Search results for "DISCOVERY"

Photoinduced functionalization of the C-20 methyl group of the nor-diterpene atractyligenin

2001

Abstract Irradiation of the nor-diterpene atractyligenin at λ =254 nm in methanol gave, on one hand, the decarboxylation product, and provided, on the other hand, the transformation of the C-20 angular methyl into a methylene-carbomethoxy group. A photochemical pathway involving formation of C-19/C-20 bond is suggested.

Dimethoxy Aromatic Compounds. VIII. Degenerate Dealkylation-Realkylation Reaction of 1-Bis(2,4-dimethoxyphenyl)-2-methylpropane.

1994

The condensation reaction under acid condition of the benzylic alcohols 1, 2 and 3 with the hexadeutero dimethoxybenzenes 4, 5 and 6 leads to the expected hexadeutero bis(dimethoxyphenyl)-2-methylpropanes 7, 8 and 9, respectively. However, the presence of both dodecadeutero and unlabelled 1-bis(2, 4-dimethoxyphenyl)-2-methylpropanes 10 and 11 indicates that 9 undergoes a rapid degenerate dealkylation-alkylation reaction.

Imidazole aus Aldehyden, 1,2-Diketonen und flüssigem Ammoniak. 3. Mitt. über Imidazolsynthesen mit flüssigem Ammoniak

1974

Bei der Darstellung von Imidazolen (3) aus aliphatischen oder aromatischen Aldehyden (1) und 1,2-Diketonen (2) in flussigem Ammoniak unter Druck konnen die verschiedenen Moglichkeiten der C-Substitution des Imidazolkerns realisiert werden. Imidazoles from Aldehydes, 1,2-Diketones and Liquid Ammonia If imidazoles (3) are prepared from aliphatic or aromatic aldehydes (1) and 1,2-diketones (2) in liquid ammonia under pressure, all possibilities of C-substitution of the imidazole nucleus can be realized.

Synthese von 2-(2-Aminoethyl)-4-hydroxymethyl-imidazol+ Synthesis of 2-(2-Aminoethyl)-4-(hydroxymethyl)imidazole

1982

H2-Antihistaminika, 9. Mitt. Keten-N,N-acetale mit H2-antihistaminischer Wirkung

1982

Es wurden die Keten-N,N-acetale (Ketenaminale) 4a-e dargestellt und auf ihre H2-antihistaminische Wirksamkeit untersucht. H2-Antihistaminics, IX: Ketene N, N-acetals with H2-Antihistaminic Activity The ketene N, N-acetals (keteneaminals) 4a-e were prepared and tested for their H2-antihistaminic activity.

Melaminderivate aus N′-Cyano-S,S′-dimethyl-guanidinodithioimidocarbonat

1981

Bei der Umsetzung von N′-Cyano-S,S′-dimethyl-guanidinodithioimidocarbonat mit primaren Aminen werden anstelle der erwarteten Cyanobiguanide durch spontane Zyklisierung gebildete Melaminderivate erhalten. Die Substanzen 9a–c zeigten keine H2-antihistaminische Wirksamkeit. Melamine Derivatives from S,S'-Dimethyl N'-Cyanoguanidinodithioimidocarbonate The reaction of S,S'-dimethyl N'-cyanoguanidinodithioimidocarbonate with primary amines yields melamine derivatives by spontaneous cyclization instead of the expected cyanobiguanides. The compounds 9a–c showed no H2-antihistaminic activity.

Ringoffene Serotonin-Analoga, 2. Mitt.1) Synthese von 3-(2-Aminophenyl)-propanamin- und 1-(N-Piperidino)-3-(2-aminophenyl)-3-oxo-propan-Derivaten

1983

Die Darstellung der Titelverbindungen gelingt via Mannich-Reaktion beim Einsatz geeignet substituierter Acetophenone. Die Gewinnung von 2 und seiner Derivate erfordert zusatzlich die nachfolgende durchgreifende Hydrierung der Carbonylgruppe der entsprechenden Mannichbasen. Ring-Opened Analogues of Serotonine, II: Synthesis of 3-(2-Aminophenyl)propanamine and 1-(Piperidin-1-yl)-3-(2-aminophenyl)propan-3-one and Their Derivatives The synthesis of the title compounds was achieved by Mannich reaction of suitably substituted acetophenones. The preparation of 3-(2-aminophenyl)propanamine and its derivatives requires complete hydrogenation of the carbonyl group of the Mannich bases.

Generation of hexahydroazulenes

2009

(Z)-Cyclodec-1-en-6-yne (3) generates three conjugated hexahydroazulenes 3→1k→1c, 1l under FVP conditions, whereas flash vacuum pyrolysis (FVP) of cyclodecyne (2) leads to 1,2,9-decatriene (9). We attribute the different thermal behavior of 2 (ring opening) and 3 (ring closure) to different transannular interactions. Altogether 22 constitutional isomers of hexahydroazulene should exist; three new isomers (1k, 1l, and 1m) are presented here, ten were described earlier, but the reinvestigation of the dehydration route of bicyclic alcohol 11 showed that one of the ten structures has to be revised.

NMR-Spektroskopie an Heterocyclen, 5. Mitt.13C-NMR- und massenspektrometrische Untersuchung N-substituierter Methoxy- und Hydroxy-äthylimidazole

1978

Es wird die 13C-NMR- und massenspektrometrische Untersuchung verschiedener N-substituierter Methoxy- und Hydroxy-athylimidazole beschrieben. Fur den Zerfall von 1,2-Diathyl-4-(2-hydroxyathyl)-imidazol wird ein ausfuhrliches Fragmentierungsschema angegeben. NMR-Spectroscopy of Heterocyclic Compounds, V: 13C-NMR and Mass Spectrometry of N-Substituted (2-Methoxyethyl)- and (2-Hydroxyethyl)-imidazoles The 13C-NMR and mass spectra of various N-substituted (2-methoxyethyl)- and (2-hydroxyethyl)imidazoles are described. A scheme for the fragmentation of 1,2-diethyl-4-(2-hydroxyethyl)imidazole is reported.

Massenspektrometrische Untersuchungen an 4(5)-Hydroxymethyl-imidazolen

1979

Es wurden 12 unterschiedlich substituierte Hydroxymethylimidazole massenspektrometrisch untersucht und die charakteristischen Schlusselbruchstucke beschrieben. Fur den Zerfall von 4(5)-Hydroxymethyl-imidazol (1) und 5-Hydroxymethyl-1-methyl-imidazol (8) werden Fragmentierungsschemata angegeben. Mass Spectrometry of 4(5)-Hydroxymethylimidazoles 12 substituted hydroxymethylimidazoles were investigated by mass spectrometry. The characteristic fragments are described. Schemes for the fragmentation of 4(5)-hydroxymethylimidazole (1) and 5-hydroxymethyl-1-methylimidazole (8) are reported.