Regioselective synthesis of 5,6-polymethylene-3-cyanopyridine-2(1H)-thiones and fused heterocycles based on them

Condensation of 2-hydroxymethylenecyclopentan-1-one or -cyclooctan-1-one sodium salts with cyanothioacetamide afforded 5,6-polymethylene-3-cyanopyridine-2(1H)-thiones which were regioselectively alkylated at the sulfur atom by alkyl halides. Derivatives of 3-cyanopyridine-2(1H)-thione and 2-alkylthio-3-cyanopyridine were used for regioselective synthesis of substituted heterocycles: 3-aminothieno[2,3-b]pyridines, pyrido[2,3∶2′,3′]thieno[4,5-d]pyrimidines, and pyrido[2,3∶2′,3′]thieno[4,5-d]oxazines.     

Acetoacetanilides in synthesis of 4-aryl-5-arylcarbamoyl-6-methyl-3-cyanopyridine-2(1H)-thiones

The reaction of acetoacetanilides with arylmethylenecyanothioacetamides leads to 4-aryl-5-arylcarbamoyl-6-methyl-3-cyanopyridine-2(1H)-thiones, based on which we have obtained substituted 2-alkylthiopyridines and thieno[2,3-b]pyridines.     

Reaction of 3-cyanopyridine-2(1H)-thiones with N-butyllithium

The reaction of 3-cyanopyridine-2(1 H)-thiones with BuLi in ether was studied. It was found that the metallation proceeds initially at the sulfur atom. The resulting lithium salts add a second equivalent of n-butyllithium at the CN group. The hydrolysis of the dilithium derivatives leads to 3 pentanoylpyridine-2(IH)-thiones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 231–234, February, 1996.     

Facile Synthesis of 6-Aryl-3-cyanopyridine-2-(1H)-thiones from Aryl Ketones

An improved synthesis of 6-aryl-3-cyanopyridine-2-(1H)-thiones utilizing enaminones as starting materials catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) was described. Moreover, a convenient one-pot conversion of aryl ketones to 6-aryl-3-cyanopyridine-2-(1H)-thiones was also developed in moderate to good yields (up to 80%).     

One-pot B(C6F5)3 catalyzed cascade synthesis of 2-substituted-2,3-dihydroquinazolin-4(1H)-ones

Abstract

A new and efficient B(C₆F₅)₃ catalyzed domino strategy has been developed for the synthesis of 2-substituted quinazolinones. The reaction utilizes 2-aminobenzamide and aldehydes for a one-pot protocol. A wide range of substrate scope, functional group tolerance, and operational simplicity with excellent yield are synthetically useful features.     

Synthesis of annulated heterocyclic systems based on 4-CF3- or 4-CHF2-3-cyano-(1H)-pyridine-2-thiones

A simple and convenient preparative method for the synthesis of 3-cyano-4-difluoro- and -trifluoromethylpyridine-2(1H)-thiones was developed. During studies of synthetic potential of these compounds, approaches to the synthesis of a number of annulated heterocyclic systems were suggested.     

One-pot synthesis of 3-(2-cyanophenyl)quinazolin-4(3H)-one

Anthranilonitrile reacting with formic acid at room temperature for three days gave 64% of 3-(2-cyanophenyl)quinazolin-4(3H)-one. Under similar conditions anthranilic acid. 4-nitroaniline, and 2,5-dichloroaniline were N-formylated in good yields.Institute of Organic Chemistry and Technology, Silesian Technical University, Krzywoustego, 4, 44–100 Gliwice, Poland; e-mail: wojtex@zeus.polsl.gliwice.pl. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 922–924, July, 2000.     

Synthesis of 4-alkyl-3-cyano-5,6,7,8-tetrahydroquinoline-2(1H)-thiones and their derivatives

4-Alkyl-3-cyano-5,6,7,8-tetrahydroquinoline-2(1H)-thiones, used in synthesis of substituted 2-alkylthioquinolines and thieno[2,3-b]pyridines, were obtained by condensation of cyanothioacetamide, aliphatic aldehydes, and morpholinocyclohexene.T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011 Ukraine. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913 Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 81–85, January, 1998.     

