A library of ionic liquids was prepared by varying the cations and anions. Bi-functional acidic ionic liquids were prepared by the direct combination of ionic liquids and ZnCl2. Ionic liquids were investigated in the Beckmann rearrangements. A simple, eco-friendly, and recyclable bi-functional acidic ionic liquid based protocol for Beckmann rearrangement is developed, which is based on the fine tuning of the Bronsted and the Lewis acidity of ionic liquids. (C) 2013 Elsevier B.V. All rights reserved.