Abstract
A reciprocal resolution was successfully carried out by a diastereomeric method between 1-(4-methylphenyl)-ethylamine (1) and 2-hydroxy-4-phenylbutyric acid (2); enantiomerically pure 1 was obtained from water solvent involving hydrochloric acid (0.5 mol) by using enantiomerically pure 2 as a resolving agent, while enantiomerically pure 2 was obtained from water solvent involving sodium hydroxide (0.5 mol) by using enantiomerically pure 1. Upon the optical resolution of (RS)-1 with enantiomerically pure 2, the crystal morphology of the less-soluble salt (L-salt), (R)-1·(R)-2, was changed by addition of chiral secondary amines derived from enantiomerically pure amine 1. Effective additives for the habit modification were (R,R)- and (S,S)-bis [1-(4-methylphenyl)ethyl] amine (3). The habit modification experiments showed that molecular recognition by the cavity created on the surface of the diastereomeric salt was structure-specific but not stereospecific. The X-ray crystallography of the L-salt revealed that molecular recognition between resolving agent 2 and amine 1 or chiral additive 3 was due to the cavity structure constructed with the resolving agent.
Original language | English |
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Pages (from-to) | 23-35 |
Number of pages | 13 |
Journal | Enantiomer |
Volume | 3 |
Issue number | 1 |
Publication status | Published - 1998 |
Keywords
- Crystal morphology
- Habit modification
- Less-soluble salt
- Molecular recognition
- Optical resolution
- X-ray crystallography
ASJC Scopus subject areas
- Chemistry(all)
- Biochemistry
- Biochemistry, Genetics and Molecular Biology(all)
- Organic Chemistry