Studies in the preparation of alkyl substituted thioxanthones and thioxanthenes

It has been the purpose of this investigation to study the Bethods of preparation of ethyl substituted thioxanthene. It was found that this compound cannot be prepared by application of the Friedel-Crafts Reaction at average experimental conditions. However, fusion of thiosalicylic acid with ethyl bengene under the dehydrating influence of concentrated sulfuric acid yields ethyl thioxanthone. By subsequent reduction of this keto compound, ethyl thioxanthene results. As a consequence of the failure to apply a substitution type reaction in order to synthesise etlyl thioxanthene, it can be said that thiaxanthene does not exhibit sronatio properties, at least not as far as the Friedel-Crafte Reaction is concerned.