1-Arylimidazol-2(1H)-ones are shown to be readily lithiated, using 2 mol equiv. of n-butyllithium, on the benzene ring, ortho to the heterocycle. 1-Aryl-4,5-dihydroimidazol-2(1H)-ones also undergo metalation on the aromatic substitutuent ortho to the heterocycle, but less efficiently. 1-Aryl-3-methylimidazol-2(1H)-ones are lithiated on the heterocyclic ring and then on the benzene ring ortho to the heterocycle. No ortho-directing effect was found for 1-aryl-4,5-dihydro-3-methylimidazol-2(1H)-ones.Key words: ortho-lithation, ureas for directed ortho metalation, 1-arylimidazol-2-ones, 1-arylimidazolidin-2-ones.
1-芳基咪唑-2(1H)-酮可轻松进行锂化反应,使用2摩尔当量的正丁基锂,在苯环上,在杂环的邻位发生。1-芳基-4,5-二氢咪唑-2(1H)-酮也可在芳香族取代基上,在杂环的邻位发生金属化,但效率较低。1-芳基-3-甲基咪唑-2(1H)-酮在杂环上和然后在苯环上,在杂环的邻位发生锂化。1-芳基-4,5-二氢-3-甲基咪唑-2(1H)-酮中未发现邻位导向效应。关键词:邻位锂化,尿素用于定向邻位金属化,1-芳基咪唑-2-酮,1-芳基咪唑啉-2-酮。