نتایج جستجو برای: imidazoles multicomponent nmr

تعداد نتایج: 72088  

2011
Zdeněk Jalový Robert Matyáš Jan Ottis Aleš Růžička Petr Šimůnek Miroslav Polášek

BACKGROUND Acetamidines are starting materials for synthesizing many chemical substances, such as imidazoles, pyrimidines and triazines, which are further used for biochemically active compounds as well as energetic materials. The aim of this study was to synthesise and characterise a range of acetamidinium salts in order to overcome the inconvenience connected with acetamidinium chloride, whic...

Journal: :Drug metabolism and disposition: the biological fate of chemicals 2010
Karine Bourcier Ruth Hyland Sarah Kempshall Russell Jones Jacqueline Maximilien Nicola Irvine Barry Jones

Imidazoles and triazoles represent major classes of antifungal azole derivatives. With respect to UDP-glucuronosyltransferase (UGT) enzymes, the drug metabolism focus has mainly concentrated on their inhibitory effects with little known about azoles as substrates for UGTs. N-Glucuronide metabolites of the imidazole antifungals, tioconazole and croconazole, have been reported, but there are curr...

Journal: :Chemical communications 2014
Thibaut Alzieu Johannes Lehmann Ajay B Naidu Rainer E Martin Robert Britton

We report the optimization of a neglected reaction for the rapid and direct conversion of oxazoles into N-substituted imidazoles. The utility of this microwave-promoted reaction for diversity-oriented synthesis is demonstrated in the preparation of >40 N-substituted imidazoles, including α-imidazolyl esters.

Journal: :Chemical communications 2012
Sami Lakhdar Mahiuddin Baidya Herbert Mayr

The imidazoles 1a-g add to the CC-double bond of the iminium ion 2 with rate constants as predicted by the equation log k = s(N)(N + E). Unfavourable proton shifts from the imidazolium unit to the enamine fragment in the adduct 3 account for the failure of imidazoles to take part in iminium-activated aza-Michael additions to enals.

Journal: :Organic letters 2004
Scott E Wolkenberg David D Wisnoski William H Leister Yi Wang Zhijian Zhao Craig W Lindsley

[reaction: see text] A simple, high-yielding synthesis of 2,4,5-trisubstituted imidazoles from 1,2-diketones and aldehydes in the presence of NH(4)OAc is described. Under microwave irradiation, alkyl-, aryl-, and heteroaryl-substituted imidazoles are formed in yields ranging from 80 to 99%. Short syntheses of lepidiline B and trifenagrel illustrate the utility of this approach.

2003
S. Prabakar R. A. Assink N. K. Raman S. A. Myers C. J. Brinker

High resolution 295i and 170 NMR spectroscopy has been used to identify selfand cross-condensation products in sols prepared from tetraethoxysilane (TEOS) and organically modified triethoxysilanes (RTES, where R is a methyl, ethyl or phenyl group). The sols were prepared by the acid catalyzed hydrolysis of TEOS and RTES with H20/Si mole ratios of 0.15, 0.3 or 0.5. Resonance assignments were mad...

Journal: :Organic & biomolecular chemistry 2015
Reuben Ovadia Aurélien Lebrun Ivan Barvik Jean-Jacques Vasseur Carine Baraguey Karine Alvarez

A solution phase synthesis of peptide nucleic acid monomers and dimers was developed by using microwave-promoted Ugi multicomponent reactions. A mixture of a functionalized amine, a carboxymethyl nucleobase, paraformaldehyde and an isocyanide as building blocks generates PNA monomers which are then partially deprotected and used in a second Ugi 4CC reaction, leading to PNA dimers. Conformationa...

Journal: :European Journal of Organic Chemistry 2022

An olefin cross-metathesis method applicable for the preparation of 4-(alk-1-en-1-yl)-1H-imidazoles was developed. The optimized conditions afforded a high-rate, selective, and high yielding reaction that comprise traditionally unreactive imidazole kernel as substrate. A variety backbone functionalized imidazoles were synthesized in good to yields by using this method.

Journal: :Acta pharmaceutica 2010
Satyajit Dutta

A series of 2-substituted-4,5-diphenyl imidazoles 1a-j were synthesized by refluxing benzil with different substituted aldehydes in the presence of ammonium acetate and glacial acetic acid. Structures of the synthesized compounds were confirmed on the basis of IR, 1H NMR and mass spectral data. Compounds 1a-j were screened for anthelmintic activity. Test results revealed that compounds showed p...

Journal: :Acta pharmaceutica 2013
Subramaniyan Arulmurugan Helen P Kavitha

2 The present work deals with the synthesis of some novel heterocyclic compounds such as benzoxazoles , 7, 13 and 19, imidazoles 3, 8, 14 and 20, benzimidazoles 4, 9, 15 and 21, and tetrazoles 10, 16, and 22. The synthesized compounds were characterized by IR, 1H NMR, mass spectrometry and elemental analysis. The compounds were evaluated for cytotoxicity against human cancer cell lines such as ...

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