The Mechanochemical Beckmann Rearrangement: An Eco-efficient “Cut-and-Paste” Strategy to Design the “Good Old Amide Bond”

Discovered over a century ago, Beckmann rearrangement is still today fully compliant with all the green chemistry principles and consistent key aspects of sustainable development. Herein, we report on mechanochemical procedure allowing design new amide frameworks via an eco-efficient “cut-and-paste” process C–C C–N bonds oxime backbone. We combined inexpensive readily available reagents, such as p-tosyl imidazole (p-Ts-Im) oxalic acid, to prepare smoothly in good high yields library structurally different amides, including value-added marketed compounds ε-caprolactam active pharmaceutical ingredient (API) paracetamol. This solvent-free has also been optimized successfully extended several ketones serving precursors.