Synthesis and activity of a new class of dual acting norepinephrine and serotonin reuptake inhibitors: 3-(1H-indol-1-yl)-3-arylpropan-1-amines

Article abstract of DOI:10.1016/j.bmc.2006.08.039

Compounds with a combination of norepinephrine and serotonin reuptake inhibition have been approved in the US and Europe for a number of indications, including major depressive disorder and pain disorders such as diabetic neuropathy and fibromyalgia. Efforts to design selective norepinephrine reuptake inhibitors based on SAR from the aryloxypropanamine series of monoamine reuptake inhibitors have led to the identification of a potent new class of dual acting norepinephrine and serotonin reuptake inhibitors, namely the 3-(1H-indol-1-yl)-3-arylpropan-1-amines.

Full text of DOI:10.1016/j.bmc.2006.08.039

Bioorganic & Medicinal Chemistry 14 (2006) 8455–8466
Synthesis and activity of a new class of dual acting norepinephrine
and serotonin reuptake inhibitors: 3-(1H-indol-1-yl)-
3-arylpropan-1-amines
Paige E. Mahaney,a,* An T. Vu,a Casey C. McComas,a Puwen Zhang,a Lisa M. Nogle,b
William L. Watts,b Ani Sarkahian,b,ꢀ Liza Leventhal,c Nicole R. Sullivan,c
Albert J. Uvegesc and Eugene J. Trybulskia
aChemical and Screening Sciences, Discovery Medicinal Chemistry, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA
bDiscovery Analytical Chemistry—Chemical Technologies, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA
cDepartment of Neuroscience, Wyeth Research, CN 8000, Princeton, NJ 08543, USA
Received 24 July 2006; revised 22 August 2006; accepted 28 August 2006
Available online 14 September 2006
Abstract—Compounds with a combination of norepinephrine and serotonin reuptake inhibition have been approved in the US and
Europe for a number of indications, including major depressive disorder and pain disorders such as diabetic neuropathy and fibro-
myalgia. Efforts to design selective norepinephrine reuptake inhibitors based on SAR from the aryloxypropanamine series of mono-
amine reuptake inhibitors have led to the identification of a potent new class of dual acting norepinephrine and serotonin reuptake
inhibitors, namely the 3-(1H-indol-1-yl)-3-arylpropan-1-amines.
ꢀ 2006 Elsevier Ltd. All rights reserved.
CH3
N
1. Introduction
S
H3C
OH
Drugs that selectively inhibit norepinephrine reuptake,
including reboxetine (7), nisoxetine (5), and atomoxetine
(6), are marketed for the treatment of major depressive
disorder (MDD) and, more recently, attention deficit
hyperactivity disorder (ADHD). In addition, these com-
pounds have been reported to show efficacy for chronic
pain disorders such as fibromyalgia1,2 and low back
pain.1 Compounds that possess a combination of nor-
epinephrine and serotonin reuptake inhibition, such as
venlafaxine (1), duloxetine (2), and milnacipran (3),
have been approved in the US and Europe for a number
of indications including MDD and pain disorders such
as diabetic neuropathy and fibromyalgia. Furthermore,
these compounds have been reported to show efficacy
for other ailments such as stress urinary incontinence
(SUI)3–6 and ADHD.7,8
CH3
O
N
H
H3C
O
(S)-Duloxetine (2)
Venlafaxine (1)
CH3
N
H3C
O
N
CH3
CH3
Milnacipran (3)
Compounds containing an aryloxypropanamine moiety
have long been recognized as monoamine reuptake
inhibitors. Their selectivity profile for the norepineph-
rine and serotonin transporters depends upon the substi-
tution pattern of the aryloxy ring (see Table 1).
Compounds that contain a substituent in the 20-position
of the aryloxy ring [e.g., nisoxetine (5), atomoxetine (6),
and reboxetine (7)] are generally selective norepineph-
rine reuptake inhibitors (NRIs) while compounds that
have a substituent in the 40-position [e.g., fluoxetine (4)
and paroxetine (8)] are selective serotonin reuptake
Keywords: Monoamine reuptake inhibitors; Norepinephrine reuptake
inhibitors; Serotonin reuptake inhibitors; Aryloxypropanamines.
*
Corresponding author. Tel.: +1 484 865 0627; fax: +1 484 865
9399; e-mail: mahanep@wyeth.com
ꢀ
Present address: GlaxoSmithKline, King of Prussia, PA 19406-0939,
USA.
0968-0896/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2006.08.039

8456
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
Table 1. Inhibitory activity at the human norepinephrine and seroto-
nin transporters of compounds within the aryloxypropanamine class
CH3
N
N
F3C
4'
H
CH3
CH3
O
OCH3
N
3'
O
N
H
3
1
2
9a
2'
H
Fluoxetine (4)
Nisoxetine (5)
F
2. Chemistry
CH3
N
O
NH
O
O
O
NH
O
The synthesis of the 3-(1H-indol-1-yl)-3-arylpropan-1-
amines 9, depicted in Scheme 1, was designed to provide
significant insight into the structure–activity relationship
(SAR) within the series. This synthesis not only enabled
an examination of the effect of chirality within the series
(racemate 9 versus R-enantiomer 16 and S-enantiomer
17), but it also provided information about the relative
potencies of tertiary amines 15 versus secondary amines
9 and indolines 14 versus indoles 15. Starting with an
appropriately substituted acetophenone 10, a Mannich
reaction using paraformaldehyde and dimethylamine
hydrochloride afforded the 3-dimethylamino-1-phenyl-
1-propanone hydrochlorides (11a–b)9 which were readily
reduced to form alcohols 12a–b10 using aqueous sodium
borohydride. Formation of the mesylate with metha-
nesulfonyl chloride and triethylamine followed by treat-
ment with the appropriately substituted indoline11 and
potassium carbonate yielded the desired indoline adduct
14 using a two-step, one-pot procedure. For similar sys-
tems, it has been reported that this process occurs by
in situ generation of an azetidinium ion followed by regio-
H
OEt
O
CH3
Reboxetine (7)
Paroxetine (8)
Atomoxetine (6)
Compound Name
hNET hSERT hSERT
a
b
IC50
(nM)
IC50
(nM)
IC50/hNET
c
IC50
2
4
5
6
7
8
(S)-Duloxetine
4
563
6
3
10
0.75
0.02
46
Fluoxetine
Nisoxetine
Atomoxetine
Reboxetine
Paroxetine
277
48
3
16
81
3
100
242
2
0.02
a Inhibition of norepinephrine uptake in MDCK-Net6 cells, stably
transfected with human NET.
b Inhibition of serotonin uptake in JAR cells, stably transfected with
human SERT.
c Unitless value as a ratio in which higher numbers represent relatively
greater NET selectivity. A value of 1 represents no selectivity.
inhibitors (SRIs). Duloxetine (2), which contains a
phenyl group fused at the 20- and 30-positions, has sim-
ilar potencies for the two transporters.
HCl
OH
O
O
a
X
CH3
b
X
CH3
X
N
N
CH3
CH3
A drug discovery project was initiated to identify
novel and selective norepinephrine reuptake inhibi-
tors for screening in a panel of predictive animal
models. Thus, a series of 3-(1H-indol-1-yl)-3-arylpro-
pan-1-amines 9, which contained an indole ring as a
replacement for the aryloxy group in the aryloxypro-
panamine scaffold, was designed. This scaffold was
anticipated to be a selective NRI, because it incor-
porated the 20-substituent, found to provide selectiv-
ity in the aryloxypropanamine series, into a fused,
pyrrole ring. Compounds were screened in vitro in
MDCK-Net6 cells that were stably transfected with
the human norepinephrine transporter (hNET).
These cells were then treated with the test com-
pound followed by [3H]NE to initiate norepinephrine
(NE) uptake. Once the cells were washed and lysed,
uptake of [3H]NE was measured by collection of
counts per minute (cpm) data. Uptake into JAR
cells that were stably transfected with the human
serotonin transporter (hSERT) was similarly mea-
sured. Target in vitro profiles for drug candidates
included an IC50 < 50 nM and selectivity over
hSERT. As expected, compound 9a and its fluorinat-
ed analogs were potent NRIs, however, surprisingly,
they were also potent SRIs. Herein, we report the
synthesis and activity of a new series of potent
NRIs that also exhibit potent inhibition of serotonin
reuptake, namely the 3-(1H-indol-1-yl)-3-arylpropan-
1-amines 9.
11a, X = H
11b, X = F
12a, X = H
12b, X = F
10a, X = H
10b, X = F
X
CH3
H3C N
R
CH3
N
CH3
c
d
X
N
14a-e, X = H
14f-j, X = F
13a, X = H
13b, X = F
X
X
R
R
e
CH3
f
CH3
N
N
N
N
H
CH3
9a-e, X = H
9f-j, X = F
15a-e, X = H
15f-j, X = F
X
X
R
R
CH3
CH3
+
N
N
g
N
N
H
H
17a-e, X = H
17f-j, X = F
16a-e, X = H
16f-j, X = F
Scheme 1. Synthesis of 3-(1H-indol-1-yl)-3-arylpropan-1-amines.
Reagents and conditions: (a) paraformaldehyde, dimethylamine
hydrochloride, EtOH, reflux, 80–88% yield; (b) sodium borohydride,
H2O, 90–93% yield; (c) MsCl, Et3N, CH3CN; (d) indoline, K2CO3; 47–
81% yield depending on indoline substitution; (e) MnO2, CH2Cl2,
reflux, 71–98% yield; (f) ACE-Cl, DIEA, CH2Cl2, then MeOH, reflux,
68–91% yield; (g) chiral SFC.

