The simple and easily prepared Brønsted acidic ionic liquid (BAIL) could act as both the solvent and catalyst and could be easily recovered and reused at least six times without considerable loss in catalytic activity. Moreover, the direct amidation of carboxylic acids and amines in a stoichiometric proportion could be catalyzed efficiently by BAIL with a broad substrate scope, a multigram scale, and a significant sustainability improvement [scalable up to 100 mmol, (process mass intensity) PMI (reaction and purification) < 3]. Notably, the water formed during condensation did not inhibit the direct amidation. This protocol could be used to efficiently, greenly, and sustainably prepare amides and has broad applications in organic chemistry.

中文翻译：

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使用可重复使用的 Brønsted 酸性离子液体作为催化剂和溶剂，从羧酸和等量的胺中可持续合成酰胺

简单易制备的 Brønsted 酸性离子液体 (BAIL) 既可以作为溶剂又可以作为催化剂，并且可以很容易地回收和重复使用至少六次，而不会显着降低催化活性。此外，BAIL 可以有效地催化化学计量比例的羧酸和胺的直接酰胺化，具有广泛的底物范围、数克规模和显着的可持续性改进 [可扩展到 100 mmol，（过程质量强度）PMI（反应和纯化）<3]。值得注意的是，冷凝过程中形成的水​​并没有抑制直接酰胺化。该协议可用于高效、绿色和可持续地制备酰胺，在有机化学中具有广泛的应用。