4-Chloro-4’-hydroxybenzophenone (Fenofibrate EP Impurity A; Fenofibrate USP Related Compound A) the impurity of Fenofibric acid (42017-89-0), the active metabolite of fenofibrate which increases Apolipoprotein A-I–Mediated High-Density Lipoprotein Biogenesis by enhancing transcription of ATP-Binding cassette transporter A1 gene in a liver X receptor–dependent manner.
Preparation by Fries rearrangement of phenyl p-chloro-benzoate,
? in the presence of aluminium chloride, without solvent, at 160° for 5 min, between 120° and 160° (good yield) or at 130° for 1 h, then at 160° for 1 h (10%) or in refluxing chlorobenzene for 10 h (52%);
? in the presence of trifluoromethanesulfonic acid at 45–55° (94%).
