FeCl3-DMF complex has been tested on Friedel-Crafts reaction of 2(3H)-benzoxazolone and 2(3H)-benzothiazolone with acid chlorides and anhydrides as acylating agents. In these conditions, the 6-acyl-2(3H)-benzoxazolones and 6-acyl-2(3H)-benzothiazolones were obtained in yields ranging from 52 to 89%.