5'-Chloro-2'-hydroxypropiophenone

Preparation by Fries rearrangement of 4-chlorophenyl propionate without solvent,
with titanium tetrachloride at 50° for 3 h (59%)
Preparation by acylation of p-chlorophenol with propionic acid in the presence of boron trifluoride in a sealed tube at 150° for 5 h (82%).