One-step synthesis of ϵ-caprolactam via the liquid phase catalytic nitrosation of cyclohexane in the presence of concentrated sulfuric acid

Abstract

A simple and efficient approach for the synthesis of ϵ-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series of novel AlVPO composites were prepared by an impregnation method and the composites were then employed to catalyze the nitrosation reaction of cyclohexane and nitrosyl sulfuric acid. Compared to the reaction using fuming sulfuric acid, the selectivity for the desired product was significantly improved using this one-step catalytic process. This method affords a shortcut to prepare ϵ-caprolactam and its analogs from cyclohexane.

Key words： cyclohexane; ϵ-caprolactam; AlVPO composite catalysts; one-step synthesis; concentrated sulfuric acid

Acknowledgments

The authors are grateful for the financial support for this work by the National Natural Science Foundation of China (Grant Nos. 21006081 and 21276216), the Scientific Research Fund of Hunan Provincial Education Department (Nos. 11B122, 09K035 and 08B087), and the Natural Science Foundation of Hunan Province (No. 11JJ3024).

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