Bisindoles. 14. Electrophilic substitution reactions in the di(5-indolyl) oxide series

Chemistry of Heterocyclic Compounds - Some electrophilic substitution reactions in the di(5-indolyl) oxide series were studied. The Vilsmeier and Mannich reactions and diazo coupling and...     

Bisindoles 27. Electrophilic substitution reactions of 7,7-dichlorobis(5-indolyl)methanes

Formylation, aminomethylation and acetylation have been studied as the most characteristic electrophilic substitution reactions of 7,7-dichlorobis(5-indolyl)-methane and its diethyl ester.For Communication 26 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1363–1366, October, 1989.     

Benzindoles. 18. Some electrophilic substitution reactions involving the hydrogen atoms in 4,5,6,7-dibenzindole

The principal electrophilic substitution reactions involving the hydrogen atom of 4,5,6,7-dibenzindole — the Vilsmeier reaction, the Mannich reaction, diazo coupling, and acylation — were studied, and a qualitative comparison of its reactivities with indole and 4,5- and 6,7-benzindoles was made. It was established that 4,5,6,7-dibenzindole has the most clearly expressed electron-donor properties. The structures of the synthesized compounds were proved by data from the IR, UV, PMR, and mass spectra.See [1] for communication 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 366–370, March, 1979.     

Bisindoles. 10. Synthesis of 1,2-(5,5′-diindolyl)ethane

A 2,2-diethoxycarbonyl derivative of a new bisindole system, viz., 1,2-(5,5-diindolyl)ethane, was obtained by cyclization of ethyl pyruvate sym-4,4-diphenyleneethanedihydrazone. 5-(-Phenylethyl)-2-ethoxycarbonylindole was also isolated in very low yield from the reaction products. Saponification of the 2,2-diethoxycarbonyl derivative gave the corresponding dicarboxylic acid, the thermal decarboxylation of which leads to the formation of 1,2-(5,5-diindolyl) ethane. The syn,syn and anti,anti forms of ethyl pyruvate sym-4,4-diphenyleneethane-dihydrazone were also obtained and characterized.See [1, 2] for Communications 8 and 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 348–351, March, 1982.     

Bisindoles. 11. Electrophilic substitution reactions in the bis(5-indolyl) sulfone series and data on the reactivity indexes of some bisindoles

The principles of the electron density distribution in 5,5-bis-1H-indole, bis(5-indolyl)methane, and bis(5-indolyl) sulfone were determined on the basis of quantum-chemical calculations. Several electrophilic substitution reactions in the bis(5-indolyl) sulfone series were realized.See [1] for Communication 10.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1653–1656, December, 1982.     

1,2-Diphenylimidazo[1,2-a]benzimidazole in electrophilic substitution reactions

Vilsmeier formylation of 1,2-diphenylimidazo[1,2-a]benzimidazole leads to the 3-formyl derivative, while heating with acetic anhydride in sulfuric acid gives the 3-acetyl derivative. The nitration of this benzimidazole with potassium nitrate in sulfuric acid gives a mixture of mono-, di-, and trinitro derivatives. Bromination in chloroform leads to a mixture containing the mono- and dibromo derivatives. The structures of the compounds obtained were confirmed by their IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1251–1254, September, 1981.     

Relationships and features of electrophilic substitution reactions in the azole series

On the basis of an analysis of the results from quantum-chemical calculation of model systems, together with published experimental data, a study has been made of the influence of the structure of azoles on their capability for electrophilic substitution reactions proceedings either through the traditiional addition-abstraction mechanism or through the formation of ylides.     

Retrieval and analysis of transition states in electrophilic substitution reactions of the carborane(12) series

The transition states of the reaction of electrophilic substitution in a series of ortho-, meta-, and para-carboranes were found by calculations in the B3PW91/6-31G(d,p) and B3LYP/6-31G(d,p) approximations. The key role of catalyst was demonstrated in the reactions of halogenation and alkylation. The reaction selectivity of electrophilic alkylation by CH₃Br in the presence of AlCl₃ should be lower than that of the chlorination reaction.     

Acid-induced dimerisation of 1,2-di(thien-2-yl)ethanone

Treatment of 1,2-di(thien-2-yl)ethanone with aqueous 75% (v/v) sulfuric acid gives a dimer in which the units are linked head-to-head via a thiophene-tetrahydrothiophene bond.     

2-(2-furyl)imidazo[1,2-a]pyrimidine synthesis and electrophilic substitution reactions

The synthesis of 2-(2-furyl)imidazo[1,2-a]pyrimidine has been carried out. Azocoupling, nitrosation, and bromination by 1 mole of bromine occur at position 3 of the bicycle. Reaction with 2 mol of bromine gives the 3,5‰-disubstituted derivative. Bromination using 1 mol of bromine in 40% hydrobromic acid and sulfonation occur initially at the 5‰ position of the furyl group. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 565–570, April, 2006.     

