Synthesis of acetylenic derivatives of 1,4-dioxane

Cyclic ketals — 2,5-dimethyl-2,5-bis(4-penten-2-ynyloxy)-1,4-dioxane and 2,5-dimethyl-2,5-bis(3-phenyl-2-propynyloxy)-1,4-dioxane — were isolated in the reaction of propargyl alcohol with vinyl- and phenylethynylcarbinols in the presence of HgO-BF₃.O(C₂H₅)₂ catalytic system.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1029–1030, August, 1986.     

4-(5-Arylvinyl-2-oxazolyl)- and 4-(5-arylbutadienyl-2-oxazolyl)-naphthalic anhydrides

4-(5-Arylvinyl-2-oxazolyl)- and 4-(5-arylbutadienyl-2-oxazolyl)naphthalic anhydrides were synthesized by a phosphonate modification of the Wittig reaction from 4-(5-bromomethyl-2-oxazolyl)naphthalic anhydride. The structures of the aryl radicals and the steric hindrance created by some of them have a substantial effect on the absorption and luminescence of these compounds in solution. The introduction of each of the vinylene groups between the aryl and heterocyclic radicals causes approximately identical shifts in the spectra, but the Stokesian shift increases. These effects are reinforced considerably under the influence of electron-donor substituents in the aryl radical. The luminescence maxima of the investigated substances range from 515 to 710 nm, and the absolute quantum yields range from 0.12 to 0.51.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 611–613, May, 1977.     

Synthesis and spectral-luminescence properties of stilbene derivatives with two unconjugated fluorophores

Compounds that contain 2,5-diphenyloxazole and 2,5-diphenyl-1,3,4-oxadiazole fluorophore groupings that are not conjugated with one another were obtained by the phosphonate modification of the Wittig reaction from 2-[4 (3)-bromomethylphenyl]-5-(2-tosylaminophenyl)-1,3,4-oxadiazoles and 2-phenyl-5-[4(3)-formylphenyl]-1,3-oxazoles. The absorption and fluorescence spectra of the compounds obtained and the individual fluorophores that constitute the molecules of these compounds were investigated. Intramolecular nonradiating transfer of the electronic excitation energy between the fluorophores that make up the compounds and in binary mixtures of the corresponding luminophores was observed in solutions and in polymeric matrices.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1188–1191, September, 1982.     

Condensed imidazo-1,2,4-azines. 4. Synthesis of 1,4-Dihydroimidazo[1,5-c]-1,2,4-triazine derivatives

The reaction of 2-methyl-4(5)-nitro- and 2-methyl-4(5)-nitro-5(4)-bromoimidazoles with -halo ketones was investigated, during which a number of 1-acylmethyl-substituted 2-methyl-4-nitro- and 2-methyl-4-nitro-5-bromoimidazoles were obtained. 1,4-Dihydro derivatives of imidazo[1,5-c]-1,2,4-triazine were synthesized by reaction of the latter with hydrazine and its monosubstituted derivatives. The structures of the 1-acylmethyl-substituted 2-methyl-4-nitro-5-bromoimidazoles and 1,4-dihydro derivatives of imidazo[1,5-c]-1,2,4-triazine were confirmed by their IR, PMR, and mass spectra.See [1–3] for Communications 1–3, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 833–837, June, 1981.     

Reaction of dimethylamines with epimeric (at the 2 and 4 positions) trans-2-methyl- and trans-1,2-dimethyl-4-vinylethynyldecahydro-4-quinolols

A mixture of the corresponding 4-(4-dimethylamino-1,2-butadienyl)- and 4-(4-dimethylamino-1-butynyl)decahydro-4-quinolols, with predominance of the allene components, is formed from each vinylacetylenic alcohol as a result of the addition of diethylamine to epimeric (at the 2 and 4 positions) trans-2-methyl- and trans-1,2-dimethyl-4-vinylethynyldecahydro-4-quinolols. On the basis of the PMR spectra and data on the stabilities of allenic and acetylenic diamino alcohols under the conditions of their formation, it was concluded that the addition of dimethylamine to 4-vinylethynyldecahydro-4-quinolols proceeds simultaneously via two pathways — at the 1,4 and 3,4 positions of the vinylethynyl substituent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 940–945, July, 1976.The authors thank A. S. Fridman and T. E. Prokof'ev for their participation in the discussion of the PMR spectra.     

