Benzindoles

Schiff bases in the angular benzindole series that were obtained from 3-formyl[4, 5]- and-[6,7]benzindoles and aromatic amines, on the one hand, and 3-amino[4,5]- and -[6,7]benzindoles and salicylaldehyde, on the other, are described. It is shown that the conformations in each of the [6,7] and [4,5] isomers are identical and are independent of the substituent; this is a consequence of their nonplanar structures.See [1] for communication 18.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 909–915, July, 1979.     

Benzindoles

The synthesis of -(6,7-benzindol-3-yl)butyric acid and its derivatives has been effected. It has been shown that the Fischer cyclization of the -naphthylhydrazone of -formylvaleric acid leads to the formation of considerable amounts of esters of ,-di[3-(3'-alkoxycarbonylpropyl)-6,7-benzindol-2-yl]caproic acid, in addition to the desired product.For Communication II, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 951–953, July, 1970.     

Benzindoles

On the basis of the analogy in the PMR spectra of the products of nitrosation of indole and benzindoles it was established that the nitrosation of [4,5]benzindole leads to 1-nitroso-3-oximido-2-([4,5]benzindol-3-yl)-[4,5]benzindoline, while nitrosation of [6,7]benzindoles leads to 3-oximmo-2-([6,7]benzindol-3-yl)-[6,7]benzindolenine.See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 940–942, July, 1974.     

Benzindoles

Condensation of 9-phenanthrylhydrazine hydrochloride with pyruvic acid and its ethyl ester gave the corresponding hydrazones, Fischer cyclization of which yielded 2-carboxy- and 2-carbethoxy-4,5,6,7-dibenzindoles. 4,5,6,7-Dibenzindole was obtained by decarboxylation of 2-carboxy-4,5,6,7-dibenzindole, and its IR, UR, PMR, mass, and luminescence spectra were studied.See [1] for communication XV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1061–1065, August, 1978.     

Benzindoles

A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.     

Benzindoles

Crotonic condensation of 3-formyl[4,5]- and 3-formyl[6,7]benzindoles with acetone on aluminum oxide or methylation of them with dimethyl sulfate in aqueous acetone solution in the presence of KOH gave [4, 5]- and [6,7]benzoskatolideneacetones. A number of 3-formylbenzindoles with various substituents in the pyrrole portion of the molecule are described.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1257–1261, September, 1975.     

Benzindoles

By the Nenitzescu reductive cyclization of o,-dinitrostyrenes, 5,6,7,8-tetrahydrobenzo[f]indole has been obtained from 3-nitro-2-(-nitrovinyl)-5,6,7,8-tetrahydronaphthalene.For Communication III, see [2].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1083–1085, August, 1970.     

Benzindoles

The behavior of tetrahydro[4,5]- and tetrahydro[6,7]benzinodoles in the Vilsmeier reaction was investigated. It was established that the steric hindrance created by the cyclohexane ring condensed in the 4 and 5 positions has a substantial effect on the character of the reaction of tetrahydrobenzindoles with various N,N-disubstituted amines. A case of N-acylation in the investigated reactions is described. 3-Formyl-4,5,6,7-tetrahydro[4,5]- and 6,7,8,9-tetrahydro[6,7]-benzindoles were converted to the corresponding tryptamines.See [1] for communication 16.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–365, March, 1979.     

Benzindoles. 24. Synthesis and some properties of 5,6-benzotryptamine hydrochloride

An improved method for the synthesis of 5,6-benzotryptamine hydrochloride from 3-hydroxy-2-naphthoic acid was developed; this method makes it possible to obtain the final product and a number of intermediates in high yields. The PMR spectra and the peculiarities of conjugation in the linear benzindole molecule are discussed.See [1] for communication 23.Translated from. Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 346–348, March, 1984.     

Benzindoles. 23. 2-formyl- and 3-formyl-4,5-benzindoles

It is shown that, in addition to the usually formed 3-formyl-4,5-benzindole, 2-formyl-4,5-benzindole can be obtained via the Vilsmeier reaction. The IR, PMR, and UV spectra of the 2- and 3-formyl isomers are compared, and their possible conformations are discussed.See [1] for Communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 343–345, March, 1984.     

Benzindoles XII. Spectra and three-dimensional structures of [6,7]- and [4,5]benzoskatolideneacetones

It was found by means of their ER, UV, and PMR spectra that [6,7]benzoskatolideneacetones have a side chain in the trans-s-cis form, whereas the [4, 5] isomers have a side chain in the cis-s-cis form. It was concluded from the integral intensities of the bands of the vibrations of the double bond (A_C=C)) and the parameters of the UV spectra that the investigated molecules have a planar structure. The A_C=C) integral intensities in the IR spectra exceed the previously observed values and, in the case of [6,7]benzoskatolideneacetones, reach ～6· 10⁴ mole^?1liter·cm^?2.     

Benzindoles. 21. Structures of the products of the wittig reaction in the angular benzindole series

-Phenyl--(1H-benzo[g] indol-3-yl)ethylene and -phenyl--(3H-benzo[e] indol-l-yl)-ethylene were obtained in the form of two geometrical isomers by reaction of 3-formyl-1H-benzo[g]- and 1-formyl-3H-benzo[e] indoles with benzylidenetriphenylphosphorane in tert-butyl alcohol containing potassium tert-butoxide. The configurations of the compounds obtained were established on the basis of data from the PMR spectra.See [1] for Communication 20.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1380–1382, October, 1980.     

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.     

Benzindoles. 24. Reduction of nitro-2,3-dimethyl[4,5]- and nitro-2,3-dimethyl[6,7]benzindoles

The reduction of nitro-2,3-dimethyl[4,5]- and -[6,7]benzindoles was studied; Benzindoles were obtained with an amino group in the benzene ring. Individual isomers can be separated as the acyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1481–1484, November, 1986.     

Benzindoles. 21. Nitration of 3-formyl[4, 5]-and 3-formyl [6,7] benzindoles

It was established that products of monosubstitution of 4-nitro- and 7-nitro-3-formyl[4,5] benzindoles and products of disubstitution of 4,8-dinitro- and 7,8-dinitro-3-formyl [4,5] benzindoles are formed in low yields in the nitration of 3-formyl [4,5]benzindole with sodium nitrate in concentrated sulfuric acid. Similar nitration of 3-formyl [6,7] benzindole leads to 9-nitro- and 5, 6-dinitro-3-formyl [6,7]benzindoles. The 3-formylnitrobenzindoles obtained were converted to nitrovinyl derivatives by condensation with nitromethane.See [1] for Communication [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–955, July, 1980.