The present invention provides a compound of formula I';or a pharmaceutically acceptable salt thereof, wherein R1, R2, R3, R5, B1, X and n are defined herein. The invention also relates a method for manufacturing the compounds of the invention, and its therapeutic uses. The present invention further provides a combination of pharmacologically active agents and a pharmaceutical composition.本發明提供一種式I'化合物,或其醫藥學上可接受之鹽,其中R1、R2、R3、R5、B1、X及n係如本文中所定義。本發明亦係關於一種製造本發明化合物之方法及本發明化合物之治療用途。本發明進一步提供一種藥理學活性劑之組合及一種醫藥組合物。