Carbon-branched carbohydrate chirons: synthesis of C-3 and C-4-branched sugar lactones derived from d-erythronolactone

Two carbon chain extensions using a Wittig reaction on both a 1-deoxy ribulose derivative and a C-2-branched erythrose derivative are reported. Subsequent dihydroxylation resulted in the synthesis of C-3 and C-4 methyl-branched sugar lactones, the useful synthetic building blocks. Control of the stereoselectivity of both the Wittig reaction and the dihydroxylation is investigated, and 3-C-methyl and 4-C-methyl d-altrono-1,4-lactones and d-glucono-1,4-lactone and 4-C-hydroxymethyl-d-altrono-1,4-lactone were synthesised.     

Hetarylethylene derivatives of 2,5-diaryloxazoles and 2,5-diarloxadiazoles and their luminescence and scintillation properties

A number of new organic luminophores were synthesized via the Wittig reaction from 2-(4-bromomethylphenyl)-5-phenyloxazole or 2-(4-bromomethylphenyl)-5-phenyl-1,3,4-oxadiazole and various heterocyclic aldehydes containing a thiophene ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1267–1270, September, 1986.     

Synthesis of styryl-substituted 2-phenyl- and 1,2-diphenylcyclopenta[b]-chromenes

A number of styryl derivatives that are capable of undergoing formylation and acylation at the side CH=CH group were obtained from 1,2-diphenyl-3-formyl- and 2-phenyl-1,3-diformylcyclopenta[b]chromene by means of the Wittig reaction. It was observed that the Wittig reaction is structurally selective for 2-phenyl-1,3-diformylcyclopenta [b] chromene; the reaction proceeds only at the aldehyde group in the 3 position. Sulfuration of 2-phenyl-1,3-distyrylcyclopenta[b]chromene with sulfur leads to the formation of a new system —benzo[2,3]thiepino[4,54,5]cyclopenta[b]chromene. A significant bathochromic effect of the styryl groups on the electronic spectra of the cyclopentachromenes was noted.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1324–1328, October, 1978.     

Simultaneous Calorimetric and Potentiometric Investigations on Some Uncatalyzed Bromate Oscillators (UBOs)

Simultaneous calorimetric and potentiometric/thermometric measurements were performed on three uncatalyzed bromate oscillators (UBOs) showing distinct temporal structures. The following UBOs were chosen: a) the gallic acid (3,4,5-trihydroxy benzoic acid)—bromate; b) the 1-hydroxy-4-[(1-hydroxy-2-methylamino)ethyl] benzene (HME)—bromate; and c) the 1,4-cyclohexanedione (CHD)—bromate system. Their oscillating reactions were monitored by an isoperibolic batch calorimeter of the Calvet-type at 20°C and with a quasi-adiabatic Dewar setup at room temperature, and in addition by platinum/calomel potentiometry and thermometry. Shape of the calorimetric curves, number and duration of the oscillations and their frequencies varied considerably between these three UBOs. The underlying chemical reaction schemes are discussed in connection with the energetic background.This revised version was published online in November 2005 with corrections to the Cover Date.     

Synthesis of unsaturated derivatives of 2,5-dimethyl-4-phenylpyridine and 3-methyl-2-azafluorene

A substituted butadiene — 1-phenyl-4-(5-methyl-4-phenyl-2-pyridyl)buta-1,3-diene with a trans, trans configuration — was obtained by condensation of 2,5-dimethyl-4-phenylpyridine with cinnamaldehyde. Two 3-methyl-9-cinnamylidene-2-azafluorene isomers are formed as a result of condensation of the same aldehyde with 3-methyl-2-azafluorene. Data from the PMR and IR spectra were used to prove the configuration of the compounds obtained. It was established that the condensation of 3-methyl-2-azafluorene with salicylaldehyde gives 3-methyl-9-(2-hydroxybenzylidene)-2-azafluorene, which has a zwitterionic structure, and 1,2-bis(3-methyl-2-aza-9-fluorenylidene)ethane. Ideas regarding the chemical mechanism of the formation of the latter are presented. The preparation of an unsaturated alcohol — 3-methyl-9-allyl-2-aza-9-fluorenol — is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 82–86, January, 1978.     

