3-nitropyridinium Salts Research Articles

Indoles from 3-nitropyridinium salts: an extension of the transformation method on 5-substituted indoles

Abstract The method of indole preparation by transformation of 3-nitropyridinium salts was successfully extended to the synthesis of indoles containing substituents Cl, PhS, CN, Ac and COOEt on the 5-position.

Indoles from 3-nitropyridinium salts: A new route to chiral indoles and indolines

Abstract (S)-1-(1-Methylbenzyl)-2,4,6-trimethylindole was prepared by interaction of (S)-isopropyliden(1-methylbenzyl)amine with 1,2,4,6-tetramethyl-3-nitropyridinium iodide. The indoles thus prepared undergo diastereoselective hydride reduction and debenzylation to afford chiral (S)-2,4,6-trimethylindoline with high yield and optical purity up to 76%.

Nuclear magnetic resonance spectra of polyalkylindoles obtained by transformations of 3-nitropyridenium salts

Data are correlated on the 1E and 13C NMR spectra of a representative series of polyalkylindoles obtained by the reaction of alkyl-substituted 3-nitropyridinium salts with ketimines. It has been shown that the use of a combined approach to the interpretation of the 1H and 13C NMR spectra enables reliable information to be obtained on the structure of these previously unknown indole derivatives. The long range 13C-H coupling constants give particularly valuable information. A reliable demonstration of the structure of the reaction products is the basis for establishing the route of the indolization.

Scheme of transformation of 3-nitropyridinium salts into indoles

Abstract A mechanistic scheme for the transformation of 3-nitropyridinium salt into indoles by action of N-alkylketimines (or mixture of the corresponding ketones and amines) is discussed.

Indoles from 3-nitropyridinium salts 9. Methyl ethyl ketone N-methylimine in the indolization of 1-methyl-3-nitropyridinium salts

In a study of the direction of the indolization of alkyl-substituted 3-nitropyridinium salts in reaction with methyl ethyl ketone N-methylimine as a function of the structure of the salts, it has been established that in the presence of a substituent at position 4, initial attack at position 6 by the most substituted enamine form of the imine leads to preferential formation of 7-methylindole whereas in its absence the regioselectivity of the process is reduced and in the indole mixture the fraction of 3-methylindole increases.

ChemInform Abstract: Formation of 6‐Nitrodihydro‐ and 6‐Nitrotetrahydroquinolines. Another Transformation of 3‐Nitropyridinium Salts Under the Action of N‐Methylacetonimine.

ChemInformVolume 19, Issue 48 Heterocyclic Compounds ChemInform Abstract: Formation of 6-Nitrodihydro- and 6-Nitrotetrahydroquinolines. Another Transformation of 3-Nitropyridinium Salts Under the Action of N-Methylacetonimine. M. A. YUROVSKAYA, M. A. YUROVSKAYA Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorA. Z. AFANAS'EV, A. Z. AFANAS'EV Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorV. A. CHERTKOV, V. A. CHERTKOV Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorYU. G. BUNDEL', YU. G. BUNDEL' Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this author M. A. YUROVSKAYA, M. A. YUROVSKAYA Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorA. Z. AFANAS'EV, A. Z. AFANAS'EV Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorV. A. CHERTKOV, V. A. CHERTKOV Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this authorYU. G. BUNDEL', YU. G. BUNDEL' Moskovskii gos. univ. im. Lomonosova, Moskva 119899Search for more papers by this author First published: November 29, 1988 https://doi.org/10.1002/chin.198848165Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue48November 29, 1988 RelatedInformation

Synthesis of indoles from pyridinium salts 5. Secondary amines in the reaction of 3-nitropyridinium salts with acetone

The use of secondary amines in the reaction of 3-nitropyridinium salts with acetone makes it possible to isolate stable intermediates in the formation of indoles — (o-N,N-dialkylaminobenzyl)ketones — and to observe new reaction pathways — the formation of bisindolylpropanes and p-nitroanilines.

Formation of 6-nitrodihydro- and 6-nitrotetrahydroquinolines. Another reaction of 3-nitropyridinium salts with N-methylacetonimine

Formation of 6-nitrodihydro- and 6-nitrotetrahydroquinolines. Another reaction of 3-nitropyridinium salts with N-methylacetonimine

Synthesis of indoles from pyridinium salts. 4. Ketimines in the synthesis of indoles from 3-nitropyridinium salts

The possibility of using certain ketimines in place of mixtures of ketone and amine in the synthesis of indoles from 3-nitropyridinium salts has been demonstrated. The use of ketimines leads, in many cases, to increased yields of indoles and simplifies their isolation. It has been established that the rate of indole formation is considerably increased in polar aprotic solvents.

Synthesis of indoles from pyridinium salts

The reaction of 1,2,5,6-tetramethyl-3-nitropyridinium perchlorate with acetone and piperidine on a solid carrier has given the novel, relatively stable 3-nitropyridine anhydro-base, 1,2,5-trimethyl-3-nitro-6-methylene-1,6-dihydropyridine, which bears alkyl groups only. This anhydro-base has been shown not to be an intermediate in the synthesis of indoles from 3-nitropyridinium salts.