Reactions of 3-oxo-2,3-dihydrobenzofuran with alkyl 2-cyano-3-alkoxypropenoate and alkyl 2-alkoxycarbonyl-3-alkoxypropenoate. Synthesis of pyran derivatives

3-Oxo-2,3-dihydrobenzofuran reacted with ethyl 2-cyano-3-ethoxypropenoate, methyl 2-cyano-3-methoxy-propenoate affording compounds 3 (2-(2-cyano-2-alkoxycarbonylvinyl)-3-hydroxybenzofuran) obtained as a mixture of Z + E isomers. Methyl 2-methoxycarbonyl-3-methoxypropenoate gave compound 4 . Malonic compounds added on 2-dimethylaminomethylene-3-oxo-2,3-dihydrobenzofuran 6 for giving compound 3 or 2-oxo-3-methoxycarbonyl-2H-pyrano[3,2-b]benzofuran 8 . Compound 8 was also obtained by heating compound 4 in xylene.     

Synthesis of 2H-Thiopyrans by Rhodium(II) Acetate-Catalyzed Reaction of 4-Amino-2,5-dihydro-3-thiophenecarbonitriles with a-Diazocarbonyl Compounds II [1]

Summary.  The reaction of 4-amino-2,5-dihydro-2- and -5-methyl-3-thiophenecarbonitriles with α-diazocarbonyl compounds in the presence of rhodium(II) acetate gave regioselectively 4-cyano-2H-thiopyrans (C₂-S insertion) in moderate to good yields; 5-cyano-2H-thiopyrans (C₅-S insertion) were not isolated. The starting compounds were synthesized by reaction of tetrahydro-2- and -5-methyl-4-oxo-3-thiophenecarbonitriles with morpholine, piperidine, and pyrrolidine in the presence of formic acid in ethanol. Received November 13, 2000. Accepted December 12, 2000     

Reaction of 3-Methyleneisocamphanone with Derivatives of Malonic Acid

Reaction of 3-methyleneisocamphanone with malononitrile, ethyl cyanoacetate or diethyl malonate in the presence of catalytic quantities of alkali or under catalysis with tetramethylguanidine in ethanol proceeds according to classical scheme of the Michael reaction and gives rise to 3-exo-(2,2-dicyanoethyl)-, 3-exo-(2-cyano-2-ethoxycarbonylethyl)-, or 3-exo-(2,2-diethoxycarbonylethyl)isocamphanone respectively. When the reaction with ethyl cyanoacetate and diethyl malonate is carried out in methanol occurs transalkylation of the ester groups resulting in the corresponding methyl esters, and in THF occurs hydrolysis to form carboxylic acids. In ethanol or methanol in the presence of equimolar or excess amounts of alkali compounds with cyano groups suffer cyclization into the corresponding 2-alkoxy-3-cyano- or 1-alkoxy-3-alkoxycarbonyl-7,7,8-trimethylbicyclo[2.2.1]hepteno[2.3-b]pyridines. In THF partially form analogous tricyclic 2-hydroxypyridines.     

Synthesis of 2-Amino-4-aryl-3-cyano-4H-pyrano and 2-Amino-3-cyanothieno Derivatives of Cyclopentanonopimaric Acid

Condensation of cyclopentanonopimaric acid with malononitrile in the presence of p-methoxybenzaldehyde or elemental sulfur gave the corresponding fused 2-amino-3-cyano-4-(4-methoxyphenyl)-4H-pyrano and 2-amino-3-cyanothieno derivatives.     

Reactions of α,β-unsaturated ketones with cyanoacetamide

3-Aryl-1-phenyl-2-propen-1-ones Ia-f and aroylphenylacetylenes Va-d reacted under reflux for 3 hours with cyanoacetamide in the presence of sodium ethoxide to give the corresponding 4-aryl-3-cyano-6-phenyl-2-(1H)pyridones VI. However, when ketones Ia-e were refluxed with cyanoacetamide for one hour in the presence of sodium ethoxide or piperidine, they gave the corresponding 4-aryl-3-cyano-3,4-dihydro-6-phenyl-2-(1H)pyridones IIIa-e, which upon heating with selenium gave the corresponding 2-pyridones VI. The structures of the products are based on chemical and spectroscopic evidence.     

