The present invention relates to compounds of formula (I): wherein R1 to R3, A, X and n are as defined herein. The compounds of formula (I) are useful as inhibitors of leukotriene A4 hydrolase (LTA4H) and treating LTA4H related disorder. The present invention also relates to pharmaceutical compositions comprising the compounds of formula (I), methods of using these compounds in the treatment of various diseases and disorders, and processes for preparing these compounds.本發明係關於一種式(I)之化合物:其中R1至R3、A、X及n係如文中所定義。式(I)之化合物可用作白三烯素A4水解酶(LTA4H)之抑制劑及用於治療與LTA4H相關之病症。本發明亦係關於包含式(I)之化合物之醫藥組合物、使用該類化合物於治療各類疾病及病症上之方法及製備該類化合物之方法。