Discovery of novel 1-azoniabicyclo[2.2.2]octane muscarinic acetylcholine receptor antagonists

Article abstract of DOI:10.1021/jm801601v

A novel 4-hydroxyl(diphenyl)methyl substituted quinuclidine series was discovered as a very promising class of muscarinic antagonists. The structure-activity relationships of the connectivity of the diphenyl moiety to the quinuclidine core and around the ring nitrogen side chain are described. Computational docking studies using an homology model of the M₃ receptor readily explained the observed structure-activity relationship of the various compounds. Compound 14o was identified as a very potent, slowly reversible M₃ antagonist with a very long in vivo duration of bronchoprotection.

Full text of DOI:10.1021/jm801601v

J. Med. Chem. 2009, 52, 2493–2505
2493
Discovery of Novel 1-Azoniabicyclo[2.2.2]octane Muscarinic Acetylcholine Receptor Antagonists
Dramane I. Laine´,* Brent McCleland, Sonia Thomas, Christopher Neipp, Brian Underwood, Jeremy Dufour,
Katherine L. Widdowson, Michael R. Palovich, Frank E. Blaney, James J. Foley, Edward F. Webb, Mark A. Luttmann,
Miriam Burman, Kristen Belmonte, and Michael Salmon
GlaxoSmithKline, Respiratory CEDD, 709 Swedeland Road, P.O. Box 1539, King of Prussia, PennsylVania 19406-0939
ReceiVed December 18, 2008
A novel 4-hydroxyl(diphenyl)methyl substituted quinuclidine series was discovered as a very promising
class of muscarinic antagonists. The structure-activity relationships of the connectivity of the diphenyl
moiety to the quinuclidine core and around the ring nitrogen side chain are described. Computational docking
studies using an homology model of the M3 receptor readily explained the observed structure-activity
relationship of the various compounds. Compound 14o was identified as a very potent, slowly reversible
M3 antagonist with a very long in vivo duration of bronchoprotection.
Introduction
Muscarinic acetylcholine receptors (mAChRsa) belong to the
superfamily of G-protein coupled 7-transmembrane (TM) recep-
tors. Five subtypes of mAChRs, termed M1-M5, have been
identified to-date.1,2 The mAChRs are widely distributed in
mammalian organs where they mediate many of the vital
functions.1-3 In the lungs, mAChRs have been localized to
smooth muscle in the trachea and bronchi, the submucosal
glands, and the parasympathetic ganglia.4 The three subtypes
of mAChRs, which are known to exert their physiological effect
in the lungs through the action of the native ligand, acetylcho-
line, are the M1, M2, and M3 receptors.4 The M3 mAChRs are
located on the airway smooth muscle and also on the pulmonary
submucosal glands where they mediate muscle contraction and
mucus secretion respectively.5,6 The M2 mAChRs, which make
up the majority of the cholinergic receptor population on airway
smooth muscle, are also located on postganglionic parasympa-
thetic nerves,7 where their role is autoinhibitory, to provide
tightly regulated control of acetylcholine release. M1 mAChRs
are found in the pulmonary parasympathetic ganglia where they
function to facilitate neurotransmission.8
mAChR dysfunction in the lungs has been noted in a variety
of different pathophysiological states.9 In particular, in asthma
and chronic obstructive pulmonary disease (COPD), inflamma-
tory conditions lead to loss of inhibitory M2 mAChR autore-
ceptor function on parasympathetic nerves supplying the
pulmonary smooth muscle, causing increased acetylcholine
release following vagal nerve stimulation.10 This mAChR
dysfunction results in airway hyperreactivity and hyperrespon-
siveness mediated by increased stimulation of M3 mAChRs,
which in turn lead to the constriction of the airways. Thus
mAChR antagonists, particularly of the M3 subtype, are useful
therapeutics in mAChR-mediated disease states and particularly
COPD. Inhaled anticholinergic agents approved for the treatment
Figure 1. General Strategy.
of COPD include ipratropium bromide, oxitropium bromide,
and more recently tiotropium bromide.11 Ipratropium and
oxitropium have relatively short durations of bronchodilation
(4-8 h), whereas tiotropium has a duration of action of over
24 h, making it suitable for once-daily treatment.12 As part of
a general strategy to develop new respiratory products, our goal
was to discover novel long-acting muscarinic antagonists.
In previous communications, our research team disclosed
several series of mAChR antagonists, which act as potent and
highly efficacious muscarinic antagonists.13,14 To provide some
structural diversity in our investigation, we turned our attention
to compounds possessing a [2.2.2] bicyclic core (Figure 1). Such
molecules would possess the key pharmacophoric features for
muscarinic activity, i.e., a positive center and two aromatic
groups, connected together via an alkyl linker. The [2.2.2]
quinuclidine ring is a known muscarinic pharmacophore,15,16
providing a certain degree of confidence that this approach could
succeed. As outlined in Figure 1, our general strategy was
primarily based on the exploration of the length and connectivity
point of the linker as well as the chemical space around the
aromatic moieties and the N substituents. Other areas of
investigation were the ring size and the replacement of the
hydroxyl group. In the course of our study, the azabicyclic
derivatives were evaluated for their muscarinic affinity using
recombinant muscarinic M1, M2, and M3 receptors. Some
selected compounds were also further investigated in a meta-
choline-induced bronchoconstriction model in the mouse. In this
paper, we report the synthesis, structure-activity relationship
(SAR) at the M3 receptor, and pharmacological evaluation of
this new series of muscarinic antagonists.
* To whom correspondence should be addressed. Phone: 1-610-270-7889.
Fax: 1-610-270-4451. E-mail: dramane.i.laine@gsk.com.
a Abbreviations: mAChR, muscarinic acetycholine receptor; TM, trans-
membrane;COPD,chronicobstructivepulmonarydisease;SAR,structure-activity
relationship; ACh, acetylcholine; CHO, Chinese hamster ovary; FLIPR,
fluorometric imaging plate reader; SPA, scintillation proximity assay; Penh,
enhanced pause; i.n., intranasal; GPCR, G-protein coupled receptor; ECL,
extracellular loop; MLR, multiple linear regression, NQ, not quantifiable;
ESI, electrospray ionization; HRMS, high resolution mass spectrum; SD,
steepest descent; ABNR, adopted basis Newton-Raphson; LC, liquid
chromatography.
Chemistry
The preparation of the 3-substituted azabicyclic derivatives
is depicted in Scheme 1. The commercially available 3-quinu-
10.1021/jm801601v CCC: $40.75
2009 American Chemical Society
Published on Web 03/24/2009

2494 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Scheme 1. Preparation of the C-3 Substituted Derivativesa
Laine´ et al.
bronchial tissues from primary, secondary, or tertiary airways
obtained at autopsy, cut into strips, and then connected to force-
displacement transducers suspended in standard organ baths.
Tissue strips were preincubated with the test compound for 2 h
and then incubated with increasing concentrations of carbachol.
The mechanical responses were recorded isometrically, and the
potencies of the compounds were determined as pA2 values.
To assess reversibility and to calculate the off-rate, the
antagonists were allowed to equilibrate with the bronchial strips
until they reached maximum inhibition of carbachol-induced
contraction. At this point, antagonists were removed from the
perfusate and tissues were superfused with buffer containing
carbachol with tension recovery measured over time. The results
are expressed as the time in minutes for 50% reversal of
antagonist blockade of carbachol-induced contraction (off t50).
