4-Hydroxy-4'-nitrobenzophenone

Preparation

Obtained by Fries rearrangement of phenyl p-nitro-benzoate with aluminium chloride,
? without solvent at 140° for 30 min (52%), at 120° for 2 h (21%) or first at 130° for 1 h, then at 160° for 1 h (2%);
? in refluxing chlorobenzene for 5 h (24%).