I. N. Bardasov

Heterocyclization of michael adducts of β-diketones with arylmethylidene derivatives of malononitrile dimers

Reaction of arylmethylidene derivatives of malononitrile dimer with 1,3-cyclohexanediones in anhydrous methanol in the presence of sodium methylate as catalyst affords 4-amino-5-aryl-2-methoxy-6-oxo-5,6,7,8,9,10-hexahydrobenzo[b][1,8]naphthyridine-3-carbonitrile. In the presence of strong electron-donor substituents in the benzene ring the reaction takes another route resulting in 4-amino-2-aryl-6-methoxypyridine-3,5-dicarbonitriles.

Comparative in vivo evaluation of polyalkoxy substituted 4H-chromenes and oxa-podophyllotoxins as microtubule destabilizing agents in the phenotypic sea urchin embryo assay.

A series of polyalkoxy substituted 7-hydroxy- and 7-methoxy-4-aryl-4H-chromenes were evaluated using the sea urchin embryo model to yield several compounds exhibiting potent antimitotic microtubule destabilizing activity. Data obtained by the assay were further confirmed in the NCI60 human cancer cell screen. The replacement of methylenedioxy ring A and lactone ring D in podophyllotoxin analogues by 7-methoxy, 2-NH2, and 3-CN groups in 4-aryl-4H-chromenes resulted in potent antimitotic microtubule destabilizing agents. Feasible synthesis and high yields render 7-methoxy-4H-chromenes to be a promising series for further anticancer drug development.

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.

Synthesis of 2,2,3,3-tetracyanocyclopropyl ketones and their reactions with oxygen-centered nucleophiles

A procedure for the synthesis of 2,2,3,3-tetracyanocyclopropyl ketones has been developed on the basis of three-component Wideqvist reaction of dihydroxymethyl ketones, 2-bromomalononitrile, and malononitrile. The presence of five electron-withdrawing groups in the resulting cyclopropyl ketones determines high acidity of proton in the cyclopropane ring. Facile deprotonation by the action of bases promotes opening of the three-membered ring with formation of either 1,1,3,3-tetracyanopropenides or (in the presence of alcohols or oximes), [2-alkoxy(aminooxy)-5-amino-4-cyanofuran-3(2H)-ylidene]malononitriles. The reaction with acetone oxime was not accompanied by cleavage of the three-membered ring, and nucleophilic attack was directed at the cyano groups in the trans position with respect to the carbonyl group to give the corresponding (1R*,5S*,6R*)-4-amino-2,2-bis(prop-2-ylideneaminooxy)-3-azabicyclo[3.1.0]hex-3-ene-1,5-dicarbonitriles.

Reaction of 4-aryl-2-aminobuta-1,3-diene-1,1,3-tricarbonitriles with CH-nucleophiles. I. Synthesis of 5-aryl-2,4-diamino-8,8-dimethyl-6-oxo-6,7,8,9-tetrahydro-5H-chromeno-[2,3-b]pyridine -3-carbonitriles

Abstract5-Aryl-2,4-diamino-8,8-dimethyl-6-oxo-6,7,8,9-tetrahydro-5H-chromeno[2,3-b]pyridine-3-carbonitriles were synthesized from 4-aryl-2-aminobuta-1,3-diene-1,1,3-tricarbonitriles and dimedone.

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.

One-step transformation of tetracyanocyclopropyl ketones into pyrrolo[3,4-c]pyridine derivatives

Tetracyanocyclopropyl ketones obtainable via modified Wideqvist reaction are accessible and convenient precursors of a number of heterocyclic systems [1–3]. Reactions of cyclopropyl ketones Ia–Ic with alkoxides give rise to 2-[2-alkoxy-5-amino-4-cyano-2-phenylfuran-3(2H)-ylidene]malononitriles [3]. We anticipated that replacement of the ketone acetal fragment in the latter by more labile semiacetal moiety should facilitate recyclization of the furan ring into pyrrole. Such transformation could be promoted using hydroxide ion instead of alkoxide in reactions with cyclopropyl ketones Ia–Ic. The above assumption was verified by studying the reaction of cyclopropyl ketones Ia–Ic with aqueous sodium hydroxide. We found that this reaction involves not only expected recyclization of furan ring into pyrrole but also annelation of pyridine ring. The structure of compounds IIa–IIc isolated by neutralization of the reaction mixture with a solution of sulfuric acid was confirmed by the H NMR and mass spectra. The H NMR spectra contained singlets at δ 7.12– 7.69 and 8.78–9.02 ppm, which were assigned to the hydroxy and NH protons, respectively, in the pyrrole ring. The NH proton in the pyridine ring resonated as

One-step synthesis of chromeno[2,3-b]pyridines

Three-component condensation of aliphatic aldehydes with resorcinol and malononitrile dimer (2-aminoprop-1-ene-1,1,3-tricarbonitrile) afforded the corresponding 5-alkyl-2,4-diamino-8-hydroxy-5H-chromeno[2,3-b]pyridine-3-dicarbonitriles.

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.