The present invention relates to a compound of formulaI, and to a pharmaceutically suitable acid addition salt thereof with a good affinity to the trace amine associated receptors (TAARs), especially for TAAR1, for the treatment of certain CNS diseases.本發明係關於下式化合物I, 及其醫藥上適宜之酸加成鹽,其等對於示蹤胺相關受體(trace amine associated receptor;TAAR)(尤其是TAAR1)具有良好親和力,其可用於治療某些CNS疾病。