Synthesis of Imidazole Derivatives Using 2-Unsubstituted 1H-Imidazole 3-Oxides

Mlostoń, Grzegorz; Celeda, Małgorzata; Prakash, G. K. Surya; Oláh, George A.; Heimgartner, Heinz

doi:10.1002/(sici)1522-2675(20000412)83:4<728::aid-hlca728>3.0.co;2-b

Cited by 30 publications

(21 citation statements)

References 18 publications

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“…The same conclusion was formulated in the case of other optically active imidazole N-oxides described in our previous papers. 8 2-Unsubstituted imidazole N-oxides are versatile starting materials for the preparation of other imidazole derivatives, such as the parent imidazoles, 8 imidazole-2-thiones, 8 imidazolones, 17 and (imidazol-2-yl)acetates. 18 In addition, imidazole N-oxides or the corresponding parent compounds have been alkylated to give imidazolium salts, which display properties of ionic liquids.…”

Section: Resultsmentioning

confidence: 99%

Optically active imidazole N-oxides derived from l-prolinamine1

Mlostoń

Wróblewska

Obijalska

et al. 2013

Tetrahedron: Asymmetry

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Starting with (S)-1-benzylprolinamine and alpha-hydroxyimino ketones, enantiomerically pure bisheterocyclic imidazole N-oxides bearing the (S)-configured N-benzyl(pyrrolidin-2-yl)methyl residue were prepared. These N-oxides reacted with 2,2,4,4-tetramethylcyclobutane-1,3-dithione to give the corresponding optically active imidazole-2-thione derivatives via a sulfur transfer reaction. Reduction of the N-oxides with Raney-nickel led to deoxygenation, whereas catalytic hydrogenation (Pd/C) in ethanol occurred with simultaneous deoxygenation and debenzylation, leading to optically active 1-(pyrrolidin-2-yl)methyl-1H-imidazoles. Alkylation of the prepared imidazole N-oxides and their respective imidazoles with butyl and hexyl bromide and subsequent anion exchange gave optically active N-alkoxy-and N-alkylimidazolium tetrafluoroborates, respectively, with the properties of 'room temperature ionic liquids'.

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Section: Resultsmentioning

confidence: 99%

Optically active imidazole N-oxides derived from l-prolinamine1

Mlostoń

Wróblewska

Obijalska

et al. 2013

Tetrahedron: Asymmetry

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“…However, a recent paper describes the preparation of 1-methylimidazole N 3 -oxide by treatment of 1-methylimidazole in THF with H 2 O 2 at room temperature [10]. Starting with imidazole Noxides, preparations of imidazole-2-thiones [7], 2-cyanoimidazoles [11], as well as parent imidazoles via deoxygenation with PCl 3 [12] were reported. Furthermore the isomerization to…”

Section: Introduction -Imidazole N-oxides Are Interesting Compounds mentioning

confidence: 99%

Reactions of 2-Unsubstituted 1H-Imidazole 3-Oxides with 2,2-Bis(trifluoromethyl)ethene-1,1-dicarbonitrile: A Stepwise 1,3-Dipolar Cycloaddition

Mlostoń

Jasiński

Linden

et al. 2006

HCA

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The reaction of 1,4,5-trisubstituted 1H-imidazole-3-oxides 1 with 2,2-bis(trifluoromethyl)ethene-1,1-dicarbonitrile (7, BTF) yielded the corresponding 1,3-dihydro-2H-imidazol-2-ones 10 and 2-(1,3-dihydro-2H-imidazol-2-ylidene)malononitriles 11, respectively, depending on the solvent used. In one example, a 1 : 1 complex, 12, of the 1H-imidazole 3-oxide and hexafluoroacetone hydrate was isolated as a second product. The formation of the products is explained by a stepwise 1,3-dipolar cycloaddition and subsequent fragmentation. The structures of 11d and 12 were established by X-ray crystallography.

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“…After chromatographic workup, benzo[c][1,5]naphthyridine-6-carbonitrile (4) and benzo[h][1,6]naphthyridine-5-carbonitrile (5) were obtained in good yields. The reaction mechanism for the formation of compounds 4 and 5 is analogous to that proposed for the cyanation of azine N-oxides [11,12]: silylation of the N-oxide leads to the benzonaphthyridinium ion A, which adds a cyanide ion to give the intermediate B and which, in turn, eliminates Me 3 SiOH.…”

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confidence: 82%

“…In recent years, synthetic methods for the formation of C-C bonds using silanes have been studied extensively [8][9][10][11]. Fundamental work by Vorbrüggen on the cyanation of N-oxides of 6-membered heterocycles using Me 3 SiCN has opened new perspectives for the synthesis of cyano derivatives [12].…”

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confidence: 99%