Heterocyclic pleiadiene analogs

The UV, PMR, and ESR spectra as well as the magnetic susceptibilities of 1- and 2- substituted perimidine, aceperimidine, and a number of compounds related to them were measured and discussed. The results obtained indicate that the distribution of the -electron density in the perimidine system is very nonuniform, which is in agreement with quantum-mechanical calculations. This is particularly manifested in the depressed diamagnetism of perimidines, the presence of an ESR signal for them, and in the shift of the chemical shifts of the protons to high field. Owing to the high-lying upper occupied molecular orbital, the perimidines are extremely strong donors and readily form charge-transfer complexes.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 543–552, April, 1971.     

Heterocyclic analogs of pleiadiene

The IR spectra, basicities in acetonitrile, and electronic absorption spectra in neutral, acidic, and alkaline media of mono-, di-, tri-, and tetranitroperimidines were studied. Opinions regarding the reasons for the deep coloration of nitroperimidines, their fine structure in various media, and the form (cation or base) in which they undergo electrophilic substitution reactions are expressed.See [1] for Communication 45.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 84–92, January, 1980.     

Heterocyclic analogs of pleiadiene

Aceperimidine and its 1- and 2-substituted derivatives are nitrated in the 4 and 9 positions to give mono- or dinitro derivatives, depending on the amount of nitric acid.     

Heterocyclic analogs of pleiadiene

2,3-Dihydro derivatives of perimidine were obtained in high yields by the action of lithium aluminum hydride or sodium borohydride on perimidinium salts and 1,3-dialkylperimidones.     

Heterocyclic analogs of pleiadiene

It was established by IR and PMR spectroscopy that 2-acylamino-1-alkylperimidines and 2-acetamido-1-methylnapth[2,3-d]imidazole exist in the nonaromatic acylimino form in the crystalline state and in solution. 2-Acetamido-4,5-diphenylimidazole exists in the acylamino form in the solid state and in solution. 2-Acetamido derivatives of 1-methylbenzimidazole and 1-methyl- and 3-methylnapth[1,2-d]imidazoles, for which a shift to favor the acylimino form is observed only in solution, occupy an intermediate position. It is concluded that the relative aromaticities of the heterosystems and the strength of the intramolecular hydrogen bond in the imino form affect the position of the tautomeric equilibrium.See [1] for communication XXXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 113–121, January, 1978.     

Heterocyclic analogs of pleiadiene

Electron-acceptor substituents (phenyl, benzyl, methoxymethyl, acetonyl, and phenacyl) in the 1 position of perimidine do not have an appreciable effect on the ease of opening of the perimidine ring under the influence of aroyl chlorides in the presence of mild bases. However, some of them (C₆H₅ and CH₃OCH₂) substantially hinder the step involving the cyclization of the pseudo bases to arylperimidines under the influence of alkalis. It was shown by kinetic measurements that substituents in the N-aroyl group of N-methyl-N-formyl-N-aroyl-1,8-naphthalenediamines have virtually no effect on the rate of cyclization in alkaline media. A mechanism for the alkaline and acidic cyclization of the pseudo bases is proposed on the basis of the regularities observed. 1,2-Diarylperimidines were synthesized for the first time.See [1] for communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1125–1131, August, 1978.     

Heterocyclic analogs of pleiadiene

It is shown that the N anion of perimidine displays ambident character in its reactions with benzyl and allyl halides and gives products of C alkylation in the 4 position in addition to N-substituted perimidines.See [1] for communication 43.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 964–967, July, 1979.     

Heterocyclic analogs of pleiadiene

The corresponding 1--dialkylaminoethylperimidines were obtained by the action of -dialkylaminoethyl chloride hydrochlorides on perimidines in alkaline media. Some of the compounds obtained form substituted 2-aminoperimidines and 2-perimidone on reaction with sodium amide or alkali. 2-Morpholino- and 2-piperidino-1-methylperimidines are obtained from 1-methyl-2-chloroperimidine and morpholine or piperidine. The synthesized compounds have weak bacteriostatic, fungistatic, and tuberculostatic activity.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 418–421, March, 1974.     

Heterocyclic analogs of pleiadiene

N-substituted derivatives of perimidine and aceperimidine are readily aminated by sodium amide in position 2 with the formation of previously unknown 2-amino derivatives. Some other reactions taking place at the -carbon atom of perimidine have also been studied: direct hydroxylation with caustic potash, the ammonolysis of the 2-chloro derivatives, the action of alkalis on the quarternary salts, and the direct thiolation of the perimidines with sulfur, leading to 2-mercaptoperimidines.For Communication III, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1129–1132, August, 1970.     

Heterocyclic analogs of pleiadiene

An analysis of the ionization constants and IR and UV spectra, and quantum-mechanical calculations demonstrate that 2-aminoperimidines (I) and 2-aminoaceperimidines (II) display a higher tendency for a shift in the tautomeric equilibrium to favor the imino form than 2-amino derivatives of 4,5-diphenylimidazole, benzimidazole, and angular and linear naphthimidazoles.See [1] for communication VI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 807–813, June, 1971.     

Heterocyclic analogs of pleiadiene

Chlorination of 1,3-dimethylperimidone, 1,3-dimethyl-2,3-dihydroperimidine, and the 1,3-dimethylperitnidinium cation with 1-chlorobenzotriazole and sulfuryl chloride gave their dichloro, trichloro, and tetrachloro derivatives. It was established that the chlorination reactions of 1,3-dimethyl derivatives of perimidone and 2,3-dihydroperimidine are controlled by the magnitudes of the charges and, despite the unfavorable steric conditions, take place in the 4 and 9 positions, whereas chlorination of the 1,3-dimethylperimidinium cation takes place primarily in the 6 and 7 positions of the perimidine system.See [1] for communication XXXVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1406–1412, October, 1978.     

