alpha-Chlorination of acetophenones using 1,3-dichloro-5,5-dimethylhydantoin

A novel method for the synthesis of a-chloroacetophenones using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) and p -toluenesulfonic acid in methanol at 30-35 degrees C is described. Substituted acetophenones at the para position or meta position of aromatic ring give a-chloroacetophenones in high yield. However, reaction of o -nitroacetophenone does not take place under the same condition.