Reactions of tetracyanoethylene with N′-arylbenzamidines: A route to 2-phenyl-3 H -imidazo[4,5- b ]quinoline-9-carbonitriles
AuthorMirallai, Styliana I.
Koutentis, Panayiotis Andreas
SourceJournal of Organic Chemistry
Google Scholar check
MetadataShow full item record
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. © 2013 American Chemical Society.
Showing items related by title, author, creator and subject.
Synthesis of fused 1,2,4-dithiazines and 1,2,3,5-trithiazepines Koyioni, Maria G.; Manoli, Maria; Koutentis, Panayiotis Andreas (2014)Reacting ( Z)-N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)-1H-pyrazol-5-amines 5 with Et2NH and then with concd H2SO4 gives 5H-pyrazolo[3,4-e ][1,2,4]dithiazine-3-carbonitriles 7 in good yields (74-85%) and 6H-pyrazolo-[3,4 ...
Photochemistry of an azido-functionalized cryptand: Controlling the reactivity of an extremely long-lived singlet aryl nitrene by complexation to alkali cations Bucher, G.; Tönshoff, C.; Nicolaïdes, Andrew N. (2005)Photolysis of the cryptand 1, bearing an intraannular azido substituent, results in a complex photochemistry. Low-temperature photolysis yields the triplet nitrene 32, which has been characterized by EPR spectroscopy. Small ...
The preparation of dicyano-1,3,4-thiadiazole and tricyanothiazole via 1,2,3-dithiazole chemistry Christoforou, Irene C.; Kalogirou, Andreas S.; Koutentis, Panayiotis Andreas (2009)Treatment of 1,2-bis(4-chloro-5H-1,2,3-dithiazol-5-ylidene)hydrazine 4 with benzyltriethylammonium iodide (1 equiv) affords dicyano-1,3,4-thiadiazole 3 and 5-cyano-1,3,4-thiadiazole-2-carboxamide 5 in 79 and 21% yields, ...