Synthesis of 4-alkyl-6-amino-3,5-dicyano-2(1H)-pyridinethiones

Condensation of aliphatic aldehydes with cyanothioacetamide has given 4-alkyl-6-amino-3,5-dicyano-2(1H)-pyridinethiones, which have also been synthesized by recyclization of 4-alkyl-2,6-diamino-4H-thiopyrans. Substituted 2-alkylthiopyridines and thieno[2,3-b]pyridines have been prepared from the pyridinethiones. 2,6-Diamino-4-isopropyl-3,5-dicyano-4H-thiopyran and 6-amino-4-isobutyl-2-methylthio-3,5-dicyanopyridine have been studied by x-ray crystallography.T. G. Shevchenko State Teaching Institute, Lugansk 348011. A. N. Nesmeyanov Institute of Organoelemental Compounds, Moscow 117813. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1655–1663, December, 1997.     

Transformation of 4-aryl(heteryl)-2,6-diamino-3,5-dicyano-4H-thiopyrans into substituted acrylonitriles, 1,4-dihydropyridines, 2,3,4,7-tetrahydrothiazolo[3,2-a]pyridine, and 4,7-dihydrothieno[2,3-b]pyridine

Cross-recyclization of 4-aryl(heteryl)-2,6-diamino-3,5-dicyano-4H-thiopyrans with α-bromoketones or alkyl halides formed substituted 3-aryl-2-(4-R-thiazol-2-yl)acrylonitriles, 2-alkylsulfanyl-1,4-dihydropyridines, 2,3,4,7-tetrahydrothiazolo[3,2-a]pyridine, and 4,7-dihydrothieno[2,3-b]pyridine.     

Novel Approaches to Synthesis of 4-Alkyl-6-amino-5-cyano-3-methyl(propyl, phenyl)-2H,4H-pyrano[2,3-c]pyrazoles

We have obtained 4-alkyl-6-amino-5-cyano-3-methyl(propyl, phenyl)-2H,4H-pyrano[2,3-c]pyrazoles by reaction of 4-alkylmethylene-3-substituted 5-pyrazolones with malononitrile or cyanothioacetamide. We have used X-ray diffraction to study the structure of 6-amino-5-cyano-4-isopropyl(hexyl)-3-phenyl-2H,4H-pyrano[2,3-c]pyrazoles.     

Fused Pyrimidine Systems: XVII. Imidazo- and Pyrimidopyrido[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-ones

2-(Allylamino)pyrido[3,2-d]pyrimidin-4(3H)-one was converted to linearly fused dihydroimidazo- [1,2-a]pyrido[3,2-d]pyrimidine on heating in polyphosphoric acid, whereas its reactions with molecular iodine and chlorosulfanylarenes afforded mainly angularly fused analogs. 2-(Cinnamylamino)pyrido[3,2-d]pyrimidin- 4(3H)-one reacted with polyphosphoric acid and chlorosulfanylarenes to give linear pyrido[3,2-d]pyrimido-[1,2-a]pyrimidinones, and its iodocyclization led to the formation of angularly fused derivative.     

Synthesis and structure of 6-amino-3,5-dicyano-4-heptylpyridine-2(1H)-thione

Condensation of caprylic aldehyde with cyanothioacetamide taken in a ratio of 1:2 affords 6-amino-3,5-dicyano-4-heptylpyridine-2(1H)-thione. The structure of the thione was studied by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 196–198, January, 1997.     

First representatives of quinolino-1,3,2-dioxaphosphorinanes

Cyclophosphorylation of 7-(1,1,1,3,3,3-hexafluorohydroxyisopropyl)-8-hydroxyquinoline with trivalent phosphorus reagents affords the first representatives of quinolino-1,3,2-dioxaphosphorinanes. The crystal structure of 4,4-bis(trifluoromethyl)-2-diethylamino-2-thio(quinolino-7,8)-1,3,2-dioxaphosphor(v)inane has been studied. A substantial effect of substituents at the P atom on the conformation of the phosphor(v)inane fragment of the molecule has been established.Dedicated to Academician of the RAS N. S. Zefirov (on his 60th birthday).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1817–1820, September, 1995.This work was supported within the framework of the State Program on Fine Organic Synthesis and by the Russian Foundation for Basic Research (Project No. 95-03-09030a).     

Heterocyclization of 1,3-Butadienethiolates

Condensation of derivatives of ethoxymethylenecyanoacetic acid with cyanothioacetamide with base catalysis gave butadienethiolates and mercaptopyridines. On interaction with alkyl halides, butadienethiolates are cyclized into alkylthiopyridines, but their reactions with phenacyl bromides give substituted thiazoles.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 589–596, April, 2005.     

Cyclohexene-4-carbaldehyde in the Synthesis of 4-(Cyclohex-3-enyl)-Substituted 4 H -Chromenes, 4 H -Thiopyrans, 1,4,5,6,7,8-Hexahydroquinolines, 1,4-Dihydropyridines, Pyridines, and 6,7-Dihydro-5 H -[1]pyrindines

Cyclocondensation of cyclohexene-4-carbaldehyde in the presence of morpholine with CH acids [malonodinitrile, dimedone, 1,3-cyclohexanedione, ethyl acetoacetate, cyanothioacetamide, β-aminophenol, resorcinol, and 4-(cyclopent-1-enyl)morpholine] yields the corresponding 4-(cyclohex-3-enyl)-substituted 4H-chromenes, 4H-thiopyrans, 1,4,5,6,7,8-hexahydroquinolines, 1,4-dihydropyridines, and 6,7-dihydro-5H-[1]pyrindines. __________ Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 10, 2005, pp. 1612–1619. Original Russian Text Copyright ? 2005 by Dyachenko.     

Unexpected formation of 4-aryl-3-cyano-6-phenylpyridine-2(1H-thiones from the reaction of arylmethylenecyanothioacetamides with benzoyl-1,1,1-trifluoroacetone

4-Aryl-3-cyano-6-phenylpyridine-2(1H)-thiones, used in the synthesis of substituted 2-alkylthiopyridines, thieno[2,3-b]pyridines, and 1,4-di(pyridin-2-ylthio)butane, have been synthesized by the condensation of arylmethylenecyanothioacetamides with benzoyl-1,1,1-trifluoroacetone. The reaction path includes the formation of the Michael adduct which undergoes loss of the acyl group. The structure of 3-cyano-2-methylthio-4-(1-naphthyl)-6-phenylpyridine has been studied by X-ray crystallography. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, 1821–1828, December 2005.