With a benzene ring and six membered cyclic ketone in its molecular structure, alpha-tetralone is used for the synthesis of many compounds, including sertraline, an antidepressant, and the insecticide carbaryl.
Showa Denko estimates that the world market for sertraline is Y 300 billion (€2.24bn) per year, and that the market for alpha-tetralone as a pharmaceutical/agrochemical intermediate exceeds Y 5 billion 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, researchers have been looking for a more environment-friendly production method.
Showa Denko makes use of a new solid acid catalyst for alpha-tetralone synthesis that offers several advantages.
For example, compared with the conventional method that uses aluminium chloride or other metallic reagents, it provides a substantial reduction in the volume of wastes. More than 1,000 tons a year of alpha-tetralone is being produced as a pharmaceutical/agrochemical intermediate, generating approximately 6,000 tons of metallic compounds as waste.
Moreover, 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.
The new technology also 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. Development efforts are under way for an anticonvulsant and a drug for treating obesity, using alpha-benzosuberone as an intermediate.