computational values were in good agreement with the experimental results according to the calculations based on all selected equations, however, the modified Apelblat equation stood out to be the higher suitable with the higher accuracy. The thermodynamic properties of the solution process, including the Gibbs energy, enthalpy, and entropy were calculated by the van’t Hoff equation. The calculated thermodynamic parameters indicated that in each studied solvent the dissolution process of Boc-(R)-3-amino-4-(2,4,5-trifluorophenyl)butanoic acid is endothermic.

Measurement and Correlation of the Solubility of Antioxidant 626 in Alcohols

Low boiling point alcohols are promising solvents for crystallizing Antioxidant 626. The solubilities of Antioxidant 626 in methanol, ethanol, 2-propanol, n-propanol, and tert-butyl alcohol have been measured between 302 and 334 K at an interval of 5 K by the static analytical method. The modified Apelblat equation, the Buchowski-Ksiazaczak λh equation, and the ideal model were applied to correlate the experimental solubility data. The modified Apelblat equation was more consistent than the other two equations. Subsequently, it was used to derive the standard apparent molar enthalpy of the process of Antioxidant 626 dissolving in methanol, ethanol, 2-propanol, n-propanol, and tert-butyl alcohol, respectively. In addition, the calculated thermodynamic data indicate that the dissolution of Antioxidant 626 in the studied solvents is an endothermic process.

Solubility and Solution Thermodynamics of Diphenoxylate in Different Pure Solvents

The solubility data of diphenoxylate in pure solvents of water, methanol, ethanol, acetone, acetonitrile, 2-propanol were measured within the temperature range of 293.15–318.15 K by a static analytical method under atmospheric pressure. Several commonly used thermodynamic models, including the ideal solution model, the modified Apelblat equation and the Buchowski-Ksiazaczak λh equation, were applied to correlate the experimental solubility data. The experimental results show that the solubility increases with the increasing temperature, and the highest solubility is in methanol, the lowest in pure water. Results of these measurements were well-correlated with the three equations above, but the modified Apelblat equation is more suitable in regressing the solubility data of diphenoxylate. Through the Van’t Hoff equation, the enthalpy and the entropy in different solvents can be calculated.

Measurement and correlation of the solubility of maleic anhydride in different organic solvents

Data on corresponding solid–liquid equilibrium of maleic anhydride in different organic solvents are essential for industrial design and further theoretical studies. In this study, the solubilities of maleic anhydride were measured in DMF, methanol, acetic acid, acetonitrile, acetone, ethyl acetate, 2-propanol and n-butyl alcohol with the temperature range of 278.15–323.15K by the analytical stirred-flask method under atmospheric pressure. The experiment results indicated that the solubility of maleic anhydride was highest in DMF and followed by methanol, acetic acid, acetonitrile, acetone, ethyl acetate, 2-propanol and n-butyl alcohol. For the temperature range investigated, the solubilities of maleic anhydride in the organic solvents increased with increasing temperature. Results of these measurements were well-correlated with the modified Apelblat equation, the Buchowski–Ksiazaczak λh equation and the van’t Hoff equation. The calculated solubilities showed good agreement with the experimental data. The modified Apelblat equation was found to regress the solubility data is higher accuracy than the Buchowski–Ksiazaczak λh equation. The experimental data and model parameters would be useful for optimizing the process of purification of maleic anhydride in industry.

Solubility of Fumaric Acid in Aqueous Alcohol Solutions

The solubility of fumaric acid in aqueous alcohol solutions was experimentally measured over the temperature range of (278.15–333.15) K by employing an analytical stirred-flask method. The experimental data showed that the solubility of fumaric acid in the binary mixtures increases with increases of both temperature and mass fraction of the organic solvents. The experimental data were well correlated with the modified Apelblat equation and the Buchowski–Ksiazaczak λh equation. In addition, the calculated solubilities showed good agreement with the experimental results. It was found that the modified Apelblat equation gave better correlation results than the Buchowski–Ksiazaczak λh equation. The experimental results should be useful for optimizing the process of purification of fumaric acid in industry.

Solubility of 1-(3-Bromopropoxy)-4-Chlorobenzene in Aqueous Ethanol Mixtures From (273.15 to 303.15) K

1-(3-Bromopropoxy)-4-chlorobenzene is an important intermediate for the manufacture of omoconazole nitrate. The solubilities of 1-(3-bromopropoxy)-4-chlorobenzene in aqueous ethanol solutions were measured within the temperature range of (273.15–303.15) K using a laser monitoring system. For the temperature range investigated, the solubilities of 1-(3-bromopropoxy)-4-chlorobenzene in the aqueous ethanol mixtures increase with increasing temperature. The solubility data were regressed by the Buchowski–Ksiazaczak λh and the modified Apelblat models. The modified Apelblat equation and the Buchowski–Ksiazaczak λh equation provided accurate mathematical representations of the experimental results. The calculated solubilities showed good agreement with the experimental data. The root-mean-square deviations of the modified Apelblat model were lower than those of the Buchowski–Ksiazaczak λh model. This study provided valuable data for the purification of 1-(3-bromopropoxy)-4-chlorobenzene by crystallization.

Solubility of chlocyphos in different solvents

Chlocyphos is a novel highly acidic and efficient resolving agent. Solubility of chlocyphos in methanol, ethanol, isopropyl alcohol, tert-butyl alcohol, glacial acetic acid and water from 278.15K to 348.15K was determined by using a static equilibrium method in this paper. The solubility data of chlocyphos in methanol, ethanol, isopropyl alcohol, tert-butyl alcohol and water were correlated well with modified Apelblat equation, and the experimental data of chlocyphos in glacial acetic acid were correlated well with the Buchowski–Ksiazaczak λh equation. Results of these measurements can be used for purification of chlocyphos and preparation of optical amine obtained by resolution using chlocyphos.

Solubility of itaconic acid in different organic solvents: Experimental measurement and thermodynamic modeling

Data on corresponding solid–liquid equilibrium of itaconic acid in different organic solvents are essential for industrial design and further theoretical studies. In this study, the solubility of itaconic acid was measured in methanol, ethanol, 1-propanol, acetonitrile, 2-propanol, ethyl acetate, and acetone with the temperature range of 283.15–328.15 K by the analytical stirred-flask method under atmospheric pressure. The experiment results showed that the solubility of itaconic acid was highest in methanol and followed by 2-propanol, ethanol and 1-propanol. For the temperature range investigated, the solubilities of itaconic acid in the solvents increased with increasing temperature. Results of these measurements were well-correlated with the modified Apelblat equation and the Buchowski–Ksiazaczak λh equation. The calculated solubilities showed good agreement with the experimental data. The modified Apelblat equation was found to regress the solubility data much better than the Buchowski–Ksiazaczak λh equation.