The in vivo efficacy of the compounds was determined by their
airway responsiveness to methacholine in a mouse plethysmog-
raphy model. Barometric plethysmography was used to measure
enhanced pause (Penh), a unitless measure that has been shown
to correlate with the changes in airway resistance that occur
during bronchial challenge with methacholine.20 Mice were
pretreated intranasally (i.n.) with a solution of the compound
in 50 µL of vehicle (10% DMSO) and were then placed in the
plethysmography chamber a given amount of time following
drug administration. For potency determination, a dose response
to a given compound was performed, and all Penh measurements
were taken 15 min following i.n. drug administration. For
duration of action determination, Penh measurements were taken
anywhere from 15 min to 96 h following i.n. drug administration.
a Reagents and conditions: (a) See ref 15; (b) PhMgBr (4-5 equiv), THF;
(c) PhCH2CH2Br, CH3CN, CHCl3.
clidinone 1 was transformed into the ethyl ester 2b (n ) 1) in
four steps following procedures previously described in the
literature.17 Further condensation of 2b with phenylmagnesium
bromide afforded the tertiary alcohol 3b. N-Alklyation of 3b
with phenethyl bromide gave the corresponding quinuclidium
quaternary salt 4b. In a similar fashion to 2b, the commercially
available ester 2a (n ) 0) was processed to the corresponding
tertiary amine 3a and quaternary ammonium 4a.
As shown in Scheme 2, the 4-subsitututed azabicyclic
derivatives were obtained from the commercially available ethyl
4-piperidinecarboxylate precursor 5 in four synthetic steps.
Compound 5 was reacted sequentially with 1-bromo-2-chloro-
ethane in the presence of potassium carbonate and then with
LDA in THF to give the quinuclidine intermediate 8. Subsequent
condensation of 8 with an organometallic reagent resulted in
the formation of the tertiary alcohol 10, which could be further
processed to the nitrile derivative 12 by treatment with TMSCN
and AlCl3. N-Alkylation of 10 and 12 with 2-bromoethyl
phenylmethyl ether resulted in the formation of the correspond-
ing quaternary salts 14o and 16. A similar synthetic route was
also used for the preparation of the [2.2.1] derivatives 13 and
15 from the ester derivative 7, which could be prepared from
the spiro derivative 6 by following procedures previously
described in the literature.18 Compounds from Tables 2-4 were
prepared in an analogous manner to 14o but replacing 2-bro-
moethyl phenylmethyl ether with the appropriate alkylating
agents (14a-n, 14p-r, Table 2 and 17a-o, Table 3) or
PhMgBr with the appropriate organometallic reagent (18a-e,
Table 4).
Results and Discussion
To determine the most prominent SAR features (attachment
point and length of the linker, N substitution) around the
quinuclidine ring, we first proceeded with a rapid examination
of the series of analogues shown in Table 1. The hydroxyl-
(diphenyl)methyl quinuclidine derivatives 3a, 10, and 19
exhibited IC50 > 1000 nM at the M3 receptor. In contrast, the
homoanalogue 3b, which incorporated an extra methylene spacer
between the diaryl moiety and the quinuclidine ring, was 7 fold
more potent than 3a. A homology model of the M3 muscarinic
receptor was constructed using the X-ray structure of bovine
rhodopsin as a template21 and will be used throughout this paper
to provide a posterior rationalization of our results. Although
several more recent GPCR structures have been solved by
crystallography, no improvement has been observed with these
over the use of rhodopsin as a template. In particular, it seems
unlikely that the helical segment found in the second extracel-
lular loop of the ꢀ-2 receptor structure will be common to other
family members. Docking of the three compounds 3a, 10, and
19 suggested that a common mode of binding existed for the
hydroxyl(diphenyl)methyl group, which mainly consisted of a
strong hydrogen bond between the hydroxyl hydrogen and
ser7:46. The phenyl rings of this group sit in a hydrophobic pocket
lined by met2:58, ile2:53, phe6:44, and tyr7:43 (Figure 2a).22
Pharmacology
The functional activities and potencies of the synthesized
compounds were evaluated by calcium mobilization assays to
determine inhibition of acetylcholine(Ach)-induced receptor-
activation at cloned human M3 receptors expressed in Chinese
hamster ovary (CHO) cells. The inhibitory potency of a
compound was evaluated at a single ACh concentration to
determine its IC50. When a compound IC50 was lower than 10
nM, antagonist potency was further quantified with a pA2 by
measuring the ratio of the M3 EC50 in the presence and absence
of the compound.19 The functional reversibility of antagonist
blockade of the receptor was evaluated by a similar methodology
following 90 min incubation with vehicle, 1.0, 10, or 100 nM
compound, and washout of vehicle or compound for 180 min
using 18 buffer changes. Following washout, cells were
stimulated with ACh and calcium mobilization was measured
by fluorometric imaging plate reader (FLIPR). Antagonist
binding was also assessed in radioligand binding assays
conducted using cell membrane preparations from CHO cells
expressing human M1, M2, or M3 receptors in a scintillation
proximity assay (SPA) with 0.5 nM [3H]-N-methyl scopolamine
as the ligand. The binding potency was determined as a Ki.
Functional activity of antagonists was determined in human
With an N-unsubstituted quinuclidine, the protonated nitrogen
tends to form highly directional hydrogen bonds or salt bridges.
This is reflected in a localized positive electrostatic potential
as shown in Figure 3, left. The expected binding site, which is
the conserved (in aminergic G-protein coupled receptors (GPCRs))
asp3:32 residue in TM3, already has three hydrogen bonds from
ser2:57, tyr7:39, and tyr7:43. In addition to breaking these hydrogen
bonds upon formation of a salt bridge with the quinuclidine
nitrogen, the three compounds cannot readily adopt a conforma-
tion where the NH is orientated toward the aspartate without

1-Azoniabicyclo[2.2.2]octane mAChR Antagonists
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8 2495
Scheme 2. Preparation of the C-4 Substituted Derivativesa
a Reagents and conditions: (a) 1-bromo-2-chloroethane, K2CO3, acetone; then LDA, THF; (b) PhLi (2.5 eq), THF; (c) AlCl3, TMSCN, DCE, 85 °C; (d)
PhCH2CH2Br, CH3CN, CHCl3.
Table 1. Structure and M3 Activity of Initial Leads
Table 2. M3 Activity of Quinuclidinium Salts 14a-s
M3 activity
a
a
no.
attachment point
n
R
M3 potency IC50 (nM)
no.
R
IC50 (nM)
pA2
19
3a
10
3b
4a
4b
14a
2
3
4
3
3
3
4
0
0
0
1
0
1
0
6599
1104
1068
145
2824
122
14a
14b
14c
14d
14e
14f
14g
14h
14i
14j
14k
14l
14m
14n
14o
14p
14q
-(CH2)2Ph
-Me
87
935
1956
104
208
135
30
<10
850
486
<10
9.5
29509
829
<10
<10
306
-CH2-cPr
-Et
2-phenylethyl
2-phenylethyl
2-phenylethyl
-Pr
-Bu
87
-(CH2)2OMe
-(CH2)2OPh
-(CH2)2NH2
-(CH2)2OH
-(CH2)3OPh
-(CH2)4OPh
-(CH2)3OH
-(CH2)3OMe
-(CH2)2OCH2Ph
-(CH2)4Ph
-(CH2)5OPh
a Values are the mean of two or more independent assays.
9.1
disrupting the binding of the hydroxyl(diphenyl)methyl group.
Compound 3b, however, can dock reasonably close to the
aspartate although tyr7:39 and tyr7:43 must rotate out of the way
to accommodate the quinuclidine ring. The increased binding
energy of the salt bridge in 3b is reflected in its increased
potency as shown in Table 1. Formation of a quaternary center
causes the positive charge to diffuse around the hydrogens of
the methylene groups adjacent to the nitrogen (Figure 3, right).
Quaternary compounds therefore favor nondirectional elec-
trostatic interactions, especially of the π-cation type. In
compound 14a, the attachment of a phenethyl chain onto the N
atom of the quinuclidine ring led to a significant increase in
potency compared to the N-unsubstituted compound 10. In
contrast, the N-phenethyl derivatives 4a and 4b were in the same
potency range as their respective parent compounds 3a and 3b.
