Refine
Has Fulltext
- yes (119)
Is part of the Bibliography
- yes (119)
Year of publication
Document Type
- Journal article (119) (remove)
Keywords
- Anorganische Chemie (119) (remove)
Institute
Die Synthese der (2-Aminoethyl)cycloalkylphenylsilanole Sb (Sila-Trihexyphenidyl), 6b (SilaCycrimin), 7 b (Sila-Procyclidin) und Sb wird beschrieben. Sb- Sb wurden - ausgehend von Cl\(_2\)(C\(_6\)H\(_5\))SiCH = CH\(_2\) (9) - durch eine fünfstufige Reaktionsfolge mit einer Gesamtausbeute von 32- 40% erhalten. Am isolierten Ileum des Meerschweinchens wurden die C/Si-Paare Sa, b- 8a, b vergleichend auf ihre antimuskarinische Aktivität geprüft. Die durch die Sila-Substilution von Sa-8a erreichte Zunahme der Affinität zum Muskarinrezeptor ist deutlich weniger ausgeprägt als bei den strukturverwandten C/Si-Paaren I a, b- 4a, b.
Die erstmalige Synthese der (Thioacetoxy-S-methyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) und der (Mercaptomethyl) diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) wird beschrieben. Während sich die Silane 9 und 10 leicht handhaben lassen, neigen die strukturanalogen (Hydroxymethyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) zu einer basenkatalysierten Zersetzung (Bildung oligomerer (polymerer) Alkoxysilane und Wasserstoff). Im Gegensatz zu den thermisch labilen (Acetoxymethyl)diorganylsilanen (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ Umlagerung zu den entsprechenden Acetoxy(methyl) diorganylsilanen (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) und CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) {6)) sind die Thio-Analoga 9 und 10 thermisch stabil (I-molare Lösungen in C\(_6\)D\(_6\), 30 h bei 180 o C).
In the molecular structure of the title compound, C34H58B2N2, each B atom of the diborane(4) is connected to one dimethylamino group and one Tip ligand (Tip = 2,4,6-triisopropylphenyl). These findings indicate that the increased steric demand of the Tip groups exerts influence solely on the B—B separation but not on the overall geometry of the title compound.
Das Sila-Dimetacrin (3a), ein Sila-Analogon des Psychopharmakons Dimetacrin (2), und sein N,N-Diethylderivat 3 b sowie sein 3-Chlorderivat 3 c wurden, von den o-Halogenanilinen 4 a- c ausgehend, über die teilweise unbekannten Stufen 5 a- c bis 10a- d synthetisiert, in ihren Eigenschaften beschrieben und in ihrer Struktur über Elementaranalysen, \(^1\)H-NMR- und Massenspektren sichergestellt. Die Synthese des Zwischenproduktes Bis(2-bromphenyl)amin (9a) konnte optimiert werden.
In an attempt to assess the structural requirements of hexahydro-sila-difenidol for potency and selectivity, a series of analogues modified in the amino group and the phenyl ring were investigated for their affinity to muscarinic M1- (rabbit vas deferens), Mr (guinea-pig atria) and Mr (guinea-pig ileum) receptors. All compounds were competitive antagonists in the three tissues. Their affinities to the three muscarinic receptor subtypes differed by more than two orders of magnitude and the observed receptor selectivities were not associated with high affinity. The pyrrolidino and hexamethyleneimino analogues, compounds substituted in the phenylring with a methoxy group or a chlorine atom as weil as p-fluoro-hexahydro-difenidol displayed the same affinity profile as the parent compound, hexahydro-sila-difenidol: M1 = M3 > M2 • A different selectivity patternwas observed for p-fluoro-hexahydro-sila-difenidol: M3 > M1 > M2 • This compound exhibited its highest affinity for M3-receptors in guinea-pig ileum (pA 2 = 7.84), intermediate affinity for M1-receptors in rabbit vas deferens (pA 2 = 6.68) and lowest affinity for the Mrreceptors in guinea-pig atria (pA 2 = 6.01). This receptor selectivity profile of p-fluoro-hexahydro-sila-difenidol was confirmed in ganglia (M1), atria (M2 ) and ileum (M 3 ) of the rat. Furthermore, dose ratios obtained with either pirenzepine (Mt) or hexahydrosila- difenidol (M2 and M3) and the p-fluoro analogue used in combination suggested that the antagonism was additive, implying mutual competition with a single population of muscarinic receptor subtypes. These results indicate that p-fluoro-hexahydro-sila-difenidol represents a valuable tool for characterization of muscarinic receptor subtypes.
A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.
(C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)X (1 a: X = Cl; 1 b: X = I) und C\(_6\)H\(_5\)(CH\(_3\))Si(H)CH\(_2\)CI (10) reagieren mit LiOCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (2b) zu den Alkoxysilanen (C\(_6\)H\(_5\))\(_2\)Si(CH\(_3\))OCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (5) bzw. C\(_6\)H\(_5\)(CH\(_3\))\(_2\)SiOCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (12). Die Bildung dieser unerwarteten Reaktionsprodukte wird durch einen nucleophilen Angriff des Alkoxids am Si-Atom gedeutet. dem sich eine intramolekulare 1 ,2-Hydridverschiebung vom Si zum C und Eliminierung von Cl e anschließt. Mit weichen Basen, wie z. B. I (-) und (-)SCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\), wurden dagegen "normale" Substitutionsreaktionen am C-Atom der SiCH\(_2\)Cl-Gruppe beobachtet