P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
8457
Table 2. Inhibitory activity at the human norepinephrine and seroto-
nin transporters of compounds within the N,N-dimethyl-3-arylpropan-
1-amine series
b
a
HO
Cl
N
Cl
X
X
18
R
R
19
CH3
CH3
N
N
N
N
CH3
CH3
14
15
c
CH3
N
N
N
Cl
H
Compound
X
R
H
hNET
a
hSERT
b
IC50
(nM)
hSERT
IC50/hNET
IC50
(nM)
16a
20
c
IC50
Scheme 2. Enantiospecific synthesis of (3R)-3-(1H-indol-1-yl)-N-meth-
yl-3-phenylpropan-1-amine. Reagents and conditions: (a) i—MsCl,
TEA, Et2O, 0 ꢁC, ii—indoline, 44% yield; (b) MnO2, ClCH2CH2Cl,
70 ꢁC, 98% yield; (c) MeNH2, EtOH, 90 ꢁC, 75% yield.
14a
14b
14c
14d
14e
14f
14g
14h
14i
H
H
H
H
H
F
495
984
4-F
5-F
6-F
7-F
H
1289
1067
79
103
0.08
selective ring-opening.12 The indoline adduct 14 was read-
ily oxidized with manganese (IV) oxide to form the corre-
sponding indole 15. This product was then
N-demethylatedwith1-chloroethylchloroformate13 toaf-
fordthecorresponding3-(1H-indol-1-yl)-3-arylpropan-1-
methylamine 9. Inclusion of diisopropylethylamine to this
reaction resulted in a significant increase in isolated yields.
Separationoftheenantiomersofracemic9bychiralsuper-
critical fluid chromatography afforded both the R-enan-
tiomer 16 and the S-enantiomer 17 in high optical purity.
430
F
4-F
5-F
6-F
7-F
H
1144
1395
322
172
108
0.15
0.08
F
F
14j
F
32
603
157
191
48
4.9
15a
15b
15c
15d
15e
15f
15g
15h
15i
H
H
H
H
H
F
0.32
0.03
4-F
5-F
6-F
7-F
H
1374
>5000
2492
344
467
92
0.19
0.28
759
270
F
4-F
5-F
6-F
7-F
Assignment of the configuration of enantiomers 16 and
17 was accomplished by unequivocally establishing
the configuration of (3R)-3-(1H-indol-1-yl)-N-methyl-
3-phenylpropan-1-amine (16a) through independent
synthesis using an enantiospecific route (Scheme 2).
Assignment of the stereochemistry of subsequent com-
pounds within the series was based upon analogy.
Therefore, the mesylate of (S)-(ꢀ)-3-chloro-1-phenyl-1-
propanol (18) was generated, in situ, using metha-
nesulfonyl chloride and triethylamine, and subsequently
displaced with indoline to form chloride 19. Oxidation
to the indole followed by amination with methylamine
in ethanol afforded (3R)-3-(1H-indol-1-yl)-N-methyl-3-
phenylpropan-1-amine (16a) in 32% overall chemical
yield and 91% enantiomeric purity as measured by chiral
supercritical fluid chromatography.
F
1275
1383
158
399
0.31
F
15j
F
a Inhibition of norepinephrine uptake in MDCK-Net6 cells, stably
transfected with human NET. Desipramine (IC50 = 11.5 1.3 nM)
was used as a standard.
b Inhibition of serotonin uptake in JAR cells, stably transfected with
human SERT. Fluoxetine (IC50 = 17.7 1.2 nM) was used as a
standard.
c Unitless value as a ratio in which higher numbers represent relatively
greater NET selectivity. A value of 1 represents no selectivity.
15a, and 15f) were less potent NRIs than the 7-fluoro
analogs, but were generally more potent than the 4-,
5-, and 6-fluoro compounds. Finally, fluorine substitu-
tion on the meta position of the 3-phenyl ring had no
significant effect on the NRI potency in either series.
When a select group of compounds within scaffolds 14
and 15 was tested for serotonin reuptake inhibitory
activity, both structural classes were found to be potent
SRIs. In fact, as a whole, both scaffolds exhibited selec-
tivity for the serotonin transporter over the norepineph-
rine transporter, with the exception of compound 14j
which showed a modest, 5-fold NRI selectivity.
3. Results and discussion
Data for a series of fluoro-substituted 3-(2,3-dihydro-
1H-indol-1-yl)-
N,N-dimethyl-3-arylpropan-1-amines
14 and 3-(1H-indol-1-yl)-N,N-dimethyl-3-arylpropan-1-
amines 15 are depicted in Table 2. Both structural clas-
ses were found to possess norepinephrine reuptake
inhibitory activity. Furthermore, a comparison of these
two compound classes revealed that they possessed sim-
ilar NRI potencies. When the effect of fluorine substitu-
tion on the indole and indoline rings was examined, a
similar SAR trend was found between the two scaffolds.
In general, fluorine substitution on the 7-position of
either the indole or indoline ring provided the most
potent NRIs (14e, 14j, 15e, and 15j), while substitution
at the 4-, 5-, and 6-positions afforded compounds with
similar but weaker potencies. Compounds with no
substitution on the indole or indoline rings (14a, 14f,
Data for the corresponding series of 3-(1H-indol-1-yl)-3-
arylpropan-1-amines 9 are depicted in Table 3. In gener-
al, for NRI potency, there is a preference for the second-
ary amines (9a–9j) when compared to the tertiary
amines (15a–15j, Table 2). For example, the unsubstitut-
ed indole analog containing an N,N-dimethylamine
(15a) exhibited an IC50 value in the NRI functional
assay of 603 nM; the corresponding secondary amine
(9a) was nearly 13 times more potent with an IC50 value
of 47 nM. Similarly, the more potent 3-(7-fluoro-1H-

8458
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
Table 3. Inhibitory activity at the human norepinephrine, serotonin, and dopamine transporters of compounds within the (3-(1H-indol-1-yl)-N-
methyl-3-phenylpropan-1-amine series
X
R
CH3
*
N
N
H
a
c
e
Compound Stereochemistry
X
R
H
hNET IC50
(nM)
hNET Kib hSERT IC50
hSERT IC50
d
/
hDAT IC50
(nM)
hDAT % inhibition
at 1 lMe
(nM)
(nM)
hNET IC50
9a
9b
Racemic
Racemic
H
H
H
H
H
F
47
32
132
57
25
46
25
57
69
23
24
35
59
37
39
23
80
11
118
19
29
41
12
81
28
24
47
27
74
37
26
327
38
7.0
0.3
1243
4-F 154
9c
9d
Racemic
Racemic
5-F
6-F
7-F
H
55
87
99
86
24
9e
Racemic
Racemic
9f
9g
1163
Racemic
Racemic
F
4-F
9h
9i
F
5-F 335
Racemic
Racemic
F
6-F
7-F
H
68
22
34
9j
F
16a
16b
16c
16d
16e
16f
16g
16h
16i
16j
17a
17b
17c
17d
17e
17f
17g
17h
17i
17j
R
R
R
R
R
R
R
R
R
R
S
H
H
H
H
H
F
491
21
14.4
5.5
0.4
1.2
1.4
0.2
7.3
>21
3.4
5.6
8.4
0.8
0.3
17.8
1.9
0.1
0.8
1.0
3.0
3.3
3200
563
4-F 115
5-F
6-F
7-F
H
82
96
44
91
22
30
22%g
15%g
12%g
111
62
14
4100
1950
F
4-F
160
23%f
236
56
F
5-F 284
F
6-F
7-F
H
69
10
33
12
20%g
26%g
F
H
H
H
H
H
F
276
9
>10,000
680
S
4-F
S
5-F 313
105
196
34
19%g
20%g
16%g
S
6-F
7-F
H
11
18
86
28
91
84
35
S
S
12
23
>10,000
550
S
F
4-F
5-F
6-F
7-F
S
F
89
S
F
248
117
14%g
35%g
S
F
a Inhibition of norepinephrine uptake in MDCK-Net6 cells, stably transfected with human NET. Desipramine (IC50 = 11.5 1.3 nM) was used as a
standard.
b Inhibition of [3H] nisoxetine binding to membranes from MDCK-Net6 cells, stably transfected with human NET. Desipramine
(Ki = 2.3 0.13 nM) was used as a standard.
c Inhibition of serotonin uptake in JAR cells, stably transfected with human SERT. Fluoxetine (IC50 = 17.7 1.2 nM) was used as a standard.
d Unitless value as a ratio in which higher numbers represent relatively greater NET selectivity. A value of 1 represents no selectivity.
e Inhibition of [3H]WIN-35,428 binding to membranes from CHO cells expressing recombinant hDAT. Mazindol (IC50 = 22.6 1.6 nM) was used as
a standard.
f Percent inhibition measured at a concentration of 6000 nM.
g Percent inhibition measured at a concentration of 2000 nM.
indol-1-yl)-3-(3-fluorophenyl)-N,N-dimethylpropan-1-
amine (15j) had an IC50 value of 158 nM while the
corresponding secondary amine (9j) exhibited a 7-fold
increase in potency with an IC50 value of 22 nM.
analogs containing no substitution on the 3-phenyl group
(17b and 17d, respectively) were nearly 10-fold more
potent than their corresponding R-enantiomers (16b
and 16d) and racemates (9b and 9d). For example, the
racemate of the 6-fluoroindole analog 9d exhibited an
NRI IC50 value of 87 nM while the R-enantiomer 16d
showed a similar potency (IC50 value of 96 nM). The cor-
responding S-enantiomer 17d, however, was significantly
more potent, with an IC50 value of 11 nM. It should be
noted that the Ki values for this series, determined in a
membrane-binding assay using nisoxetine as the compet-
itive radioligand, showed good agreement with the IC50
values determined in the NRI functional assay.
Whenthe purified enantiomers, 16and 17, werecompared
to their corresponding racemates in the 3-(1H-indol-1-yl)-
3-arylpropan-1-amine series, no significant difference in
NRI potency for a majority of the series (see Table 3)
was observed. For example, the unsubstituted, racemic
compound 9a exhibited an IC50 value in the functional
NRI assay of 47 nM while the R-enantiomer 16a exhibit-
ed an IC50 value of 34 nM and the S-enantiomer was
33 nM. The same is true for racemates 9c, 9e, 9f, 9g, 9i,
and 9j and their enantiomers. Surprisingly, it was found
that the S-enantiomers of the 4-, and 6-fluoroindole
The 3-(1H-indol-1-yl)-3-arylpropan-1-amines were then
tested for hNET selectivity over both hSERT and the

