Search results for "Triazole"
showing 10 items of 347 documents
ChemInform Abstract: Oxidative Cyclization of Some Aldehyde Semicarbazones Induced by Metallic Salts.
2010
The oxidative cyclization of some aldehyde semicarbazones 10 with four different oxidizing agents has been effected. The structure of the semicarbazones and the nature of cyclizing agent affected the rate and yield of cyclization but they did not show any influence on the regiochemistry of reaction. In fact, 1,2,4-triazoline 20 was the only heterocyclic ring obtained by the cyclization reaction.
H2-Antihistaminika, 33. Mitt. Synthese und H2-antagonistische Aktivität heteroaromatischer (Thio)Carboxamide und Triazol(thi)on-Derivate des Piperidi…
1987
Die Zyklisierung der (Thio)Semicarbazide la, b mit N-Cyan-diphenylimidocarbonat, N-Cyan-dimethyldithioimidocarbonat, Aminocrotonsaurenitril und Acetessigester gibt die heteroaromatischen (Thio)Carboxamide 5a, b und 7–9. Beim Einwirken von NaOH auf die (Thio)Biharnstoffe 12 und 13 sowie die (Oxa)Thiadiazoldiamine 19 und 20 werden die Triazol(thi)one 15 und 17 erhalten. Am Vorhof des Meerschweinchens zeigen 5a, 7 und 8 eine mit Cimetidin vergleichbare Histamin-H2-antagonistische Wirkung. H2-Antihistaminics, XXXIII: Synthesis and H2-Antagonistic Activity of Heteroaromatic (Thio)Carboxamides and Triazole(thi)one-Derivatives of Piperidinomethylphenoxypropylamine The (thio)semicarbazides la, b ar…
Oxidative cyclization of aldehyde thiosemicarbazones induced by potassium ferricyanide and by tris(p-bromophenyl)amino hexachloroantimoniate. A joint…
2005
The oxidative ring closure reaction of some aryl-substituted thiosemicarbazones induced by "bona fide" one-electron abstracting agents was investigated, by means of both experimental and computational techniques. The corresponding 1,2,4-triazole derivatives were the only cyclization products observed. The occurrence of two slightly different mechanistic pathways for the reaction is discussed.
ChemInform Abstract: Pyrrolo[3,4-e][1,2,3]triazolo[1,5-a]pyrimidine and Pyrrolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine. New Tricyclic Ring Systems of…
2001
Derivatives of the new ring system pyrrolo[3,4-e][1,2,3] triazolo[1,5-a]pyrimidine 6 were prepared in high yields in one step by reaction of 3-azidopyrrole 3 and substituted acetonitriles. Compound 6b rearranged, upon heating in dimethyl sulfoxide in the presence of water, to pyrrolo[3,4-d][1,2,3]triazolo-[1,5-a]pyrimidine 7.
ChemInform Abstract: 1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, Through 1,3-Dipolar Cycloadditions
2014
1,3-Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3-triazole core through 1,3-dipolar cycloaddition reactions. The 1,2,3-triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an ill…
Systematic investigation of the adsorption and inhibition properties of a new clickable 1,2,3‐triazole compound for mild steel in 1 M HCl medium
2021
A Straightforward Route to Homoallyl-Homocrotylamines Promoted by a Titanium Complex
2012
I�-Allyltitanium complexes, generated in situ from 1,3-dienes and Cp2TiH, react with benzotriazole derivatives to give homoallylic amines in good yields. Under similar conditions, triple cascade reactions (allyltitanation followed by cationic 2-aza-Cope rearrangement followed by a second allyltitanation) occur from bis(benzotriazolyl) compounds affording a straightforward route to homoallyl-(E)-homocrotylamines. A theoretical study provides further insight into the factors that govern the selectivity of this sequence of reactions. The titanium-promoted reductive coupling of 1,3-dienes with bis(benzotriazolyl) compounds as substrates led selectively to homoallyl-homocrotylamines through a tr…
ChemInform Abstract: Synthesis of Novel 1,2,5,6-Tetrahydro-4H-pyrrolo[3,2,1-ij]quinolines via Benzotriazole Methodology.
2010
Abstract Pyrroloquinolines have been synthesized reacting 1-(benzotriazol-1(2)-ylmethyl)indolines with unactivated and electron-rich alkenes in the presence of p-toluenesulfonic acid catalyst. Mixtures of the expected diastereomers were obtained and some of them separated in their respective components. X-Ray diffraction along with two-dimensional NMR experiments was needed to assist the determination for both the structures of the precursors and products.
Synthesis of novel 1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolines via benzotriazole methodology
2001
Abstract Pyrroloquinolines have been synthesized reacting 1-(benzotriazol-1(2)-ylmethyl)indolines with unactivated and electron-rich alkenes in the presence of p-toluenesulfonic acid catalyst. Mixtures of the expected diastereomers were obtained and some of them separated in their respective components. X-Ray diffraction along with two-dimensional NMR experiments was needed to assist the determination for both the structures of the precursors and products.
ChemInform Abstract: Reaction of Diphenyldiazomethane with N-Methyloxy- and N-Ethyloxycarbonyl-N-(2,2,2-trichloroethylidene)amines.
2010
Reaction of the title imines with diphenyldiazomethane gives a Δ3-1,3,4-triazoline, which leads, after loss of dinitrogen, to a transient azomethine ylide. Subsequent elimination of ethyl or methyl chloroformate gives the unexpected 1,1-diphenyl-4,4-dichloro-2-aza-1,3-butadiene.