122947-94-8Relevant articles and documents
Synthesis of a new imidazo[4,5-b]pyridin-5-one via a vicarious nucleophilic substitution of hydrogen
Crozet, Maxime D.,Suspène, Clément,Kaafarani, Mustapha,Crozet, Michel P.,Vanelle, Patrice
, p. 1629 - 1635 (2007/10/03)
A new imidazo [4,5-b]pyridin-5-one was prepared in five steps from 4(5)-nitro-1H-imidazole via a vicarious nucleophilic substitution of hydrogen of 1-benzyl-4-nitro-1H-imidazole with the carbanion generated from chloroform and potassium tert-butoxide. Hydrolysis of 1-benzyl-5-dichloromethyl-4-nitro-1H- imidazole and Knoevenagel condensation between the resulting aldehyde and diethyl malonate catalyzed by titanium(IV) chloride gave the corresponding 4-nitroimidazole bearing at 4 position the diethyl methylenemalonate group. Reduction and cyclization afforded the required ethyl 1-benzyl-5-oxo-4,5- dihydro-1H-imidazo[4,5-b]pyridine-6-carboxylate.
Dihalomethylation of Nitroarenes via Vicarious Nucleophilic Substitution of Hydrogen with Trihalomethyl Carbanions
Makosza, M.,Owczarczyk, Z.
, p. 5094 - 5100 (2007/10/02)
Trichloro- and tribromomethyl carbanions generated by deprotonation of haloforms with potassium tert-butoxide in a THF-DMF mixture at ca. -70 deg C react with a variety of carbocyclic and heterocyclic nitroarenes according to the vicarious nucleophilic substitution scheme.The reaction provides an efficient and convenient way for the direct introduction of dihalomethyl substituents ortho and para to the nitro group, which in turn can be hydrolyzed to produce nitroaryl aldehydes.
