Direct nitration and acetylation of the furan nucleus of 1-alkyl-2-[Β -(2′-furyl) vinyl]-benzimidazoles

The direct nitration and acetylation of 1-methyl-, 1-ethyl-, and 1-benzyl-2-[-(2-furyl)vinyl]benzimidazoles has given the corresponding 1-alkyl- and 1-benzyl-2-[-(5-nitro-2-furyl)vinyl]benzimidazoles and 1-alkyl- and 1-benzyl-2-[-(5-acetyl-2-furyl)vinyl]benzimidazoles. The UV spectra of these compounds have been recorded and their ionization constants have been determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 6, pp. 832–834, June, 1970.     

Research on the chemistry of 2-hetarylbenzimidazole. 3. Reaction of 1-methyl-2-(5′-methyl-2′-hetaryl) benzimidazoles with electrophilic reagents

A number of new derivatives of 1-methyl-2-(5-methyl-2-hetaryl)benzimidazole were synthesized by electrophilic substitution. The substituent enters the position of the 4-hetaryl ring. A furan ring that contains a methyl group in the 5 position undergoes profound destructive oxidation under the influence of acetyl nitrate. Depending on the conditions, bromination leads to the formation of bromo derivatives that are substituted in the benzene or hetaryl ring.See [7] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 520–523, April, 1981.     

Syntheses in the field of 5-nitro-2-furylpolyalkenals and 5-nitro-2-furylpolyalkenones

A series of, -bis(5-nitro-2-furyl)poryalkenones has been synthesized by the condensation of 5-nitro-2-furylalkenones with 5-nitrofuran aldehydes in acetic acid (concentrated sulfuric acid catalyst). In the , -bis(5-nitro-2-furyl)polyalkenone series, the keto group acts as a partial insulator of conjugation, which is shown most clearly in the case of 1,3-bis(5-nitro-2-furyl)prop-2-en-1-one and 1,5-bis(5-nitro-2-furyl)-penta-2,4-dien-1-one, i.e. compounds having the keto group directly linked to a 5-nitrofuran ring. The electronic spectra of the semicarbazones of the, -bis(5-nitro-2-furyl)polyalkenones exhibit a stronger disturbing effect of the conjugation in the molecule than in the case of the ketones, which may be connected with a disturbance of coplanarity. In a number of cases, the infrared spectra of the, -bis(5-nitro-2-furyl)polyalkenones exhibit splitting of the symmetrical and antisymmetrical vibrations of the nitro group.For part VII, see [1].Preliminary results of the present investigation were given for the first time at the 2-nd All-union Scientific Conference on the Chemistry of Furan Compounds, Saratov, 23–26 January, 1962, see [2].     

Über Tetrahydrospiro [cyclohexan-1,4′(1′H)-chinazolin]-2′(3′H)-one

Zusammenfassung Cyclohexanon bzw. Cyclopentanon sowie ihre durch Aldolreaktion entstehenden Dimeren reagieren mit Harnstoff im sauren Medium zu 5,6,7,8-Tetrahydrospiro[cyclohexan-1,4(1H)-chinazolin]-3(2H)-onen (2) bzw. zum Dihydrospiro-(cyclopentan-1,4(1H)-5H-cyclopenta[d]pyrimidin)-2(3H)-on (10). Substituierte Harnsotoffe geben Gemische der isomeren 5,6,7,8-Tetrahydro- und 4a,5,6,7-Tetrahydroverbindungen (2, 3) bzw. 6,7-Dihydro-tH- und 5,6-Dihydro-4aH-verbindungen (10, 11). Charakteristisch für2 (3),10 (11) ist die Reaktivität der Kernstellen 8 bzw. 7 gegenüber elektrophilen Agentien (2f-v, 3f-j, 9 a-i, 10 d-f). Äthylmalonsäurebis-trichlorphenylester bzw. Formaldehyd und prim. Amine führen2 in ein partiell hydriertes 1H-Pyrido[3,2,1-ij]chinazolintrion (6) bzw. 1H-Pyrimido[5,6,1-ij]chinazolinon (7) über. Die 1-Alkylverbindungen (2) geben mit Formaldehyd und primären Aminen Hexahydro-8a-hydroxy-4a,8-propanospiro-(cyclohexan-1,4(1H)-pyrido[4,3-d]pyrimidin)-2(3H)-one (8).

