Synthesis of a New Imidazo[4,5-b]pyridin-5-one via a Vicarious Nucleophilic Substitution of Hydrogen
作者:Patrice Vanelle、Maxime D. Crozet、Mustapha Kaafarani、Michel P. Crozet、Clément Suspène
DOI:10.3987/com-04-10069
日期:——
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(1V) 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.
以 4(5)-nitro-1H-imidazole 为原料,通过 1-benzyl-4-nitro-1H-imidazole 的氢替代亲核取代,五步制备出一种新的咪唑并[4,5-b]pyridin-5-one与由氯仿和叔丁醇钾产生的碳负离子。1-苄基-5-二氯甲基-4-硝基-1H-咪唑的水解和所得醛与丙二酸二乙酯在氯化钛(1V) 催化下的Knoevenagel 缩合得到相应的4-硝基咪唑,该4-硝基咪唑在4 位具有亚甲基丙二酸二乙酯基团。还原和环化得到所需的 1-苄基-5-氧代-4,5-二氢-1H-咪唑并[4,5-b]吡啶-6-羧酸乙酯。