A convenient and efficient synthesis of 1-aryl-2,2-dichloroethanones

1-Arylethanones are readily chlorinated with an aqueous HCl-H2O2 system using ethanol as a cosolvent. The reaction proceeds rapidly and results in selective conversion of 1-arylethanones into 1-aryl-2,2-dichloroethanones in yields of 48-89%, depending on the nature of the substituent in the aryl group.