β‐Enamino diketones were cyclocondensed with 2‐aminobenzimidazole to selectively furnish 1,2‐ or 1,4‐regioisomers of benzo[4,5]imidazo[1,2‐a]pyrimidines. The selectivity of the reaction was found to be mainly due to the nature of the group (trifluoromethyl or carboxyethyl) attached to the ketone moiety.
将β-烯
氨基二酮与
2-氨基苯并咪唑进行环缩合反应,以选择性提供苯并[4,5]
咪唑并[1,2- a ]
嘧啶的1,2-或1,4-区域异构体。发现反应的选择性主要是由于与酮部分相连的基团(三
氟甲基或羧乙基)的性质。