Pyridyl-substituted [1,3]Dithiolo-[4,5-<Emphasis Type="Italic">b</Emphasis>][1,4]dithiine-2-thiones

We have obtained 5-(2-pyridyl)[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione for the first time by cycloaddition of 2-ethynylpyridine to 4,5-dihydro-1,3-dithioltrithione (isotrithionedithiol). We have studied this thione, 5-(2-pyridyl)- and 5-(4-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thiones by mass spectroscopy and also IR, UV, ¹H and ¹³C NMR spectra. We have determined the crystal and molecular structure of 5-(2-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 429–434, March, 2005.     

Synthesis and properties of pyrimido[4,5-<Emphasis Type="Italic">a</Emphasis>]- and pyrido[4,3-<Emphasis Type="Italic">a</Emphasis>]carbazole derivatives

Methods for the synthesis of substituted pyrimido [4,5-a]- and pyrido[4,3-a]carbazoles were proposed. Condensation of 2-(dimethylaminomethylene)-6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-one with guanidine and thiourea afforded 2-amino-8-methyl-6,11-dihydro-5H-pyrimido[4,5-a]carbazole and 8-methyl-3,5,6,11-tetrahydro-2H-pyrimido[4,5-a]carbazole-2-thione, respectively. The reaction of cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide with dimethylformamide dimethyl acetal gave N-(dimethylamino-methylene)cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide. Cyclization of the latter yielded 1-cyano-8-methyl-3,5,6,11-tetrahydro-2H-pyrido[4,3-a]carbazol-2-one.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2740–2744, December, 2004.     

Synthesis and reactivity of thieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridine-2,3-diamines

It has been established that the interaction of N¹-(2-hydroxyphenylmethylthieno[2,3-b]pyrid-3-yl)arylamides with hydrazine hydrate leads to thieno[2,3-b]pyridine-2,3-diamines. It was shown that the reaction of the latter with acetylacetone and acetoacetic ester occurs regioselectively at the amino group in position 3 of the thiophene ring. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1400–1408, September, 2007.     

4-(10-Methyl-10H-phenothiazin-3-yl)-1,4-dihydropyridines, 4,5-dihydroindeno[1,2-<Emphasis Type="Italic">b</Emphasis>]-and 5,5-dioxo-4,5-dihydrobenzo-thieno[3,2-<Emphasis Type="Italic">b</Emphasis>]pyridines

Different modifications of the Hantzsch synthesis using 10-methyl-10H-phenothiazine-3-carbaldehyde gave 4-(10-methyl-10H-phenothiazin-3-yl)-substituted 1,4-dihydropyridine-3,5-di-, 5-oxo-4,5-dihydro-1H-indeno[1,2-b]pyridine-, and 5,5-dioxo-4,5-dihydro-1H-5λ⁶-benzo[4,5]thieno[3,2-b]pyridine-3-carboxylic esters. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 280–288, February, 2007.     

Halogenation of 2-Unsubstituted and 2-Methylimidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridine Derivatives

Halogenation of 2-unsubstituted and 2-methylimidazo[4,5-b]pyridines and their N-methyl derivatives with bromine and chlorine in acetic acid takes different pathways, depending on the acetic acid concentration. The bromination in 50% aqueous acetic acid gives only 6-bromoimidazo[4,5-b]pyridines; bromination and chlorination of 2-unsubstituted imidazo[4,5-b]pyridines in glacial acetic acid leads to 5,6-dibromo(dichloro)imidazo[4,5-b]pyridin-2-ones, and bromination of 2-methylimidazo[4,5-b]pyridines in glacial acetic acid involves both the pyridine ring and the 2-methyl group to afford the corresponding 6-bromo-2-tribromomethylimidazo[4,5-b]pyridines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 457–461.Original Russian Text Copyright © 2005 by Yutilov, Lopatinskaya, Smolyar, Gres’ko.     

Synthesis of substituted octahydrochromeno[3,2-<Emphasis Type="Italic">i</Emphasis>]quinazoline-2(1<Emphasis Type="Italic">H</Emphasis>)-thiones

Condensation of 8-arylidenehexahydroquinazoline-2-thiones with di- and trihydroxybenzenes affords the new heterocyclic system, viz., octahydrochromeno[3,2-i]quinazoline-2(1H)-thiones, in which the substituents in both the chromane and quinazoline rings can be varied over a wide range. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1456–1460, June, 2005.     

