The invention relates to compounds of formula I:and pharmaceutically acceptable salts thereof wherein A, X, R1, R4and n are as defined herein. In addition, the present invention relates to methods of manufacturing and methods of using the compounds of formula I as well as pharmaceutical compositions containing such compounds. The compounds may be useful in treating diseases and conditions mediated by TRPA1, such as pain.本發明係關於式I化合物:及其醫藥學上可接受之鹽,其中A、X、R1、R4及n如本文所定義。此外,本發明係關於式I化合物之製造方法及使用方法以及含有此類化合物之醫藥組合物。該等化合物可適用於治療由TRPA1介導之疾病及病狀,諸如疼痛。