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Heterocycles, XXV: tetrahydrospiro [cyclohexane-1,4(1H)-quinazoline]-2(3H)-ones

Cyclohexanone and cyclopentanone, resp., as well as their dimers (formed by aldol reaction) react with urea in the presence of acids to 5,6,7,8-tetrahydrospiro[cyclohexane-1,4-(1H)-quinazoline]-3(2H)-ones (2) and to the dihydrospiro-(cyclopentane-1,4(2H)-5H-cyclopenta[d]pyrimidine)-2(3H)-one (10), resp. Substituted ureas give the isomeric 5,6,7,8-tetrahydro- and 4a,5,6,7-tetrahydro compounds (2, 3), and 6,7-dihydro-5H- and 5,6-dihydro-4aH-compounds (10, 11), resp. Characteristic for2 (3),10 (11) is the reactivity of the nuclear places 8 and 7 with electrophilic agents (2f-v, 3f-j, 9a-i, 10d-f). Ethylmalonic acid bistrichlorophenylester resp. formaldehyde and primary amines react with2 to the partially-hydrogenated 1H-pyrido[3,2,1-ij]-quinazolinetrione (6) and 1H-pyrimido[5,6,1-ij]-quinazolinone (7), resp. The 1-alkyl compounds (2) give with formaldehyde and primary amines hexahydro-8a-hydroxy-4a, 8-propanospiro(cyclohexane-1,4-(1H)-pyrido[4,3-d]pyrimidine)-2(3H)-ones (8).

     

Bromination of 2 -(2′-furyl)imidaz o[1, 2-a]pyridine and its derivatives

The action of bromine and N-bromosuccinimide on 2-(2-furyl)imidazo[1,2-a]pyridine and its 3-nitroso, 5-bromo, and 5-nitro derivatives was studiedTranslated from Khimiya Geterotsklicheskikh Soedinenii, No. 5, pp. 691–695, May, 1972.     

Synthesis and study of L-arabinopyranosides of 5- and 6-nitroindoles

Condensation of 5- or 6-nitroindoline with L-arabinose gave 1--L-arabinopyranosyl-5 (or 6)-nitroindolines, which, after acetylation, dehydrogenation, and removal of the protective groups, are converted to 1--L-arabinopyranosyl-5(or 6)-nitroindoles and then to the corresponding amino derivatives. 1--L-Arabinopyranosyl-6-nitro-3-bromo-(iodo)indoles were obtained. The selective 2-O- and 3-O-deacetylation of 1-(2, 3, 4-tri-O-acetyl)--L-arabinopyranosyl-6-nitroindole was accomplished.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 224–229, February, 1979.     

Research on the chemistry of 2-hetarylbenzimidazoles. 4. Oxidation of 1-methyl-2-(5′-methyl-2′-hetaryl)benzimidazoles

The methyl group in 1-methyl-2-(5-methyl-2-hetaryl)benzimidazoles (hetaryl = furyl and thienyl) was oxidized. It was found that a salt of a carboxylic acid, which in an acidic medium loses carbon dioxide to give 1-methyl-2-(2-furyl)-benzimidazole, is formed when 1-methy1-2-(5-methyl-2-furyl)benzimidazole is treated with an aqueous solution of potassium permanganate. The carboxy derivative of thiophene is considerably more stable. Oxidation by means of selenium dioxide leads to the corresponding 5-formyl derivative. The structures of the compounds obtained were confirmed by data from the IR and PMR spectra.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1089–1091, August, 1982.     

Podand-porphyrins with peripheral chelates

Alkylation of 5-(3-nitro-4-hydroxyphenyl)-10,15,20-triphenylporphyrin with chloropyridines[2,6-dichloromethyl-and 2-chloromethyl-6-(2-nitrophenoxymethylpyridine)] as well as condensation by a mixed-aldehyde method starting with formylpyridines [2-(2-nitro-4-formylphenoxymethyl)-6-(2-nitrophenoxy-methyl-) or 2,6-di(2-nitro-4-formylphenoxymethyl)pyridine], benzaldehyde, and pyrrole are used to synthesize previously unknown podand-porphyrins containing from one to four peripheral chelates.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 475–481, April, 1991.     

Synthesis of some substituted 2- and 4-[2′-(5″-nitro-2″-furyl)vinyl]-quinolines

A series of 2- and 4-[2-(5-nitro-2-furyl)vinyl]quinolines were synthesized by catalytic condensation of 5-nitrofurfural with 2- and 4-methylquinolines. 2-Methylquinoline (quinaldine) and its substituted derivatives also react when the starting reagents are fused directly.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 253–255, February, 1976.     

