A mild and efficient way to prepare epsilon-caprolactam by using a novel salt related with ionic liquids

作者：Vilas Miguel; Tojo Emilia^*

来源：Tetrahedron Letters, 2010, 51(31): 4125-4128.

DOI：10.1016/j.tetlet.2010.05.145

• Ionic liquid
• Beckmann rearrangement
• Ketoximes
• epsilon-Caprolactam

The Beckmann rearrangement of several ketoximes has been performed by treatment with tosyl chloride, using ionic liquids as both solvent and catalyst, without the need of any other promoter. High levels of conversion and selectivity were observed in the majority of experiments. Work-up is very simple and the product can be isolated in high yields. When the method was applied to cyclohexanone oxime, the novel salt [TMG][TsO] instead of the ionic liquid was used. This procedure afforded a conversion of 100% to obtain pure epsilon-caprolactam in a 98% yield. [TMG][TsO] is easy to prepare, cheap, and not corrosive. It can be recovered and reused.

• 出版日期2010-8-4