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Obtaining optically pure compounds in an eco‐friendly and cost‐efficient manner plays an important role in human health and pharmaceutical industry. Racemic separation using multistage stereoselective liquid–liquid extraction has become one of the most practical and effective approach to access homochiral enantiomers. Currently, chiral ionic liquids (CILs) with structural designability have become a promising chiral additive and enable them as adjustable candidates for racemic separation. Herein, a high‐effective stereoselective liquid–liquid extraction process composed of imidazolium cations and amino acid‐derived anions as the chiral additive was established for racemic 2‐cyclohexylmandelic acid (CHMA) separation. We have systematically investigated the choice of organic solvent, concentration of CIL, extraction temperature, and the pH of aqueous phase. For three‐stage stereoselective extraction, the maximum enantiomeric excess (e.e.) for CHMA was reached up to 40.6%. Furthermore, the mechanism of steric effect and stereoselective capacity between the CILs and racemic CHMA was discussed and simulated. We envision that the work will facilitate the development of CILs in multistage liquid–liquid extraction and promote the large‐scale production of optically pure enantiomers. [ABSTRACT FROM AUTHOR]

A spectroscopic method of chemical analysis is used to determine the mole fraction solubilities of 3,5-dimethoxybenzoic acid dissolved in propanenitrile, in eleven additional alkanol solvents (1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-methyl-1-propanol, 2-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 2-ethyl-1-hexanol, cyclopentanol) and in three additional alkyl alkanoate solvents (isopropyl acetate, tert-butyl acetate, methyl butyrate) at 298.15 K. Results from our experimental measurements, combined with published partition coefficient and solubility data, are used to calculate the Abraham model solute descriptors of the monomeric form of 3,5-dimethoxybenzoic acid. In total 62 experimental data points were used in the computation. The calculated solute descriptors describe the experimental solubility and partition coefficient data to within an overall standard deviation of 0.064 log units. [ABSTRACT FROM AUTHOR]

An effective approach to separate chiral (2S,4S)-1-(tert-butoxy carbonyl)-4-(methoxymethyl) pyrrolidine-2-carboxylic acid ((2S,4S)-TBMP)) from mixed (2S,4S)-TBMP and (2S,4R)-1-(tert-butoxy carbonyl)-4-(methoxymethyl) pyrrolidine-2-carboxylic acid ((2S,4R)-TBMP), an important intermediate for the anti-HCV drug Velpatasvir, was developed for the first time, eliminating the need for salinization and dissociation processes and several organic solvents with water. Conceivable binding modes were set up by Gaussian calculation, and the separation process was designed and studied based on the calculation. The results showed that only the monohydrate of (2S,4S)-TBMP could be crystallized since three hydrogen bonds were formed between (2S,4S)-TBMP and water, which resulted in more stability and isomer separation. Compared to the original approach, our new approach exhibits a remarkable 17.4% increase in yield, a 43.3% rise in atom economy (AE), a 43.3% improvement in reaction mass efficiency (RME), and a substantial 32.0 g g−1 reduction in process mass intensity (PMI). An industrial-scale implementation was set up successfully according to the new approach, achieving a batch capacity of 100 kg. [ABSTRACT FROM AUTHOR]