P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
8459
dopamine transporter (hDAT) (Table 3), and, while the
compounds exhibited only weak affinity for hDAT, as a
series, the 3-(1H-indol-1-yl)-3-arylpropan-1-amines were
found to be potent SRIs. When the potencies of the pure
enantiomers in the serotonin reuptake assay were com-
pared to their corresponding racemates, no significant
difference was observed (9a vs 16a and 17a, and 9b vs
16b and 17b). When selectivities for hNET over hSERT
were compared, there was generally no difference be-
tween the R- and S-enantiomers; however, exceptions
exist. Both the (3R)-3-(4-fluoro-1H-indol-1-yl)-3-(3-flu-
orophenyl)-N-methylpropan-1-amine (16g) and the
(3R)-3-(5-fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N-
methylpropan-1-amine (16h) were significantly more
selective NRIs than SRIs compared to their correspond-
ing S-enantiomer (17g and 17h) (7.3-fold vs 0.82 and
>20-fold vs 0.98, respectively). In addition, (3S)-3-(6-flu-
oro-1H-indol-1-yl)-N-methyl-3-phenylpropan-1-amine
(17d) was nearly 18-fold selective for hNET compared to
hSERT while the corresponding R-enantiomer (16d)
exhibited nearly equal potencies for both transporters.
It is interesting that by altering only the position of a
fluorine group within the molecule, selectivity ratios
from 0.14 to >20 (a range of 150) could be achieved.
was assessed by 1H NMR and an LC/UV/MS method.14
Biological results were obtained on compounds of >97%
chemical purity as determined by the above methods.
5.2. 3-(Dimethylamino)-1-(3-fluorophenyl)propan-1-ol
(12b)
A solution of 3-(dimethylamino)-1-(3-fluorophenyl)-1-
propanone (11b) (11.99 g, 51.75 mmol) in water
(110 mL) at 0 ꢁC was treated with sodium borohydride
(2.49 g, 65.72 mmol) in small portions. The reaction mix-
ture was allowed to warm to room temperature, where it
was stirred for 2 h. After which time, acetone (5 mL) fol-
lowed by concentrated HCl (14 mL) was added and the
reaction mixture was stirred at room temperature for
30 min. The reaction mixture was then extracted with
methylene chloride (50 mL) and the aqueous layer was
basified to pH 10 by the addition of a 2 N aqueous solu-
tion of sodium hydroxide. The product was then extract-
ed with methylene chloride (3· 50 mL), dried over
MgSO4, and concentrated to yield pure 12b (9.39 g,
92%) as a colorless oil. 1H NMR (DMSO-d6, 400 MHz)
d 1.69 (q, J = 6.7 Hz, 2H), 2.12 (s, 6H), 2.25–2.31 (m,
2H), 4.64 (t, J = 6.4, 1H), 5.57 (br s, 1H), 7.03 (dddd,
J = 0.9, 2.7, 9.0, 9.0, 1H), 7.11–7.16 (m, 2H), 7.35 (dd,
J = 7.9, 13.9, 1H); HRMS: calcd for C11H16FNO + H+,
198.1288. Found (ESI, [M+H]+), 198.1281.
4. Conclusions
Efforts to design selective NRIs based on SAR from the
aryloxypropanamine series of monoamine reuptake
inhibitors have led to the identification of the 3-(1H-in-
dol-1-yl)-3-arylpropan-1-amines, a potent new class of
dual acting norepinephrine and serotonin reuptake inhib-
itors. The selectivity profile for hNET and hSERT of this
series of compounds spans a wide range, with selectivity
ratios from 0.14 to >20, differing only by minor changes
in substitution. Furthermore, these compounds exhibit
good selectivity over the dopamine transporter.
5.3. General procedure 1: 3-(2,3-dihydro-1H-indol-1-yl)-
N,N-dimethyl-3-phenylpropan-1-amines (14a–14j)
A solution of the appropriately substituted 3-(dimeth-
ylamino)-1-arylpropan-1-ol (2.72 mmol) in acetonitrile
(20 mL) was treated with triethylamine (0.45 mL,
3.26 mmol) followed by the dropwise addition of meth-
anesulfonyl chloride (0.23 mL, 2.99 mmol). The reaction
mixture was stirred at room temperature for 3 h, after
which time indoline (0.92 mL, 8.16 mmol, 3 equiv) fol-
lowed by potassium carbonate (752 mg, 5.44 mmol)
was added. The reaction mixture was stirred at room
temperature for 14 h then the reaction mixture was fil-
tered and the filtrate was concentrated at reduced pres-
sure. The product was purified via Biotage Horizonꢂ
[25 M, silica, gradient from 0% (20% methanol/methy-
lene chloride)/methylene chloride to 55% (20% metha-
nol/methylene chloride)/methylene chloride].
5. Experimental
5.1. General methods: chemistry
Solvents were purchased as anhydrous grade and were
used without further purification. Melting points were
measured on a Mel-Temp II (Laboratory Device, Inc.)
melting point apparatus and are uncorrected. 1H
NMR spectra were recorded on a Varian INOVA 400
instrument, and chemical shifts are reported in d values
(parts per million, ppm) relative to an internal standard
tetramethylsilane in CDCl3 or DMSO-d6. In all cases,
NMR spectra of enantiomers were essentially identical
to their corresponding racemates. Electrospray (ESI)
mass spectra were recorded using a Waters Alliance-
ZMD mass spectrometer. Electron impact ionization
(EI, EE = 70 eV) mass spectra were recorded on a Finn-
igan Trace mass spectrometer. Combustion analyses
were performed by Robertson Microlit. Analytical thin
layer chromatography (TLC) was performed on pre-
coated plates (silica gel, 60 F-254) and were visualized
using UV light and/or staining with a phosphomolybdic
acid solution in ethanol. In general, compound purity
5.3.1.
3-(2,3-Dihydro-1H-indol-1-yl)-N,N-dimethyl-3-
phenylpropan-1-amine (14a). Yield: 72% of a light pale
yellow oil; 1H NMR (DMSO-d6, 400 MHz) d 2.06–
2.25 (m, 2H), 2.25 (s, 6H), 2.33–2.49 (m, 2H), 2.81–
2.87 (m, 2H), 3.12–3.20 (m, 1H), 3.50 (ddd, J = 6.4,
9.0, 9.0 Hz, 1H), 4.76 (t, J = 7.8 Hz, 1H), 6.46 (t,
J = 7.2 Hz, 1H), 6.58 (d, J = 7.8 Hz, 1H), 6.91–6.95
(m, 2H), 7.22–7.26 (m, 1H), 7.30–7.37 (m, 4H); MS
(ES) m/z 281.1; HRMS: calcd for C19H24N2 + H+,
281.20122. Found (ESI, [M+H]+), 281.2003.
5.3.2. 3-(4-Fluoro-2,3-dihydro-1H-indol-1-yl)-N,N-di-
methyl-3-phenylpropan-1-amine (14b). Yield: 51% of a
1
colorless oil; H NMR (DMSO-d6, 400 MHz) d 1.99–
2.15 (m, 2H), 2.15 (s, 6H), 2.24–2.27 (m, 2H), 2.89
(t, J= 9.4 Hz, 2H), 3.26 (q, J = 9.6 Hz, 1H), 3.60

