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Nagoya-shi, Japan

Saigo K.,Kochi University of Technology | Sakai K.,Toray Fine Chemicals Co.
Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry | Year: 2011

In order to overcome trial-and-error situation in the enantioseparation by the diastereomeric salt formation, we carried out systematic studies on the enantioseparation of racemic 1-arylethylamines with/without a substituent on the aryl group by using enantiopure arylglycolic acids. The studies revealed that there are three factors for the growth and stabilization of less-soluble diastereomeric salt crystals; 1) infinite hydrogen bonding interaction to form a 21-column, which enables a crystal to grow in one dimension, 2) effective van der Waals interaction between the columns to make the crystal growable in a three-dimensional manner, and 3) sufficient CH-π interaction in/ between the columns, which also play an important role for three-dimensional crystal growth. On the basis of the observations, we propose molecular length rule and aromatic ring rule, which realize efficient van der Waals interaction and CH-π interaction, respectively. Keeping in mind of these requirements for the molecular structure of a resolving agent, we industrialized an elegant process for the enantioseparation of racemic 1-phenylethylamine into the (R) -form, which is one of the most valuable chiral auxiliaries in the synthesis of drugs/drug intermediates in industrial scales, with (R) -mandelic acid upon optimizing conditions such as solvent, molar ratio, concentration, temperature, and additive, as well as the recycling process of (R) mandelic acid and the racemizing process of (S) -1-phenylethylamine remained. Source

Kitamoto Y.,Tohoku University | Suzuki K.,Tohoku University | Morohashi N.,Tohoku University | Sakai K.,Toray Fine Chemicals Co. | Hattori T.,Tohoku University
Journal of Organic Chemistry | Year: 2013

Dielectrically controlled resolution (DCR) has been achieved during the crystallization of (S)-1-phenylethylamides of racemic 1,1'-binaphthalene-2,2'- dicarboxylic acid (RSa,S)-1. For example, a water well-shaped plot is obtained for the diastereomeric excess (de) of the deposited amide versus the solvent permittivity (ε) for the crystallization of (RSa,S)-1 from three-component mixed solvents, consisting of 25 vol % of dichloromethane and 75 vol % of varying ratios of two solvents (i.e., an alcohol and either hexane or water). The de value drastically changes within two narrow ε ranges and diastereomerically pure crystals of either (Ra,S)-1 (13.9 ≤ ε ≤ 17.9) or (Sa,S)-1·CH2Cl 2 (ε ≤ 11.9 and ε ≥ 21.8) deposit, depending on the solvent permittivity. X-ray crystallographic analyses reveal that the major difference between the crystal structures of (Sa,S)-1 and (R a,S)-1 is the presence of solvent molecules that fill the spatial voids in the (Sa,S)-1 crystals. The ε-dependence of the chemical shifts of (Sa,S)-1 and (Ra,S)-1 suggests that their aggregation states are similar in the same solvents and change discontinuously at two ε values. The ε-dependence of the C=O stretching vibrations suggests that the lower ε is a transition point where the amide molecules, which aggregate through intermolecular hydrogen bonds in low-permittivity solvents, begin to dissociate. An absorption experiment suggests that dichloromethane is easily incorporated into solvent-free (Sa,S)-1 crystals in high-permittivity solvents. On the basis of these observations, a feasible molecular mechanism is proposed for the present DCR phenomenon. © 2012 American Chemical Society. Source

Sakurai R.,Iwaki Meisei University | Sakai K.,Toray Fine Chemicals Co. | Kodama K.,Saitama University | Yamaura M.,Iwaki Meisei University
Tetrahedron Asymmetry | Year: 2012

A useful key intermediate for the dipeptidyl peptidase-4 (DPP-4) inhibitor, 3-aminopiperidine 1, was successfully resolved with an enantiomerically pure resolving agent, N-tosyl-(S)-phenylalanine 2, to give both stereoisomers (R)-1 and (S)-1 as a less-soluble diastereomeric salt with (S)-2, via a dielectrically controlled resolution (DCR) phenomenon. © 2012 Elsevier Ltd. All rights reserved. Source

Toray Fine Chemicals Co. | Date: 2014-03-13

A method produces optically active trans-1,2-diaminocyclohexane, in which a crystal of optically active trans-1,2-diaminocyclohexane is obtained by crystallization from a solution of optically active trans-1,2-diaminocyclohexane. Optically active trans-1,2-diaminocyclohexane with high purity is obtained in a favorable yield from a solution of optically active trans-1,2-diaminocyclohexane. The optically active trans-1,2-diaminocyclohexane with high purity is useful as a raw material for a large number of medicines.

Toray Fine Chemicals Co. | Date: 2012-12-05

The curable composition is a curable composition including a liquid polysulfide polymer containing 8% by weight or more of thiol groups in one molecule, an epoxy resin, and an amine, in which the liquid polysulfide polymer is wherein R is a two valent or three valent organic group containing a OCH

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