Docking of 14a into the M3 receptor model showed good
π-cation interactions with trp6:48, tyr6:51, and tyr7:39. The
quaternary center also formed nonspecific electrostatic interac-
tions with asp3:32 and ser3:36 (Figure 2b). The hydroxyl(diphe-
nyl)methyl group docked in the same pocket as before with the
hydrogen bond to ser7:46. What was particularly interesting was
that the terminal phenethyl chain sat in a hydrophobic pocket
9.4
8.0
10.5
9.3
a Values are the mean of two or more independent assays.
bounded by leu3:29, val6:55, tyr3:33, and a phenylalanine, phe4:79
,
in the extracellular loop 2 (ECL2) domain. There was a
particularly good π-π stacking interaction with tyr3:33. These
results suggested that further exploration of the SAR around
the pending chain of 4-hydroxy(diphenyl)methyl substituted
quinuclidium salts had the potential to lead to further potency
increase. Such C3 symmetric 4-substitued quinuclidines would
also possess the added advantages to be achiral entities and more
readily accessible synthetically. Consequently, we focused our
attention primarily on this series of molecules.
Table 2 shows the SAR of a series of analogues in which
various pending chains were attached to the quinuclidine
nitrogen. Compounds with small alkyl chains (14b-f) were less
potent than the phenethyl analog 14a. This is in agreement with

2496 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Table 3. Effect of Substitution of the Benzyl Moiety on M3 Activity
Laine´ et al.
from both tyr6:51 and ser3:36. This however, has the effect of
pulling the terminal phenyl group down from the hydrophobic
pocket so that it forms far from ideal π-π interactions with
tyr3:33 and phe4:79. Also this lowering of the ligand in the pocket
results in less favorable π-cation and other electrostatic
interactions around the quaternary center. Compound 14o,
however, shows much better interactions overall. There is only
one hydrogen bond between the benzyloxy oxygen and tyr6:
51,but ser3:36 now show a good electrostatic interaction with the
quaternary center as does asp3:32. The quaternary center also
shows π-cation interactions with trp6:48 and tyr7:39. Removal
of the phenyl ring as in 14m and 14n resulted as expected in
significant loss of activity, in agreement with what was observed
for 14i and 14j. The modeling is therefore in excellent agreement
with the observed activities.
M3 activity
no.
R2
IC50 (nM)a
pA2
14o
17a
17b
17c
17d
17e
17f
17g
17h
17i
17k
17l
17m
17n
17o
H
<10
<10
39
10.5
8.7
3-OMe
4-tBu
4-F
<10
<10
<10
<10
<10
5403
<10
<10
22
10.1
10.2
10.4
9.4
4-Cl
4-Br
4-CN
3-F
2-CN
3-Br
3-Me
2-Br
4-Me
2-Me
2-F
Next we investigated the effect of substituting the side chain
aromatic ring by preparing a series of analogues of 14o (Table
3). Generally, we found that introducing any group at the ortho
position was detrimental to activity (compounds 17h, 17n, and
17n). In fact, with the exception of the 3-fluoro analogue (17g),
all compounds had a lower pA2 value than the unsubstituted
compound. This would suggest that the effect of substitution
was largely steric. A multiple linear regression study (MLR)
was performed using a variety of steric parameters (substituent
volume, Verloop L and B1 values, ellipsoid volume, etc.), but
no satisfactory MLR equations were obtained. Docking studies
however did shed some light on these substituent effects. The
least potent analogue was the 2-cyano compound (17h). Upon
docking, this was shown to have a large detrimental effect on
the electrostatic interactions around the quinuclidine quaternary
center. In particular, asp3:32 was forced to rotate away from the
quinuclidine’s adjacent methylene group and thus form a
hydrogen bond with tyr7:43. Tyr7:39 was also displaced, resulting
in a weakening of its π-cation interaction (Figure 5a). Whereas
the loss of potency with compound 17h was mostly electrostatic,
the 4-tert-butyl analogue (17b) was found to displace the
aromatic side chains surrounding the terminal phenyl ring of
the ligand (Figure 5b). Thus the tert-butyl group itself formed
a hydrophobic interaction with trp7:35, but the other π-stacking
residues, trp3:28, tyr7:39, phe4:79, and tyr3:33, were further from
the terminal phenyl ring than in the unsubstituted compound
14o.
10.6
9.9
10.0
8.5
10.4
8.4
<10
13
<10
10.4
a Values are the mean of two or more independent assays.
Table 4. Modification to the Diphenyl Portion of 14o
M3 activity
no.
R3
IC50 (nM)a
pA2
14o
18a
18b
18c
18d
18e
H
4-F
3-OMe
3-F
4-OMe
4-Me
<10
<10
17
<10
36
10.5
10.2
9.6
12
a Values are the mean of two or more independent assays.
the docking studies, which showed that these compounds would
not have the π-π stacking interaction with tyr3:33. However,
the ether derivative, 14g, was found to be 3-fold more active
than 14a, suggesting than the presence of an oxygen atom on
the ring could be beneficial to activity, probably through the
acceptance of a hydrogen bond from a nearby residue. The most
likely candidates for this were tyr6:51 and ser3:36. Replacement
of the terminal methyl of 14g with a phenyl ring as in compound
14h further increases the potency, whereas both the amine 14i
and the alcohol 14j were found to lose significant activity. On
the basis of these initial results, we then examined the sequential
introduction of methylene spacers onto the side chain. This
would maintain the hydrogen bond to the ether oxygen but
would also allow the phenyl ring to pick up additional π-π
interactions with other aromatic residues such as trp7:35 or the
ECL2 phe4:79 higher up in the binding pocket. We found that
the maximum chain length between the quinuclidine ring and
the phenyl ring was four atoms as exemplified by compounds
14k, 14o, and 14p. In particular, we observed that the benzyloxy
derivative 14o was an order of magnitude more potent at the
receptor than 14k and 14p, suggesting that the γ-positioning
of the oxygen on the chain is optimum. The docking of 14k
and 14o is shown in parts a and b of Figure 4, respectively.
Compound 14k has hydrogen bonds to the phenoxy oxygen
As shown in Table 4, we also explored briefly the substitution
of the diphenylmethyl portion. The most active compounds of
this study were the fluoro substituted derivatives 18a and 18c,
which were slightly less potent at M3 than 14o but significantly
more potent than the corresponding methoxy derivatives 18b
and 18d. These results suggested that substitution of these
two aromatic rings was unlikely to lead to a greater potency
increase and consequently was not investigated any further.
These results are comparable to some previous observations
made in a carbamate series developed by our team.23
We also explored the effect of substituting the hydroxyl group
with a nitrile moiety. As shown in Table 5, this transformation
resulted in a marked potency decrease for compound 16. Finally,
the slight reduction of the carbocycle size of 14o to a [2.2.1]
system was a change that was tolerated but also led to a decrease
in potency (compounds 13 and 15).
On the basis of their high potencies at M3, the pharmacologi-
cal profiles compounds 14o and 14k were further investigated.
As shown in Table 6, radioligand binding studies demonstrated
that both compounds potently competed with [3H]-N-methyl
scopolamine binding to any of the three muscarinic receptors

1-Azoniabicyclo[2.2.2]octane mAChR Antagonists
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8 2497
Figure 2. (a) Compound 10 docked in the M3 receptor model showing the hydrogen bond of the ligand hydroxyl to ser7:46 and the hydrophobic
interactions between the two phenyl rings and tyr7:43. met2:58, ile2:53, and phe6:44. Tyr7:39, tyr7:43, and ser2:57 form hydrogen bonds with asp3:32, which
as can be seen, cannot approach the quinuclidine NH. Instead, it forms a hydrogen bond with tyr7:51. (b) Compound 14a docking where the
hydroxydiphenylmethyl group has the same interactions as compound 10. The methylene groups adjacent to the nitrogen of the quaternary center
are now surrounded by asp3:32, ser3:36, trp6:48, tyr6:51, and tyr7:39 (not shown). The pendant phenethyl group lies between tyr3:33 and phe4:79
.
