Search results for "DISCOVERY"
showing 10 items of 4119 documents
Facile synthesis of pyrazoles and pyrroles via thermolysis of tetrazolo[1,5-b]pyridazines, tetrazolo[1,5-a]pyrimidines and tetrazolo[1,5-a]pyridines
2000
Abstract A simple and high yielding preparation of pyrazoles and pyrroles is described. Thermolysis of tetrazolo[1,5- b ]pyridazines, tetrazolo[1,5- a ]pyrimidines and tetrazolo[1,5- a ]pyridines allowed easy ring contraction thus providing a facile preparation of cyanopyrazole and cyanopyrrole heterocycles. Since the cyano group is a versatile precursor of other functionalities, the reaction appears of particular interest for the construction of a variety of pyrazoles and pyrroles. The simple preparation of the starting tetrazole derivatives, the relatively mild conditions employed, and the very short reaction times make this versatile procedure of great synthetic utility and applicable bo…
Synthesis of (+)-podocarp-8(14)-en-13-one and methyl-(+)-13-oxo-podocarp-8(14)-en-18-oate from abietic acid
1985
Abstract An efficient method for the preparation of (+)-podocarp-8(14)-en-13-one 6 and methyl-(+)-13-oxo-podocarp-8(14)-en-18-oate 8 from abietic acid is described.
Aryl radicals by copper(II) oxidation of hydrazines: A new method for the oxidative and reductive arylation of alkenes
1989
Abstract A new source of aryl radicals interesting from the preparative point of view has been found in the reaction of arylhydrazines and copper(II) sulfate. The process allows selectively both the reductive and oxidative arylation of alkenes.
Addition of organolithium reagents to cinnamic acids
1999
Abstract Reaction of tert -butyllithium with p - and m -substituted cinnamic acids at low temperature affords mixtures of 1,4- and 1,3-addition products, whose composition depend on the nature of the substituents. Electron-donating and electron-withdrawing groups favour 1,4- and 1,3-additions, respectively. Linear correlations are obtained with electronic effect and with radical substituent constants.
Triazolopyridines. Part 9. The synthesis of7-amino(1,2,3)triazolo(1,5-a)pyridines
1989
Abstract Regiospecific lithiation of (1,2,3) triazolo(1,5-a)pyridines (1) and (4) with subsequent reaction with styryl azide gave small yields of the 7-aminotriazolopyridines (6) and (7). A longer larger scale synthesis of compounds (6) and (7) is described giving overall yields of 17 and 25%, starting from 2-amino-6-methyl (9) or 2-amino-6-ethyl pyridine (19).
Zentral dämpfende Wirkstoffe, 7. Mitt. Kernsubstituierte (Diallylamino)-1,3,5-triazine
1988
Aus der Umsetzung von 2,4-Dichlor-6-(diallylamino)-1,3,5-triazin (1) mit langkettigen primaren (2a-b) und cyclischen sekundaren (2c-f) Aminen gehen die kernsubstituierten Chlor-diallylamino-1,3,5-triazine (3a-f) hervor. Ein fur Strukturtyp 3 charakteristischer ms Fragmentierungsweg beinhaltet die Umbildung der Diallylaminogruppe zum Aziridinring. Unter den neu entwickelten Verbindungen findet sich zentral dampfende Wirksamkeit besonders in 3a ausgepragt. Daruber hinaus weist Strukturtyp 3 Antiprotozoen-, anthelminthische und insektenwachstumsregulatorische Wirkung auf. CNS Depressants, VII: (Diallylamino)-1,3,5-triazines Substituted at the Triazine Nucleus The reaction of 2,4-dichloro-6-(di…
H2-Antihistaminika, 35. Mitt. Synthese und H2-antagonistische Wirkung imidazolylmethylthioalkyl-substituierter 1,2,4-Triazole
1987
Es wurden mono-, di- und trisubstituierte 1,2,4-Triazolderivate dargestellt und auf Histamin-H2-antagonistische Aktivitat untersucht. H2-Antihistaminics, XXXV: Synthesis and H2-Antagonistic Activity of Imidazolylmethylthioalkyl-Substituted 1,2,4-Triazoles Mono-, di- and trisubstituted 1,2,4-triazoles were prepared and tested for histamine H2-antagonistic activity.
H2-Antihistaminika, 11. Mitt.1) Zyklische Guanidine mit H2-antihistaminischer Wirkung
1983
Es wurden zyklische Guanidine dargestellt und auf ihre H2-antihistaminische Wirksamkeit untersucht. H2-Antihistaminics, XI: Cyclic Guanidines with H2-Antihistaminic Activity Cyclic guanidines were prepared and tested for their H2-antihistaminic activity.
Zentral dämpfende Wirkstoffe, 2. Mitt.1) 3-Substituierte 4-Hydroxypyrimido[1,2-a]benzimidazol-2-one
1983
Aus der Umsetzung von 2-Aminobenzimidazol (1) mit den Malonestern 2a–g gehen die 4-Hydroxypyrimido[1,2–a]benzimidazol-2-one 3a–g hervor, unter denen sich Vertreter mit zentral dampfenden, hypertensiven, fungiziden und antibakteriellen Eigenschaften finden. Centrally Dampening Drugs, II: 3-Substituted 4-Hydroxypyrimido[1,2-a]benzimidazol-2-ones The 4-hydroxypyrimido[1,2-a]benzimidazol-2-ones 3a–g obtained by reacting 2-aminobenzimidazole (1) with the malonic acid esters 2a–g exhibit centrally dampening, hypertensive, fungicidal, and antibacterial properties.
Trichomonazide Wirkstoffe, 3. Mitt. Aryloxy-chlor-1,3,5-triazine
1987
Die Umsetzung von 2,4-Dichlor-6-(dihexylamino)-1,3,5-triazin (1) mit Phenolen (2) fuhrt bei niedrigen Temperaturen zu den Monoaryloxy-chlor-1,3,5-triazinen (3a–c), unter drastischeren Reaktionsbedingungen zu den Bis-(aryloxy)-1,3,5-triazinen (4c–d). Fur die neuen Verbindungstypen ist besonders charakteristisch die massenspektroskopische Abspaltung der Aryloxygruppen, beispielsweise in 4c der Ubergang von m/z 504 nach m/z 383. Auffallende trichomonazide und blutzuckersenkende Wirkungen vermag insbesondere 3b auszulosen. Trichomonacidal Agents, III: Aryloxy chloro- 1,3,5-triazines The reaction of 2,4-dichloro-6-(dihexylamino)-1,3,5-triazine (1) with the phenols 2 leads at low temperatures to …