8460
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
(q, J = 7.6 Hz, 1H), 4.78 (t, J = 7.9 Hz, 1H), 6.25 (t, J =
8.6 Hz, 1H), 6.41 (d, J = 7.9 Hz, 1H), 6.95 (dd, J = 6.2,
8.1 Hz, 1H), 7.25–7.27 (m, 1H), 7.30–7.37 (m, 4H);
MS (ES) m/z 299.1; HRMS: calcd for C19H23FN2 + H+,
299.19180. Found (ESI, [M+H]+), 299.1793.
5.3.8. 3-(5-Fluoro-2,3-dihydro-1H-indol-1-yl)-3-(3-fluoro-
phenyl)-N,N-dimethylpropan-1-amine (14h). Yield: 51%
of a colorless oil; 1H NMR (DMSO-d6, 400 MHz) d
1.94–2.13 (m, 2H), 2.13 (s, 6H), 2.14–2.29 (m, 2H),
2.84–2.86 (m, 2H), 3.21 (q, J = 9.4 Hz, 1H), 3.51 (q,
J = 8.8 Hz, 1H), 4.70 (t, J = 6.8 Hz, 1H), 6.50 (dd,
J = 4.4, 8.6 Hz, 1H), 6.73 (ddd, J = 2.0, 8.6, 8.6 Hz,
1H), 6.83 (dd, J = 2.7, 8.6 Hz, 1H) 7.06–7.08 (m, 1H),
7.18–7.24 (m, 2H), 7.36 (dd, J = 7.9, 14.1 Hz, 1H); MS
(ES) m/z 317.1; HRMS: calcd for C19H22F2N2 + H+,
317.1824. Found (ESI, [M+H]+), 317.1842.
5.3.3. 3-(5-Fluoro-2,3-dihydro-1H-indol-1-yl)-N,N-dimeth-
yl-3-phenylpropan-1-amine (14c). Yield: 49% of a color-
less oil; 1H NMR (DMSO-d6, 400 MHz) d 1.95–2.14
(m, 2H), 2.14 (s, 6H), 2.17–2.30 (m, 2H), 2.80–2.90 (m,
2H), 3.16–3.23 (m, 1H), 3.47–3.53 (m, 1H), 4.68 (t,
J = 7.7 Hz, 1H), 6.48–6.52 (m, 1H), 6.70–6.77 (m, 1H),
6.80–6.85 (m, 1H), 7.16–7.26 (m, 2H), 7.30–7.39 (m,
3H); MS (ES) m/z 299.1; HRMS: calcd for
C19H23FN2 + H+, 299.1918. Found (ESI, [M+H]+),
299.1993.
5.3.9. 3-(6-Fluoro-2,3-dihydro-1H-indol-1-yl)-3-(3-fluoro-
phenyl)-N,N-dimethylpropan-1-amine (14i). Yield: 75% of
1
a colorless oil; H NMR (DMSO-d6, 400 MHz) d 2.22–
2.34 (m, 1H), 2.38–2.48 (m, 1H), 2.49 (s, 6H), 2.75–2.88
(m, 3H), 2.89–3.20 (m, 2H), 3.56–3.62 (m, 1H), 4.89 (dd,
J = 6.0, 9.4 Hz, 1H), 6.25 (ddd, J = 2.3, 7.9, 10.0 Hz,
1H), 6.61 (dd, J = 2.3, 11.2 Hz, 1H), 6.92 (dd, J = 6.2,
8.0 Hz, 1H), 7.14 (ddd, J = 2.6, 8.3, 8.3 Hz, 1H),
7.22–7.27 (m, 2H), 7.42 (ddd, J = 6.2, 7.9, 7.9 Hz, 1H);
MS (ES) m/z 317.1; HRMS: calcd for C19H22F2N2 + H+,
317.1824. Found (ESI, [M+H]+), 317.1826.
5.3.4.
3-(6-Fluoro-2,3-dihydro-1H-indol-1-yl)-N,N-di-
methyl-3-phenylpropan-1-amine (14d). Yield: 64% of
a colorless oil; 1H NMR (DMSO-d6, 400 MHz) d
2.24–2.34 (m, 1H), 2.40–2.51 (m, 1H), 2.49 (s, 6H),
2.74–2.85 (m, 3H), 3.00–3.20 (m, 2H), 3.56–3.64 (m,
1H), 4.87 (dd, J = 5.8, 9.2 Hz, 1H), 6.23 (ddd, J = 2.3,
8.0, 10.0 Hz, 1H), 6.59 (dd, J = 2.3, 11.1 Hz, 1H), 6.91
(dd, J = 6.1, 7.7 Hz, 1H), 7.28–7.41 (m, 5H); MS (ES)
m/z 299.1; HRMS: calcd for C19H23FN2 + H+,
299.19180. Found (ESI, [M+H]+), 299.1950.
5.3.10. 3-(7-Fluoro-2,3-dihydro-1H-indol-1-yl)-3-(3-fluoro-
phenyl)-N,N-dimethylpropan-1-amine (14j). Yield: 47%
of a colorless oil; 1H NMR (DMSO-d6, 400 MHz) d
2.06–2.15 (m, 2H), 2.15 (s, 6H), 2.27-2.31 (m, 2H),
2.86-2.91 (m, 2H), 3.13 (q, J = 9.7 Hz, 1H), 3.53 (ddd,
J = 6.9, 9.1, 9.1 Hz, 1H), 5.07 (t, J = 6.9 Hz, 1H), 6.54
(dd, J = 4.4, 7.8 Hz, 1H), 6.81 (d, J = 8.1 Hz, 1H), 6.85
(dd, J = 8.2, 13.3 Hz, 1H) 7.08–7.16 (m, 3H), 7.37 (dd,
J = 7.8, 13.3 Hz, 1H); MS (ES) m/z 317.1; HRMS: calcd
for C19H22F2N2 + H+, 317.1824. Found (ESI, [M+H]+),
317.1811.
5.3.5. 3-(7-Fluoro-2,3-dihydro-1H-indol-1-yl)-N,N-dimeth-
yl-3-phenylpropan-1-amine (14e). Yield: 47% of a color-
less oil; 1H NMR (DMSO-d6, 400 MHz) d 2.05–2.17
(m, 2H), 2.17 (s, 6H), 2.30–2.36 (m, 2H), 2.83–2.89 (m,
2H), 3.11 (q, J = 9.4 Hz, 1H), 3.51 (ddd, J = 6.2, 9.5,
9.5 Hz, 1H), 5.06 (t, J = 7.6 Hz, 1H), 6.49–6.54 (m,
1H), 6.79 (d, J = 7.3 Hz, 1H), 6.84 (dd, J = 8.8,
13.2 Hz, 1H), 7.23–7.27 (m, 1H), 7.30–7.35 (m, 4H);
MS (ES) m/z 299.1; HRMS: calcd for C19H23FN2 + H+,
299.19180. Found (ESI, [M+H]+), 299.1900.
5.4. General procedure 2: 3-(1H-indol-1-yl)-N,N-dimeth-
yl-3-phenylpropan-1-amines (15a–15j)
5.3.6. 3-(2,3-Dihydro-1H-indol-1-yl)-3-(3-fluorophenyl)-
N,N-dimethylpropan-1-amine (14f). Yield: 81% of a pale
purple oil; H NMR (DMSO-d6, 400 MHz) d 1.90–2.10
A solution of the appropriate 3-(2,3-dihydro-1H-indol-
1-yl)-N,N-dimethyl-3-phenylpropan-1-amine (1.95 mmol)
in methylene chloride (10 mL) was treated with manga-
nese (IV) oxide (19.5 mmol, 1.70 g). The reaction mix-
ture was heated at reflux for 30 min after which time
the reaction was filtered through a pad of Celite which
was washed several times with methylene chloride. The
filtrate was then concentrated under reduced pressure,
and the product was purified via Biotage Horizonꢂ
[25 M, silica, gradient from 0% (20% methanol/methy-
lene chloride)/methylene chloride to 40% (20% metha-
nol/methylene chloride)/methylene chloride].
1
(m, 2H), 2.07 (s, 6H), 2.22–2.30 (m, 2H), 2.77–2.83 (m,
2H), 3.13 (q, J = 9.0 Hz, 1H), 3.50 (ddd, J = 6.8, 9.0,
9.0 Hz, 1H), 4.76 (t, J = 7.4 Hz, 1H), 6.41 (t,
J = 7.5 Hz, 1H), 6.50 (d, J = 7.8 Hz, 1H), 6.85–6.90
(m, 2H), 7.01 (ddd, J = 1.9, 7.8, 7.8 Hz, 1H), 7.11–7.15
(m, 2H), 7.31 (ddd, J = 6.0, 7.9, 7.9 Hz, 1H); MS (ES)
m/z 299.1; HRMS: calcd for C19H23FN2 + H+,
299.19180. Found (ESI, [M+H]+), 299.1906.
5.3.7. 3-(4-Fluoro-2,3-dihydro-1H-indol-1-yl)-3-(3-fluoro-
phenyl)-N,N-dimethylpropan-1-amine (14g). Yield: 64%
of a colorless oil; 1H NMR (DMSO-d6, 400 MHz) d
1.92–2.10 (m, 2H), 2.07 (s, 6H), 2.15–2.21 (m, 2H),
2.85 (t, J= 8.7 Hz, 2H), 3.23 (q, J = 9.1 Hz, 1H), 3.55
(q, J = 8.2 Hz, 1H), 4.74 (t, J = 7.1 Hz, 1H), 6.20 (t,
J = 8.5 Hz, 1H), 6.36 (d, J = 7.9 Hz, 1H), 6.90 (ddd,
J = 6.2, 7.9, 7.9 Hz, 1H), 7.03 (dddd, J = 1.8, 1.8, 9.1,
11.7 Hz, 1H), 7.10–7.15 (m, 2H), 7.31 (ddd, J = 5.9,
7.8, 7.8 Hz, 1H); MS (ES) m/z 317.1; HRMS: calcd for
C19H22F2N2 + H+, 317.1824. Found (ESI, [M+H]+),
317.1835.
5.4.1. 3-(1H-Indol-1-yl)-N,N-dimethyl-3-phenylpropan-1-
amine (15a). Yield: 98% of a colorless oil; 1H NMR
(DMSO-d6, 400 MHz) d 2.05–2.19 (m, 2H), 2.10 (s,
6H), 2.30–2.40 (m, 1H), 2.48–2.53 (m, 1H), 5.70 (dd,
J = 6.4, 9.0 Hz, 1H), 6.51 (d, J = 3.2 Hz, 1H), 6.98 (t,
J = 7.5 Hz, 1H), 7.06 (t, J = 7.6 Hz, 1H), 7.22 (t,
J = 7.2 Hz, 1H), 7.29 (t, J = 7.6 Hz, 3H), 7.35–7.37
(m, 2H), 7.50 (dd, J = 7.8, 14.1 Hz, 1H), 7.72 (d,
J = 3.2 Hz, 1H); MS (ES) m/z 279.1; HRMS: calcd for
C19H22N2 + H+, 279.18557. Found (ESI, [M+H]+),
279.1845.

