Beckmann rearrangement of acetophenone oximes to the corresponding amides organo-catalyzed by trifluoroacetic acid for sustainable NSAIDs synthesis
作者:Giuseppe Quartarone、Elia Rancan、Lucio Ronchin、Andrea Vavasori
DOI:10.1016/j.apcata.2013.12.026
日期:2014.2
The Beckmann rearrangement of acetophenone oximes to the corresponding amides (4-hydroxyacetophenone oxime to N-acetyl-4-hydroxyacetanilide and acetophenone oxime to N-phenylacetamide) is investigated by using trifluoroacetic acid (TFA) as catalyst. The reaction occurs either in the presence or in the absence of a suitable solvent. High selectivity and practically quantitative yield to amide is achieved
以三氟乙酸(TFA)为催化剂,研究了苯乙酮肟对相应酰胺的贝克曼重排(4-羟基苯乙酮肟对N-乙酰基-4-羟基乙酰苯胺和苯乙酮肟对N-苯基乙酰胺)。该反应在存在或不存在合适溶剂的情况下发生。在TFA /底物> 3的两种情况下,均可获得高选择性和对酰胺的定量收率。TFA和溶剂(无论何时存在)均可通过蒸馏轻松重复使用,因为不会发生酰胺质子化。该反应通过多步反应路径进行,并且TFA的作用不仅与它的酸度有关,而且还主要与它形成反应性三氟乙酰化中间体的能力有关。特别地,高反应性三氟乙酰化酰胺实际上是有效的催化剂。