Diazabicycloalkanes with nitrogen atoms in bridgehead positions. 16. Synthesis and properties of benzo[b]-1,4-diazabicyclo[2.2.2]octene and dibenzo[b,e]-1,4-diazabicyclo[2.2.2]octadiene,containing primary aromatic amino acids

4-Aminobenzo[1,2-b]-1,4-diazabicyclo[2.2.2]octene and 4-aminodibenzo[1,2-b, e]-1,4-diazabicyclo[2.2.2]octadiene have been prepared by cyclization reactions of N--chloroethyl derivatives of 1,2,4-triaminobenzene and aminophenazine, and subsequent catalytic hydrogenation of the corresponding 4-nitrobenzo[1,2-b]-1,4-diazabicyclo[2.2.2]octene and 4-benzylaminodibenzo[1,2-b,e]-1,4-diazabicyclo[2.2.2]-octadiene. Using the conversion of these compounds to azides as an example, we have demonstrated the feasibility of applying these primary aromatic amines for the synthesis of derivatives of these heterocycles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 831–837, June, 1988.     

Synthetic studies in the field of chlorobium chlorophyll

By the condensation of -halogenomethyl derivatives of pyrroles with -unsubstituted pyrroles the synthesis of the following unsymmetrical dipyrrolylmethanes has been effected: 5-benzyloxycarbonyl-5-ethoxycarbonyl-3, 3-di(-methoxycarbonylethyl)-4,4-dimethyl-2,2-dipyrrolylmethane (IIIa), 5-benzyloxycarbonyl-5-ethoxycarbonyl-3-(-methoxycarbonylethyl)-4, 4-diniethyl-3-n-propyl-2,2-dipyrrolylmethane(IIIb), 3-acetyl-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIIc), and 3-bromo-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIId). Hydrogenation of the unsymmetrical dipyrrolylmethanes IIIa, b, c, and d has given the corresponding monocarboxylic acids IVa, b, c, and d. The formylation of the dipyrrolylmethanemonocarboxylic acid IVa has given 5-ethoxycarbonyl-5-formyl-3,3-di(-methoxycarbonylethyl)-4, 4-dimethyl-2,2-dipyrrolylmethane (V).For communication II, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1045–1047, August, 1970.     

Cobalt(II) and nickel(II) chloride complexes with some 2-(4′-Methyl-2′-pyridyl and 2′- or 8′-quinolyl)benz-X-azoles

Summary Complexes of general formula ML_mCl₂ · nH₂O, where M=cobalt(II) or nickel(II); L=2-(4-methyl, 2-pyridyl)-benzimidazole (mpbi), 2-(4-methyl, 2-pyridyl)benzothiazole (mpbt), 2-(4-methyl, 2-pyridyl)benzoxazole (mpbo), 2-(4-methyl, 2-quinolyl)benzoxazole (mqbo), or 2-(4-methyl, 8-quinolyl)benzoxazole (mqbo); m=1,2; n=0–3, were prepared and characterized by t.g.a., conductance and magnetic measurements, i.r. and diffuse-reflectance electronic spectra.All the ligands behave as bidentate and coordinate through the pyridine- and isoxazole-nitrogen atoms.The nickel complexes have distorted octahedral or fivecoordinate structures. The cobalt complexes arepseudo-tet- rahedral except Co(mpbo)₂Cl₂·2H₂O where the metal is six-coordinate.     

9-(2′,5′-Dimethyl-4′-pyridyl)fluorene in syntheses of fluorospirodihydrofuropyridine and pyridofluoranthene

1,2,5-Trimethyl-4-(9-fluorenylidene)piperidine, which is formed by condensation of fluorene with 1,2,5-trimethyl-4-piperidone, is converted catalytically to 9(2,5-dimethyl-4-pyridyl)fluorene, from which 2-methylpyrido[4,5-a]fluoranthene and its demethylated analog were obtained by catalytic dehydrocyclization. Oxidation of 9-(2,5-dimethy1-4-pyridyl)fluorene gave 9-(2,5-dimethyl-4-pyridyl)9-fluorenol and fluorene-9-spiro-4-(6-oxo-2-carboxypyrido[4,5-c]-4-6-dihydrofuran). 6-Methyl-2-phenyl-7-(9-fluorenyl)indolizine was synthesized by the Chichibabin method.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1087–1090, August, 1978.     