P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
8461
5.4.2. 3-(4-Fluoro-1H-indol-1-yl)-N,N-dimethyl-3-phenyl-
propan-1-amine (15b). Yield: 74% of a colorless oil; H
C19H20F2N2 + H+, 315.16673. Found (ESI, [M+H]+),
315.1649.
1
NMR (DMSO-d6, 400 MHz) d 2.03–2.17 (m, 2H), 2.09
(s, 6H), 2.31–2.41 (m, 1H), 2.49–2.56 (m, 1H), 5.72
(dd, J = 6.4, 9.0 Hz, 1H), 6.58 (d, J = 3.2 Hz, 1H), 6.77
(dd, J = 7.8, 10.6 Hz, 1H), 7.06 (ddd, J = 5.4, 8.1,
8.1 Hz, 1H), 7.23 (t, J = 7.2 Hz, 1H), 7.31 (t,
J = 7.1 Hz, 2H), 7.37 (t, J = 6.9 Hz, 3H), 7.79 (d,
J = 3.2 Hz, 1H); MS (ES) m/z 297.2; HRMS: calcd for
C19H21FN2 + H+, 297.17615. Found (ESI, [M+H]+),
297.1659.
5.4.8. 3-(5-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N,N-
dimethylpropan-1-amine (15h). Yield: 71% of a colorless
oil; 1H NMR (DMSO-d6, 400 MHz) d 2.03–2.15 (m,
2H), 2.09 (s, 6H), 2.30–2.40 (m, 1H), 2.47–2.54 (m,
1H), 5.72 (dd, J = 6.4, 9.1 Hz, 1H), 6.52 (d,
J = 3.1 Hz, 1H), 6.93 (ddd, J = 2.4, 9.2, 9.2 Hz, 1H),
7.07 (ddd, J = 1.8, 7.8, 7.8 Hz, 1H), 7.19–7.23 (m,
2H), 7.29 (dd, J = 2.6, 9.9 Hz, 1H), 7.34 (q, J = 6.3
Hz, 1H), 7.53 (dd, J = 4.6, 9.1 Hz, 1H), 7.84 (d,
J = 3.2 Hz, 1H); MS (ES) m/z 315.2; HRMS: calcd
for C19H20F2N2 + H+, 315.16673. Found (ESI,
[M+H]+), 315.1652.
5.4.3. 3-(5-Fluoro-1H-indol-1-yl)-N,N-dimethyl-3-phenyl-
propan-1-amine (15c). Yield: 72% of a colorless oil; H
1
NMR (DMSO-d6, 400 MHz) d 2.02–2.16 (m, 2H), 2.09
(s, 6H), 2.30–2.40 (m, 1H), 2.45–2.53 (m, 1H), 5.65
(dd, J = 6.4, 9.0 Hz, 1H), 6.50 (d, J = 3.2 Hz, 1H), 6.92
(ddd, J = 2.6, 9.2, 9.2 Hz, 1H), 7.20–7.24 (m, 1H),
7.26–7.37 (m, 5H), 7.50 (dd, J = 4.5, 9.0 Hz, 2H), 7.80
(d, J = 3.2 Hz, 1H); MS (ES) m/z 297.2; HRMS: calcd
for C19H21FN2 + H+, 297.17615. Found (ESI,
[M+H]+), 297.1750.
5.4.9. 3-(6-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N,N-
dimethylpropan-1-amine (15i). Yield: 83% of a colorless
oil; 1H NMR (DMSO-d6, 400 MHz) d 2.02–2.17 (m,
2H), 2.09 (s, 6H), 2.31–2.39 (m, 1H), 2.49–2.54 (m,
1H), 5.68 (dd, J = 6.3, 9.2 Hz, 1H), 6.54 (d, J = 3.2 Hz,
1H), 6.86 (ddd, J = 6.4, 9.7, 9.7 Hz, 1H), 7.07 (ddd,
J = 2.1, 7.4, 7.4 Hz, 1H), 7.23–7.28 (m, 2H), 7.32–7.38
(m, 1H), 7.43 (dd, J = 2.3, 10.6 Hz, 1H), 7.52 (dd,
J = 5.5, 8.6 Hz, 1H), 7.76 (d, J = 3.3 Hz, 1H); MS (ES)
m/z 315.3; HRMS: calcd for C19H20F2N2 + H+,
315.1667. Found (ESI, [M+H]+), 315.1623.
5.4.4. 3-(6-Fluoro-1H-indol-1-yl)-N,N-dimethyl-3-phenyl-
propan-1-amine (15d). Yield: 75% of a colorless oil; H
1
NMR (DMSO-d6, 400 MHz) d 2.03–2.18 (m, 2H), 2.10
(s, 6H), 2.30–2.39 (m, 1H), 2.45–2.53 (m, 1H), 5.65
(dd, J = 6.4, 9.0 Hz, 1H), 6.52 (d, J = 3.2 Hz, 1H), 6.85
(ddd, J = 1.3, 7.4, 7.4 Hz, 1H), 7.23 (t, J = 7.6 Hz,
1H), 7.31 (t, J = 7.3 Hz, 2H), 7.36–7.40 (m, 3H), 7.51
(dd, J = 5.3, 8.7 Hz, 1H), 7.73 (d, J = 3.2 Hz, 1H) ;
MS (ES) m/z 297.2; HRMS: calcd for C19H21FN2 + H+,
297.17615. Found (ESI, [M+H]+), 297.1750.
5.4.10. 3-(7-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-
N,N-dimethylpropan-1-amine (15j). Yield: 78% of a col-
1
orless oil; H NMR (DMSO-d6, 400 MHz) d 2.10–2.20
(m, 2H), 2.11 (s, 6H), 2.31–2.40 (m, 1H), 2.49–2.58 (m,
1H), 5.93 (dd, J = 6.8, 8.8 Hz, 1H), 6.62 (dd, J = 2.4,
3.1 Hz, 1H), 6.85–6.98 (m, 2H), 7.04–7.10 (m, 3H),
7.31–7.39 (m, 2H), 7.84 (d, J = 3.2 Hz, 1H); MS (ES)
m/z 315.1; HRMS: calcd for C19H20F2N2 + H+,
315.1667. Found (ESI, [M+H]+), 315.1623.
5.4.5. 3-(7-Fluoro-1H-indol-1-yl)-N,N-dimethyl-3-phenyl-
propan-1-amine (15e). Yield: 89% of a colorless oil; H
1
NMR (DMSO-d6, 400 MHz) d 2.09–2.21 (m, 2H), 2.11
(s, 6H), 2.30–2.39 (m, 1H), 2.49–2.58 (m, 1H), 5.91
(dd, J = 6.8, 8.6 Hz, 1H), 6.60 (t, J = 2.4 Hz, 1H),
6.82–6.98 (m, 2H), 7.20–7.36 (m, 6H), 7.81 (d,
J = 3.2 Hz, 1H); MS (ES) m/z 297.1; HRMS: calcd for
C19H21FN2 + H+, 297.17615. Found (ESI, [M+H]+),
297.1772.
5.5. General procedure 3: 3-(1H-indol-1-yl)-N-methyl-3-
phenylpropan-1-amines (9a–9j)
A solution of 3-(1H-indol-1-yl)-N,N-dimethyl-3-phenyl-
propan-1-amine (1.38 mmol) in methylene chloride
(2 mL)
and
diisopropylethylamine
(0.42 mL,
5.4.6. 3-(3-Fluorophenyl)-3-(1H-indol-1-yl)-N,N-dimeth-
ylpropan-1-amine (15f). Yield: 88% of a colorless oil;
1H NMR (DMSO-d6, 400 MHz) d 1.99–2.12 (m, 2H),
2.04 (s, 6H), 2.26–2.48 (m, 1H), 2.49–2.50 (m, 1H),
5.68 (dd, J = 6.4, 9.2 Hz, 1H), 6.47 (d, J = 3.2 Hz, 1H),
6.94 (t, J = 7.1 Hz, 1H), 6.96–7.05 (m, 2H), 7.13–7.17
(m, 2H), 7.27 (ddd, J = 6.7, 8.3, 8.3 Hz, 1H), 7.46 (t,
J = 8.0, 2H), 7.70 (d, J = 3.2 Hz, 1H); MS (ES) m/z
297.1; HRMS: calcd for C19H21FN2 + H+, 297.17615.
Found (ESI, [M+H]+), 297.1761.
2.42 mmol) was treated with 1-chloroethyl chlorofor-
mate (0.26 mL, 2.42 mmol). The reaction mixture was
stirred at room temperature for 2 h (until the starting
material had disappeared as analyzed by TLC) after
which time the methylene chloride was evaporated at re-
duced pressure and the resulting residue was dissolved
in methanol (2 mL) and heated at reflux for 3 h. The
methanol was then evaporated at reduced pressure
and the product was purified via Biotage Horizonꢂ
[25 M, silica, gradient from 0% (20% methanol/methy-
lene chloride)/methylene chloride to 60% (20% metha-
nol/methylene chloride)/methylene chloride]. The
purified product was converted to the hydrochloride
salt by dissolving the free base in methylene chloride
(2 mL) and adding a 4 N HCl solution in dioxane (1.2
equiv). The solvents were then evaporated at reduced
pressure and the resulting residue was dissolved in water
(2 mL) and lyophilized to afford the hydrochloride salt
as a white powder.
5.4.7. 3-(4-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N,N-
dimethylpropan-1-amine (15g). Yield: 74% of a colorless
oil; 1H NMR (DMSO-d6, 400 MHz) d 2.02–2.17 (m,
2H), 2.09 (s, 6H), 2.31–2.42 (m, 1H), 2.49–2.59 (m,
1H), 5.75 (dd, J = 6.4, 9.1 Hz, 1H), 6.60 (d, J = 3.3 Hz,
1H), 6.79 (dd, J = 7.6, 10.6 Hz, 1H), 7.02–7.10 (m,
2H), 7.20–7.28 (m, 2H), 7.31–7.41 (m, 2H), 7.82 (d,
J = 3.3 Hz, 1H); MS (ES) m/z 315.2; HRMS: calcd for