Heterocyclic analogs of pleiadiene

1-Substituted and 1,2-disubstituted perimidines and their quaternary salts react with organometallic compounds to give almost exclusively products of addition to the C=N bond. The latter are readily oxidized by chloranil or manganese dioxide to the corresponding 2-substituted perimidines. Metallation (8%) in the 2 position occurs only in the reaction of n-butyllithium with 1-methylperimidine. 1-Methyl-2-chloroperimidine reacts with organolithium compounds to give mainly 2-substituted perimidines.     

Heterocyclic analogs of pleiadiene

The problem of the participation of a N-atom of the pyrrole type in six-membered heteroaromatic systems has been considered within the framework of Hückel's molecular orbital method. The -electronic characteristics of heterocyclic analogs of pleiadiene and a number of heteroaromatic compounds related to them have been considered from the point of view of reactivity, structure, and physical properties.For part I, see [1].The authors express their thanks to Prof. V. I. Minkin for providing results of calculations on the angular and linear naphthoimidazoles and for consultation on questions connected with the application of the method of molecular orbitals.     

Heterocyclic analogs of pleiadiene

The behavior of N-methyl derivatives of perimidine (I), aceperimidine (VI), aceperimidylene (VII), naphth[2,3-d]imidazole (V), benzimidazole (II), and 1H- and 3H-naphth[1,2-d]imidazoles (III, IV) with respect to n-butyllithium was studied. Compounds I and V–VII add n-butyllithium to the C=N bond to give 2-n-butyl-2,3-dihydro derivatives, whereas II–IV are metallated to give 2-lithio derivatives. The different reactivities of I, V–VII, and II–IV are explained by the reduced aromatic character and high polarization of the C=N bond in I and V–VII. The investigated compounds are arranged in the following order with respect to the ease of undergoing basic deuterium exchange at the C-H bond V>II>III>IV>VII>I>VI. There is no correlation between the rate of deuterium exchange and the behavior of I–VII with respect to butyllithium.See [1] for communication XXX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1544–1548, November, 1977.     

Heterocyclic analogs of pleiadiene

The corresponding phenalenones are formed immediately in the reaction of 1,3-dialkyl-substituted perimidones, thioperimidones, and 2,3-dihydroperimidines with propiolic acids and -keto acid esters in polyphosphoric acid (PPA) at 40–75°C. Acylation of the perimidone and 2,3-dihydroperimidine derivatives with cinnamic and acrylic acids in PPA occurs in the 6 position and is accompanied by recyclization with the formation of a dihydrophenalenone ring. Acylation of 1,3-dialkylperimidones with aliphatic acids in PPA leads to 6,7-diacyl derivatives, by crotonization of which the corresponding phenalenones were also synthesized. The properties of the compounds are discussed.See [1] for communication XXXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 833–842, June, 1978.     

Heterocyclic analogs of pleiadiene

Derivatives of a new heteroaromatic system — aceperimidylene — were obtained by dehydrogenation of aceperimidine and its substituted derivatives. The physical properties of the aceperimidylenes provide evidence that they have greater aromatic character than perimidines.See [1] for communication XXITranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 539–544, April, 1976.     

Heterocyclic analogs of pleiadiene

1-Methylperimidine adds phenylsodium and phenyllithium to the C=N bond to give 1-methyl-2-phenyl-2, 3-dihydroperimidines. However, if benzophenone is present in the reaction mixture, a mixture of 1-methyl-2-phenylperimidine and l-methyl-2, 4-diphenylperimidine (when phenylsodium is used) or l-methyl-2-phenyl-4-(-hydroxybenzhydryl)perimidine (when phenyllithium is used) is formed. It is assumed that the formation of products involving substitution in the naphthalene ring is associated with the participation of C₆H₅ and (C₆H₅)₂C-O^– radical particles that are formed on reaction of the phenylmetallic compound with benzophenone.See [1] for communication XXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 697–701, May, 1976.     

Heterocyclic analogs of pleiadiene

1,2-Disubstituted perimidine and aceperimidine methiodides react with aqueous alkali solutions to give pseudo bases corresponding to the acyclic form.See [1] for communication IX.Deceased.The letters a and b in formulas I–V pertain, respectively, to the perimidines and aceperimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 849–851, June, 1973.     

Heterocyclic analogs of pleiadiene 61. 2-cyano- and 2-carbamoylperimidines

Treatment of 1-R-2 chloroperimidines with potassium or sodium cyanides in DMSO solution leads to facile substitution of the chlorine atom by the CN group and formation of previously unknown 1-R-2-cyanoperimidines. The latter upon heating in polyphosphoric acid are converted to 1-R-2-carbomoylperimidines in good yield.For Communication 60, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 804–806, June, 1993.     

Heterocyclic analogs of pleiadiene. 53. Properties of 1,9-trimethyleneperimidene

The behavior of 1,9-trimethyleneperimidine (3,4,5,6-tetrahydropyrido [3,2sl-k,Z]-perimidine) with respect to nucleophilic agents was studied. It is shown that the properties of 1,9-trimethyleneperimidine are virtually the same as the properties of 1-alkylperimidines.See [1] for communication 52.Translated from Khimiya Geterotsiklicheskihk Soedinenii, No. 8, pp. 980–982, July, 1981.