A robust and straightforward protocol has been developed for the synthesis of a diverse array of dimethyl acetal protected benz­imidazole-2-carboxaldehydes by reacting various 2-amino aniline derivatives with methyl 4,4-dimethoxy-3-oxobutanoate using the task-specific­ imidazolium ionic liquid (HBIm·TFA) as a promoter for N-C/C-N annulation processes. The present protocol offers several advantages over existing protocols, such as single-step process, short reaction times, very mild reaction conditions, high yields, ease of purification, recovery and reusability of the catalyst, and scale-up of the reaction.

中文翻译：

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任务特定的离子液体介导的无溶剂协议，用于直接访问二甲基乙缩醛保护的苯并咪唑2-羧醛

通过使用任务特定的咪唑鎓离子使各种2-氨基苯胺衍生物与4,4-二甲氧基-3-氧代丁酸甲酯反应，已经开发出了一种鲁棒而简单的方案，用于合成各种由二甲基乙缩醛保护的苯并咪唑-2-甲醛的阵列。液体（HBIm·TFA）作为NC / CN环空工艺的促进剂。本方案相对于现有方案具有多个优点，例如单步法，短反应时间，非常温和的反应条件，高收率，催化剂的易于纯化，回收和可再利用性以及反应规模。