S. V. Karpov

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: II. Synthesis of 2-[2-(alkylsulfanyl)-5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidenepropanedinitriles by reaction with thiols

Reactions of 2-aroyl-1,1,3,3-tetracyanopropenides with thiols in acid medium led to the formation of the corresponding 2-alkylsulfanyl-substituted 2-(5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidene)propanedinitriles.

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: I. Synthesis of 2-[5-amino-2-aryl-2-chloro-4-cyanofuran-3(2H)-ylidene]-propanedinitriles by reaction of potassium 2-aroyl-1,1,3,3-tetracyanopropenides with concentrated hydrochloric acid

Potassium 2-aroyl-1,1,3,3-tetracyanopropenides reacted with concentrated hydrochloric acid to give the corresponding 2-[5-amino-2-aryl-2-chloro-4-cyanofuran-3(2H)-ylidene]propanedinitriles.

Reaction of 2,2,3,3-tetracyanocyclopropyl ketones with sodium and potassium hydroxides

Reaction of 2,2,3,3-tetracyanocyclopropyl ketones with water solution of sodium hydroxide after neutralization with sulfuric acid leads to the formation of 4-amino-1-hydroxy-3,6-dioxo-2,3,5,6-tetrahydro-1Hpyrrolo[3,4-c]pyridine-7-carbonitriles. Pivaloyltetracyanocyclopropane reacts in another way and is converted into sodium 6a-tert-butyl-3,4-dicyano-5-oxo-1,5,6,6a-tetrahydropyrrolo[2,3-b]pyrrol-2-olate. 1-Benzoyl-1-methylcyclopropane-2,2,3,3-tetracarbonitrile reacts with the sodium hydroxide with the retention of the threemembered ring and the formation of 11-methyl-4-phenyl-3,5,9-triazatetracyclo[5.3.1.01,7.04,11]undecane-2,6,8,10-tetraone.

Synthesis and X-ray Characterization of Alkali Metal 2-Acyl-1,1,3,3-tetracyanopropenides.

A novel route for synthesis of 2-acyl-1,1,3,3-tetracyanopropenides (ATCN) salts in high yields and excellent purities starting from readily available methyl ketones, malononitrile, bromine, and alkali metal acetates is reported. The starting aryl(heteroaryl) methyl ketones were oxidized to the corresponding α-ketoaldehydes by new a DMSO-NaBr-H2SO4 oxidation system in yields up to 90% within a short reaction time of 8-10 min. The subsequent stages of ATCN preparation are realized in aqueous media without use of any toxic solvents, in accordance with principle 5 of green chemistry. Lithium, sodium, potassium, rubidium, and cesium 2-benzoyl-1,1,3,3-tetracyanopropenides were characterized by X-ray diffraction analysis. These salts show a good potential for synthesis of five- and six-membered heterocycles and may serve as potentially useful ligands in coordination and supramolecular chemistry.

A new route to highly substituted thieno[2,3- b ]pyridines via cascade heterocyclization of 2-acyl-1,1,3,3-tetracyanopropenide salts

n 2-Acyl-1,1,3,3-tetracyanopropenides undergo cascade heterocyclization under the action of mercaptoacetic esters, leading to the formation of new 3,6-diamino-4-aroyl-5-cyanothieno[2,3-b]pyridine-2-carboxylates. The fast and convenient synthetic way to highly substituted thieno[2,3-b]pyridine scaffold is described.

2-acyl(aroyl)-1,1,3,3-tetracyanopropenides: V. Reaction with hydrazine hydrate

Reactions of 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with hydrazine hydrate followed by neutralization led to the formation of 2-amino-4-[hydrazono(aryl)methyl]-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles.

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: IV. Synthesis of 1-alkyl(aryl)-4-amino-6-iodo-3-oxo-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitriles

The reaction of sodium 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with hydroiodic acid at heating led to the formation of 1-alkyl(aryl)-4-amino-6-iodo-3-oxo-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitriles.

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: III. Heterocyclization by the action of hydrogen halides

Abstract2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides reacted with hydrogen halides along two concurrent pathways with formation of furan or pyridine derivatives. The reaction in butan-2-ol afforded 2-amino-4-acyl-(aroyl)-6-halopyridine-3,5-dicarbonitriles, whereas the major products in the reactions with HCl and HBr in aqueous solution were the corresponding 2-(5-amino-2-aryl-2-chloro(bromo)-4-cyano-2,3-dihydrofuran-3-ylidene)malononitriles. The reaction with aqueous hydrogen iodide was accompanied by reductive deiodination and produced 2-(5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidene)malononitriles.

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: VI. Reaction with hydrogen halides

Reactions of 2-aroyl-1,1,3,3-tetracyanopropenides with hydrogen halides in solvents of low dielectric permittivity result in the formation of 6-amino-2-aroyl-2-halopyridine-3,5-dicarbonitriles. 2-Acyl-1,1,3,3-tetracyanopropenides under similar conditions afford 2-(2-alkylidene-5-amino-4-cyano-2,3-dihydrofuran-3-ylidene)propanedinitriles. In solvents of high dielectric permittivity the result of the reaction depends on the nature of the hydrogen halide and the acyl(aroyl) substituent: With HCl and HBr 2-aroyl-1,1,3,3-tetracyanopropenides form 2-(5-amino-2-aryl-2-halo-4-cyano-2,3-dihydrofuran-3-ylidene)-propanedinitriles, and 2-acyl-1,1,3,3-tetracyanopropenides give 2-(2-alkylidene-5-amino-4-cyano-2,3-dihydrofuran-3-ylidene)propanedinitriles; with HI depending on the reaction conditions and the structure of the acyl substituent 2-(5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidene)propanedinitriles, 2-(5-amino-4-cyano-2,3-dihydrofuran-3-ylidene) propane-dinitrile, 2-amino-4-(dimethoxybenzyl)-6-iodo-5-cyanonicotinamide, 4-amino-6-iodo-3-oxo-2,3-dihydro-1H-pyrrolo[3,4-c]pyridine-7-carbonitrile, or 4-amino-6-iodo-3-oxo-1-ethylidene-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitrile are obtained.

Reactions of tetracyanocyclopropyl ketones with ammonia and primary amines

Reactions of aliphatic 2,2,3,3-tetracyanocyclopropyl ketones with aqueous ammonia afforded 4-alkyl- 4-amino-2-oxo-3-azabicyclo[3.1.0]hexane-1,6,6-tricarbonitriles with conservation of the three-membered ring. Reactions of the same compounds with primary amines were accompanied by opening of the cyclopropane ring, and they led to the formation of 5-amino-6,6a-dimethyl-2-oxo-1,2,6,6a-tetrahydropyrrolo[2,3-b]-pyrrole-3,4-dicarbonitriles as a result of successive heterocyclizations.