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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 1967-1975 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates, VI. Polymeric Amino Acid Derivatives as Optically Active AdsorbensStarting with optically active amino acids, the polyacrylamides 3a-h, 5a-d and 6a, b the polymethacrylamides 8a-c and the polyacrylic ester 6f were synthesized. The separation efficiencies of these polymers were determined by chromatography of racemic mandelic acid and mandelamide, respectively. The best separations of the enantiomers of both racemates were observed on the phenylalanine derivatives 3e and 5a.
    Notes: Die Polyacrylamide 3a-h, 5a-d und 6a, b die Polymethacrylamide 8a-c und der Polyacrylsäureester 6f wurden aus optisch aktiven Aminosäurederivaten hergestellt und auf ihre Trennwirkung durch Chromatographie racem. Mandelsäure sowie racem. Mandelamids geprüft. Die beste Trennung der Enantiomeren beider Racemate wurde an den Phenylalaninderivaten 3e und 5a beobachtet.
    Additional Material: 1 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4616-4619 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation, Optical Purity and Configuration of the Enantiomers of FlecainideThe chiral antiarrhythmic drug flecainide (rac-1) was resolved by fractional crystallization of the diastereomeric salts with optically active mandelic acid. Derivatization with (+)-1-phenylethyl isocyanate and analytical separation of the diastereomers 3 by HPLC on silica gel confirmed the optical purity of the enantiomers. CD-Spectra of the N-chloro derivatives established the absolute configuration: (-)-1 is R-, (+)-1 S-configurated.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1188-1197 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates, IV. Separation Efficiency of Optically Active poly [N-((S)-1-phenylethyl)acrylamide] Depending on the Polymerisation ProcedureThe optically active suspension polymers 2a-o were synthesized from N-[(S)-1-phenylethyl]-acrylamide [(S)-1] by systematic variation of the polymerisation procedure. These adsorbents whose separation efficiencies were determined by chromatography of racemic mandelic acid separated the enantiomers with very different results. Depending on the synthesis of 2, the optical yields were between 0(2e, f, n, o) and 43% (2i, j). Additionally, 2d separated the enantiomers of mandelamide, the optical yield being 35%. Furthermore, investigations on the particle structure of these adsorbents and the preparative partial separation of 3 are reported.
    Notes: Die optisch aktiven Suspensionspolymerisate 2a-o wurden aus N-[(S)-1-Phenyläthyl]acrylamid [(S)-1] unter systematischer Variation der Versuchsbedingungen hergestellt und auf ihre Trennwirkung durch Chromatographie racem. Mandelsäure geprüft. Die Enantiomeren wurden sehr unterschiedlich getrennt. Je nach Herstellung von 2 schwankten die optischen Ausbeuten von 0 (2e, f, n, o) bis 43% (2i, j). Bei der Trennung von racem. Mandelamid an 2d betrug sie 35%. Ferner wird über Untersuchungen zur Kornstruktur der Polymeren sowie über die präparative Anreicherung der Enantiomeren von 3 berichtet.
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2732-2734 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chloroquine Enantiomers by Chromatographic Resolution and SynthesisThe chromatographic resolution of the antimalarial drug chloroquine (1) on an optically active polyamide is described. The results reveal that the optical purity of chloroquine formerly resolved with d-bromocamphorsulfonic acid was 12% only. A facile synthesis of the enantiomers via the optically active diamine 4 is given.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 2031-2035 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chromatographie Resolutions of Racemates, IX. Chlorotalidone-, Chlorotalidone Methyl Ether-, and Oxazepam EnantiomersThe racemic drugs chlorotalidone (2a) and oxazepam (3) are completely, chlorotalidone methyl ether (2b) partially resolved by chromatography on the optically active amide 1. 2a and 3 racemize under the influence of acids and bases.
    Additional Material: 2 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 2318-2322 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chromatographie Resolutions of Racemates, X. Optical Resolutions of Thalidomide and Other Glutarimide DerivativesRacem. thalidomide (1a) is resolved completely by chromatography on the chiral polyamide 2e in an analytical as well as preparative scale. The glutarimides 1b - d are partially resolved. Both enantiomers of 1b and one enantiomer of 1d were isolated by recycling chromatography.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4620-4622 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Configuration of the Praziquantel EnantiomersThe levorotatory (methanol) enantiomer of the anthelminthic agent praziquantel (rac-1) is R-, the dextrorotatory S-configurated. This assignment is based upon CD-spectra of both enantiomers and additionally confirmed by conversion of (+)- and (-)-2 to the pyrazinoisoquinolines 3 of known configuration.