Figure 3. (left) A partial electron density surface around the protonated nitrogen of the quinuclidine in compound 10. The electrostatic potential
plotted on this surface shows a highly localized positive (blue) region around the NH group. (right) In compound 14a, the same surface surrounding
the adjacent methylenes of the phenethyl quaternary salt shows a diffused positive charge surrounding the quinuclidine nitrogen.
Figure 4. (a) Compound 14k docked in the M3 model. There are strong hydrogen bonds between the phenoxy oxygen and ser3:36 and tyr6:51. Trp6:48
is not especially close to the quaternary center, and phe4:79 and tyr3:33 are not making good interactions with the terminal phenyl ring. (b) Compound
14o in the M3 model showing much better interactions with the quaternary center. The benzyloxy oxygen has only one hydrogen bond with tyr6:51
.
There are good π-π interactions between the terminal phenyl ring and phe4:79, trp3:28 (not shown), and trp7:35
.
subtypes (M1-M3). At the M3 receptor, 14o had a higher affinity
(Ki: 0.06 nM) than 14k (Ki: 0.14 nM). This potency difference
is in agreement with the pA2 values previously discussed. The
binding assays also showed that both compounds were pan
active muscarinic antagonists with strong affinities with the M1
and M2 receptors.

2498 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Laine´ et al.
Figure 5. The backbone ribbons have been removed for clarity. (a) the docking of the 2-cyano analogue, 17h (pink), overlaid with the docking
of the unsubstituted compound, 14o (orange). There is considerable displacement of the residues around the quaternary methylenes, especially
tyr7:39 and asp3:32. The latter in fact is now oriented away from the quinuclidine and forms a strong hydrogen bond with tyr7:43. Trp3:28 is displaced
away from its orthogonal π-π interaction with the terminal phenyl ring. (b) In the docking of compound 17b, there is a general weakening of the
π-π interactions around the terminal phenyl ring. The tert-butyl group forms a hydrophobic interaction with trp7:35 (top middle), while the other
π-stacking residues, trp3:28, tyr7:39, phe4:79, and tyr3:33, are all displaced further away from the phenyl ring of the ligand.
Figure 6. Concentration-dependent shifts in actylcholine concentration response curve after 90 min incubation with 14o and 14k and reversibility
following a 180 min wash-out at the human M3 receptor.
Table 5. [2.2.1] and Nitriles
Studies to evaluate the reversibility of the compounds at the
M3 receptor were conducted in the FLIPR assay using a 90 min
incubation followed by a 180 min washout period. As shown
in Figure 6, following the washout, acetylcholine concentration-
response curves did not fully reverse to levels obtained in the
absence of drug at any concentration of 14o tested. These data
indicate that antagonist blockade of the receptor remained after
washout, suggesting that 14o is slowly reversible at the M3
receptor. In contrast, compound 14k was found to be fully
reversible under the same conditions.
The compounds were also evaluated against the endogenous
receptors in isolated human bronchial tissues strips. In these
studies, 14o and 14k were potent inhibitors at the endogenous
human M3 receptors of carbachol-induced contractions, with
pA2’s of 9.5 and 8.9, respectively. In an additional study, the
off-rates from endogenous muscarinic receptors were determined
on human tissues superfused with buffer containing carbachol
in the presence of antagonist. At 10 nM, 14o had a off t50 of
145 min compared to 61 min for 14k. Taken together, these in
vitro data suggest that the longer off rate of 14o may be a
function of its lower reversibility and higher potency at the M3
receptor.
M3 activity
IC50 (nM)a
no.
n
R4
pA2
14o
16
13
2
2
1
1
OH
CN
OH
CN
<10
<10
<10
<10
10.5
8.5
9.4
9.3
15
a Values are the mean of two or more independent assays.
to minimize potential systemic-mediated side effects.24,25 Con-
sidering these characteristics, the compounds were examined
in our mouse in vivo model. Following intranasal administration,
14k and 14o demonstrated potent inhibition of metacholine-
induced bronchoconstriction with respective ED50 of 0.08 and
0.02 µg. When dosed at the ED80, the compounds exhibited very
long duration of action. Greater than 50% bronchoprotection
was observed at 34 h for 14k and at 48 h for 14o.
As reported in Table 6, the pharmacokinetic profiles of both
compounds in the rat were characterized by low oral bioavail-
ability and high plasma clearance. These properties are preferred
to optimize the topical efficacy of these agents in the lungs and
Conclusion
In conclusion, this work has led to the identification of a
4-substituted quinuclidine series as a very promising class of

1-Azoniabicyclo[2.2.2]octane mAChR Antagonists
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8 2499
Table 6. Additional Data on Selected Compound
binding affinity (Ki)a
in vitro tissue studies
mouse in vivo studies
PK properties
c
d
off t50
ED50
duratione
(h)
Clf
Ff,g
(%)
b
no.
M1
M2
M3
pA2
(min)
(µg/mouse)
species
(ml/min/kg)
14k
14o
0.64
0.16
0.94
0.15
0.13
0.06
8.9
9.5
57
145
0.08
0.02
34 (0.5 ug)
>48 (0.05 ug)
rat
rat
37
92
NQh
NQh
a Radioligand binding assays were conducted using CHO cell membrane preparations in SPA format vs 0.5 nM [3H]-N-methyl scopolamine. Values are
the mean of three independent assays. b Potency against carbachol-induced contraction in human bronchus. c Reversal time for 50% of carbachol-induced
contraction to return in human bronchus after incubation to maximum relaxation at [10 nM] antagonist. d Potency in conscious mice against MCh-induced
bronchoconstriction. e Duration of bronchoprotection in conscious mice against MCh-induced bronchoconstriction. Time to 50% loss of maximum protection
(dose) f Cl: systemic plasma clearance. iv doses: 3.5 mg/kg (14k), 0.5 mg/kg (14o). g F: percent bioavailability. po doses: 7.1 mg/kg (14k), 2 mg/kg (14o).
h NQ ) no quantifiable plasma levels following oral administration.
min. The reaction was allowed to warm up to room temperature,
then heated to 60 °C for three and a half-hours and then cooled to
room temperature overnight. The reaction was cooled to 0 °C and
quenched with saturated NH4Cl (aqueous) and then evaporated to
dryness under vacuum. H2O and EtOAc were added, and the
aqueous phase was further extracted with EtOAc. The combined
organic layers were dried over MgSO4, filtered, and concentrated
under vacuum. The crude product was purified by preparatory
HPLC to give the TFA salt of the title compound, which was
subsequently converted to its free base utilizing saturated K2CO3
to give the desired compound 3a (0.0633 g, 29.3%). LC/MS (ES)
muscarinic antagonists. Through optimizing the connectivity of
the diphenyl moiety to the quinuclidine core as well as the nature
and substitution of the ring nitrogen side chain, compounds 14k
and 14o were identified as very potent M3 antagonists. Com-
putational docking studies using a homology model of the M3
receptor readily explained the observed SAR of the various
compounds. Kinetic washout studies at the human M3 cloned
receptor and in human bronchus showed that 14o had a slower
reversibility profile than 14k, correlating with its higher potency
at the receptor. Compound 14o also displayed longer in vivo
activity in a mouse bronchoconstriction model than 14k. Taken
together, these results suggest that 14o has a better likelihood
than 14k of achieving long duration of bronchodilation in
humans. Further pharmacological studies of these compounds
will be reported elsewhere.
