One-pot synthesis of 2,4,5-tri-substituted-1H-imidazoles promoted by trichloromelamine (original) (raw)
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RSC Adv., 2014
Trityl chloride (TrCl or Ph 3 CCl) efficiently catalyzes the one-pot multi-component condensation of benzil with aldehydes, primary amines and ammonium acetate under neutral and solvent-free conditions to give 1,2,4,5-tetrasubstituted imidazoles in high to excellent yields and in short reaction times. Mechanistically, it is attractive that trityl chloride promotes the reaction by in situ generation of trityl carbocation (Ph 3 C + ).
Tetrahedron Letters, 2008
InCl 3 Á3H 2 O was found to be a mild and effective catalyst for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted imidazoles at room temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields.
One pot three-component synthesis of imidazole derivatives using NH3/NH4Cl
2017
Imidazole is a planar, five membered heteroaromatic molecule with pyrrole type and pyridine type annular nitrogens. Several approaches are available of imidazoles from alpha halo ketones, aminonitrile, aldehyde ect. Reactivity of imidazole and benzimidazole is referred from sets of resonance structure in which the dipolar contributors have finite importance. Imidazoles among the principal groups of heterocyclic compounds that have biological properties. Due to the presence of imidazole rings in natural products and active pharmaceutical ingredients, different ways for the synthesis of heterocyclic compounds of this type investigated. The aim of this project is substituted derivatives 2,4,5-Imidazoles. In this study, three-substituted imidazole compounds synthesized using ammonium chloride as a catalyst cost in terms of reflux were studied. Reaction with aldehydes and ammonium acetate Acenaphthene quinone in crowding conditions in the presence of ammonium chloride was performed suc...
Arkivoc, 2012
The reaction of nitrones, formed in situ by reaction of hydroxylamines and aldehydes, with 2azido acrylates results in the formation of 1,2,4,5-tetrasubstituted imidazoles has been developed. This three-component reaction allows for the formation of a diverse array of imidazole derivatives with moderate to excellent yields.
A mild, eecient and environmentally friendly method has been developed for the green synthesis of 2,4,5-trisubstituted imidazoles via a three-component one-pot condensation of 1,2-diketones, diammonium hydrogen phosphate, (NH4)2HPO4 (DAHP) and aryl aldehydes in water under reeux conditions. The DAHP shows remarkable activities for the synthesis of title compounds. The key advantages of this method over conventional methods are experimental simplicity, good functional group tolerance, excellent yields, short routine, and selectivity, without the need for a transition metal or base catalyst.
PROSPECTS FOR THE CHEMISTRY OF IMIDAZOLE DERIVATIVES (Review)
Chemical Journal of Kazakhstan
The problem of creating new effective domestic pharmacological preparations, including the development of the methods for obtaining biologically active substances in compliance with the “green chemistry” principles, are among the priority areas for the development of chemical science. The choice of an initial molecule, which carries the potential of biological activity, is the guarantor of a successful experimental search. Imidazole derivatives occupy a unique place in the medicinal chemistry. An imidazole cycle is part of the natural compounds such as histamine, biotin, some alkaloids and nucleic acids, and is a structural fragment of medicinal preparations. The goalof the present review is to analyze the publications on the chemistry of imidazole derivatives with an emphasis on the methods of obtaining biologically active and other practically useful molecules with an obligatory imidazole cycle. The objects of the study:imidazole derivatives. The examples of the routes of synthesi...