ChemInform Abstract: Reaction of Dicyanomethylenes with Aromatic Nitroso Compounds.

Bespalov, B. P.; Abolin, A. G.; Bel'skii, V. K.; Zavodnik, V. E.; Соболев, А. Н.; Chetkina, L. A.

doi:10.1002/chin.199146104

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While there are many examples of the preparation of quinolines via electrocyclic ring closures followed by elimination of a leaving group to regain aromaticity, − there are very few examples that afford quinolines fused to five- , and six-membered rings, , and only one example involving an ylidenemalononitrile; cyclization of 2,2′-(2-{[4-(dialkylamino)phenyl]-imino}-1 H -indene-1,3(2 H )-diylidene)dimalononitriles 24 affords 2-[2-(dialkylamino)-11-cyano-6 H -indeno[2,1- b ]quinolin-6-ylidene)malononitriles 25 in low yields (Scheme ) …”

Section: Results and Discussionmentioning

confidence: 99%

Reactions of Tetracyanoethylene withN′-Arylbenzamidines: A Route to 2-Phenyl-3H-imidazo[4,5-b]quinoline-9-carbonitriles

2013

View full text Add to dashboard Cite

Eight 2-phenyl-3H-imidazo[4,5-b]quinoline-9-carbonitriles 15 are prepared in four steps from N'-arylbenzamidines 11 and tetracyanoethylene (TCNE) in ~70-90% yields. The transformation involves the initial formation of N-aryl-N'-(1,2,2-tricyanovinyl)benzamidines 12 in 87-99% yields, which in MeCN undergo a 5-exodig cyclization to give the 2-[1-aryl-5-imino-2-phenyl-1H-imidazol-4(5H)-ylidene]malononitriles 13 in 84-92% yields, while in MeOH the (Z)-2-[2-phenyl-4-(arylimino)-1H-imidazol-5(4H)-ylidene]malononitriles 14 are formed in 85-94% yields. The imidazoles 14 can also be prepared directly from imidazoles 13 via a Dimroth rearrangement in either neat MeOH or in DCM with DBU. Subsequent thermolysis of imidazoles 14 in diphenyl ether affords 2-phenyl-3H-imidazo[4,5-b]quinoline-9-carbonitriles 15 in near quantitative yields. Mechanistic rationale is provided for all transformations.

show abstract