title: Separation of pyridine derivatives from synthetic mixtures by pH-zone-refining counter-current chromatography.
abstract: Three novel pyridine derivatives were successfully separated from their partially purified synthetic mixtures by pH-zone-refining counter-current chromatography using a multilayer coil planet centrifuge designed in our laboratory. After equilibration of a two-phase solvent system consisting of methyl tert-butyl ether-tetrahydrofuran-water at an optimized volume ratio of 4:6:7, triethylamine (10 mM) was added to the organic phase as a retainer and hydrochloric acid (10 mM) to the aqueous phase as an eluter. Separation runs of 1.20, 1.16, and 1.15 g of three samples yielded three pyridine derivatives in weights of 306, 255, and 314 mg at a high purity of over 98.5, 99.0, and 98.2% (determined by HPLC), respectively. The structures were identified by electron impact mass spectrometry and (1)H NMR.
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, Zhejiang Province 310032, PR China.
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Tong
authors.forename: Jizhong
authors.initials: J
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Lou
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods; D002625:Chemistry, Organic / Q000379:methods; D002845:Chromatography / Q000379:methods*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004583:Electrons; D005021:Ethylamines / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D008956:Models, Chemical; D011725:Pyridines / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013997:Time Factors
chemical_list: D005021:Ethylamines; D011725:Pyridines; D012997:Solvents; C016162:triethylamine