1
m/z 294 (M + H)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.51
(d, J ) 7.33 Hz, 2 H), 7.46 (d, J ) 7.07 Hz, 2 H), 7.29 (q, J )
8.17 Hz, 4 H), 7.20-7.10 (m, 2 H), 5.76 (s, 1 H), 3.01-2.82 (m,
5 H), 2.80-2.73 (m, 1 H), 2.42-2.31 (m, 1 H), 1.67-1.60 (m, 1
H), 1.53-1.46 (m, 2 H), 1.15-1.26 (m, 1 H). HRMS calcd for
(C20H24NO) 294.1852, found 294.18499.
2-(1-Azabicyclo[2.2.2]oct-3-yl)-1,1-diphenylethanol (3b). A
solution of phenylmagnesium bromide (3.0 M in diethyl ether, 8.5
mL, 25.5 mmol) was chilled down to 0 °C under argon. Ethyl
1-azabicyclo[2.2.2]oct-3-ylacetate (2b) (1.0296 g, 5.22 mmol) in
THF (10 mL) was slowly added to the reaction mixture at 0 °C
over 50 min. The reaction was allowed to warm up to room
temperature and then heated to 55 °C overnight. The reaction was
cooled to 0 °C, quenched with saturated NH4Cl (aqueous), and then
evaporated to dryness under vacuum. H2O and EtOAc were added,
and the aqueous phase was further extracted with EtOAc. The
combined organic layers were dried over MgSO4, filtered, and
concentrated under vacuum. The crude product was purified by
preparatory HPLC to give the title compound (0.560 g, 35%). LC/
Experimental Section
Chemistry. All materials and reagents were used as is unless
otherwise indicated. Air- or moisture-sensitive reactions were carried
out under a nitrogen atmosphere. Flash chromatography was
performed using silica gel (EM Science, 230-400 mesh) under
standard techniques or using silica gel cartridges (RediSep normal
phase disposable flash columns) on an Isco CombiFlash. Preparative
and analytical HPLC were carried out on a Gilson 306 HPLC
system. Unless otherwise stated, the conditions for the preparative
reverse phase HPLC purifications used YMC Combiscreen ODS-A
75 mm × 30 mm (30 mL/min; gradient, (A) acetonitrile, (B) water;
1
10-80% A during 10 min) with UV detection at 214 nm. The H
1
MS (ES) m/z 308 (M + H)+. H NMR (400 MHz, DMSO-d6) δ
NMR spectra were recorded at 400 MHz using a Bruker Avance
400 spectrometer. Chemical shifts are reported in parts per million
(ppm) downfield of tetramethylsilane (δ scale). Multiplicity is
indicated as follows: s (singlet), d (doublet), t (triplet), q (quartet),
and m (multiplet). Coupling constants (J) are reported in hertz and
refer to apparent multiplicities and not true coupling constants. Mass
spectra were recorded on an Applied Biosystems MDS Sciex API
150EX single quadrupole mass spectrometer with an electrospray
ionization (ESI) source. Elemental analyses were performed by
Quantitative Technologies, Inc., Whitehouse, NJ. High-resolution
mass spectral (HRMS) data were determined on a Bruker Daltonics
7T FTICR-MS equipped with an Apollo ESI interface. The purity
of the tested compounds not subjected to combustion analysis was
determined by liquid chromatography (LC) on a Schimadzu LC
system. Unless stated otherwise, the conditions for the LC used an
Aquasil C18 40 mm × 1 mm column (flow rate: 300 µL/min, 10%
solution A, 90% solution B; A: water with 0.02% TFA; B:
acetonitrile with 0.018% TFA, duration 4.2 min) with UV detection
at 214 nm. All reported compounds, with the exception of 17b,
possess a purity of at least 95%.
ppm 7.47-7.41 (m, 4H), 7.30-7.24 (m, 4H), 7.19-7.13 (m, 2H),
5.47 (s, 1H), 2.72-2.50 (m, 5H), 2.48-2.43 (m, 1H), 2.37-2.32
(m, 2H), 1.85-1.65 (m, 2H), 1.52-1.45 (m, 2H), 1.38-1.30 (m,
2H). HRMS calcd for (C21H26NO) 308.2009, found 308.2008.
3-[Hydroxy(diphenyl)methyl]-1-(2-phenylethyl)-1-
azoniabicyclo[2.2.2]octane Bromide (4a). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-3-yl(diphenyl)-
methanol (3a) (0.040 g, 0.136 mmol) and (2-bromoethyl)benzene
(0.028 mL, 0.204 mmol) in 2CH3CN/3CHCl3 (4.5 mL) were reacted
to give the desired product (0.0284 g, 43.5%). LC/MS (ES) m/z
1
398 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.49 (t, J )
6.40 Hz, 4 H), 7.40-7.17 (m, 11 H), 5.73 (s, 1 H), 3.54-3.42 (m,
1 H), 3.40-3.23 (m, 4 H), 3.18 (d, J ) 5.02 Hz, 1 H), 3.16-3.06
(m, 1 H), 2.98-2.82 (m, 2 H), 2.63-2.56 (m, 1 H), 2.17-2.01
(m, 2 H), 1.92-1.63 (m, 4 H). HRMS calcd for (C28H32NO)
398.2478, found 398.2477.
3-(2-Hydroxy-2,2-diphenylethyl)-1-(2-phenylethyl)-1-
azoniabicyclo[2.2.2]octane Bromide (4b). Following the general
procedure outlined in 14h, 2-(1-azabicyclo[2.2.2]oct-3-yl)-1,1-
diphenylethanol hydrochloride (3b) (0.100 g, 0.291 mmol) (Note:
Triethylamine (0.41 mL, 0.291 mmol) was added to the reaction
to basify 3b) and (2-bromoethyl)benzene (0.060 mL, 0.436 mmol)
in 2CH3CN/3CHCl3 (1.5 mL) were reacted to give the desired
The syntheses and characterizations of intermediates 2b, 6, 7,
and test compound 19 have already been reported.17,18,31
1-Azabicyclo[2.2.2]oct-3-yl(diphenyl)methanol (3a). A solution
of phenylmagnesium bromide (3.0 M in diethyl ether, 1.1 mL, 3.3
mmol) was chilled down to 0 °C under argon. Methyl 1-azabicyclo-
[2.2.2]octane-3-carboxylate (2a) (0.125 g, 0.74 mmol) in THF (5
mL) was slowly added to the reaction mixture at 0 °C over 30
1
product (0.0558 g, 39.0%). LC/MS (ES) m/z 412 (M)+. H NMR
(400 MHz, DMSO-d6) δ ppm 7.58-7.45 (m, 4 H), 7.39-7.17 (m,
11 H), 6.19 (s, 1 H), 3.57-3.36 (m, 9 H), 3.08-2.83 (m, 3 H),

2500 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Laine´ et al.
2.57-2.52 (m, 2 H), 2.08-1.94 (m, 1 H), 1.88-1.76 (m, 1 H),
1.73 (br s, 1 H), 1.69-1.54 (m, 1 H). HRMS calcd for (C29H34NO)
412.2635, found 412.2630.
vacuum to remove the CH3CN. The resulting water layer was
basified to pH ) 12 with 5 N NaOH and then extracted with EtOAc
(3 × 150 mL). The combined fractions were dried over MgSO4,
filtered, and concentrated under vacuum to give the title compound
(0.53 g, 56.7%). LC/MS (ES) m/z 289 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.48-7.40 (m, 8 H), 7.40-7.32 (m, 2 H),
2.83-2.76 (m, 2 H), 2.68-2.61 (m, 2 H), 2.57 (br s, 2 H),
1.68-1.61 (m, 4 H).
