The 8-thiabicyclo(3.2.1)octanes analogs such as O-4210 have been prepared.[6] A representative set of analogs is listed below.
MAT IC50 (nM) 8-thiabicyclo[3.2.1]octanes
X
Com
DAT
SERT
Com
DAT
SERT
Com
DAT
SERT
H
1a
910
>10uM
2a
140
>8uM
3a
117
>3uM
F
1b
220
>30uM
2b
59
>11uM
3b
38
494
Cl
1c
13
>10uM
2c
11
1uM
3c
9.6
33
Br
1d
9.1
>25uM
2d
6.0
342
3d
6.0
14
I
1e
6.7
>8uM
2e
9.0
70
3e
14
10
Cl2
1f
4.5
>3uM
2f
6.9
99
3f
5.7
8.0
BN
1g
8.0
>1uM
2g
8.0
36
3g
16
13
It had been hypothesized that transporter binding of the tropanes might include ionic bonding of the central tropane nitrogen. But it turned out that at this site neither ionic nor hydrogen bonding is a prerequisite for potent monoamine reuptake inhibition. Oxa- and thia-analogs of RTI-111 are potent inhibitors, and even an N-replacement by methylene holds the potency within the same magnitude.[6][7][8] However, N-quaternisation (N-dimethyl) considerably reduces DAT affinity.
In this SAR, the focus is on seeing the effect of changing 8-NMe to S, O, or CH2. Both enantiomers, as well as the racemates are presented in several cases for comparison.
^Meltzer PC, Blundell P, Chen Z, Yong YF, Madras BK (March 1999). "Bicyclo[3.2.1]octanes: synthesis and inhibition of binding at the dopamine and serotonin transporters". Bioorganic & Medicinal Chemistry Letters. 9 (6): 857–62. doi:10.1016/s0960-894x(99)00098-0. PMID10206550.
^WO application 9740859, Madras BK, Meltzer PC, "Bridge-substituted Tropanes and Uses", published 6 November 1997, assigned to Harvard College
^Madras BK, Fahey MA, Miller GM, De La Garza R, Goulet M, Spealman RD, Meltzer PC, George SR, O'Dowd BF, Bonab AA, Livni E, Fischman AJ (October 2003). "Non-amine-based dopamine transporter (reuptake) inhibitors retain properties of amine-based progenitors". European Journal of Pharmacology. 479 (1–3): 41–51. doi:10.1016/j.ejphar.2003.08.055. PMID14612136.
^Goulet M, Miller GM, Bendor J, Liu S, Meltzer PC, Madras BK (December 2001). "Non-amines, drugs without an amine nitrogen, potently block serotonin transport: novel antidepressant candidates?". Synapse. 42 (3). New York, N.Y.: 129–40. doi:10.1002/syn.1108. PMID11746710. S2CID22341553.