Showa Denko K.K. (SDK) has developed a new catalyst for synthesizing alpha-tetralone, an important intermediate in the production of pharmaceuticals and agrochemicals. The catalyst is the fruit of SDK's participation in the national project for developing new solid acid catalyst processes, which forms part of "Development of Next-Generation Chemical Process Technology" program implemented by the New Energy and Industrial Technology Development Organization (NEDO) and the Japan Chemical Innovation Institute (JCII).
Having both a benzene ring and six membered cyclic ketone in its molecular structure, alpha-tetralone is used for the synthesis of carbaryl (insecticide) and sertraline (antidepressant). The world market for sertraline is approx. 300 billion yen per year. Thus, the market for alpha-tetralone as a pharmaceutical/agrochemical intermediate is expected to exceed 5 billion yen a year.
Currently, alpha-tetralone is being produced using metallic reagents, such as aluminum chloride, and through multi-stage reaction processes. Since this production method results in a large volume of wastes, it has been pointed out that a more environment-friendly production method is necessary.
SDK has developed the innovative solid acid catalyst for alpha-tetralone synthesis by fully utilizing its expertise in catalyst development for acetic acid, ethyl acetate and other chemicals. The new catalyst technology offers the following advantages:
1) Compared with the conventional method that uses aluminum chloride or other metallic reagents, the new solid acid catalyst technology enables a substantial reduction in the volume of wastes.
2) alpha-tetralone can be produced by one step from p-xylene, or other benzene derivatives, and cyclic lactone. This substantially reduces production cost compared with the conventional multi-stage synthesis.
3) The new technology enables the synthesis of alpha-benzosuberone with a benzene ring and seven membered cyclic ketone, which is under development as a new pharmaceutical/agrochemical intermediate.