Isokinetic correlation analysis of the series of electrophilic substitution reactions ofo-substituted phenylmercurials

Isokinetic relationships of the series of electrophilic substitution reactions ofo-substituted phenylmercurials are studied, and the results show, for the first time, that isokinetic correlation analysis can reveal the dominant factor in the system of the reactions. The analysis of S_E2 ofo-substituted phenylmercuric chlorides indicates that the steric effect ofo-substituents is the predominant factor when I₂ is used as electrophilic agent, however, the electronic effect ofo-substituents would become the predominant factor when HCl is used as the electrophilic agent. In S_E1 ofo-substituted phenylmercuric chlorides, the results of the analysis display that the predominant factor is the field effects ofo-substituents. The determination of predominant factors in those reactions would provide further scientific basis for those reaction mechanisms.     

Conversions of 9-bromo(cyano)-4-azafluorenes and 1,2-di(4-azafluoren-9-yl)ethane under conditions of the Michael reaction

9-Bromo(cyano)-4-azaflourenes are converted to di(4-azafluorylidene-9) or 9,9-di (-cyanoethyl)-4-azafluorene under the conditions of the Michael reaction (acrylonitrile, ethoxytrimethylphenylammonium), depending on the temperature. 1,2-Di(4-azafluoren-9-yl)ethane was synthesized, and its cyanoethylation was performed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1525–1527, November, 1984.     

Isokinetic correlation analysis of the series of electrophilic substitution reactions of o-substituted phenylmercurials

Isokinetic relationships of the series of electrophilic substitution reactions of o-substi-tuted phenylmercurials are studied, and the results show, for the first time, that isokinetic correlation analysis can reveal the dominant factor in the system of the reactions. The analysis of SE2 of o-substituted phenylmercuric chlorides indicates that the steric effect of o-substituents is the predominant factor when I2 is used as electrophilic agent, however, the electronic effect of o-substituents would become the predominant factor when HCI is used as the electrophilic agent. In SE1 of o-substituted phenylmercuric chlorides, the results of the analysis display that the predominant factor is the field effects of o-substituents. The determination of predominant factors in those reactions would provide further scientific basis for those reaction mechanisms.     

Pyrroloindoles. 2. Some electrophilic substitution reactions in the 1H, 6H-pyrrolo[2, 3-e] indole series

As expected, the 3 and 8 positions are the reaction centers of 1H, 6H-pyrrolo-[2, 3-e] indole in the Vilsmeier-Haack and Mannich reactions. Diazo coupling takes place primarily in the 3 position and leads primarily to monosubstitution products. 6,8-Diacetyl-1H,6H-pyrrolo [2,3-e]indole and 1,8-diacetyl-1H, 6H-pyrrolo-[2,3-e] indole were isolated from the acetylation products.See [1] for communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 639–644, May, 1980.     

Investigations in the imidazole series LXXIV. Electrophilic substitution reactions in the pyrrolo[1,2-a]imidazole series

The formylation, acetylation, hydroxymethylation, azo coupling, nitrosation, nitration, and chloromercuration of pyrrolo[1,2-a]imidazole derivatives were studied. The PMR spectra were used to establish that all of these reactions proceed at the 5 position or, if it is occupied, at the 7 position of the two-ring system. When the 5 and 7 positions are free, the formation of 5,7-disubstituted pyrrolo[1,2-a]imidazoles is possible.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 405–409, March, 1972.     

Titanium(III) and vanadium(III) chloride complexes with 2-pyridylphenylacetonitrile and 1,2-dicyano-1,2-diphenyl-1,2-di(2′-pyridyl)ethane

Summary 2-Pyridylphenylacetonitrile (ppa) and 1,2-dicyano-1,2-diphenyl-1,2-di(2-pyridyl)ethane (dcppe) react with titanium(III) and vanadium(III) chlorides yielding complexes of formulae: [TiCl₃(ppa)₂], [TiCl₃(ppa)₃], [VCl₃(ppa)], [TiCl₃(dcppe)] and [(VCl₃)₂(dcppe)]. The results obtained suggest pentacoordinated structures for complexes, except for [TiCl₃(ppa)₃] where an hexacoordinated stereochemistry around the metal is proposed.     

Synthesis and antimicrobial activity of N-(indol-5-yl)trifluoroacetamides and indol-5-ylaminium trifluoroacetates substituted in the pyrrole ring

Russian Chemical Bulletin - Based on a series of 1H-indol-5-ylamines substituted in the pyrrole ring, the corresponding N-(indol-5-yl)trifluoroacetamides and indol-5-ylaminium trifluoroacetates...