1-Azabicyclo[2.2.2]oct-4-yl(diphenyl)acetonitrile (12). Fol-
lowing the general procedure outlined in 11, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (0.3055 g, 1.04 mmol), AlCl3 (0.6675
g, 5.04 mmol), and TMSCN (0.68 mL, 5.10 mmol) in 1,2-
dichloroethane (17 mL) were reacted to give the desired product
(0.185 g, 59.7%). LC/MS (ES) m/z 303 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.48 (d, J ) 7.81 Hz, 4 H), 7.40 (t, J ) 7.55
Hz, 4 H), 7.34 (d, J ) 7.30 Hz, 2 H), 2.80 (t, J ) 7.55 Hz, 6 H),
1.75 (t, J ) 7.55 Hz, 6 H).
Ethyl 1-Azabicyclo[2.2.2]octane-4-carboxylate (8). To a solu-
tion of ethyl nipecotate (5) (20.0 mL, 130 mmol) in acetone (180
mL) was added 1-bromo-2-chloroethane (21.6 mL, 260 mmol)
followed by anhydrous K2CO3 (27.12 g, 196 mmol). The reaction
mixture was stirred for 24 h and then concentrated under vacuum.
The resulting residue was treated with H2O (75 mL) and extracted
with Et2O. The combined organic layers were dried with MgSO4,
filtered, and concentrated under vacuum. Purification of the crude
residue by flash chromatography (50% Et2O/50% hexane) on silica
gel gave ethyl 1-(2-chloroethyl)-4-piperidinecarboxylate (10.99 g,
38.6%). LC/MS (ES) m/z 220 (M + H)+. A solution of ethyl 1-(2-
chloroethyl)-4-piperidinecarboxylate (20.42 g, 92.9 mmol) in THF
(600 mL) was cooled to -50 °C under Ar. LDA (2.0 M in heptane/
THF/ethyl benzene, 70 mL, 140 mmol) was slowly added to the
solution at -50 °C over 25 min. The reaction was warmed up to
room temperature over 16 h. The reaction was quenched with
K2CO3 (saturated aqueous) (500 mL) and extracted with Et2O (3
× 500 mL). The combined organic layers were dried over MgSO4,
filtered, and concentrated under vacuum. The resulting orange oil
was coevaporated three times with DCM to remove excess ethyl
benzene to give the title compound (16.29 g, 95.7%). LC/MS (ES)
4-[Hydroxy(diphenyl)methyl]-1-{2-[(phenylmethyl)oxy]ethyl}-
1-azoniabicyclo[2.2.1]heptane Bromide (13). Following the gen-
eral procedure outlined in 14c, 1-azabicyclo[2.2.1]hept-4-yl(diphe-
nyl)methanol (9) (50 mg, 0.18 mmol) and 2-bromoethyl phenylmethyl
ether (0.04 mL, 0.25 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were
reacted to give the desired product (32 mg, 36%). LC/MS (ES)
1
m/z 414 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.44 (d, J
1
m/z 184 (M + H)+. H NMR (400 MHz, DMSO-d6) δ ppm 4.05
) 7.58 Hz, 4 H), 7.42-7.25 (m, 11 H), 6.41 (s, 1 H), 4.53 (s, 2
H), 3.86-3.79 (m, 2 H), 3.72-3.65 (m, 4 H), 3.61-3.54 (m, 4 H),
2.20-2.12 (m, 2 H), 2.04-1.97 (m, 2 H). HRMS calcd for
(C28H32NO2) 414.2428, found 414.2429.
(q, J ) 7.07 Hz, 2 H), 2.74 (t, J ) 7.58 Hz, 6 H), 1.58 (t, J ) 7.58
Hz, 6 H), 1.17 (t, J ) 7.07 Hz, 3 H).
1-Azabicyclo[2.2.1]hept-4-yl(diphenyl)methanol (9). A solution
of ethyl 1-azabicyclo[2.2.1]heptane-4-carboxylate (7) (4 g, 23
mmol) in THF (60 mL) was added dropwise to a solution of
phenyllithium (1.5 M in 70% cyclohexane/30% diethyl ether, 63.1
mL, 94.6 mmol) precooled to -30 °C under Ar. The reaction was
warmed to RT and stirred for 16 h. The reaction was treated with
water and extracted with ethyl acetate. The combined extracts were
washed with brine, dried (MgSO4), filtered, and concentrated in
vacuo. Trituration (diethyl ether) and then filtration afforded the
title compound (3.595 g, 54%). LC/MS (ES) m/z 280 (M + H)+.
1H NMR (400 MHz, DMSO-d6) δ ppm 7.53-7.49 (m, 4 H),
7.34-7.22 (m, 6 H), 2.89-2.86 (m, 2 H), 2.76-2.73 (m, 4 H),
1.91-1.86 (m, 2 H), 1.73-1.64 (m, 2 H).
4-[Hydroxy(diphenyl)methyl]-1-(2-phenylethyl)-1-azoniabicy-
clo[2.2.2]octane Bromide (14a). To a solution of 1-azabicyclo-
[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0775 g, 0.264 mmol) in
CH3CN/DCM/MeOH (2 mL/2 mL/1 mL) was added (2-bromoet-
hyl)benzene (0.38 mL, 2.78 mmol). The solution was allowed to
stir at room temperature for 4 days and then concentrated under
vacuum to give a white solid. This residue was dissolved in DMSO
and purified by preparatory HPLC to give the title compound
(0.0612 g, 48.6%). LC/MS (ES) m/z 398 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.56 (d, J ) 7.51 Hz, 4 H), 7.36-7.23 (m, 11
H), 5.96 (s, 1 H), 3.47 (t, J ) 7.49 Hz, 6 H), 3.32-3.28 (m, 2 H),
2.99-2.95 (m, 2 H), 2.03 (t, J ) 7.49 Hz, 6 H). HRMS calcd for
(C28H32NO) 398.2478, found 398.2478.
1-Azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10). A solution
of phenyllithium (1.5-1.7 M in 70 cyclohexane/30 ether, 20.0 mL,
32 mmol) was chilled down to -30 °C under Argon. Ethyl
1-azabicyclo[2.2.2]octane-4-carboxylate (8) (1.51 g, 8.23 mmol)
in THF (20 mL) was slowly added to the reaction mixture at -30
°C over 25 min. The reaction was allowed to warm up to room
temperature over 16 h. The reaction was quenched with H2O and
then evaporated to dryness under vacuum. H2O and EtOAc were
added, causing a white solid to crash out. This solid was filtered
off to give the title compound (0.79 g). The aqueous phase was
further extracted with EtOAc, the combined organic layers were
dried over MgSO4, filtered, and concentrated under vacuum. The
crude product was treated with EtOAc and hexane and filtered to
yield more of the title compound (0.67 g). Total yield (1.46 g,
4-[Hydroxy(diphenyl)methyl]-1-methyl-1-azoniabicyclo[2.2.2]-
octane Bromide (14b). Following the general procedure outlined
in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0638
g, 0.217 mmol) and bromomethane (2.0 M in t-butylmethyl ether,
0.250 mL, 0.500 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were reacted
to give the desired product (0.0739 g, 88.0%). LC/MS (ES) m/z
308(M)+. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J ) 7.58
Hz, 4 H), 7.33 (t, J ) 7.58 Hz, 4 H), 7.27-7.22 (m, 2 H), 5.96 (s,
1 H), 3.40 (t, J ) 7.58 Hz, 6 H), 2.87 (s, 3 H), 2.04-1.93 (m, 6
H). HRMS calcd for (C21H26NO) 308.2009, found 308.2008.