8462
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
5.5.1.
3-(1H-Indol-1-yl)-N-methyl-3-phenylpropan-1-
2H), 7.76 (d, J = 3.2 Hz, 1H), 8.83 (br s, 2H); MS (ES)
m/z 283.1; HRMS: calcd for C18H19FN2 + H+,
283.1605. Found (ESI, [M+H]+), 283.1570.
amine hydrochloride (9a). Yield: 72%; 1H NMR
(DMSO-d6, 400 MHz) d 2.24 (s, 3H), 2.31–2.43 (m,
3H), 2.47–2.52 (m, 1H), 5.76 (dd, J = 6.2, 8.5 Hz, 1H),
6.51 (d, J = 3.2 Hz, 1H), 6.98 (t, J = 7.8 Hz, 1H), 7.07
(t, J = 8.2 Hz, 1H), 7.22 (t, J = 7.1 Hz, 1H), 7.27–7.35
(m, 5H), 7.51 (dd, J = 7.7, 12.4 Hz, 1H), 7.70 (d,
J = 3.2 Hz, 1H), 8.74 (br s, 2H); MS (ES) m/z 265.1;
HRMS: calcd for C18H20N2 + H+, 265.16992. Found
(ESI, [M+H]+), 265.1682.
5.5.7. 3-(4-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N-
methylpropan-1-amine hydrochloride (9g). Yield: 91%;
1H NMR (DMSO-d6, 400 MHz) d 2.52 (s, 3H), 2.60–
2.69 (m, 1H), 2.71–2.82 (m, 2H), 2.86–2.92 (m, 1H),
6.00 (br s, 1H), 6.65 (d, J = 3.3 Hz, 1H), 6.82 (dd,
J = 7.8, 10.5 Hz, 1H), 7.07–7.13 (m, 2H), 7.20 (d,
J = 7.8 Hz, 1H), 7.25 (dd, J = 2.3, 9.73 Hz, 1H), 7.25
(q, J = 6.2 Hz, 1H), 7.45 (d, J = 8.3 Hz, 1H), 7.84 (d,
J = 3.3 Hz, 1H), 9.23 (br s, 2H); MS (ES) m/z 301.0;
HRMS: calcd for C18H18F2N2 + H+, 301.1510. Found
(ESI, [M+H]+), 301.1503.
5.5.2. 3-(4-Fluoro-1H-indol-1-yl)-N-methyl-3-phenylpro-
pan-1-amine hydrochloride (9b). Yield: 71%; H NMR
1
(DMSO-d6, 400 MHz) d 2.53 (s, 3H), 2.59–2.66 (m,
1H), 2.72–2.82 (m, 2H), 2.87–2.91 (m, 1H), 5.95 (dd,
J = 6.0, 8.3 Hz, 1H), 6.63 (d, J = 3.2 Hz, 1H), 6.80 (dd,
J = 7.7, 10.5 Hz, 1H), 7.09 (ddd, J = 5.4, 8.1, 8.1 Hz,
1H), 7.25–7.29 (m, 1H), 7.32–7.38 (m, 4H), 7.42 (d,
J = 8.3 Hz, 1H), 7.80 (d, J = 3.2 Hz, 1H), 9.10 (br s,
2H); MS (ES) m/z 283.0; HRMS: calcd for
C18H19FN2 + H+, 283.16050. Found (ESI, [M+H]+),
283.1597.
5.5.8. 3-(5-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N-
methylpropan-1-amine hydrochloride (9h). Yield: 68%;
1H NMR (DMSO-d6, 400 MHz) d 2.45–2.58 (m, 1H),
2.50 (s, 3H), 2.60–2.78 (m, 2H), 2.79–2.90 (m, 1H),
5.87 (dd, J = 6.8, 8.7 Hz, 1H), 6.53 (d, J = 3.2 Hz, 1H),
6.93 (ddd, J = 2.6, 9.2, 9.2 Hz, 1H), 7.07 (dddd,
J = 1.8, 1.8, 8.3, 8.3 Hz, 1H), 7.11–7.17 (m, 2H), 7.28
(dd, J = 2.4, 9.7 Hz, 1H), 7.34 (ddd, J = 6.3, 8.1,
8.1 Hz, 1H), 7.50 (dd, J = 4.4, 9.0 Hz, 1H), 7.78 (d,
J = 3.2 Hz, 1H), 8.78 (br s, 2H); MS (ES) m/z 301.0;
HRMS: calcd for C18H18F2N2 + H+, 301.1510. Found
(ESI, [M+H]+), 301.1530.
5.5.3. 3-(5-Fluoro-1H-indol-1-yl)-N-methyl-3-phenylpro-
pan-1-amine hydrochloride (9c). Yield: 71%; H NMR
1
(DMSO-d6, 400 MHz) d 2.52 (s, 3H), 2.52–2.63 (m, 1H),
2.71–2.79 (m, 2H), 2.85–2.90 (m, 1H), 5.92 (dd, J = 6.3,
8.8 Hz, 1H), 6.55 (d, J = 3.2 Hz, 1H), 6.95 (ddd, J = 2.6,
9.4, 9.4 Hz, 1H), 7.24–7.35 (m, 6H), 7.42 (dd, J = 4.5,
9.0 Hz, 1H), 7.82 (d, J = 3.2 Hz, 1H), 9.03 (br s, 2H);
MS (ES) m/z 283.0; HRMS: calcd for C18H19FN2 + H+,
283.1605. Found (ESI, [M+H]+), 283.1602.
5.5.9. 3-(6-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N-
methylpropan-1-amine hydrochloride (9i). Yield: 78%;
1H NMR (DMSO-d6, 400 MHz) d 2.52–2.62 (m, 1H),
2.55 (s, 3H), 2.66–2.79 (m, 2H), 2.83–2.93 (m, 1H),
5.88 (t, J = 8.1 Hz, 1H), 6.60 (d, J = 3.2 Hz, 1H), 6.90
(dddd, J = 2.3, 8.7, 8.7, 10.9 Hz, 1H), 7.13 (ddd,
J = 1.9, 8.3, 8.3 Hz, 1H), 7.20–7.25 (m, 2H), 7.40 (ddd,
J = 6.2, 7.9 Hz, 1H), 7.46 (dd, J = 1.9, 8.7 Hz, 1H),
7.55 (dd, J = 5.5, 7.9 Hz, 1H), 7.74 (d, J = 3.2 Hz, 1H),
8.81 (br s, 2H); MS (ES) m/z 301.0; HRMS: calcd for
C18H18F2N2 + H+, 301.1510. Found (ESI, [M+H]+),
301.1477.
5.5.4. 3-(6-Fluoro-1H-indol-1-yl)-N-methyl-3-phenylpro-
pan-1-amine hydrochloride (9d). Yield: 69%; H NMR
1
(DMSO-d6, 400 MHz) d 2.53 (s, 3H), 2.53–2.63 (m,
1H), 2.72–2.80 (m, 2H), 2.86–2.91 (m, 1H), 5.88 (dd,
J = 6.2, 8.6 Hz, 1H), 6.57 (d, J = 3.1 Hz, 1H), 6.88
(dddd, J = 2.4, 2.4, 9.7, 11.0 Hz, 1H), 7.25–7.29 (m,
1H), 7.32–7.39 (m, 4H), 7.45 (dd, J = 2.2, 10.6 Hz,
1H), 7.54 (dd, J = 5.5, 8.6 Hz, 1H), 7.72 (d, J = 3.3 Hz,
1H), 9.04 (br s, 2H); MS (ES) m/z 283.0; HRMS: calcd
for C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1602.
5.5.10. 3-(7-Fluoro-1H-indol-1-yl)-3-(3-fluorophenyl)-N-
methylpropan-1-amine hydrochloride (9j). Yield: 89%;
1H NMR (DMSO-d6, 400 MHz) d 2.54 (s, 3H), 2.54–
2.64 (m, 1H), 2.71–2.89 (m, 2H), 2.92–3.01 (m, 1H),
5.97 (dd, J = 5.6, 9.7 Hz, 1H), 6.68 (t, J = 2.7 Hz, 1H),
6.90 (dd, J = 7.7, 13.2 Hz, 1H), 6.96–7.06 (m, 3H),
7.11 (ddd, J = 2.2, 8.8, 8.8 Hz, 1H), 7.35–7.41 (m, 2H),
7.86 (d, J = 3.3 Hz, 1H), 9.00 (br s, 2H); MS (ES) m/z
301.0; HRMS: calcd for C18H18F2N2 + H+, 301.1510.
Found (ESI, [M+H]+), 301.1528.
5.5.5. 3-(7-Fluoro-1H-indol-1-yl)-N-methyl-3-phenylpro-
pan-1-amine hydrochloride (9e). Yield: 91%; H NMR
1
(DMSO-d6, 400 MHz) d 2.49–2.60 (m, 1H), 2.56 (s,
3H), 2.67–2.90 (m, 2H), 2.92–3.00 (m, 1H), 5.92 (dd,
J = 5.8, 9.6 Hz, 1H), 6.66 (t, J = 3.1 Hz, 1H), 6.90 (dd,
J = 7.2, 13.2 Hz, 1H), 6.98 (ddd, J = 4.6, 7.8, 7.8 Hz,
1H), 7.21–7.38 (m, 6H), 7.80 (d, J = 3.3 Hz, 1H), 8.68
(br s, 2H); MS (ES) m/z 283.0; HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1624.
5.6. General procedure 4: chiral supercritical fluid chro-
matography resolution of 3-(1H-indol-1-yl)-N-methyl-3-
phenylpropan-1-amines (16a–16j and 17a–17j)
5.5.6. 3-(3-Fluorophenyl)-3-(1H-indol-1-yl)-N-methylpro-
pan-1-amine hydrochloride (9f). Yield: 84%; H NMR
1
The racemic material was dissolved in methanol at a
concentration of approximately 40 mg/mL, and the
resulting solution was injected onto the Supercritical
Fluid Chromatography (SFC) instrument with a volume
of 1.0 mL per injection. The baseline resolved enantio-
mers were collected using a Berger MultiGram Prep
(DMSO-d6, 400 MHz) d 2.53 (s, 3H), 2.55–2.68 (m,
1H), 2.70–2.79 (m, 2H), 2.85–2.92 (m, 1H), 5.93 (dd,
J = 6.4, 8.6 Hz, 1H), 6.58 (t, J = 3.2 Hz, 1H), 7.02 (t,
J = 7.7 Hz, 1H), 7.08–7.13 (m, 2H), 7.17–7.20 (m, 2H),
7.38 (ddd, J = 5.9, 8.2, 8.2 Hz, 1H), 7.55 (d, J = 8.2 Hz,

