Rapid construction of acridines via BF3•Et2O promoted cyclization of 2-phenylamino benzophenones

A concise and practical strategy for the rapid construction of acridines from 2-phenylamino benzophenone promoted by BF3•Et2O has been developed. The reaction goes through the intramolecular Friedel–Crafts acylation and dehydration with a facile work-up procedure. It shows good functional group tolerance and the yields of acridines are mostly in range of 90–99 %. The efficiency of this reaction is tremendously high, which can be completed within 30 min. Gram-scale synthesis and synthetic application experiment illustrate the practical utility of the method as a synthetic tool. Photoluminescence spectra indicate these acridines are promising candidates for OLEDs and make this new methodology great potentials in materials.