1-(Cyclopropylmethyl)-4-[hydroxy(diphenyl)methyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14c). To a solution of
1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0552 g, 0.188
mmol) in 2CH3CN/3CHCl3 (2.5 mL) was added (bromomethyl)-
cyclopropane (0.025 mL, 0.257 mmol). The solution was heated
at 60 °C for 16 h, cooled down to room temperature, and the
solvents were evaporated under vacuum. The residue was taken
up in 2.5 mL of DMSO and purified by preparatory HPLC (without
TFA) to give the title compound (0.031 9 g, 39.9%). LC/MS (ES)
1
60.7%). LC/MS (ES) m/z 294 (M + H)+. H NMR (400 MHz,
DMSO-d6) δ ppm 7.53 (d, J ) 7.58 Hz, 4 H), 7.27 (t, J ) 7.58
Hz, 4 H), 7.21-7.13 (m, 2 H), 5.43 (s, 1 H), 2.73 (d, J ) 7.58 Hz,
6 H), 1.65 (d, J ) 7.58 Hz, 6 H). Anal. (C20H23NO) C, H, N. HRMS
calcd for (C20H24NO) 294.1852, found 294.1852.
1-Azabicyclo[2.2.1]hept-4-yl(diphenyl)acetonitrile (11). To a
suspension of 1-azabicyclo[2.2.1]hept-4-yl(diphenyl)methanol (9)
(0.906 g, 3.24 mmol) in 1,2-dichloroethane (48 mL) was added
AlCl3 (2.028 g, 15.3 mmol). The reaction was allowed to stir for
10 min, and then TMSCN (2.04 mL, 15.3 mmol) was added. The
reaction was sealed and heated to 85 °C overnight. The reaction
mixture was poured into a separatory funnel containing K2CO3 (aq
satd) (200 mL) and EtOAc (200 mL). Extraction with EtOAc (3 ×
200 mL) was performed. The combined organics were dried over
MgSO4, filtered, and concentrated under vacuum. The residue was
dissolved in DMSO and purified by preparatory HPLC (w/0.1%
TFA). The combined fractions were concentrated down under
1
m/z 348 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.57 (d, J
) 8.06 Hz, 4 H), 7.34 (t, J ) 7.60 Hz, 4 H), 7.57 (t, J ) 7.2 Hz,
2 H), 5.97 (s, 1 H), 3.46 (t, J ) 7.20 Hz, 6 H), 3.02 (d, J ) 6.80
Hz, 2 H), 2.03 (t, J ) 7.20 Hz, 6 H), 1.15-1.04 (m, 1 H), 0.72-0.62
(m, 2 H), 0.48-0.32 (m, 2 H). HRMS calcd for (C24H30NO)
348.2322, found 348.2321.
1-Ethyl-4-[hydroxy(diphenyl)methyl]-1-azoniabicyclo[2.2.2]-
octane Bromide (14d). Following the general procedure outlined
in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0581
g, 0.198 mmol) and bromoethane (0.030 mL, 0.402 mmol) in
2CH3CN/3CHCl3 (4.0 mL) were reacted to give the desired product

1-Azoniabicyclo[2.2.2]octane mAChR Antagonists
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8 2501
(0.0434 g, 54.9%). LC/MS (ES) m/z 322 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.55 (d, J ) 7.33 Hz, 4 H), 7.38-7.19 (m, 8
H), 6.98-6.88 (m, 3 H), 5.95 (s, 1 H), 3.99 (t, J ) 5.68 Hz, 2 H),
3.38 (t, J ) 7.45 Hz, 6 H), 3.12 (br s, 2 H), 2.01 (t, J ) 6.95 Hz,
6 H), 1.84-1.65 (m, 4 H). HRMS calcd for (C22H28NO) 322.2165,
found 322.2164.
4-[Hydroxy(diphenyl)methyl]-1-propyl-1-azoniabicyclo[2.2.2]-
octane Bromide (14e). Following the general procedure outlined
in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0518
g, 0.176 mmol) and 1-bromopropane (0.030 mL, 0.330 mmol) in
2CH3CN/3CHCl3 (4.0 mL) were reacted to give the desired product
(0.0548 g, 75.1%). LC/MS (ES) m/z 336 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.55 (d, J ) 7.55 Hz, 4 H), 7.32 (t, J ) 7.68
Hz, 4 H) 7.27-7.21 (m, 2 H), 5.95 (s, 1 H), 3.39-3.32 (m, 6 H),
3.00 (dd, J ) 12.21, 4.66 Hz, 2 H), 1.99 (t, J ) 7.43 Hz, 6 H),
1.65-1.57 (m, 2 H), 0.87 (t, J ) 7.30 Hz, 3 H). HRMS calcd for
(C23H30NO) 336.2322, found 336.2321.
1-Butyl-4-[hydroxy(diphenyl)methyl]-1-azoniabicyclo[2.2.2]-
octane Bromide (14f). Following the general procedure outlined
in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.0496
g, 0.169 mmol) and 1-bromobutane (0.030 mL, 0.279 mmol) in
2CH3CN/3CHCl3 (4.0 mL) were reacted to give the desired product
(0.0509 g, 70.7%). LC/MS (ES) m/z 350 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.55 (d, J ) 7.55 Hz, 4 H), 7.32 (t, J ) 7.68
Hz, 4 H), 7.27-7.20 (m, 2 H), 5.95 (s, 1 H), 3.36 (t, J ) 7.43 Hz,
6 H), 3.10-3.01 (m, 2 H), 1.99 (t, J ) 7.30 Hz, 6 H), 1.63-1.52
(m, 2 H), 1.33-1.21 (m, 2 H), 0.90 (t, J ) 7.30 Hz, 3 H). HRMS
calcd for (C24H32NO) 350.2478, found 350.2477.
s, 1 H), 3.45 (t, J ) 7.33 Hz, 6 H), 3.33-3.27 (m, 2 H), 3.27-3.18
(m, 2 H), 2.02 (t, J ) 7.33 Hz, 6 H). HRMS calcd for (C22H29N2O)
337.2274, found 337.2273.
4-[Hydroxy(diphenyl)methyl]-1-(2-hydroxyethyl)-1-
azoniabicyclo[2.2.2]octane Bromide (14j). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.0638 g, 0.217 mmol) and 2-bromoethanol (0.035
mL, 0.494 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were reacted to
give the desired product (0.0541 g, 60.1%). LC/MS (ES) m/z 338
1
(M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J ) 7.58
Hz, 4 H), 7.32 (t, J ) 7.58 Hz, 4 H), 7.27-7.21 (m, 2 H), 5.95 (s,
1 H), 5.21 (t, J ) 4.80 Hz, 1 H), 3.77 (q, J ) 4.88 Hz, 2 H), 3.47
(t, J ) 7.45 Hz, 6 H), 3.21-3.15 (m, 2 H), 2.00 (t, J ) 7.33 Hz,
6 H). HRMS calcd for (C22H28NO2) 338.21146, found 338.21114.
Anal. (C22H28NO2Br·0.26H2O) C, H, N, Br.
4-[Hydroxy(diphenyl)methyl]-1-[3-(phenyloxy)propyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14k). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.045 g, 0.153 mmol) and 3-bromopropyl phenyl
ether (0.035 mL, 0.222 mmol) in 2CH3CN/3CHCl3 (3.0 mL) were
reacted to give the desired product (0.0662 g, 86.0%). LC/MS (ES)
1
m/z 428 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.56 (d, J
) 7.33 Hz, 4 H), 7.36-7.22 (m, 8 H), 6.98-6.90 (m, 3 H), 5.96
(s, 1 H), 4.02 (t, J ) 5.81 Hz, 2 H), 3.43 (t, J ) 7.45 Hz, 6 H),
3.30-3.23 (m, 2 H), 2.15-2.07 (m, 2 H), 2.05-1.98 (m, 6 H).
HRMS calcd for (C29H34NO2) 428.2584, found 428.2583.