    Additional Material: 1 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 237-252 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates, III. Chromatography of Racemic Mandelic Acid on Polyacrylic Esters and Amides of Optically Active Ephedrine DerivativesThe chromatographic resolution of racemic mandelic acid on optically active polyacrylic esters and amides of ephedrine derivatives was investigated using the racemate composed of specifically labelled enantiomers. Polyacryl esters of N-alkylephedrine derivatives adsorb mandelic acid, resulting in partial resolution. Evidence is presented that these polymers have affinity for mandelic acid at two points. The stereoselectivity of adsorption is determined by the configuration at C-2 of the ephedrine portion. Also, polyamides of ephedrine derivatives affect a partial resolution of mandelic acid. In contrast to the basic derivatives, the stereoselectivity is determined by the configuration at C-1. The separation efficiency of these adsorbents is highly dependent on the polymerisation procedure.
    Notes: Die chromatographische Racemattrennung von Mandelsäure an optisch aktiven Polyacryl-säureestern und -amiden von Ephedrinderivaten wurde mit 3H/14C-doppelmarkiertem Racemat untersucht. An basischen Polyacrylsäureestern von N-Alkylephedrinderivaten wird racem. Mandelsäure - wahrscheinlich über eine Zweizentrenbindung - stereoselektiv adsorbiert, wodurch eine teilweise Auftrennung in die Antipoden erfolgt. Die Stereoselektivität der Adsorption wird durch die Konfiguration an C-2 des Ephedrinteils bestimmt. Auch Polyacrylsäureamide von Ephedrinderivaten trennen racem. Mandelsäure teilweise auf, wobei die Stereoselektivität im Gegensatz zu den basischen Derivaten von der Konfiguration an C-1 bestimmt wird. Die Trennleistung der Adsorbentien hängt sehr vom Polymerisations-verfahren ab.
    Additional Material: 3 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 2792-2798 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates V Polymeric 1-Phenylethylamine Derivatives as Optically Active Adsorbents10 new polyacryl- and polymethacrylamides (3,5) were synthesized as crosslinked suspension polymers, starting with optically active 1-phenylethylamine derivatives. Their separation efficiencies were determined by chromatography of racemic mandelic acid and mandelamide. 3 of these adsorbents separated better than the previously described 3a, the optical yields approaching 97%. These experiments demonstrate that an almost quantitative separation of racemates can be accomplished by adsorption chromatography on optically active polymers.
    Notes: 10 neue Polyacryl-bzw. Polymethacrylamide (3 bzw. 5) optisch aktiver 1-Phenyläthylamin-Derivate wurden als vernetzte Suspensionspolymerisate hergestellt und auf ihre Trennwirkung bei der Chromatographie racem. Mandelsäure und racem. Mandelamids geprüft. 3 dieser Adsorbentien trennen besser als das früher beschriebene 3a, wobei optische Ausbeuten bis zu 97% erhalten werden. Damit kann eine fast quantitative Racemattrennung durch Adsorptionschromatographie an optisch aktiven Polymeren erreicht werden.
    Additional Material: 5 Tab.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 778-787 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates, VII Preparative Resolutions on Optically Active PolyamidesThe optically active polyamides 1, 2a and b enable optical resolutions of racemates of α-substituted 2-phenylacetamides (3a-g), mandelic acid derivatives (4a-c), N-substituted acetamides (5a-d. 6, 7), N-acylamino acid esters (8a-h), and benzoin derivatives (9a-c). The amide 5c was resolved on a preparative scale yielding both optically pure enantiomers.
    Notes: Die optisch aktiven Polyamide 1, 2a und b trennen Racemate von α-substituierten 2-Phenylacetamiden (3a-g), Mandelsäurederivaten (4a-c), N-substituierten Acetamiden (5a-d, 6, 7), N-Acylaminosäureestern (8a-h) und Benzoinderivaten (9a-c). Das Amid 5c wurde im präparativen Maßstab in beide optisch reinen Enantiomeren aufgetrennt.
    Additional Material: 1 Ill.
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