Search results for "DISCOVERY"
showing 10 items of 4119 documents
Potentielle Analgetika, 5. Mitt.: Über die Synthese und pharmakologische Wirkung cyclischer Analoga des Fentanyls
1975
Cyclische Analoga des Fentanyls wurden dargestellt und pharmakologisch untersucht. Durch Verknupfung der Acyl-Seitenkette mit C-2 des Aromaten und der damit verbundenen Anderung der stereochemischen Struktur geht die analgetische Wirkung des Fentanyls verloren, jedoch besitzen die Verbindungen starke antihistiaminische Eigenschaften. Synthesis and Pharmacological Activities of Cyclic Analogues of Fentanyl. Cyclic analogues of fentanyl were synthesized and pharmacologically tested. Cyclisation of the acyl group with C-2 of the aromatic ring yielded a change in stereochemical structure. Therefore the analgesic activity of fentanyl was lost and strong antihistaminic activities appeared.
Transamidation reactions of 2-(2-sulfonylguanidino)acetamides
2007
Abstract The reactivity of a series of sulfonylguanidinoacetamides 2A–E towards amines is reported. Guanidinoacetamides 2A–C, containing the arylsulfonylimino moiety, undergo a facile transamidation to give substituted carboxamides 4A–C, through the imidazolidinone intermediate 3. Acetamide 2D, having a methanesulfonylimino substituent, affords the imidazolidinone 3D and no transamidated carboxamides 4 are detected. In the case of guanidinoacetamide 2E, with a p-nitrobenzenesulfonylimino substituent, a Smiles rearrangement was observed.
NMR-Spektroskopie an Heterocyclen, 3. Mitt.: Homologe, vinyloge und kernalkylierte Nicethamidanaloge
1976
Von homologen, vinylogen und kernalkylierten Nicethamidanalogen wurden die 13C-NMR-Shiftwerte ermittelt und mit Hilfe der 1H-NMR-Spektroskopie durch Koaleszenzbestimmung die Energiebarriere bei der gehinderten Rotation der Amidgruppe bestimmt. Homologous, Vinylogous, and Ring Alkylated Nicethamide Analogs The 13C-NMR shifts were determined for homologous, vinylogous and ring alkylated nicethamide analogs and the energy barrier of the hindered rotation of the amide group was evaluated by means of coalescence measurements with 1H-NMR.
Eine neue synthese for 3-desoxy-3-iod-zucker über alkoxyphosphoniumsalze
1979
Abstract The alkoxy phosphonium iodides of the 1,2:5,6-di-O-isopropylidene-gluco- and allofuranose are converted to the corresponding 3-iodo sugars without elimination or rearrangement.
Gekreuzt konjugierte oligomere aus pyrrol-, benzol- und carbonyl-Bausteinen
2004
Abstract Chalcones can serve as C 2 or C 3 components for the formation of 1 H -pyrroles. In particular the reaction with tosylisocyanid could be applied to the oligochalcones 2d - g with up to 6 enone units. A series of cross-conjugated oligomers 8d - g was obtained; these compounds consist of a chain of 1,4-phenylene, carbonyl and 1 H -pyrrole-3,4-diyl building blocks. The benzene rings bear two propoxy sidechains in order to enhance the solubility.
First unequivocal synthesis of dissymmetrical trans N,N′-difunctionalized 1,4,8,11-tetraazacyclotetradecane
1999
Abstract The first unequivocal synthesis of disymmetrical trans N,N′-difunctionalized tetraazamacrocycles in cyclam series is reported. This convenient four-step method can be used for the synthesis of various trans N,N′-difunctionalized tetraazamacrocycles bearing two different pendant donor arms.
Total syntheses of (+)-temisin, (+)-melitensin and related elemanolides from (-)-artemisin
1984
Abstract (+)-Temisin, (+)-melitensin, and related sesquiterpene lactones have been synthesized from (-)-artemisin.
Triazolopyridines. Part 26: The preparation of novel [1,2,3]triazolo[1,5-a]pyridine sulfoxides
2008
Abstract The regioselective synthesis of new triazolopyridine halides and sulfoxides with the substituent in all different ring positions of [1,2,3]triazolo[1,5- a ]pyridines is presented. The triazolo ring opening reaction of some representative sulfoxides to obtain disubstituted pyridines is also studied.
E-Ring extended estrone derivatives: introduction of 2-phenylcyclopentenone to the estrone D-ring via an intermolecular Pauson–Khand reaction
2006
Abstract An expedient synthetic route to E-ring extended estrone derivatives is reported. Estrone-derived cyclopentenones were accessed by an intermolecular Pauson–Khand (PK) cycloaddition. It was found that electron donating and withdrawing substituents in the arylalkyne increased and decreased the yields of PK products, respectively. The stereochemistry of the products was elucidated by X-ray and NMR studies.
Ultrasound assisted reductive cleavage of sesquiterpene γ-enonelactones
1995
Abstract Ultrasound enhances the rate of reductive cleavage of the C 6 -oxygen bond of several cis - and trans - sesquiterpene γ-enonelactones. Interestingly ultrasound overrides the stereoelectronic requirements for the reductive cleavage of the most usually occurring sesquiterpene trans -lactones.