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  • 1
    Electronic Resource
    Electronic Resource
    Determination of acipimox in capsules by differential pulse polarography (1995)
    Springer
    Microchimica acta 118 (1995), S. 147-152 
    Details
    ISSN: 1436-5073
    Keywords: acipimox ; determination of ; DPP, polarography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A differential pulse polarographic (DPP) method has been developed for the determination of acipimox in its pharmaceutical formulations. Using Sörensen buffer pH 6.0 as supporting electrolyte a single, irreversible peak occurred at −0.79 V vs an Ag/AgCl reference electrode. The peak height vs concentration plot was found to be linear over the range of 10−6 to 6 × 10−4 mol/l. The detection limit is 60ng/ml. The analysis of a series of 10 Olbetam® 250 mg capsules showed an overall standard deviation of ± 4.18 mg and a Srel of ± 1.66%, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01244354
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  • 2
    Electronic Resource
    Electronic Resource
    Reactions of hydroxyethylamino-1,4-benzoquinones with 2,4,6-trimethylbenzonitrile oxide, II (1993)
    Springer
    Monatshefte für Chemie 124 (1993), S. 1201-1205 
    Details
    ISSN: 1434-4475
    Keywords: Hydroxyethylamino-1,4-quinones ; Nitrile oxide ; 1,2-Oxazolines, 4,5-fused ; 1,3-Dipolar cycloadditions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei der Reaktion von Hydroxyethylamino-1,4-benzochinonen2a–c mit dem Nitriloxid3 werden 3,4,9a,9b-Tetrahydro-2H-1,2-oxazolo[5,4-h]1,4-benzoxazin-6(6aH)-one5 erhalten. Deren Strukturen wurden NMR-spektroskopisch — unter Einbeziehung inverser long-range13C,1H-Experimente und NOE-Differenz-Spektroskopie — aufgeklärt.
    Notes: Summary 3,4,9a,9b-Tetrahydro-2H-1,2-oxazolo[5,4-h]1,4-benzoxazin-6(6aH)-ons5a–c were obtained by the reaction of hydroxyethylamino-1,4-benzoquinones2a–c with nitrile oxide3. The structures of the cycloadducts were elucidated NMR techniques including inverse longe-range13C,1H-experiments and homonuclear NOE difference spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810029
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  • 3
    Electronic Resource
    Electronic Resource
    2H-Isoindol-4,7-dione durch Addition von Azomethinyliden an 1,4-Benzochinone (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 383-387 
    Details
    ISSN: 1434-4475
    Keywords: 2H-isoindole-4,7-diones ; 2,3,3a,7a-Tetrahydro-1H-isoindole-4,7-diones ; 2,3-Dihydro-1H-pyrrolo[2,1-a]isoindole-6,9-diones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new approach to the synthesis of 2H-isoindole-4,7-diones is described. Heating α-amino acids with carbonyl compounds generates azomethine ylides through the elimination of water and carbon dioxide. The ylides were captured by quinones forming 2H-isoindole-4,7-diones, 2,3,3a,7a-tetrahydro-1H-isoindole-4,7-diones and 2,3-dihydro-1H-pyrrolo[2,1-a]isoindole-6,9-diones. The structures were established on the basis of spectroscopy (NMR, mass).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809659
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  • 4
    Electronic Resource
    Electronic Resource
    1,2-Oxazoline durch Addition von Trimethylbenzonitriloxid an 2-Hydroxyethylamino-1,4-benzochinone und deren Chinolderivate (1990)
    Springer
    Monatshefte für Chemie 121 (1990), S. 555-564 
    Details
    ISSN: 1434-4475
    Keywords: 1,3-Dipolar addition ; 1,2-Oxazolines ; NMR-data ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Addition of trimethylbenzonitril oxide to 2-hydroxyethylamino-1,4-quinones and 3,4-dihydro-4-alkyl-8a-methoxy-2H-1,4-benzoxazin-6(8aH)-ones leads to 7,8,9a,9b-tetrahydro-3aH-1,2-oxazolo[4,5-h]-1,4-benzoxazin-4(6H)-ones. In order to determine constitution and conformation of the addition products an NMR-spectroscopic analysis and an X-ray crystal structure analysis of 6-benzyl-9a-hydroxy-3-mesityl-7,8,9a,9b-tetrahydro-3aH-1,2-oxazolo[4,5-h]-31,4-benzoxazin-4-(6H)-one3a were carried out at room temperature: C25H26N2O4,M r=418.49, monoclinic, P21/n,a=13.716(6),b=19.993(6),c=15.348(6) Å, β = 98.55(4)°,V=4162(1)Å3,Z=8,d x=1.336g/cm3,R=6.77%,R w=4.55% (2994 observables, 560 parameters).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810865
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  • 5
    Electronic Resource
    Electronic Resource
    Über Synthese und Struktur desp-Tolylbiguanid-Zimtaldehyd-Kondensates in ethanolischer Salzsäure (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 949-957 
    Details
    ISSN: 1434-4475
    Keywords: Cinnamaldehyde ; reaction with p-tolylbiguanide ; 4,6-Diamino-1,2-dihydro-s-triazine ; [4,6-Diamino-1,2-dihydro-1-(4-methylphenyl)-2-styryl-1,3,5-triazin] ; synthesis ; NMR-data ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 4-Tolybiguanide reacts with cinnamaldehyde in ethanolic hydrochloric acid atpH 1 to yield 4,6-diamino-1,2-dihydro-1-(4-methylphenyl)-2-styryl-1,3,5-triazin (5·HCl). The structure was established on the basis of NMR-techniques including two-dimensional experiments. A single crystal X-ray crystal structure analysis of5 was carried out at 100 K: C18H19N5·HCl,M r=341.84, triclinic, P 1,a=9.740(4),b=10.055(4),c=10.077(2)Å, α=75.60(2)°, β=88.92(2)°, γ=66.61(2)°,V=873.8(5)Å3,Z=2,d x=1.299 g/cm3m, μ=0.22 mm−1,R=5.57%,R w=5.56% (2451 observations, 236 parameters).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00823425