Zur Umsetzung von 3,4-Dihydro-8a-methoxy-2H-1,4-benzoxazin-6(8aH)-onen mit Diazoalkanen, 1. Mitt.

Summary 3,4-Dihydro-8a-methoxy-2H-1,4-benzoxazin-6(8aH)-ones — quinol derivatives of 2-hydroxyethylamino-1,4-benzoquinones — react with diazoalkanes to yield 2,3,9a,9b-Tetrahydro-9H-pyrazolo[3,4-h]-1,4-benzoxazin-6(6aH)-ones (3). Their structures were established on basis of NMR-techniques including two-dimensional experiments. The orientation phenomena of the reaction is discussed.

     

Reaction of o-diaminoanthraquinones with malonic ester

The reaction of 1,2- and 2,3-diaminoanthraquinones with malonic ester was studied. It was established that the reaction products are N-ethoxymalonyl-o-diaminoanthraquinones and their heterocyclic derivatives — 1H-2-ethoxycarbonylmethylanthraimidazolediones. N-Ethoxymalonlyl-2,3-anthraquinone undergoes cyclization to 1H-2,3,4,5-tetrahydroanthra(2,3-b]-1,4-diazepine-2,4,7,12-tetraone when it is heated with sodium methoxide in absolute methanol, whereas 2-N-ethoxymalonyl-1,2-diaminoanthraquinone undergoes cyclization to 1H-2-ethoxy carbonylmethy lanthra-1,2-d]imidazole-6,11-dione.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 965–968, July, 1978.     

Synthesis of 5-(5-R-2-furyl)thiazole derivatives by the reaction of 2-(5-R-furfuryl)thiuronium salts with acetic anhydride

2-Acetamide-4-methyl-5-(5-R-2-furyl)thiazoles were obtained by the reaction of 2-(5-R-furfuryl)thiuronium salts with acetic anhydride. The reaction intermediates — 2-(5-R-furfuryl)-1,3-diacetylthioureas — were isolated and characterized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–562, April, 1990.     

Three-component cyclization of hydroxylamino-substituted quinoline with reactive methylene compounds and formaldehyde: new method for the synthesis of 7-(isoxazolidin-2-yl)-6-fluoroquinolones

A one-step procedure was developed for the synthesis of new 6-fluoro-7-(isoxazolidin-2-yl)-4-oxo-1,4-dihydroquinolines. The procedure is based on the 1,3-dipolar cycloaddition of the azomethine oxide and 1,1-disubstituted alkenes, which are generated in situ from 6-fluoro-7-hydroxylamino-4-oxo-1,4-dihydroquinoline-3-carboxylic acid and CH-active compounds (dialkyl malonates, ethyl acetoacetate), respectively, in the presence of formaldehyde at 100—120 °C.     

Mass-spectrometric study of 2- and 4-azafluorenones

A mass-spectrometric study of 2- and 4-azafluorenones and their mono- and polymethyl derivatives showed that the presence of a methyl group in the benzene ring leads to a sharp increase in the relative intensity of the [M — H]⁺ ion peak. In contrast to the fragmentation of 2- and 4-azafluorenes, the mass spectra of monomethyl-substituted compounds do not contain an [M — CH₃]⁺ fragment; this is probably associated with expansion of the pyridine or benzene ring to a seven-membered ring in the step involving the formation of the molecular ion due to inclusion of the methyl group. The intensity of the [M — CO]⁺ ion peak in the mass spectra of the 4-azafluorenones is higher by a factor of two with respect to the 2-azafluorenone isomers, and the [M — HCN]⁺ and [M — H, -HCN]⁺ ion peaks observed in the mass spectra of 2-azafluorenones are absent in them.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 89–95, January, 1979.     