P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
8463
SFC (Berger Instruments, Inc. Newark, DE) under the
following conditions: Chiralcel OD-H SFC column
(5l, 250 mm L · 20 mm ID, Chiral Technologies, Inc,
Exton, PA), 35 ꢁC column temperature, 20% MeOH
with 0.2% DEA as CO2 modifier, 50 mL/min flow rate,
100 bar outlet pressure, 220 nm UV detection. The chi-
ral purity of each enantiomer was determined under
the same SFC conditions using a Chiralcel OD column
(10 l, 250 mm L · 4.6 mm ID) at 2.0 mL/min flow rate
on a Berger Analytical SFC instrument. Each enantio-
mer was converted to the hydrochloride salt by dissolv-
ing the free base in methylene chloride (2 mL) and
adding a 4 N HCl solution in dioxane (1.2 equiv). The
solvents were then evaporated at reduced pressure and
the resulting residue was dissolved in water (2 mL) and
lyophilized to afford the hydrochloride salt as a white
powder.
5.6.7. (3R)-3-(6-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (16d). The enantiomeric purity was
determined to be 99.6% (with 0.4% of the undesired
25
enantiomer) isolated as peak 2; tR: 15.31 min; ½aꢁ
D
86.9 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1617.
5.6.8. (3S)-3-(6-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (17d). The enantiomeric purity was
determined to be 98.3% (with 1.7% of the undesired
25
enantiomer) isolated as peak 1; tR: 13.91 min; ½aꢁ
D
ꢀ92.0 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1628.
5.6.9. (3R)-3-(7-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (16e). The enantiomeric purity was
determined to be 99.3% (with 0.7% of the undesired
5.6.1. (3R)-3-(1H-Indol-1-yl)-N-methyl-3-phenylpropan-
1-amine (16a). The enantiomeric purity was determined
to be 99.5% (with 0.5% of the undesired enantiomer) iso-
25
D
enantiomer) isolated as peak 2; tR: 6.98 min; ½aꢁ
138.2 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1577.
25
lated as peak 2; tR: 11.28 min; ½aꢁ 79.2 ꢁ (c 10 mg/mL,
D
MeOH); HRMS: calcd for C18H20N2 + H+, 265.1699.
Found (ESI, [M+H]+), 265.1703.
5.6.10. (3S)-3-(7-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (17e). The enantiomeric purity was
determined to be >99.9% (with <0.1% of the undesired
5.6.2. (3S)-3-(1H-Indol-1-yl)-N-methyl-3-phenylpropan-
1-amine (17a). The enantiomeric purity was determined
to be >99.9% (with <0.1% of the undesired enantiomer)
25
enantiomer) isolated as peak 1; tR: 5.60 min; ½aꢁ
D
25
isolated as peak 1; tR: 6.39 min; ½aꢁ ꢀ80.2 ꢁ (c 10 mg/
ꢀ144.8 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1585.
D
mL, MeOH); HRMS: calcd for C18H20N2 + H+,
265.1699. Found (ESI, [M+H]+), 265.1690.
5.6.3. (3R)-3-(4-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (16b). The enantiomeric purity was
determined to be >99.9% (with <0.1% of the undesired
5.6.11. (3R)-3-(3-Fluorophenyl)-3-(1H-indol-1-yl)-N-
methylpropan-1-amine (16f). The enantiomeric purity
was determined to be >99.9% (with <0.1% of the unde-
sired enantiomer) isolated as peak 2; retention time:
25
enantiomer) isolated as peak 2; tR: 7.80 min; ½aꢁ
D
25
D
79.9 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1613.
11.28 min; ½aꢁ 67.9 ꢁ (c 10 mg/mL, MeOH); HRMS:
calcd for C18H19FN2 + H+, 283.1605. Found (ESI,
[M+H]+), 283.1581.
5.6.4. (3S)-3-(4-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (17b). The enantiomeric purity was
determined to be >99.9% (with <0.1% of the undesired
5.6.12. (3S)-3-(3-Fluorophenyl)-3-(1H-indol-1-yl)-N-
methylpropan-1-amine (17f). The enantiomeric purity
was determined to be >99.9% (with <0.1% of the unde-
25
25
D
enantiomer) isolated as peak 1; tR: 4.25 min; ½aꢁ
sired enantiomer) isolated as peak 1; tR: 5.18 min; ½aꢁ
D
ꢀ90.2 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1622.
ꢀ68.9 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1599.
5.6.5. (3R)-3-(5-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (16c). The enantiomeric purity was
determined to be >99.9% (with <0.1% of the undesired
5.6.13. (3R)-3-(4-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (16g). The enantiomeric
purity was determined to be 99.3% (with 0.7% of the
enantiomer) isolated as peak 2; retention time:
undesired enantiomer) isolated as peak 2; tR: 5.83 min;
25
D
25
D
7.94 min; ½aꢁ 70.4 ꢁ (c 10 mg/mL, MeOH); HRMS:
½aꢁ 70.1 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
calcd for C18H19FN2 + H+, 283.1605. Found (ESI,
[M+H]+), 283.1589.
C18H18F2N2 + H+, 301.1511. Found (ESI, [M+H]+),
301.1493.
5.6.6. (3S)-3-(5-Fluoro-1H-indol-1-yl)-N-methyl-3-phe-
nylpropan-1-amine (17c). The enantiomeric purity was
determined to be >99.9% (with <0.1% of the undesired
5.6.14. (3S)-3-(4-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (17g). The enantiomeric
purity was determined to be 99.8% (with 0.2% of the
25
enantiomer) isolated as peak 1; tR: 5.10 min; ½aꢁ
undesired enantiomer) isolated as peak 1; tR: 4.95 min;
D
25
D
ꢀ76.0 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H19FN2 + H+, 283.1605. Found (ESI, [M+H]+),
283.1596.
½aꢁ ꢀ67.8 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H18F2N2 + H+, 301.1511. Found (ESI, [M+H]+),
301.1506.

8464
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
5.6.15. (3R)-3-(5-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (16h). The enantiomeric
purity was determined to be 99.1% (with 0.9% of the
temperature. The reaction mixture was diluted with
ethyl acetate (20 mL) and washed with aqueous
sodium bicarbonate, water, and brine. The organic
layer was dried (anhydrous sodium sulfate) and con-
centrated. The crude oil was purified by Isco flash
column chromatography (silica, 0–15% EtOAc/
hexane) to give 237 mg (44%) of pure product as a
viscous, colorless liquid. 1H NMR (CDCl3,
400 MHz) d 2.40 (m, 1H), 2.52 (m, 1H), 2.90 (m,
2H), 3.20 (dd, J = 17.9, 8.6 Hz, 1H), 3.41 (dd,
J = 15.8, 8.8 Hz, 1H), 3.58 (m, 1H), 3.68 (m, 1H),
4.94 (dd, J = 8.3, 6.8 Hz, 1H), 6.61 (m, 2H), 7.03
(m, 2H), 7.26–7.35 (m, 5H); MS (ESI) m/z 272.0
([M+H]+).
undesired enantiomer) isolated as peak 2; tR:
25
D
10.15 min; ½aꢁ 71.0 ꢁ (c 10 mg/mL, MeOH); HRMS:
calcd for C18H18F2N2 + H+, 301.1511. Found (ESI,
[M+H]+), 301.1510.
5.6.16. (3S)-3-(5-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (17h). The enantiomeric
purity was determined to be 99.7% (with 0.3% of the unde-
25
sired enantiomer) isolated as peak 1; tR: 8.30 min; ½aꢁ
D
ꢀ73.1 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H18F2N2 + H+, 301.1511. Found (ESI, [M+H]+),
301.1514.
5.8. 1-[(1R)-3-Chloro-1-phenylpropyl]-1H-indole (19)
5.6.17. (3R)-3-(6-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (16i). The enantiomeric
purity was determined to be 99.8% (with 0.2% of the
A
mixture of 1-[(1R)-3-chloro-1-phenylpropyl]indo-
line18 (160 mg, 0.589 mmol) and activated manganese
dioxide (512 mg, 5.89 mmol) in anhydrous 1,2-dichlo-
roethane (5 mL) was heated at 70 ꢁC with stirring for
30 min. The reaction mixture was diluted with ethyl
acetate (5 mL), filtered through a pad of silica gel,
and concentrated to give 156 mg (98%) of pure product
as a viscous, colorless liquid. 1H NMR (CDCl3,
400 MHz) d 2.69 (m, 1H), 2.78 (m, 1H), 3.35 (m,
1H), 3.50 (dt, J = 11.1, 5.6 Hz, 1H), 5.80 (dd, J = 9.4,
5.9 Hz, 1H), 6.55 (d, J = 3.3 Hz, 1H), 7.05–7.35 (m,
9H), 7.60 (d, J = 7.7 Hz, 1H); MS (ESI) m/z 270.0
([M+H]+).
undesired enantiomer) isolated as peak 2; tR:
25
D
10.15 min; ½aꢁ 73.5 ꢁ (c 10 mg/mL, MeOH); HRMS:
calcd for C18H18F2N2 + H+, 301.1511. Found (ESI,
[M+H]+), 301.1507.
5.6.18. (3S)-3-(6-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (17i). The enantiomeric
purity was determined to be 98.9% (with 1.1% of the
undesired enantiomer) isolated as peak 1; tR:
25
D
10.24 min; ½aꢁ ꢀ89.2 ꢁ (c 10 mg/mL, MeOH); HRMS:
calcd for C18H18F2N2 + H+, 301.1511. Found (ESI,
[M+H]+), 301.1525.
5.9. (3R)-3-(1H-indol-1-yl)-N-methyl-3-phenylpropan-1-
amine hydrochloride (16a)
5.6.19. (3R)-3-(7-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (16j). The enantiomeric
purity was determined to be 99.8% (with 0.2% of the
A mixture of 1-[(1R)-3-chloro-1-phenylpropyl]-1H-in-
dole 19 (150 mg, 0.556 mmol) and ethanolic methyl-
amine (33% in EtOH, 5 mL) in a sealed reaction vessel
was heated at 90 ꢁC for 3 h. All volatiles were removed
under reduced pressure. The oil residue was dissolved
in methylene chloride (15 mL), washed with aqueous
potassium carbonate (10 mL), dried (anhydrous sodium
sulfate), concentrated, and purified by Isco flash column
chromatography (silica, 0–15% MeOH/CH2Cl2) to give
110 mg (75%) of pure free base product as a viscous, col-
orless liquid. This was dissolved in dichloromethane
(3 mL) and treated with an ethereal solution of hydro-
chloric acid (1 M, 0.5 mL, and 0.5 mmol) with swirling.
To the resulting solution was added hexane until white
precipitate formed, which was collected, washed with
hexane, and dried in vacuo to yield 119 mg (71%) of
pure hydrochloride salt as a white powder. The enantio-
undesired enantiomer) isolated as peak 2; tR: 4.91 min;
25
D
½aꢁ 111.9 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H18F2N2 + H+, 301.1511. Found (ESI, [M+H]+),
301.1490.
5.6.20. (3S)-3-(7-Fluoro-1H-indol-1-yl)-3-(3-fluorophe-
nyl)-N-methylpropan-1-amine (17j). The enantiomeric
purity was determined to be 99.1% (with 0.9% of the
undesired enantiomer) isolated as peak 1; tR: 4.78 min;
25
D
½aꢁ ꢀ95.9 ꢁ (c 10 mg/mL, MeOH); HRMS: calcd for
C18H18F2N2 + H+, 301.1511. Found (ESI, [M+H]+),
301.1527.
5.7. 1-[(1R)-3-Chloro-1-phenylpropyl]indoline (18)
To a solution of (S)-(ꢀ)-3-chloro-1-phenyl-1-propa-
25
D
nol, purchased from Aldrich, 99% ee, ½aꢁ ꢀ25 ꢁ (c
meric purity was determined to be 91% (with 9% of the
25
D
10 mg/mL, CDCl3) (342 mg, 2.00 mmol) in dry dieth-
yl ether (8 mL) was added triethylamine (0.84 mL,
6.00 mmol) and the solution was cooled to 0 ꢁC in
an ice bath. Methanesulfonyl chloride (0.187 mL,
2.40 mmol) was added dropwise via a syringe. After
stirring at 0 ꢁC for 30 min, additional triethylamine
(0.56 mL, 4.00 mmol) was added, followed by slow
addition of indoline (0.28 mL) and the resulting mix-
ture was stirred for 48 h while warming to room
undesired enantiomer); tR: 11.22 min; ½aꢁ 79.3 ꢁ (c
1
10 mg/mL, MeOH). H NMR (DMSO-d6, 400 MHz) d
2.47 (s, 3H), 2.57 (m, 1H), 2.71 (m, 2H), 2.84 (m, 1H),
5.80 (dd, J = 8.8, 6.3 Hz, 1H), 6.50 (d, J = 3.2 Hz, 1H),
6.95 (t, J = 7.9 Hz, 1H), 7.04 (t, J = 8.2 Hz, 1H), 7.17–
7.30 (m, 5H), 7.48 (d, J = 9.0 Hz, 2H), 7.67 (d,
J = 3.3 Hz, 1H), 9.02 (br s, 2H); HRMS: m/z calcd for
C18H20N2 + H+, 265.1699. Found (ESI, [M+H]+),
265.1685.

