نتایج جستجو برای: n substituted pyrroles
تعداد نتایج: 1008175 فیلتر نتایج به سال:
An expeditious synthesis of N-substituted pyrroles has been developed by reacting 2,5-dimethoxy tetrahydrofuran and several amines using a microwave-induced molecular iodine-catalyzed reaction under solventless conditions.
TiCl2/nano-γ-Al2O3 as a new heterogeneous Lewis acid catalyst was synthesized and characterized by FE-SEM, XRD, FT-IR, EDS, XRF, BET and TGA. N-substituted pyrroles have been synthesized via Paal–Knorr reaction in the presence of TiCl2/nano-γ-Al2O3 at room temperature under solvent-free conditions.
An investigation of the reaction requirements to effect the Clauson-Kaas pyrrole synthesis led to the formulation of a new procedure that avoids the contact of pyrroles to heat or strongly acidic conditions that cause decomposition of the desired products. The procedure involves mild hydrolysis of 2,5-dimethoxytetrahydrofuran in water to the activated species 2,5-dihydroxytetrahydrofuran that r...
A simple and efficient protocol for the synthesis of N-substituted pyrroles from one-pot condensation reaction of 2, 5-dimethoxytetrahydrofuran with aryl/alkyl, sulfonyl and acyl amines in the presence of ZrOCl2•8H2O in water has been developed. This new method has the advantages of simple experimental and work-up procedure, high to excellent yields, easy availability, economical, eco-frien...
TiCl2/nano-γ-Al2O3 as a new heterogeneous Lewis acid catalyst was synthesized and characterized by FE-SEM, XRD, FT-IR, EDS, XRF, BET and TGA. N-substituted pyrroles have been synthesized via Paal–Knorr reaction in the presence of TiCl2/nano-γ-Al2O3 at room temperature under solvent-free conditions.
Pyrroles are important compounds present in biological systems, used for drug synthesis and material chemistry. A typical strategy the pyrrolic ring formation is centered on Paal–Knorr reaction, where 1,4-dicarbonyl react with amines giving N-substituted pyrrole derivatives. Often, main problem of this approach availability appropriate carbonyl compounds. Here, we report a sustainable carboxyli...
Other than triarylamines, which are protonated by strong acids both at their N-atom and aromatic rings, pyrrole its N-substituted derivatives were exclusively the carbon atoms of heteroaromatic rings. Whereas with trifluoromethane sulfonic acid (TFS) stable pyrrolium salts obtained, weaker trifluoroacetic (TFA) oligomers formed. E.g., from N-(tert-butyl)pyrrole a dimeric compound could be unamb...
(Z,Z)-Muconaldehyde reacted with primary amines to give N-substituted-2(2'-oxoethyl)-pyrroles, which were reduced to N-substituted-2-(2'-hydroxyethyl)-pyrroles by sodium borohydride. The pyrrole-forming reaction is exhibited by valine and its methyl ester, and is being developed with terminal valine in hemoglobin as a means of dose monitoring (Z,Z)-muconaldehyde, a putative metabolite of benzen...
The vibrations of pyrrole, N-deuteropyrrole, N-fluoropyrrole, N-aminopyrrole and N-methylpyrrole are studied. evolution the vibrational wavenumbers pyrrole is examined, as mass nitrogen-bonded hydrogen atom artificially increased. It found that some very sensitive to substituent bonded nitrogen, this can be viewed mixing increases; however, these mixings stablilize by time a 14 mu reached. A co...
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