Synthesis and reactions of 3-acetyl-6-methyl-2-(methylthio)pyridine

A reaction of methyllithium with 3-cyano-6-methylpyridine-2(1 H)-thione followed by alkylation of the resulting 3-acetylpyridinethione, or a direct reaction of methyllithium with 3-cyano-6-methyl-2-(methylthio)pyridine, afforded 3-acetyl-6-methyl-2-(methylthio)pyridine. The ketone obtained was examined in bromination reactions under various conditions. Bromi-nation in methanol or chloroform, proceeding through the formation of sulfonium bromides, gave substituted 3-(bromoacetyl)pyridine. A reaction of 3-acetyl-6-methyl-2-(methyl-thio)pyridine with N-bromosuccinimide in CCl4 afforded N-(pyridinesulfenyl)succinimide. The bromo ketone was used for the synthesis of various heterocyclic compounds.     

Synthesis and alkylation ofN-methylmorpholinium 5-cyano-4-(3- and 4-hydroxyphenyl)-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates

The reactions of 3- or 4-hydroxybenzaldehydes with cyanothioacetamide and Meldrum's acid in the presence ofN-methylmorpholine affordedN-methylmorpholinium 5-cyano-4-(3-or 4-hydroxyphenyl)-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates, respectively. The resulting compounds were used in the synthesis of substituted 6-alkylthio-1,2,3,4-tetrahydropyridin-2-ones. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2333–2336. December, 1999.     

Studies on the Synthesis of New 3-(3,5-Diamino-1-substituted-pyrazol-4-yl)azo-thieno[2,3-b]pyridines and 3-(2-Amino-5,7-disubstituted-pyrazolo[1,5-a]pyrimidine-3-yl)azothieno[2,3-b]pyridines

Coupling the diazonium salt of 3-amino-2-cyano-4,6-dimethylthieno[2,3-b]pyridine 1 with malononitrile 2 gave 2-cyano-3-(hydrazonomalononitrile)-4,6-dimethylthieno[2,3-b]pyridine 3 which then reacted with hydrazine compounds 4a-4h to yield corresponding 2-cyano-3-(3,5-diamino-1-substituted-pyrazol-4-yl)azo-4,6-dimethylthieno[2,3-b]pyridines 5a-5h. The 2-cyano-3-(2-amino-5,7-disubstituted-pyrazolo-[1,5-a]pyrimidine-3-yl)azo-4,6-dimethylthieno[2,3-b]pyridines 7a-7f were obtained in good yield by the cyclocondensation reaction of 2-cyano-3-(3,5-diamino-pyrazol-4-yl)azo-4,6-dimethylthieno[2,3-b]pyridine 5a with the appropriate 1,3-diketones 6a-6f under acidic condition.     

Synthesis of Azo-Sulfa Drugs Based on 2-Pyridinone and 2-Pyridinethione

Some new azo sulfa drugs 3-cyano-4,6-diphenyl-1-[4-(N-substituted)sulfamyl]phenylazo-2-pyridinone dyes (1-6) and 3-cyano-4,6-diphenyl-1-[4-(N-substituted)sulfamyl]phenylazo-2-pyridinethione dyes (1′-6′) were synthesized by coupling of 4-(N-substituted)sulfamylbenzene diazonium salts with 3-cyano-4,6-diphenyl-2-pyridinone and/or with 3-cyano-4,6-diphenyl-2-pyridin-ethione. The corresponding iron (1a-6a, 1′a-6′a), copper (1b-6b, 1′b-6′b) and mercury (1c-6c, 1′c-6′c) chelates wvere also prepared. All synthesized compounds were screened in vitro for antibacterial and antifungal activities.     

Design and synthesis of new series of 3-cyanopyridine and pyrazolopyridine derivatives

Reaction of 3-cyano-4,6-dimethyl-2-pyridone with ethyl chloroacetate afforded ethyl 2-([3-cyano-4,6-dimethylpyridin-2-yl]oxy)acetate 2 and ethyl 2-(3-cyano-4,6-dimethyl-2-oxopyridin-1[2H]-yl)acetate 3 , the reaction product yield depend on the reaction condition (potassium carbonate concentration and reaction time). These compounds used as precursors to synthesize pyridine derivatives 4 , 6-10 , 15, 17-20 , furopyridines 5, 16 , pyrazolopyridine 12 , pyridopyrazolopyrimidines 14a,b . The structure of the newly synthesized compounds was confirmed by spectral data (IR, NMR, and mass spectra) and elemental analysis.     

