Solubility Measurement and Correlation of 2-Oxindole in 12 Pure Organic Solvents

Abstract

The solubilities of 2-oxindole in 12 pure organic solvents including acetonitrile (MeCN), dichloromethane, 1,4-dioxane, ethyl acetate (EtOAc), acetone, toluene, methanol, ethanol, 2-propanol, tetrahydrofuran, 1-butanol, and 1-propanol were experimentally measured from (283.15 to 358.15) K at normal pressure p = 0.1 MPa by employing the synthetic method. The measured solubilities of 2-oxindole in these pure organic solvents were found to increase with the rise of temperature. The experimental solubilities of 2-oxindole were correlated with several thermodynamic models including the modified Apelblat equation, λh (Buchowski) equation, Wilson equation, and nonrandom two-liquid equation. These data could be applied for the large-scale synthesis of 2-oxindole with high purity.

Solubility Measurement, Model Correlation, and Solute–Solvent Interactions of Pidotimod in Nine Pure Solvents and Two Binary Solvents at Temperatures Ranging from 278.15 to 323.15 K

“…The solubility of pidotimod in 11 pure solvents and 2 binary solvent mixtures was measured by a dynamic method − and employing a laser-monitoring observation technique to determine the dissolution data.…”

“…On the basis of the local composition concept, the Wilson equation was first proposed by Wilson in 1964. ,, According to the traditional solid liquid-phase equilibrium theory, the solubility of a solid solute in a liquid solvent can be described by eq . where Δ C p and Δ V are the discrepancies of the solute molar heat capacity and solute volume between the solid–liquid phase, respectively. Under normal absolute pressure, the values of Δ C p and Δ V are often slight and also negligible.…”

“…A semiempirical equation was put forward by Renon and Prausnitz in 1968, which is similar to the Wilson model. They are both based on the concept of local composition. ,,, Moreover, A nonrandom parameter (α 12 ) reflecting the mixing system is introduced to the equation. For the pure solvent system, the equations are as follows. where …”

“…Hence, we employed a dynamic equilibrium method to determine the reliable solubility of pidotimod in a variety of pure and binary solvents within the temperature range of 278.15–323.15 K at atmospheric pressure. − Eleven pure solvents, water, methanol, benzyl alcohol, ethanol, acetone, iso -propanol, n -butanol, acetonitrile, N , N -dimethyl formamide (DMF), ethyl acetate, and butyl acetate were selected; the modified Apelblat, Wilson, and NRTL models were applied to correlate the pure solubility data, respectively. Furthermore, the mole fraction solubility of pidotimod in two binary solvents mixtures, methanol + acetone and methanol + butyl acetate was also investigated, the effects of the mass fraction of methanol in binary solvent mixtures (from 0.1 to 0.9) on the equilibrium solubility were studied, ,,− and corresponding binary solubility data were fitted by the Wilson, NRTL, and CNIBS/R–K Models.…”

Solid–Liquid Equilibrium of l-Thioproline in Nine Neat Solvents and Water + Acetonitrile Binary Solvent System from 283.15 to 323.15 K: Solubility Determination and Data Modeling

“…The crude products of l -thioproline may restrict its application in many fields and increase the difficulty in the subsequent treatment of filtration (washing and drying) and downstream operation . As the final step of producing solid substances with a small molecule, solvent crystallization is an important and a common method for separating and purifying the final products in chemical synthesis. − Meanwhile, the solubility data of solute in various solvent systems is a crucial index for designing and optimizing the crystallization process, which could play a guidance role in the selection of solvent and crystallization types. , However, to our best knowledge, no systematic data on the solubility of l -thioproline in neat or binary solvent systems have been reported. This leads to the necessity of investigating the solubility behavior in different solvent systems comprehensively.…”