This invention relates to novel compounds which are derivatives of the phosphodiesterase inhibitor, cilostazol and pharmaceutically acceptable salts thereof. This invention also provides pyrogen-free compositions comprising one or more compounds of the invention and the use of the disclosed compounds and compositions in methods of treating diseases and conditions that are treated by administration of a phosphodiesterase inhibitor, such as cilostazol. The invention also relates to the use of the disclosed compounds and compositions as reagents in analytical studies involving cilostazol.