Search results for "Zole"

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…

New syntheses of condensed heterocycles from isoxazole derivatives. V. Pyrrolo[3,4-b]pyridin-4-ones

1977

Hydrogenolysis with Raney-Nickel or iron powder in acetic acid of 2,5-diphenyl-4-nitro-3-(3,5-R,R-4-isoxazolyl)pyrrolyl ketones, prepared by the Grignard reaction of 2,5-diphenylpyrrole and 3,5-R,R-4-isoxazolecarboxilic acid chlorides followed by nitration, afforded directly the desired 6H-pyrrolo[3,4-b ]pyridin-4-ones.

New synthesis of condensed heterocycles from isoxazole derivatives VI. 2,5-Dimethyl-3-aeetyl-7-amino-1H-pyrrolo[3,2-b] pyridine

1978

A new synthesis of pyrrolo[3,2-b] pyridine starting with pyrrole ring is described. The procedure allows the synthesis of 4-azaindoles bearing a sensitive group at C-7. The nitration of 4b with nitric acid and acetic anhydride at −15° gave 5. The hydrogenation of 5 led to simultaneous reduction of N-hydroxy and nitro groups and to hydrogenolysis of the isoxazole nucleus, affording an appropriate chain of atoms to building up the pyrrolo[3,2-b] pyridine ring.

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

Photoinduced Molecular Rearrangements. The Photochemistry of Some 1,2,4-Oxadiazoles in the Presence of Nitrogen Nucleophiles. Formation of 1,2,4-Tria…

1996

The photochemistry of some 3,5-disubstituted 1,2,4-oxadiazoles in the presence of nitrogen nucleophiles [external, such as added amines or hydrazines, or internal, such as an o-aminophenyl moiety at C(3) of the oxadiazole ring] has been investigated. In the irradiation of 5-amino-(or 5-N-substituted amino) 3-phenyl-1,2,4-oxadiazoles in the presence of aliphatic primary amines (or ammonia), photolytic species arising from heterolytic cleavage of the ring O−N bond capture the nucleophilic reagent to give open-chain intermediates, which develop into 1,2,4-triazolin-5-ones. Similarly, irradiations of 3,5-diphenyl-, 3-methoxy-5-phenyl-, and 5-methyl-3-phenyl-1,2,4-oxadiazoles gave 1,2,4-triazole…

N-Substituierte Imidazole aus Aldehyden, 1,2-Diketonen, primären Aminen und flüssigem Ammoniak. 4. Mitt. über Imidazolsynthesen mit flüssigem Ammoniak

1974

N-substituierte Imidazole 5 konnen aus Aldehyden 1, 1,2-Diketonen 2 und primaren Aminen 3 in flussigem Ammoniak 4 dargestellt werden. N-substituted Imidazoles from Aldehydes, 1,2-Diketones, Primary Amines and Liquid Ammonia N-substituted imidazoles 5 can be synthesized from aldehydes 1, 1,2-diketones 2 and primary amines 3 in liquid ammonia 4.

ARGININE, HISTIDINE AND TRYPTOPHAN IN PEPTIDE SYNTHESIS. THE IMIDAZOLE FUNCTION OF HISTIDINE

1989

Synthesis of polycyclic fused benzimidazole derivatives

1977

Am easy method for the synthesis of tetraeyclie systems containing an imidazole and an iso-thiazole or an imidazole and a thiazine ring, by reacting 2H-1,3-benzothiazine-2-thion-4(3H)one with aromatic primary diarnines is reported. The structures were assigned based upon mass spectra and modes of cleavage of the compounds. The most important fragments are described.

Herbizide, 2. Mitt. 2-Trifluormethylpyrimido[1,2-a]benzimidazole

1982

Aus der Kondensation von 2-Aminobenzimidazol (1) mit den Trifluormethyl-β-Diketonen 2a-f gehen die 2-Trifluormethylpyrimido[1,2-a]benzimidazole 3a-f hervor. Auffallende herbizide Wirksamkeit vermag 3a zu entfalten. Herbicides, II: 2-(Trifluoromethyl)pyrimido[1,2-a]benzimidazoles The condensation of 2-aminobenzimidazole (1) with the trifluoromethyl-β-diketones 2a-f furnishes the 2-(trifluoromethyl)pyrimido[1,2-a]benzimidazoles 3a-f. Marked herbicidal activity is exhibited by 3a.

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…