One-pot synthesis of 4,6-diaryl-3-cyanopyridine-2(1H)-thiones and their transformation to substituted thieno[2,3-b;4,5-b]dipyridines and pyrido[3",2":4,5]thieno[3,2-d]pyrimidines

4,6-Diaryl-3-cyanopyridine-2(1H)-thiones were synthesized in one step by the reaction of elemental sulfur, malononitrile, and 2-aryl-1-aroylethylenes in the presence of excess triethylamine. The products were used in one-pot syntheses of substituted thieno[2,3-b;4,5-b]dipyridines and pyrido[3",2":4,5]thieno[3,2-d]pyrimidines.     

Alkyl derivatives of 1-aryldihydro-4(IH,3H)-pyrimidinone-2-thiones and their structure

The alkylation of 1-aryldihydro-4(IH,3H)-pyrimidinone-2-thiones goes through both at the thiol group and at the amide nitrogen atom of the heterocycle. Enlargement of the alkyl radical favors an increase in the portion of the N-alkyl derivative in the mixture. The influence of the folding of the heterocycle on its barrier to rotation around the Ph-N₁ bond was shown.Kaunas Technological University, Kaunas LT-3006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1260, September, 1996. Original article submitted March 11, 1996.     

Regioselective synthesis and properties of 3-cyano-6-thienylpyridine-2(1H)-thiones

Reactions of sodium derivatives of 2- and 3-thenoylacetaldehydes with cyanothioacetamide gave 2- and 3-cyano-6-thienylpyridine-2(1H)-thiones, which were used in the synthesis of substituted 2-alkylthiopyridines, thieno[2,3-b]pyridines, and other fused heterocycles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 365–368, February, 1998.     

Aliphatic aldehydes in synthesis of 4-alkyl-5-carbamoyl-3-cyano-6-methylpyridine-2(1H)-thiones

Condensation of isovaleric or acetic aldehydes with cyanothioacetamide and acetoacetamide leads to formation of 4-isobutyl(methyl)-5-carbamoyl-3-cyano-6-methylpyridine-2(1H)-thiones. By alkylation of 5-carbamoyl-3-cyano-4,6-dimethylpyridine-2(1H)-thione with 4-methoxyphenacyl bromide, 5-carbamoyl-3-cyano-4,6-dimethyl-2-(4-methoxybenzoyl)methylthiopyridine has been obtained.Lugansk T. G. Shevchenko State Pedagogical Institute, Lugansk 348011, Ukraine. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 228–229, February, 1999.     

Synthesis and properties of 3-cyanopyridine-2(1H)-chalcogenones. Review

Data published over the last 10 years on the synthesis, reactivity, and biological activity of 3-cyanopyridine-2(1H)-chalcogenones are reviewed. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 579–609, May, 1999.     

A simple synthesis of 5-substituted-thiophene-2 (3H)-thiones

Treatment of 1-alkyne and allene derivatives successively with two equivalents of n-Buli, one equivalent of CS₂ and then an electrophile yielded novel 5-substituted-thiophene-2 (3H)-thiones $\text{4}$.     

Combinatorial synthesis of heterocycles: solid-phase synthesis of 2-amino-4(1H)-quinazolinone derivatives

A new solid-phase synthesis of various substituted 2-amino-4(1H)-quinazolinones from a resin bound amine component is described. The amine was readily converted to the corresponding polymer bound S-methylthiopseudourea. Condensation with different substituted isatoic anhydrides afforded 2-amino-4(1H)-quinazolinone derivatives. The method is amenable for combinatorial library generation.     

3-Cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines in the synthesis of substituted 3-(aminomethyl)pyridines

The reactions of substituted 3-cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines with lithium aluminum hydride in anhydrous diethyl ether afforded the corresponding 3-aminomethyl derivatives, which were used in the synthesis of the corresponding amides.     

One-pot method for synthesis of 2-substituted 1,1-di(methoxy-NNO-azoxy)ethanes

One-pot method was developed for synthesis of 2-substituted 1,1-di(methoxy-NNO-azoxy)ethanes from 2,2-di(methoxy-NNO-azoxy)ethanol in three chemical stages.