P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
8465
5.10. General procedure 5: norepinephrine (NE) uptake
assay in cells expressing human norepinephrine trans-
porter (hNET)
terminated by vacuum filtration (Brandel) through What-
man glass fiber filters (GF/B paper), presoaked in 0.5%
polyethylenimine/H2O (PEI; Sigma Cat. No. P-3143) fol-
lowed by six washes with 800 ll of ice-cold wash buffer
(50 mM Tris–HCl, 0.9% NaCl, pH 7.4 at 4 ꢁC). Filter cir-
cles were removed to 20 ml glass vials, mixed with 5 ml of
scintillation cocktail (OptiFlour; Perkin-Elmer), and
incubated at room temperature for 8 h. The vials were
counted and DPMs were determined using a Perkin-El-
mer liquid scintillation analyzer.
5.10.1. Cell preparation. [3H] NE uptake studies were
performed using MDCK-Net6 cells stably expressing
human norepinephrine transporter (hNET)15 cultured
in growth medium containing high glucose DMEM
(Gibco, Cat. No. 11995), 10% FBS (dialyzed, heat-inac-
tivated, US Bio-Technologies, Lot FBD1129HI) and
500 lg/ml G418 (Gibco, Cat. No. 10131). Cells were
seeded at 300,000/T75 flask and split twice weekly.
5.12. General procedure 7: serotonin (hSERT) uptake
assay in cells expressing human serotonin transporter
5.10.2. Norepinephrine (NE) uptake assay. All uptake
experiments were performed in 96-well plates (Falcon
Optilux, cat #353947) in a total volume of 250 ll/well.
MDCK-Net6 cells were plated at 6000 cells/well. At
the time of the assay, the media were removed, and
200 ll assay buffer (25 mM Hepes, 120 mM NaCl,
5 mM KCl, 2.5 mM CaCl2, 1.2 mM MgSO4Æ7H2O,
2 mg/ml glucose, 0.2 mg/ml ascorbic acid, and 1 lM
pargyline, pH 7.4) was added to each well. Twenty-five
microliters of each test compound was subsequently
added to plates in triplicate and incubated at 37 ꢁC for
5 min. All test compounds were dissolved in 100%
DMSO and diluted in 4% DMSO/H2O, and assayed
using a 7-point dose response curve (1 nM–10 lM).
Next, 25 ll [3H] NE (74.9 Ci/mmol, Perkin-Elmer,
Boston, MA) was added to all wells and incubated at
37 ꢁC for an additional 5 min. The final concentration
of [3H] NE was 16 nM. The reaction mixture was termi-
nated by aspiration and washed with ice-cold 50 mM
Tris (pH 7.4). The plates were left to air dry for roughly
30 min, and the MDCK-Net6 cells were lysed by the
addition of 25 ll of 0.25 M NaOH. Hundred microliters
of Microscint-20 was added to each well (Packard,
Perkin-Elmer, Boston, MA), and the plates were count-
ed using a TopCount (Perkin-Elmer, Downer’s Grove,
IL) liquid scintillation counter.
5.12.1. Cell preparation. [3H] 5-HT uptake studies were
performed using JAR cells (human placental choriocar-
cinoma; ATCC Cat. No. HTB-144) natively expressing
the human serotonin transporter (hSERT), and cultured
in growth medium containing RPMI 1640 (Gibco, Cat.
No. 72400), 10% FBS (Irvine, Cat. No. 3000), 1% sodi-
um pyruvate (Gibco, Cat. No. 1136), and 0.25% glucose.
Cells were seeded at 250,000 cells/T75 flask and split
twice weekly. For the SERT uptake assay, JAR cells
were incubated for 24 h with 40 nM staurosporine to en-
hance the expression of the hSERT. Following an addi-
tional 24 h the cells were assayed for the [3H] 5-HT
uptake.16
5.12.2. Serotonin (5-HT) uptake assay. All uptake exper-
iments were performed in 96-well plates (Falcon Opti-
lux, cat #353947) in a total volume of 250 ll/well.
JAR cells were plated at 90,000 cells/well. At the time
of the assay, the media was removed, and 200 ll assay
buffer (25 mM Hepes, 120 mM NaCl, 5 mM KCl,
2.5 mM CaCl2, 1.2 mM MgSO4Æ7H2O, 2 mg/ml glucose,
0.2 mg/ml ascorbic acid, 1 lM pargyline, pH 7.4) was
added to each well. Twenty-five microliters of each test
compound was subsequently added to plates in triplicate
and incubated at 37 ꢁC for 5 min. All test compounds
were dissolved in 100% DMSO and diluted in 4%
DMSO/H2O, and assayed using a 7-point dose–response
curve (1 nM–10 lM). Next, 25 ll [3H] 5-HT (30 Ci/
mmol, Perkin-Elmer, Boston, MA) was added to all
wells for the SERT assay and incubated at 37 ꢁC for
an additional 5 min. The final concentration of [3H] 5-
HT was 12 nM. The reaction mixture was terminated
by aspiration and the mixture was washed with ice-cold
50 mM Tris (pH 7.4). The plates were centrifuged
(3000 rpm for 5 min) prior to aspiration of the superna-
tant. The JAR cells underwent another wash step, cen-
trifuged, and aspirated again. The plates were left to
air dry for roughly 30 min, and the JAR cells were lysed
by the addition of 25 ll of 0.25 M NaOH. Hundred
microliters of Microscint-20 was added to each well
(Packard, Perkin-Elmer, Boston, MA), and the plates
were counted using a TopCount (Perkin-Elmer, Down-
er’s Grove, IL) liquid scintillation counter.
5.11. General procedure 6: radioligand binding assay in
membranes containing the human norepinephrine
transporter
Frozen membranes (Perkin-Elmer RBHNETM, 2.8 mg/
ml), were suspended in binding buffer (50 mM Tris–
HCl, 300 mM NaCl, and 5 mM KCl, pH 7.4) and pre-
pared to approximately 2.8 lg protein per 20 ll aliquot.
Test compounds were dissolved in 100% DMSO to
10 mM and further dilutions (0.1–10 lM) made in 4%
DMSO/H2O. Binding reactions were incubated in poly-
propylene 96-well format strip tubes (Denville Scientific;
Cat. No. B1259). Binding buffer (100 ll) was added to
each assay tube followed by the addition of 20 ll of 2·
binding buffer to account for compounds diluted in 4%
DMSO/H2O. Compounds were added at a volume of
20 ll. Next, 40 ll of the radioligand, [3H] nisoxetine,
diluted in binding buffer, was dispensed to yield a final as-
say concentration of 4 nM. Non-specific binding was
determined by a saturating concentration of desipramine
(1 lM; prepared as the test compounds). The reactions
were vortexed and incubated while shaking for 60 min
at room temperature. The binding reaction mixture was
5.13. General procedure 8: dopamine transporter (hDAT)
membrane binding assay
Frozen membranes (Perkin-Elmer RBHDATM) were
suspended in binding buffer (50 mM Tris–HCl, 100 mM

8466
P. E. Mahaney et al. / Bioorg. Med. Chem. 14 (2006) 8455–8466
NaCl, pH 7.4) and prepared to approximately 9.8 lg pro-
tein/ml, and 160 ll of the homogenized suspended mem-
branes was added to polypropylene 96-well format strip
tubes (Denville Scientific; Cat. No. B1259). Test com-
pounds were dissolved in 100% DMSO to 10 mM and
further dilutions (0.1–10 lM) made in 4% DMSO/H2O.
Compounds were added at a volume of 20 ll and pre-in-
cubated with the test compounds for 20 min at 4 ꢁC on a
Titer Plate Shaker at a speed setting of six. Next, 20 ll of
the radioligand, [3H] WIN-35,428, diluted in binding
buffer, was dispensed to yield a final assay concentration
of 32 nM, the Kd value estimated for [3H] WIN-35,428
for hDAT membranes was 29.7 nM. Non-specific bind-
ing was determined by a saturating concentration of
mazindol (10 lM; prepared as the test compounds).
The reactions were vortexed and incubated while shaking
for 2 h at 4 ꢁC. The binding reaction mixture was termi-
nated by vacuum filtration (Brandel) through Whatman
glass fiber filters (GF/B paper), presoaked in 0.5% poly-
ethylenimine/H2O (PEI; Sigma Cat. No. P-3143) fol-
lowed by six washes with 800 ll of ice cold wash buffer
(50 mM Tris–HCl, 0.9% NaCl, pH 7.4 at 4 ꢁC). Filter cir-
cles were removed to 7 ml glass vials, mixed with 5 ml of
scintillation cocktail (OptiFlour; Perkin-Elmer), and
incubated at room temperature for 8 h. The vials were
counted and DPMs were determined using a Perkin-El-
mer liquid scintillation analyzer.
Taylor Spangler, and Kelly Sullivan for performing
the biological assays.
References and notes
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5.14. General procedure 9: analysis of results
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Positive controls were run on each plate for all assays.
Calculations of IC50 were performed using a sigmoidal
non-linear regression program (Prism Graphpad 3 Soft-
ware, San Diego, CA). In this program, maximum up-
take is represented by those wells supplemented with
assay buffer, and non-specific uptake is determined by
wells treated with positive controls.
13. Olofson, R. A.; Martz, J. T.; Senet, J.-P.; Piteau, M.;
Malfroot, T. J. Org. Chem. 1984, 49, 2081–2082.
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method. The mass spectrometry was performed on a
Waters ZQ quadrupole MS scanned from 100 to 800 amu.
The UV was detected on a Waters 996 PDA at 254 nm.
The LC was performed on a Waters 2790 HPLC instru-
ment using a Keystone Aquasil column (2 · 50 mm, 5 lm).
All compounds were run using a linear gradient from
100% mobile phase A (95:5 water/CH3CN with 10 mM
ammonium acetate) to 100% mobile phase B (95:5
CH3CN/water with 10 mM ammonium acetate) over
4 min at a rate of 0.8 mL/min.
Acknowledgments
The authors thank members of the Discovery Analytical
Chemistry group in Chemical Technologies at Wyeth,
particularly Scott Brecker, Christopher Petucci, Rebecca
Dooley, Diane Andraka and Oliver McConnell for com-
pound analysis. Their efforts and dedication are greatly
appreciated. In addition, we thank Geoff Hornby,
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