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Polyfunctional 4-(3-cyanopyridin-2-ylthio)acetoacetates were used in the synthesis of 4-hydroxy-1H-thieno[2,3-b:4,5-b]dipyridin-2-ones. The latter were used in reactions with arylidene-malononitriles or in three-component reactions with aldehydes and malononitrile to give 2-amino-4-aryl-3-cyano-5-oxo-5,6-dihydro-4H-pyrano[2,3-d]pyrido[3',2':4,5]thieno[3,2-b]pyridines. Utilizing 4-(3-cyanopyridin-2-ylthio)acetoacetates and arylidenemalononitriles or aldehydes and malononitrile, we developed a method for the synthesis of substituted 3-alkoxycarbonyl-6-amino-4-aryl-2-(3-cyanopyridin-2-ylthiomethyl)-4H-pyrans. Reactions of substituted 4-(3-cyanopyridin-2-ylthio)acetoacetates with hydrazine hydrate yielded substituted 3-hydroxypyrazoles, which were further used for the preparation of 6-amino-4-aryl-5-cyano-3-(pyrid-2-ylthiomethylene)-2,4-dihydropyrano[2,3-c]pyrazoles. Analogously, ethyl 4-(3-cyano-1,4-dihydropyridin-2-ylthio)acetoacetates were used for the synthesis of substituted 2-amino-4H-pyrans.

[Reaction: see text]. Readily available N-acylbenzotriazoles 2a-l (derived from a variety of aliphatic, (hetero)aromatic, and N-protected alpha-amino carboxylic acids) smoothly convert primary 3a-c and alpha-functionalized primary nitroalkanes 3d into the corresponding alpha-nitro ketones 5a-p in yields of 39-86% (average 63%).

The allyllithium generated from 1-[(2EZ)-3-chloroprop-2-enyl]-1H-1,2,3-benzotriazole (5) and LDA, in the presence of HMPA, reacts with enolizable and nonenolizable carbonyls solely at the CCl terminus to give 1-(2-oxiranylvinyl)benzotriazoles 6a−g in 61−82% yields. Allyllithiums generated from 6a,c reacted exclusively at the CBt terminus to give 10a−d in 68−88% yields. Acidic hydrolysis of (oxiranylvinyl)benzotriazoles 6a−g and 10a−d provided 4-hydroxyalk-2-en-1-one derivatives 12a,b,c,e,g, 13a−d, and furan 14 in 54−86% yields.

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.

Substituted 2-amino-4-aryl-3-cyano-5-oxo-5,6-dihydro-4H-pyrano[2,3-d]pyrido[3",2":4,5]thieno[3,2-b]pyridines were synthesized by the reactions of 4-hydroxy-1H-thieno[2,3-b;4,5-b]dipyridin-2-ones with arylidenemalononitriles or by the three-component reactions of hydroxythienodipyridinones with aldehydes and malononitrile in DMF in the presence of triethylamine. Methods for syntheses of substituted 3-alkoxycarbonyl-6-amino-4-aryl-2-(3-cyanopyridin-2-ylthiomethyl)-4H-pyrans were developed on the basis of the reactions of 4-(3-cyanopyridin-2-ylthio)acetoacetates and arylidenemalononitriles or aldehydes and malononitrile. Ethyl 4-(3-cyanopyridin-2-ylthio)acetoacetate and 4-methoxybenzylidenecyanothioacetamide were used for the synthesis of 6-(pyridin-2-ylthiomethyl)-3-cyanopyridine-2(1H)-thione.