Synthesis of 8-thiabicyclo[3.2.1]octanes and their binding affinity for the dopamine and serotonin transporters

Abstract: Cocaine is a potent stimulant of the central nervous system. Its reinforcing and stimulant properties have been associated with inhibition of the dopamine transporter (DAT) on presynaptic neurons. In the search for medications for cocaine abuse, we have prepared 2-carbomethoxy-3-aryl-8-thiabicyclo[3.2.1]octane analogues of cocaine. We report that this class of compounds provides potent and selective inhibitors of the DAT and SERT. The selectivity resulted from reduced activity at the SERT. The 3β-(3,4-dichlorophenyl) analogue inhibits the DAT and SERT with a potency of IC50 =5.7nM and 8.0nM, respectively. The 3-(3,4-dichlorophenyl)-2,3-unsaturated analogue inhibits the DAT potently (IC50 =4.5nM) and selectively (>800-fold vs SERT). Biological enantioselectivity of DAT inhibition was limited for both the 3-aryl-2,3-unsaturated and the 3α-aryl analogues (2-fold), but more robust (>10-fold) for the 3β-aryl analogues. The (1R)-configuration provided the eutomers. [Copyright &y& Elsevier]