نتایج جستجو برای: heterocyclic

تعداد نتایج: 9423  

In this protocol, we report a novel approach for the synthesis of a new class of heterocyclic 1H-1,2,3-triazole-modified peptidomimetic compounds. The process consists of an Ugi four-component condensation reaction of amines, an isocyanide, an aldehyde and acids followed by a Huisgen 1,3-dipolar cycloaddition reaction with an azide group in the presence of a catalytic amount of CuSO4</...

Ketenimines and azadienes are transient intermediates in organic chemistry especially in elimination-addition processes and in the formation of heterocyclic systems. These compounds play a considerable role as intermediates in the synthesis of heterocyclic ring systems. In this present research synthesis of novel ketenimines and azadienes via multicomponent reactions (MCRs...

Bita Mohtat Hoorieh Djahaniani Maryam Amir Afshari Shokoh Sadat Ghafori

This work describes a fast, mild, convenient and simple method for preparing of nitrogen heterocyclic derivatives by MCR reaction under solvent-free condition.

2008
Jia Pan Li Yang Zhi-Hua Mao Ling-Ling Weng

In the title compound, C(16)H(17)FN(2)O(4)·H(2)O, the dihedral angle between the heterocyclic ring and the benzene ring is 5.77 (9)°, that between the heterocycle and the ethoxy-carbonyl plane is 15.5 (1)°, and that between the heterocyclic ring and the cyclopropane ring is 67.75 (13)°. In the crystal structure, mol-ecules are linked into a ribbon-like structure along the c axis by N-H⋯O and O-...

2007
Luiza Găină Castelia Cristea Claudia Moldovan Dan Porumb Emanoil Surducan Călin Deleanu Abdalah Mahamoud Jacques Barbe Ioan A. Silberg

Application of a dynamic microwave power system in the chemical synthesis of some phenothiazine and quinoline derivatives is described. Heterocyclic ring formation, aromatic nucleophilic substitution and heterocyclic aldehydes/ketones condensation reactions were performed on solid support, or under solvent free reaction conditions. The microwave-assisted Duff formylation of phenothiazine was ac...

2016
Saqib Faisal Pradip K. Maity Qin Zang Alan Rolfe Paul R. Hanson

The development of new ROMP-derived silica-immobilized heterocyclic phosphate reagents and their application in purification-free protocols is reported. Grafting of norbornenyl norbornenyl-functionalized (Nb-tagged) silica particles with functionalized Nb-tagged heterocyclic phosphate monomers efficiently yield high-load, hybrid silica-immobilized oligomeric heterobenzyl phosphates (Si-OHBP) an...

2011
Suman Bala Minaxi Saini Sunil Kamboj

Oxazolones are five membered heterocyclic compounds containing nitrogen and oxygen as hetero atoms. The C-2 and C-4 positions of the oxazolone are crucial for their various biological activities. N-substituted oxazolones also participated in variety of intermolecular reactions. Considering these properties, various research workers have shown a keen interest in this small heterocyclic moiety as...

Journal: :Organic letters 2012
Nathan A Romero Benjamin M Klepser Carolyn E Anderson

A new Au(III)-catalyzed tandem amination-hydration reaction has been discovered, leading to the formation of α-(N-2-pyridonyl)ketones and heterocyclic analogues in good to excellent yields (14 examples, 48-90%). This reaction demonstrates the unusual use of a heterocyclic sp(2) nitrogen nucleophile in a gold-catalyzed 6-endo-dig cyclization. The tandem process allows rapid access to α-(N-2-pyri...

Journal: :Bioorganic & medicinal chemistry letters 2001
R A Smith J Barbosa C L Blum M A Bobko Y V Caringal R Dally J S Johnson M E Katz N Kennure J Kingery-Wood W Lee T B Lowinger J Lyons V Marsh D H Rogers S Swartz T Walling H Wild

Heterocyclic ureas, such as N-3-thienyl N'-aryl ureas, have been identified as novel inhibitors of raf kinase, a key mediator in the ras signal transduction pathway. Structure-activity relationships were established, and the potency of the screening hit was improved 10-fold to IC(50)=1.7 microM. A combinatorial synthesis approach enabled the identification of a breakthrough lead (IC(50)=0.54 mi...

Journal: :Organic & biomolecular chemistry 2014
David E Stephens Gabriel Chavez Martin Valdes Monica Dovalina Hadi D Arman Oleg V Larionov

The scope and mechanistic implications of the direct transformation of heterocyclic N-oxides to 2-trifluoromethyl-, and related perfluoroalkyl- and perfluoroaryl-substituted N-heterocycles has been studied. The reaction is effected by perfluoroalkyl- and perfluorophenyltrimethylsilane in the presence of strong base. In situ displacement of the para-fluoro substituent in the pentafluorophenyl ri...

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