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  • 1
    Electronic Resource
    Electronic Resource
    Preparation of trimethyl-2-hydroxyethylarsonium (arsenocholine) compounds (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 1 (1987), S. 403-412 
    Details
    ISSN: 0268-2605
    Keywords: Trimethyl-2-hydroxyethylarsonium salts ; arsenocholine ; trimethyl-2-haloethylarsonium bromide ; trimethyl-2-acetoxyethylarsonium bromide ; acetylarsenocholine ; trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide ; 1H and 13C NMR spectra ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Trimethyl-2-X-ethylarsonium salts (X=OH, Cl, Br, CH3COO; anion=Br) and trimethyl-2-diethoxyethylarsonium bromide were prepared from trimethylarsine and the appropriate organic bromides in sealed tubes at elevated temperatures or by refluxing the neat reagents. The yields ranged from 33 to 85%. Anion exchange reactions produced the arsonium iodides, nitrates, acetates, tosylates, tetraphenylborates, picrates, hydroxides, and carbonates. Arsenocholine bromide (X=OH) was phosphorylated with concentrated phosphoric acid. The product was isolated as the barium salt. Treatment of the barium salt with sulfuric acid yielded trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide. These substances were synthesized to serve as precursors for arsenic- containing phospholipids and as standards for the chromatographic identification of arsenocholines. The synthesized compounds were characterized by elemental analyses and 1H and 13C NMR spectroscopy. The shifts of the arsenic compounds were compared with those of the corresponding nitrogen compounds and found to be sufficiently different to be used for the identification of these compounds in their mixtures.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590010504
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  • 2
    Electronic Resource
    Electronic Resource
    On the reaction of catenapoly(diphenoxy-λ5-phosphazene) with sulfur trioxide (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 191-202 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of catenapoly(diphenoxy-λ5-phosphazene) (1) with SO3 in 1,2-dichloroethane at 15°C, applying a mole ratio m = [SO3]/[--P(OC6H5)2N - ] ≤ 1,0 and subsequent quenching with water, leads to catenapoly(diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate) (2) containing up to 57% protonated nitrogen. At m 〉 1,0 C-sulfonation occurs, resulting in the formation of water-soluble catenapoly[diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate-co-bis(sulfophenoxy)-λ5-phosphazenium hydrogen sulfate] (3). The latter can be converted into catenapoly[diphenoxy-λ5-phosphazene-co-bis(sulfophenoxy)-λ5-phosphazene] (4b) by treatment with alkali and subsequent percolating through a cation exchange resin. Analytical results show that C-sulfonation is preceded by the formation of a polymer-SO3 donor-acceptor complex.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900120
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  • 3
    Electronic Resource
    Electronic Resource
    1H and 13C NMR spectra of the opioid analgesics metazocine, pentazocine and cyclazocine (1988)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 26 (1988), S. 693-700 
    Details
    ISSN: 0749-1581
    Keywords: 1H NMR ; 13C NMR ; Benzomorphans ; 2D NMR ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The high-frequency 1 and 13C NMR spectra (at 500 and 75.47 MHz, respectively) of metazocine (MTZ) fumarate, pentazocine (PTZ) and cyclazocine (CLZ) hydrochlorides in 2H2O solution were recorded and analysed with the aid of both homonuclear 1H—1H and heteronuclear 13C—1H chemical shift correlation experiments. At neutral pH all compounds were found to be configurationally heterogeneous, with the N-equatorial isomer more populated than the N-axial isomer (ratio ca 80:20). The low-intensity peaks of the superimposed spectral pattern of the less populated isomer were also assigned on correlative grounds in both the 1H and 13C NMR spectra of MTZ, PTZ and CLZ. The occurrence of distinct spectra for the two configurational isomers was diagnostic of a ‘slow’ exchange process on the NMR time-scale at the field frequencies employed for the experiments, thus suggesting a high-energy barrier to interconversion. The experimental proton-proton coupling constants measured for the N-equatorial form of MTZ, PTZ and CLZ were consistent with a chair conformation of the piperdinic ring in all compounds. The distinct relative agonist-antagonist potencies of the drugs investigated could therefore not be correlated with the above-described configurational and conformational features.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260260811
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