An efficient method is developed for the synthesis of functionalizedbenzimidazoles and perimidines by the condensation of aryl diamines with β‐carbonyl compounds catalyzed by ytterbiumchloride. The reactions give good yields under mild conditions. A mechanism involving a lanthanide activated CCbondcleavage is proposed.
Benzimidazol-Derivate und verwandte Heterocyclen V. Die Kondensation von o-Phenylendiamin mit aliphatischen und alicyclischen ?-Ketoestern
作者:A. Rossi、A. Hunger、J. Kebrle、K. Hoffmann
DOI:10.1002/hlca.19600430515
日期:——
The products of the condensation of o-phenylenediamine with ethyl acetoacetate were re-investigated. Depending on the reaction conditions, 2-methylbenzimidazole (II), 2-isopropenyl-benzimidazole-2-one (VI) and 4,7-dihydro-5-methyl-1H-2,3-benzo-1,4-diazepin-7-one (IV) were obtained. 2-Acetonylbenzimidazole, which had erroneously been described in the literature, could not be isolated from the above