Syntheses of Thioxanthone Carboxylic Acids andTheir Derivatives

Sixteen different thioxanthonecarboxylic acids and their derivatives were prepared by aromatic nucleophilic substitution, intramolecular acylation and esterification. Five esters among them are new compounds. Reaction conditions were modified and its mechanism were discussed. The compounds were identified by iR ,MS and element analysis. The relationship between the wavelength of maximum absorption and structure was also explained.