Symmetrical trichlorotriazine derivatives such as 2,4,6-trichloro-1,3,5-triazine and trichloroisocyanuric acid were explored as Vilsmeier–Haack type reagents in the presence of N,N-dimethylacetamide for the effective synthesis of 3-acetyl-2-chloroquinolines from acetanilides. Ultrasonication led to shorter reaction times than conventional heating and gave yields comparable to those obtained under reflux conditions.