Condensation of α-substituted furfurals with methyl ethyl ketone

The reaction of 5-halo- and 5-nitrofurfurals with methyl ethyl ketone was investigated. It was established that the 5-halofurfurals form 1,5-bis (5-halo-2-furyl)-2-methyl-1,4-pentadien-3-ones in alkaline media. In acid medium, 5-nitrofurfural gives primarily 1-(5-nitro-2-furyl)-2-methyl-1-buten-3-one, which readily condenses with halofurfurals in alkaline media. The IR spectra of the pentadienones are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1162–1166, September, 1971.     

Nitration,amination, and halogenation of Di-O-methylphloracetophenone

Chlorination of the title compound gave 5- and 3-chloro-2-hydroxy-4,6-dimethoxyacetophenone. The nitration of its acetate, followed successively by reduction, diazotization, and reaction with cuprous chloride, gave the 3-substituted series, 2-acetoxy-4,6-dimethoxy-3-nitroacetophenone, 3-amino-2-hydroxy-4,6-dimethoxyacetophenone, and 3-chloro-2-hydroxy-4,6-methoxyacetophenone, respectively. The orientation of substituents in the products was proved. The amino and chloro members of the isomeric 5-substituted series were availablevia 2-hydroxy-4,6-dimethoxy-5-phenylazoacetophenone, the product of the reaction of the title compound with benzenediazonium chloride.

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Nitrierung, Aminierung und Halogenierung von Di-O-methylphloracetophenon

Zusammenfassung Chlorierung der Titelverbindung gab 5- und 3-Chlor-2-hydroxy-4,6-dimethoxyacetophenon. Die Nitrierung des Acetats, gefolgt von Reduktion, Diazotierung und Reaktion mit CuCl ergab die 3-substituierte Reihe: 2-Acetoxy-4,6-dimethoxy-3-nitroacetophenon, 3-Amino-2-hydroxy-4,6-dimethoxyacetophenon und 3-Chlor-2-hydroxy-4,6-dimethoxyacetophenon. Die Orientierung der Substituenten wird diskutiert. Die Amino- und Chlorderivate der isomeren 5-substituierten Reihe sind über 2-Hydroxy-4,6-dimethoxy-5-phenylacetophenon zugängig, dem Produkt der Reaktion der Titelverbindung mit Phenyldiazoniumchlorid.

     

Oxidative cyclisation of chalcones with thallium(III)nitrate: Synthesis of (Z)-2-phenylmethylene-7-nitro-3(2H)-benzofuranones

Oxidation of 2-hydroxy-3-nitrochalcones with thallium(III) nitrate gives (Z)-2-phenylmethylene-7-nitrobenzofuran-3(2H)-one derivatives, rather than the more usual 1,2-diaryl-3,3-dimethoxypropan-1-ones or the corresponding isoflavones.

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Oxydative Cyclisierung von Chalconen mit Thallium(III)nitrat: Synthese von (Z)-2-Phenylmethylen-7-nitro-3(2H)-benzofuranonen (Kurze Mitteilung)

Zusammenfassung Die Oxidation von 2-Hydroxy-3-nitrochalconen mit Thallium(III)nitrat ergab (Z)-2-Phenylmethylen-7-nitro-3(2H)-benzofuranon-Derivate und nicht die üblichen 1,2-Diaryl-3,3-dimethoxypropan-1-one bzw. die entsprechenden Isoflavone.

     

Nitrosation and bromination of 6-(2'-furyl)imidazo[2,1-b]thiazole and its derivatives

The action of nitrosating agents and bromine on 6-(2-furyl)imidazo[2,1-b]thiazole and its 3-methyl, 5-bromo, and 5-nitro derivatives was studied. The structures of the products were proved by UV, IR, and PMR spectroscopy and thin-layer chromatography.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1353–1358, October, 1972.     