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  • 6
    Electronic Resource
    Electronic Resource
    4a,6-Bis-(N-methlanilino)-7-hydroxy-2,3,8-trimethyl-4a,9a-dihydro-xanthen-1,4-dion: Ein thermolyseprodukt von 6-(N-methylanilino)-7a-methyl-3a,7a-dihydroindazol-4,7-dion (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 545-549 
    Details
    ISSN: 1434-4475
    Keywords: Dihydroxanthenedione ; 2D-NMR ; 1H-13C-Shift-correlation ; COLOC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 4a,6-Bis-(N-methylanilino)-7-hydroxy-2,3,8-trimethyl-4a,9a-dihydro-xanthene-dione (4) was obtained by thermolysis of 6-(N-methylanilino)-7a-methyl-3a,7a-dihydroindazol-4,7-dione (1) The structure was determined on basis of 1D- and 2D-NMR techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809808
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  • 7
    Electronic Resource
    Electronic Resource
    1,2-Thiazole durch Ringtransformation von 2H-Thiopyran-2-thionen (1992)
    Springer
    Monatshefte für Chemie 123 (1992), S. 133-143 
    Details
    ISSN: 1434-4475
    Keywords: Oxidative cyclization ; 1,2-Thiazoles ; 13C-NMR-data ; X-Ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Aminolyses of 4-dialkylamino-2-methylthiothiopyranes halides with ammonia leads to 4-amino-2-dialkylaminothiopyranylium halides. On treatment with alkali these products are hydrolyzed to N,N-dialkyl-3-amino-2,4-hexadienthioamides, which react with peroxide under oxidative cyclization to 5-dialkylamino-1,2-thiazoles. In order to determine the structures of the unsaturated thioamides and isothiazoles13C-NMR-spectroscopic analysis and a single crystal X-ray structure analysis of 5-dimethylamino-3-(2-methyl-1-propenyl)-1,2-thiazole (6 a) at 100K were carried out: C9H14N2S,M r=182.28, monoclinic, P 21/a,a=11.622(2),b=6.303 (1),c=13.678(2), β=104.49(3)°,V=970.1(3)Å3,Z=4,d x=1.248 g/cm3, μ=27.0 mm−1,R=4.93%,R w=4.84% (1 672 observations, 157 parameters).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01045306
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  • 8
    Electronic Resource
    Electronic Resource
    Zur Umsetzung von 8a-Methoxy-3,4-dihydro-2H-1,4-benzoxazin-6(8aH)-onen mit Diazoalkanen, 2. Mitt. (1992)
    Springer
    Monatshefte für Chemie 123 (1992), S. 899-910 
    Details
    ISSN: 1434-4475
    Keywords: 1,3-Dipolar cycloaddition of 3,4-dihydro-2H-benzoxazin-6(8aH)-ones with diazoalkanes ; Hexahydro-pyrazolobenzoxazin-6(2H)-ones ; NMR-investigation ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 8a-Methoxy-3,4-dihydro-2H-1,4-benzoxazin-6(8aH)-ones2 undergo regio- and stereospecific 1,3-dipolar cycloaddition reactions with diazomethane or diazoethane to yield 3,4,6a,9,9a,9b-hexahydro-pyrazolo[3,4-h][1,4]benzoxazin-6(2H)-ones3, which slowly isomerize in solution to give the 3,4,8,9,9a,9b-hexahydro-pyrazolo[3,4-h][1,4]benzoxazin-6(2H)-ones5. The carbon of the diazoalkane dipole is attached to carbon C-8 of the benzoxazinone. The structures of the obtained products were determined by1H- and13C-NMR spectroscopy. An X-ray crystal structure analysis of3 a was carried out at room temperature:C11H15N3O3,M r =237.26, orthorhombic, Pc21n,a=9.173 (5),b=9.133 (4),c=13.281 (6),V=1112.6 (9) Å3,Z=4,d x =1.416 g/cm−3, μ=0.93 cm−1,R=4.33%,R w =3.95% (919 observations, 168 parameters).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811545
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  • 9
    Electronic Resource
    Electronic Resource
    Zur Umsetzung von 3,4-Dihydro-8a-methoxy-2H-1,4-benzoxazin-6(8aH)-onen mit Diazoalkanen, 1. Mitt. (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 51-57 
    Details
    ISSN: 1434-4475
    Keywords: Tetrahydro-pyrazolo-benzoxazinones ; 1,3-Dipolar cycloaddition ; NMR-data
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 3,4-Dihydro-8a-methoxy-2H-1,4-benzoxazin-6(8aH)-ones — quinol derivatives of 2-hydroxyethylamino-1,4-benzoquinones — react with diazoalkanes to yield 2,3,9a,9b-Tetrahydro-9H-pyrazolo[3,4-h]-1,4-benzoxazin-6(6aH)-ones (3). Their structures were established on basis of NMR-techniques including two-dimensional experiments. The orientation phenomena of the reaction is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00815165
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  • 10
    Electronic Resource
    Electronic Resource
    The structure of hellebrin (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 443-444 
    Details
    ISSN: 0947-3440
    Keywords: Helleborus ; Hellebrin ; Carbohydrates ; Glycosides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structure of hellebrin (1) was investigated by using 2D NMR techniques (COSY, TOCSY, ROESY, HMQC, HMBC) and its structure determined as 3-β-O-(β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl)hellebrigenin. The complete assignment of the proton and carbon NMR signals is given.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199519950257
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