Stereoselective Synthesis and Alkylation of N-Methylmorpholinium 4,5-trans-4-(2-chlorophenyl)-3-cyano-6-hydroxy-5-(2-thenoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine-2-thiolate. Molecular and Crystal Structure of 4,5-trans-4-(2-chlorophenyl)-3-cyano-6-hydroxy-2-methallylthio-5-(2-thenoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine

The condensation of 2-chlorobenzaldehyde with cyanothioacetamide and 2-thenoyltrifluoroacetone in the presence of N-methylmorpholine takes place stereoselectively and leads to the formation of N-methylmorpholinium 4,5-trans-4-(2-chlorophenyl)-3-cyano-6-hydroxy-5-(2-thenoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine-2-thiolate. The latter was used to synthesize the corresponding 2-alkylthiotetrahydropyridines. The structure of 4,5-trans-4-(2-chlorophenyl)-3-cyano-6-hydroxy-2-methallylthio-5-(2-thenoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine was determined by X-ray crystallographic analysis.     

A new example of the three-component reaction: nucleophilic ring opening in cyclopropenones by cyanide ions in the presence of water or alcohols

3-Methyl-2,3-diphenyl-and 3-methyl-2-phenylcyclopropenones react with NaCN and water or alcohols as nucleophiles in the presence of NaHSO₄ to give novel compounds, namely, 3-cyano-2,3-diphenylpropionic acid or alkyl 3-cyano-2,3-diphenyl-and alkyl 3-cyano-2-methyl-3-phenylpropionates. A reaction mechanism was proposed. The anti-(R*R*)-diastereomer was found to be the major reaction product. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2066–2069, September, 2005.     

Studies on the synthesis of some styryl-3-cyano-2(1H)-pyridinethiones and polyfunctionally substituted 3-aminothieno[2,3-b]-pyridine derivatives

The 3-cyano-4,6-dimethyl-2(1H)-pyridinethione was condensed with benzaldehyde in basic solution leads to styryl-3-cyano-2(1H)-pyridinethiones. Treatment of cinnamicaldehyde with cyanothioacetamide to give cinnamylidencyanothioacetamide, which can be cyclized with the appropriate ketones to afford the 3-cyano-5,6-polymethylene-4-styryl-2(1H)-pyridinethione derivatives. The polyfunctionally substituted 3-aminothieno[2,3-b]pyridine derivatives were obtained in good yield by cyclization of 3-cyano-2(1H)-pyridinethione derivatives with appropriate α-halogeno carbonyl compounds and nitrile, respectively.     

Synthesis of 6-amino-4-aryl-5-cyano-3-(3-cyanopyridin-2-ylthiomethyl)-2,4-dihydropyrano[2,3-c]pyrazoles and their hydrogenated analogs. Molecular structure of 6-amino-5-cyano-3-(3-cyano-4,6-dimethylpyridin-2-ylthiomethyl)-4-(2-nitrophenyl)-2,4-dihydropyrano[2,3-c]pyrazole

Substituted 3-hydroxypyrazoles, which were prepared based on ethyl esters of substituted 4-(pyridin-2-ylthio)- or 4-(1,4-dihydropyridin-2-ylthio)acetoacetic acids and hydrazine hydrate, were used in the synthesis of 6-amino-4-aryl-5-cyano-3-(pyridin-2-ylthiomethyl)-2,4-dihydropyrano[2,3-c]pyrazoles. The molecular and crystal structure of 6-amino-5-cyano-3-(3-cyano-4,6-dimethylpyridin-2-ylthiomethyl)-4-(2-nitrophenyl)-2,4-dihydropyrano[2,3-c]pyrazole was established by X-ray diffraction analysis.     

Synthesis of fluorine-containing alkyl 2-cyano-3-oxocarboxylates. Reactions with nucleophiles

Fluorine-containing alkyl 2-cyano-3-oxocarboxylates were synthesized for the first time by the reaction of ethyl cyanoacetate with fluorine-substituted carboxylic acid halides or alkyl carboxylates. The reactions with hydrazine hydrate, phenylhydrazine, ando-phenylenediamine give hydrazinium (ammonium) enolates or products of acid decomposition. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1961–1965, October, 1999.     

