The present invention relates to the compound of Formulas I and its pharmaceutically acceptable salts. The present invention also provides the compositions comprising the compounds of this invention and such composition to pass through the purposes in the disease of application CFTR synergist advantageous treatment and the treatment method of illness.本發明涉及式I的化合物及其藥學上可接受的鹽。本發明還提供了包含本發明化合物的組合物，以及這樣的組合物在通過施用 CFTR增效劑有益治療的疾病和病症的治療方法中的用途。
