The invention discloses compounds of Formula I,I, wherein X1, X2, R1, and R2are as defined herein. The present invention relates to compounds and their use in the treatment of cystic fibrosis, methods for their production, pharmaceutical compositions comprising the same, and methods of treating cystic fibrosis by administering a compound of the invention.本發明揭示式I化合物,I, 其中X1、X2、R1及R2係如本文所定義。本發明係關於化合物及其在治療囊腫性纖維化中之用途,其製造方法,包含其之醫藥組合物,及藉由投與本發明化合物來治療囊腫性纖維化之方法。