Synthesis and herbicidal activity of (Z)-ethoxyethyl 2-cyano-3-(2-methylthio-5-pyridylmethylamino)acrylates

2-Methylthio-5-pyridinemethylene amine was prepared from 2-chloro-5-methylpyridine. Ethoxyethyl 2-cyano-3,3-dimethylthioacrylate was prepared from ethoxyethyl cyanoacetate, carbon disulfide, and dimethyl sulfate in 86.2% yield. Its reaction with 2-methylthio-5-pyridinemethylene amine yielded (Z)-ethoxyethyl 2-cyano-3-methylthio-3-(2-methylthio-5-pyridylmethylamino)acrylate. Ethoxyethyl (Z+E)-2-cyano-3-ethoxyacrylate was synthesized from ethoxyethyl 2-cyanoacetate and triethyl or- thoacetate in 90.7% yield, and its reaction with 2- methylthio-5-pyridinemethylene amine yielded (Z)-ethoxyethyl 2-cyano-3-methyl-3-(2-methylthio-5-pyri-dylmethylamino)acrylate. The structures of all of the products were confirmed by ¹H NMR, elemental analysis, IR, and mass spectroscopy. The herbicidal activities of the products were evaluated, and the results of bioassay showed that (Z)-ethoxyethyl 2-cyano-3-methyl-3-(2-methylthio-5-pyridylmethylamino)acrylate exhibits good herbicidal activity on rape (Brassica napus) at a dose of 1.5 kg/ha. © 2003 Wiley Periodicals, Inc. 15:67–70, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.hc10214     

Reaction of N-(4-pyridylmethyl)benzamide N-oxides with ethyl cyanoacetate in the presence of acetic anhydride

Reaction of N-(4-pyridylmethyl)benzamide N-oxides 2a-f with ethyl cyanoacetate in the presence of acetic anhydride yield dimerization compounds 3a-f and (E)-ethyl 2-cyano-3-(4-pyridyl)-3(benzoylamino)acrylates 4a-f , which react with hydrazine to give 4-cyano-3-(4-pyridyl)-3-pyrazolin-5-one 9 and the corresponding benzamides 10a-f .     

One-step synthesis of 5-acetyl-2-amino-4-aryl-3-cyano-4H-pyrano[3,2-b]indoles. Molecular and crystal structure of 5-acetyl-2-amino-4-(4"-chloro-3"-nitrophenyl)-3-cyano-4H-pyrano[3,2-b]indole

A one-step procedure was developed for the synthesis of 5-acetyl-2-amino-4-aryl-3-cyano-4H-pyrano[3,2-b]indoles involving the three-component reaction of 1-acetylindol-3(2H)-one with aromatic aldehydes and malononitrile in ethanol in the presence of triethylamine as the catalyst. The structure of 5-acetyl-2-amino-4-(4"-chloro-3"-nitrophenyl)-3-cyano-4H-pyrano[3,2-b]indole was established by X-ray diffraction analysis.     

2-氰基-3-N-烷氨基-3-(N-2-氟苯乙氨基)丙烯酸乙酯类化合物的合成及生物活性研究

把由氰基乙酸乙酯、二硫化碳、硫酸二甲酯在乙醇钠作用下反应得到的2-氰基.3,3-二甲硫基丙烯酸乙酯中间体用邻氟苯乙胺胺化,再和甲胺等烷胺进行胺化反应,合成了含氟2-氰基丙烯酸乙酯类化合物.结构经元素分析、IR、1H NMR、13C NMR等证实,抗烟草花叶病毒(TMV)生物活性的初步测定表明,所合成的化合物有一定抗TMV活性.     

Preparative synthesis of 3-cyano-4-difluoromethyl- and 3-cyano-4-trifluoromethyl-2(1H)-pyridones

An efficient procedure for the synthesis of 3-cyano-4-difluoromethyl- and 3-cyano-4-trifluoromethyl-2(1H)-pyridones was developed. The structure of one of the resulting compounds was established by X-ray diffraction analysis.