Synthesis and structure of 1-aryl-2-acetonyl(2-phenacyl)-6,7,8,9-tetrahydropyrimido[4,5-b]quinolin-4-ones

On reaction with acylating agents 1-aryl-2-methyl-6,7,8,9-tetrahydropyrimido-[4,5-b]quinolin-4-ones are acylated at the methyl group; they also react with benzaldehyde. On the basis of the PMR and UV spectra it was concluded that 1-aryl-2-acetonyl(2-phenacyl)-6,7,8,9-tetrahydropyrimido[4,5-b]quinolin-4-ones exist in two tautomeric forms with strong intramolecular hydrogen bonds of the chelate type — enaminocarbonyl and enol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1649–1653, December, 1988.     

Reaction of 3-[N-(2-naphthyl)formimidoyl]pyridine with substituted acetophenones

The reaction of 3-[N-(2-naphthyl)formimidoyl]pyridine with substituted acetophenones in the presence of a proton catalyst leads to 1-aryl-3-(3-pyridyl)benzo[f]quinolines. Noncyclic amino ketones — [1-aryl-3-(3-pyridyl)-3-(2-naphthylamino)]-1-propanones — precede the formation of the cyclic products. The IR, UV, PMR, and mass spectra of the synthesized compounds are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 351–354, March, 1989.     

Investigations of benzimidazole derivatives

3-(1-Methyl-2-benzimidazolyl)acrylic acid was obtained by the reaction of 1,2-dimethylbenzimidazole with chloral and subsequent hydrolysis of the condensation product. The hydrochloride of the chloride of this acid and its esters and amides were synthesized. The methyl and ethyl esters of the acid were synthesized by the Wittig reaction. The IR and UV spectra of the compounds obtained are presented.See [9] for Communication XXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1566–1568, November, 1970.     

Mechanism of the antioxidant action of 2,6-dimethyl-3,5-dimethoxy-carbonyl-4-(2-nitrophenyl)1,4-dihydropyridine

A comparison of data on the kinetics of the accumulation of peroxides and the ESR spectra in the case of inhibition of the autooxidation of methyl oleate by 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)1,4-dihydropyridine (I) established that the antioxidant action of the latter is exerted by the formation of a nitroxyl radical. This radical is produced analogously to the well-known scheme from 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2-nitrosophenyl)pyridine, which is generated in the reaction medium from I and methyl oleate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1120–1122, August, 1984.     

Electrosynthesis of N-Arylazoles by Electrolyzing a Mixture of Azole and 1,4-Dimethoxybenzene in a Diaphragmless Cell

An analysis is performed and data are compared on the electrosynthesis of N-arylazoles and regularities of this process in conditions of a diaphragmless galvanostatic electrolysis (Pt, MeCN, Bu₄NClO₄) of a mixture of 1,4-dimethoxybenzene (DMB) with azoles (pyrazole, triazole, their derivatives, tetrazole). Electrolysis of an azole/DMB mixture leads to the formation of products of an ortho-substitution—1,4-dimethoxy-2-(azolyl-1)benzenes—and, simultaneously, hydrolytically unstable products of an ipso-bis-attachment—1,4-dimethoxy-1,4-di-(azolyl-1)cyclohexa-2,5-dienes. The overall yield of these compounds increases upon adding a base (collidine) or an acid (AcOH) into the initial mixture, and the basicity of initial azoles substantially affects the electrosynthesis results. New notions on the nature of nucleophilic species interacting with radical cation of DMB are considered. The species in question are complexes of azoles with one another or with collidine generated at the expense of the hydrogen bond, rather than azolate ions. Furthermore, the cathodic process is largely connected not with the generation of azolate ions (as a result of the reduction of initial azoles) but with the deprotonation of onium compounds (BH⁺)—products of the interaction of azoles or collidine with protons. The mechanism of electrosynthesis of N-arylazoles is discussed. The key stages of the synthesis are the attack of a nucleophile on the ipso- and, possibly, ortho-positions of the benzene ring of radical cation of DMB, as well as the rearrangement of the intermediate cation of 1,4-dimethoxy-1-(azolyl-1)arenonium into the cation of 1-(azolyl-1)-2,5-dimethoxyarenonium, which affects both the yield and ratio of final products of the reaction mixture.