The present disclosure provides a compound represented by Formula (I) and a pharmaceutically acceptable salt which are effective as a dopamine reuptake inhibitor and a method of using the compound: wherein X is independently halo, alkyl, alkoxy or nitro; m is 0, 1, 2, 3 or 4; n is 1 or 2; R1 and R2 are independently H— or alkyl; R3 is H—, alkyl or aralkyl; and R4 is H— or aryl.