TY - JOUR A1 - Tacke, Reinhold A1 - Lange, Hartwig A1 - Bentlage, Anke A1 - Sheldrick, William S. A1 - Ernst, Ludger T1 - 2.2.5.5-Tetraorganyl-1.4-dioxa-2.5-disilacyclohexane/2,2,5,5-Tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes JF - Zeitschrift für Naturforschung B N2 - The 2,2,5,5-tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes 2a-2c were prepared by condensation of the corresponding (hydroxymethyl)diorganylsilanes 1 a-1 c. The constitution of the heterocycles was confirmed by elemental analyses, cryoscopic measurements, mass spectrometry, and NMR-spectroscopic \((^1H, ^{13}C)\) investigations. The molecular structure of 2 b was determined by X-ray diffraction analysis. KW - 1,4-Dioxa-2 KW - 5-disila-cyclohexane ring system KW - synthesis KW - structure Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128423 VL - 38 IS - 2 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Bentlage-Felten, Anke A1 - Linoh, Haryanto A1 - Magda, Stephen T1 - Sila-Analoga des Triparanols und Ethamoxytriphetols: Synthese sowie pharmakologische und toxikologische Eigenschaften T1 - Sila-analogues of Triparanol and Ethamoxytriphetol: synthesis as well as pharmacological and toxicological properties N2 - No abstract available. KW - sila-subsitution KW - triparanol KW - ethamoxytriphetol KW - hypolipidemic activity KW - toxicological properties Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86940 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Bentlage, Anke A1 - Towart, Robertson A1 - Möller, Eike T1 - Sila-pharmaca, XXV. Sila-analogues of nifedipine-like dialkyl 2,6-dimethyl-4-aryl-1,4 dihydropyridine-3,5-dicarboxylates, III N2 - IS neue C/Si-Analogenpaare (C-Verbindungen und sila- bzw. disila-substituierte Derivate), die sich strukturell vom Nifedipin ableiten, wurden synthetisiert. Diese und einige weitere C/Si-Paare wurden hinsichtlich ihrer physikochemischen und pharmakologischen Eigenschaften vergleichend untersucht. Mittels reversed-phase-Dünnschichtchromatographie wurde gezeigt, daß die Sila- bzw. Disila-Analoga lipophiler sind als die entsprechenden C-Verbindungen. Bezüglich der spasmolytischen in vitra-Aktivitäten zeigen die Si-Verbindungen in erster Näherung ähnliche Struktur-Wirkungs-Beziehungen wie ihre Carba-Analoga. Dagegen konnten hinsichtlich der ill vlva-Effekte (cardiovasculäre und antihypertensive Aktivität) in einigen Fällen große Unterschiede nachgewiesen werden. N2 - 15 new C/Si-analogue pairs (C-compounds and sila- or disila-substituted derivatives, respectively), which are structurally related to nifedipine, have been synthesized. These and some further C/Si-pairs have been investigated comparatively with respect to their physicochemical and pharmacological properties. Using reversed-phase thin-layer chromatography it was shown that both the sila- and disila-analogues are more Iipophilic than the corresponding C-compounds. With respect to the in vitra spasmolytic potencies the Si-compounds show approximately similar structure-activity relationships to their carba-analogues. However, in some cases marked differences in in vivo effects (cardiovascular and antihypertensive activity) could be demonstrated. KW - Anorganische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78357 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Link, Matthias A1 - Bentlage-Felten, Anke A1 - Zilch, Harald T1 - Zum thermischen Verhalten einiger Kohlensäure[(methylphenylsilyl)methyl]ester-Derivate T1 - On the Thermal Behaviour of Some (Methylphenylsilyl)methyl Carbonate Derivatives JF - Zeitschrift für Naturforschung B N2 - The synthesis and the thermal behaviour of the (methylphenylsilyl)methyl carbonates \(CH_3(C_6H_5)Si(H)CH_2OC(O)X (6: X = OCH_3; 7: X = Cl; 8: X = N(CH_3)_2)\) is described. 8 rearranges in toluene solution at 100 °C quantitatively to give the carbam oyloxysilane \(C_6H_5(CH_3)_2SiOC(O)N(CH_3)_2\) (11), whereas neat 6 and 7 at 135 °C undergo quantitative formation of \(C_6H_5(CH_3)_2SiOCH_3\) (12) and \(C_6H_5(CH_3)_2SiCl\) (13), respectively. The formation of 12 and 13 is explained by a rearrangement reaction (by analogy to the rearrangement of 8), follow ed by a decarboxylation. The thermally induced transformations 6 →12, 7 →13, and 8 →11 were found to be first-order reactions with half-lifes of ~2.6 h (135 °C, neat), ~4.5 h (135 °C, neat), and ~3.7 h (100 °C, in toluene), respectively. KW - decarboxylation KW - (Methylphenylsilyl)methyl carbonates KW - rearrangement KW - dimethylphenylsilyl carbonates Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128293 VL - 40 IS - 7 ER -