Acridone derivatives containing 1, 3, 4-oxadiazole and 1, 3, 4-thiadiazole rings are synthesized.Diphenylamine-2,4`-dicarboxylic acid [1] is obtained in a high yield by refluxing a mixture of 4-aminobenzoic acid and 2-chloro benzoic acid in the presence of catalytic amount of copper oxide. 9(10H)-Acridone-2-carboxylic acid [2] is synthesized in ring closure reaction by heating compound [1] in sulfuric acid followed by basic hydrolysis.Reaction of compound [2] with thiosemicarbazide in the presence of phosphorus oxychloride gave 2-[5-amino-1, 3, 4-thiadiazole-2-yl]-9(10H)-acridone