Synthesis of 6-Methylbenzo-[<Emphasis Type="Italic">b</Emphasis>]pyrido[3,2-<Emphasis Type="Italic">f</Emphasis>][1,6]naphthyridines from 4-Chloro-2-methylquinoline

4-Chloro-2-methylquinolines in reaction with 3-aminopyridine yielded 4-quinolinamines, which upon cyclisation under Vilsmeier-Haak conditions afforded the title compounds. __________ Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, 901–904, June, 2005.     

Halogenation of Imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-2-one Derivatives

Chlorination and bromination of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one and its N-methyl-substituted derivatives in acetic acid at 90–95°C leads to formation of the corresponding 5,6-dichloro(dibromo)-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones. Iodination of the same substrates with ICl under analogous conditions yields 6-iodo derivatives. Chlorination of 6-iodo-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one is accompanied by replacement of the iodine atom by chlorine with formation of 5,6-dichloro-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one. Bromination of 6-bromo- and 6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones gives 5,6-dibromo- and 5-bromo-6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, respectively.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 586–589.Original Russian Text Copyright © 2005 by Yutilov, Lopatinskaya, Smolyar, Gres’ko.     

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[<Emphasis Type="Italic">b</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]-, -[2,3-<Emphasis Type="Italic">g</Emphasis>]-, and -[3,2-<Emphasis Type="Italic">e</Emphasis>]indoles

The Sandmeyer reaction was used to prepare 2,3-dioxo-2,3-dihydrobenzo[b]furoindoles which could be reduced with diborane or with complex hydrides to give the corresponding unsubstituted as well as the 3-hydroxybenzo[b]furoindoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1683–1689, November, 2004.     

Reaction of 2-methoxy-1,3,2-dioxaphosphorino[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-4(4<Emphasis Type="Italic">H</Emphasis>)-one with hexafluoroacetone

The reaction of the di-O-trimethylsilyl derivative of 2-hydroxynicotinic acid with methyl phosphodichloridite afforded 2-methoxy-1,3,2-dioxaphosphorino[4,5-b]pyridin-4(4H )-one. The NMR spectrkscopic data suggest that the reaction of the latter with hexafluoroacetone produces unstable 2-methoxy-2,5-dioxo-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyridine, which is readily transformed into 9-methyl-2,5-dioxo-4,4- bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyrid-9-inium-2-oate. The structure of the hydrolysis product of the latter, viz., 1-methyl-3-(2-hydroxy-3,3,3-trifluoro-2- trifluoromethylpropanoyl)pyridin-2-one, was established by X-ray diffraction analysis.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1640–1646, August, 2004.     

A simple and effective synthetic approach to pyrido[2,1-<Emphasis Type="Italic">b</Emphasis>]thiazines

The reaction of partially hydrogenated 2-pyridinethiols with 1,3-dibromopropane gives substituted pyrido[2,1-b][1,3]thiazines. The structure of 7,9-dicyano-6-oxo-3,4,6,7-tetrahydro-2H-spirocyclohexane-1′,8-pyrido[2,1-b][1,3]thiazine was solved by X-ray diffraction structural analysis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1428–1433, September, 2007.     

Investigations on 2,3′-biquinolines 22. Novel and convenient method for the synthesis of benzo[5,6]indolizino-[2,1-<Emphasis Type="Italic">b</Emphasis>]quinolinium-13-thiolates and benzo-[5,6]indolizino[1,2-<Emphasis Type="Italic">c</Emphasis>]quinoline-6(5H)-thiones

We have developed a method of synthesis of benzo[5,6]indolizino[2,1-b]quinolinium-13-thiolates and 5,6-dihydrobenzo[5,6]indolizino[1,2-c]quinoline-6-thiones based on the reaction of the corresponding 1′, 2′-dialkyl-1′,2′-dihydro-2,3′-biquinolines and 1′,4′-dialkyl-1′,4′-dihydro-2,3′-biquinolines with sulfur in DMF. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 849–851, June, 2007.     

Pyrano[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidinium salts

5-Aroyl-1,3,6-trimethyluracils were converted to pyrano[4,3-d]pyrimidinium salts. Reactions of the salts obtained with ammonia, primary amines, and hydrazine were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2251–2257, November, 2007.