The synthesis of 3-hydroxy-1, 10-dimethyl-9-acridone XIII, via the initial condensation of methyl anthranilateVI and orcinol VIII in presence of heptanol and ptolylsulfonic acid, is described. The condensation of XIII with 3-chloro-3-methylbut-l-yne afforded 3, 12-dihydro-3, 3, 6, 12-tetramethyl-7H-pyrano [2, 3-c] acridin-7-one II. The structure of II has been established through the use of a study by X-ray diffraction.
