title: Optical resolution by preferential crystallization of (1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid.
abstract: The racemic structure of (1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid [(1RS,3RS)-1] was examined based on the melting point, solubility, and IR spectrum, with the aim of optical resolution by preferential crystallization. (1RS,3RS)-1 was indicated from these results to exist as a conglomerate. The successive optical resolution by preferential crystallization of (1RS,3RS)-1 yielded (1S,3S)- and (1R,3R)-1 with optical purities of 85--95% at 66--81% degrees of resolution, which were fully purified by recrystallization.
authors.affiliation: Unit of Chemistry, Faculty of Engineering and High Technology Research Center, Kansai University; Yamate-cho, Suita, Osaka 564-8680, Japan. shiraiwa@ipcku.kansai-u.ac.jp
authors.forename: Tadashi
authors.initials: T
authors.lastname: Shiraiwa
authors.forename: Ryuuichi
authors.initials: R
authors.lastname: Kiyoe
mesh_terms: D000470:Alkaloids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D003460:Crystallization; D016166:Free Radical Scavengers / Q000737:chemistry; D007546:Isoquinolines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D031299:Mucuna / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism
chemical_list: C505041:(1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid; D000470:Alkaloids; D002264:Carboxylic Acids; D016166:Free Radical Scavengers; D007546:Isoquinolines