(–)-2β-Carbomethoxy-3β-(4-bromophenyl)tropane is a semi-synthetic alkaloid in the phenyltropane group of psychostimulant compounds. First publicized in the 1990s, it has not been used enough to have gained a fully established profile. RTI-51 can be expected to have properties lying somewhere in between RTI-31 and RTI-55. It has a ratio of monoamine reuptake inhibition of dopamine > serotonin > norepinephrine which is an unusual balance of effects not produced by other commonly used compounds. It has been used in its 76Br radiolabelled form to map the distribution of dopamine transporters in the brain.