Patent ID: 7772418

Claim:
A method for producing 3, 4′ diacetoxybenzophenone comprising in order: (a) combining m-hydroxybenzoic acid, phenol, a protonic acid and a Lewis acid to form a mixture, (b) heating an agitated mixture of step (a) to a temperature in a range of 27-33° C. and a pressure of at least 5 psig to form a reaction product of 3,4′ dihydroxybenzophenone present as solids in a solution, (c) removing at least a portion of the protonic acid and Lewis acid from the formed reaction product of 3,4′ dihydroxybenzophenone, (d) contacting the reaction product of step (c) with (i) water at a temperature not greater than 10° C. and (ii) ammonium hydroxide to obtain a pH in a range of 4.5 to 6; (e) filtering a mixture of step (d) to separate 3,4′ dihydroxybenzophenone solids (f) reacting 3,4′ dihydroxybenzophenone with an acetylating agent in the presence of an inorganic acid and activated carbon to form 3,4′ diacetoxybenzophenone.