Synthesis of alkylindoles (review)

Methods for obtaining alkylindoles, excluding the Fischer synthesis and direct alkylation, developed during the last 15 years are correlated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1155–1172, September, 1987.     

1,3-dipolar cycloaddition as a method for synthesis of fullerene C60 derivatives containing heterocyclic moieties

We generalize literature data and our own experimental data on using 1,3-dipolar cycloaddition reactions for synthesis of fullerene C₆₀ derivatives containing annelated heterocyclic moieties.M. V. Lomonosov Moscow State University, Moscow 119899, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 291–297, March, 1998.     

Regioorientation in the reaction of side chain activated alkylpyridines with electrophiles

X-ray structural data has shown that condensation of sym-3-nitrocollidine with benzaldehyde occurs at the 6-methyl group. The presence of an acceptor group in the side chain of 2,6-dimethyl-4-cyanomethyl-3-nitropyridine causes condensation to occur at the activated methylene group in the 4-position.M. V. Lomonosov State University, Moscow 119899. A. N. Nesmeyanov Institute of Organoelemental Compounds, Moscow 117813. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11. pp. 1543–1550, November, 1995. Original article submitted June 10, 1995.     

Three-dimensional structure of 3-acylindoles

On the basis of a comparison of the experimental dipole moments with the calculated values, as well as data from the UV, IR, and PMR spectra, it is shown that 3-acylindoles exist in the form of equilibrium mixtures of the planar S-cis and S-trans conformers with preponderance of the latter.DeceasedTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1647–1652, December, 1982.     

Formation of pyrrolo[2,3-f]quinolines from substituted 5-methyl-6-aminomoles by the combes reaction

It is shown that the reaction of 2, 3, 5-trimethyl-6-amino-indole with 1, 3-diketones is a convenient method for the preparation of angular IH-pyrrolo[2,3-f]quinolines, while the presence of a methyl group on the pyrrolic nitrogen atom of the initial indole as a result of steric hindrance completely blocks cyclization to the corresponding pyrroloquinolines.Mordovskii State Educational Institute, Saransk 430007. Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1499–1501, November, 1995. Original article submitted May 23, 1995.     

Synthesis of indoles from pyridinium salts. 1. Recyclization of 4-alkyl-2,6-dimethyl-3-nitropyridine methiodides in the presence of ketones

A method for the synthesis of 4-alkylpolymethylindoles by recyclization of 4-alkyl-2,6-dimethyl-3-nitropyridine methiodides in the presence of ketones was developed. A method for establishing the structures of the polyalkylindoles on the basis of data from the PMR spectra and the proton-coupled ¹³C NMR spectra is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 509–518, April, 1985.     

Synthesis of Nonracemic 9-(1-Methoxycarbonylethyl)-1,2,3,4-tetrahydrocarbazole

A new approach has been proposed to the synthesis of indole derivatives containing a chiral substituent at the nitrogen atom, comprizing Fischer indolization of phenylhydrazines with a chiral substituent at the -nitrogen atom. The initial hydrazines were obtained by the alkylation (Mitsunobu reaction applying optically active esters of lactic acid) of anilines containing an electron-accepting substituent at the amino group. Subsequent removal of the activating acceptor grouping was realized by nitrosation of the chiral secondary aniline followed by reduction of the corresponding N-nitroso compound.     

Reaction of alkyl-3-nitropyridinium salts with dimethylformamide diethylacetal

Alkyl-3-nitropyridinium salts react with DMF diethylacetal to give -aminovinyl derivatives under considerably milder conditions than with the corresponding bases. The regioselectivity of this process has been studied in dependence on the structure and positions of the alkyl substituents in the initial salt.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1488–1494, November, 1993.This work was carried out with a grant from the Russian Fund for Fundamental Research (project # 93-03-4593).     

Synthesis of indoles from pyridinium salts. 7. Sterically hindered alkyl-3-nitropyridinium salts in the synthesis of indoles

The introduction of bulky alkyl substituents (iso-Pr,tert-Bu) into any positions of the starting 3-nitropyridinium salt only increases the reaction time and decreases the yields of the corresponding alkylindoles somewhat.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 805–810, June, 1989.     

1,2,3-Trimethyl-5-aminoindole in reactions with acetoacetic ester and ethoxymethylene-malonic ester

A method is proposed for obtaining N-methylpyrrolo[3,2-flquinolines with functional groups on the pyridine ring. M. E. Evsev'ev Mordovian State Pedagogical Institute, Saransk 430007. M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1486–1489, November, 1997.