Synthesis of 2-O-ethyl analogues of 3′-azido- and 3′-fluoro-2′,3′-dideoxyuridines and evaluation of their biological activity against HIV

Summary 2-O-Ethyluracil and 2-O-ethylthymine were silylated with 1,1,1,3,3,3-hexamethyldisilazane and condensed in the presence ofTMS triflate with 2,3-dideoxy-3-fluoro-D-erythro-pentofuranoside, 3-azido-2,3-dideoxy-D-erythro-pentofuranoside, and 2,3-dideoxy-3-phthalimido--D-erythro-pentofuranose derivatives to give the corresponding 2-O-ethyl nucleosides. Deprotection with saturated methanolic ammonia afforded the 2,3-dideoxy-3-fluoro-2-O-ethyluridines, whereas 3-azido-2,3-dideoxy-3-O-ethyluridine was obtained by deprotection with tetrabutylammonium fluoride in tetrahydrofuran. 3-Amino-2,3-dideoxy-3-O-ethyluridine could be obtained only by treatment of the corresponding 3-azido nucleoside with triphenylphosphine in pyridine. 3-Deoxy-2-O-ethyl-3-fluorothymidine (6b) showed moderate activity against HIV-1.

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Synthese von 2-O-Ethyl-Analogen von 3-Azido- und 3-Fluor-23-dideoxyuridinen und Bestimmung ihrer biologischen Aktivität gegenüber HIV

Zusammenfassung 2-O-Ethyluracil und 2-O-Ethylthymin wurden mit 1,1,1,3,3,3-Hexamethyldisilazan silyliert und in Gegenwart vonTMS-triflat mit 2,3-Dideoxy-3-fluoro-D-erythro-pentofuranosid, 3-Azido-2,3-dideoxy-D-erythro-pentofuranosid und 2,3-Dideoxy-3-phthalimido--D-erythro-pentofuranosederivaten zu den entsprechenden 2-O-Ethyl-Nucleosiden umgesetzt. Entfernung der Schutzgruppe mit gesättigter methanolischer Ammoniaklösung lieferte 2,3-Dideoxy-3-fluor-2-O-ethyluridin; 3-Azido-2,3-dideoxy-3-O-ethyl-uridin wurde durch Entschützung mit Tetrabutylammoniumfluorid in Tetrahydrofuran erhalten. 3-Amino-2,3-dideoxy-3-O-ethyl-uridin konnte nur durch Behandeln des entsprechenden 3-Azido-Nucleosids mit Triphenylphosphin in Pyridin hergestellt werden. 3-Deoxy-2-O-ethyl-3-fluor-thymidin (6b) zeigt geringe Aktivität gegenüber HIV-1.

     

Spectrophotometric determination of vanadium with 4-(1′H-1′,2′,4′-Triazolyl-3′-azo)-2-methylresorcinol

Summary 4-(1H-1,2,4-Triazolyl-3-azo)-2-methylresorcinol reacts with vanadium(V) at pH 8.10 (Tris-HClO₄ buffer solution) to produce a pink-violet 11 complex ( _max=525 nm,=2.55×10⁴l·mol^–1· cm^–1) in a 50% (v/v) methanol-water medium, which allows the spectrophotometric determination of 0.1 to 1.51 ppm of vanadium. The method has been applied for the determination of the vanadium content in low alloy steels.

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Spectrophotometriscbe Bestimmung von Vanadin mit 4-(1H-1,2,4-triazo-lyl-3-azo)-2-methylresorcin

Zusammenfassung Vanadin bildet bei pH 8,10 (Tris-HClO₄-buffer) mit 4-(1H-1,2,4-tri-azolyl-3-azo)-2-methylresorcin ein rosenrot-violettes Chelat, dessen Absorptionsmaximum bei 525 nm in Gegenwart von 50% Methylalkohol gemessen wird. Dieser 11-Komplex entspricht bei einer Vanadin-Konzentration von 0,1–1,51g/ml dem Beerschen Gesetz; seine molare Absorptivität ist 2,55×10⁴l·mol^–1·cm^–1. Das Verfahren wurde zur Bestimmung des Vanadins in Stahl verwendet.

     

1,2-bis(2',6'-dimethyl-i',3'-dioxa-6'-aza-2'-silacyclooctyl-2')ethane and the corresponding ethylene and acetylene derivatives

Conclusions The reaction of 1,2-bis(methyldimethoxysilyl)ethane and the corresponding ethylene and acetylene derivatives with bis(2-hydroxyethyl)methylamine gives 1,2-bis(2,6-dimethyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)ethane and the corresponding ethylene and acetylene derivatives. Analogously, 1,2-bis(vinyldimethoxysilyl)acetylene gave 1,2-bis(2-vinyl-6-methyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)acetylene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1988.