To produce the subject tetramethoxybenzophenone that is useful for synthesis of a therapeutic medicine for rheumatoid arthritis in a high yield and in an industrial scale by nitrating a specific starting compound followed by reduction of the product.
In the first step, a compound of formula I, for example, 3,3',4,4'- tetramethoxybenzophenone, is nitrated with nitrice acid in a medium containing acetic acid to 2-nitro-4,5,3',4'tetramethoxy-benzophenone. Then, in the second step, the nitrated product is reduced to 2-amino-4,5,3',4'tetramethoxy- benzophenone of formula III. In a preferred embodiment, the nitration is carried out in acetic acid as a solvent by using nitric acid of 65% concentration at a temp. of 0-40°C, and the reduction is performed by catalytic hydrogenation over a platinum catalyst carried by a support, particularly a platinum on activated carbon.
BRIEDEN WALTER DR
HEINZMANN ETIENNE
