Solubility of Phenylboronic Acid and its Cyclic Esters in Organic Solvents

Abstract

The solubilities of phenylboronic acid, its pinacol ester and azaester in organic solvents (chloroform, 3-pentanone, acetone, dipropyl ether and methylcyclohexane) have been determined experimentally by a dynamic method, in which the disappearance of turbidity was determined by measuring of light intensity using a luminance probe. Phenylboronic acid has high solubility in ether and ketones, moderate in chloroform and very low in hydrocarbon. Pinacol ester and azaester show better solubility than the parent acid in all tested solvents. For pinacol ester differences between particular solvents are small, while for azaester the differences are significant. For both esters the highest solubility is observed in chloroform and the lowest in the hydrocarbon. The results have been correlated by the Wilson, NRTL and Redlich-Kister equations. For the phenylboronic acid better correlation of the data is obtained by polynomials in comparison with the above equations. It is connected with additional acid-anhydride equilibrium in the system. The influence of polarity of the solvents on the solubility is discussed.

Equilibrium Solubility Determination and Correlation of Isobutoxyphenylboronic Acids in Organic Solvents

“…With a huge number of publications on boronic acids, there is virtually no information on the solubility of these compounds both in water and in organic solvents. Recently, we published the results of solubility studies of a series of phenylboronic compounds in water, as well as the solubility of phenylboronic acid and its cyclic esters in various types of organic solvents . The latter work discusses the difficulties in solubility studies of boronic acids compared to their derivatives, e.g., esters.…”

“…These properties of boronic acids make it difficult to correlate solubility data by equations such as NRTL, Redlich–Kister, or Wilson. The best results for phenylboronic acid were obtained using correlation based on polynomials …”

Merging Electron Deficient Boronic Centers with Electron-Withdrawing Fluorine Substituents Results in Unique Properties of Fluorinated Phenylboronic Compounds

“…It was found that 19 F NMR spectroscopy is an excellent tool to determine the composition of the fluorine-containing boronic compounds. The conducted research made it possible to explain the discrepancies occurring during previous studies of the solubility of boronic acids in organic solvents [ 76 , 77 ].…”

The design and synthesis of high efficiency adsorption materials for 1,3-propanediol: physical and chemical structure regulation

“…In order to research the effect of boronic acid content in boronic acid modied resins on the adsorption of 1,3-propanediol, the boronic acid loading of the resin was calculated. 37,38 The quantitative analysis of the boronic acid loading in Fig. 6B showed that the 4-carboxyphenylboronic acid modied resin PS-SBT owned the highest 1.220 mmol g À1 boronic acid groups and consumed about 16% chloromethyl sites, which was superior to PS-SB-Cs (0.668 mmol g À1 ) and PS-SB-Na (0.790 mmol g À1 ).…”