4-[Hydroxy(diphenyl)methyl]-1-[4-(phenyloxy)butyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14l). Following the general
procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.0604 g, 0.206 mmol) and 4-bromobutyl phenyl
ether (0.106 g, 0.463 mmol) in 2CH3CN/3CHCl3 (5.0 mL) were
reacted to give the desired product (0.0649 g, 64.9%). LC/MS (ES)
4-[Hydroxy(diphenyl)methyl]-1-[2-(methyloxy)ethyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14g). Following the general
procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.0597 g, 0.203 mmol) and 2-bromoethyl methyl
ether (0.030 mL, 0.319 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were
reacted to give the desired product (0.0372 g, 42.8%). LC/MS (ES)
1
m/z 442 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J
) 7.33 Hz, 4 H), 7.38-7.19 (m, 8 H), 6.98-6.88 (m, 3 H), 5.95
(s, 1 H), 3.99 (t, J ) 5.68 Hz, 2 H), 3.38 (t, J ) 7.45 Hz, 6 H),
3.12 (br s, 2 H), 2.01 (t, J ) 6.95 Hz, 6 H), 1.84-1.65 (m, 4 H).
HRMS calcd for (C30H36NO2) 442.2741, found 442.2735.
1
m/z 352 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J
) 7.33 Hz, 4 H), 7.32 (t, J ) 7.58 Hz, 4 H), 7.28-7.22 (m, 2 H),
5.95 (s, 1 H), 3.71-3.65 (m, 2 H), 3.44 (t, J ) 7.58 Hz, 6 H),
3.32-3.28 (2 H, m), 3.26 (s, 3 H), 2.00 (t, J ) 7.33 Hz, 6 H).
HRMS calcd for (C23H30NO2) 352.2271, found 352.2271.
4-[Hydroxy(diphenyl)methyl]-1-(3-hydroxypropyl)-1-
azoniabicyclo[2.2.2]octane Bromide (14m). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.0628 g, 0.214 mmol) and 3-bromo-1-propanol
(0.030 mL, 0.343 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were reacted
to give the desired product (0.0661 g, 71.8%). LC/MS (ES) m/z
4-[Hydroxy(diphenyl)methyl]-1-[2-(phenyloxy)ethyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14h). To a solution of
1-azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (0.055 0 g,
0.187 mmol) in 2CH3CN/3CHCl3 (2.5 mL) was added 2-bromoethyl
phenyl ether (0.06 0 g, 0.29 mmol). The solution was stirred at 60
°C for 16 h. The reaction was cooled down to room temperature
and then diluted with ethyl acetate and hexane, causing a solid to
crash out of solution. This solid was filtered off and washed with
hexane to give the title compound (0.063 g, 67.6%). LC/MS (ES)
1
352 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J )
7.58 Hz, 4 H), 7.33 (t, J ) 7.58 Hz, 4 H), 7.27-7.21 (m, 2 H),
5.96 (s, 1 H), 4.77 (t, J ) 4.93 Hz, 1 H), 3.44 (q, J ) 5.31 Hz, 2
H), 3.38 (t, J ) 7.45 Hz, 6 H), 3.17-3.10 (m, 2 H), 2.04-1.96
(m, 3 H), 1.82-1.71 (m, 2 H). HRMS calcd for (C23H30NO2)
352.2271, found 352.2270.
1
m/z 414 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J
) 7.58 Hz, 4 H), 7.36-7.28 (m, 6 H), 7.27-7.21 (m, 2 H),
7.03-6.95 (m, 3 H), 5.95 (s, 1 H), 4.40-4.36 (m, 2 H), 3.59-3.52
(m, 8 H), 2.03 (t, J ) 7.33 Hz, 6 H). HRMS calcd for (C28H32NO2)
414.2428, found 414.2427.
4-[Hydroxy(diphenyl)methyl]-1-[3-(methyloxy)propyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14n). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (0.0632 g, 0.215 mmol) and 3-bromopropyl methyl
ether (0.0461 g, 0.301 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were
reacted to give the desired product (0.0826 g, 86.0%). LC/MS (ES)
[1-(2-Aminoethyl)-1-azoniabicyclo[2.2.2]oct-4-yl](diphenyl)-
methanolate Trifluoroacetate (14i). Following the general pro-
cedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)meth-
anol (10) (0.0916 g, 0.312 mmol) and 2-(2-bromoethyl)-1H-
isoindole-1,3(2H)-dione (0.130 g, 0.512 mmol) in 2CH3CN/3CHCl3
(4.0 mL) were reacted to give 1-[2-(1,3-dioxo-1,3-dihydro-2H-
isoindol-2-yl)ethyl]-4-[hydroxy(diphenyl)methyl]-1-
azoniabicyclo[2.2.2]octane bromide (0.0881 g, 51.8%). LC/MS (ES)
m/z 467(M)+. To a solution of 1-[2-(1,3-dioxo-1,3-dihydro-2H-
isoindol-2-yl)ethyl]-4-[hydroxy(diphenyl)methyl]-1-
azoniabicyclo[2.2.2]octane bromide (0.078 g, 0.142 mmol) in EtOH
(4.0 mL) was added hydrazine (0.25 mL, 7.96 mmol). The solution
was stirred at room temperature for 16 h and then filtered. The
filtrate was concentrated and taken up in 2.5 mL of DMSO and
purified by preparatory HPLC (with TFA) to give the title
compound (0.0200 g, 31.2%). LC/MS (ES) m/z 338 (M)+. 1H NMR
(400 MHz, DMSO-d6) δ ppm 8.16 (br s, 3 H), 7.55 (d, J ) 7.33
Hz, 4 H), 7.33 (t, J ) 7.58 Hz, 4 H), 7.28-7.22 (m, 2 H), 5.99 (br
1
m/z 366 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J
) 7.07 Hz, 4 H), 7.33 (t, J ) 6.69 Hz, 4 H), 7.28-7.21 (m, 2 H),
5.95 (s, 1 H), 3.43-3.31 (m, 8 H), 3.23 (s, 3 H), 3.17-3.08 (m, 2
H), 2.04-1.96 (m, 6 H), 1.90-1.83 (m, 2 H). HRMS calcd for
(C24H32NO2) 366.2428, found 366.2427.
4-[Hydroxy(diphenyl)methyl]-1-{2-[(phenylmethyl)oxy]ethyl}-
1-azoniabicyclo[2.2.2]octane Bromide (14o). Following the gen-
eral procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphe-
nyl)methanol(10)(3.30g,11.2mmol)and2-bromoethylphenylmethyl
ether (2.31 mL, 14.6 mmol) in 2CH3CN/3CHCl3 (200 mL) were
reacted to give the desired product (2.47 g, 43.3%). LC/MS (ES)
m/z 428 (M)+. 1H NMR (DMSO-d6) δ 7.56 (d, 4H, J ) 1.2), 7.28
(m, 11H), 5.95 (s, 1H), 4.50 (s, 2H), 3.81 (d, 2H, J ) 4.0), 3.48 (t,
6H, J ) 7.2), 3.38 (d, 2H, J ) 4.0), 2.01 (t, 6H, J ) 7.2). Anal.
(C29H34NO2Br) C, H, N.

2502 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Laine´ et al.
4-[Hydroxy(diphenyl)methyl]-1-(4-phenylbutyl)-1-
azoniabicyclo[2.2.2]octane Bromide (14p). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (79 mg, 0.269 mmol) and (4-bromobutyl)benzene
(73 mg, 0.343 mmol) in 2CH3CN/3CHCl3 (5.0 mL) were reacted
to give the desired product (0.0998 g, 66.6%). LC/MS (ES) m/z
1-(2-{[(4-Fluorophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17c). Fol-
lowing the general procedure outlined in 17a, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (30 mg, 0.102 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-4-fluorobenzene (33 mg, 0.143 mmol) in
2CH3CN/3CHCl3 (3.0 mL) were reacted to give the desired product
1
(9 mg, 16%). LC/MS (ES) m/z 446 (M)+. H NMR (400 MHz,
1
426 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.54 (d, J )
MeOD) δ ppm 7.60-7.55 (m, 4 H), 7.39-7.36 (m, 2 H), 7.34-7.30
(m, 4 H), 7.26-7.22 (m, 2 H), 7.07 (ddd, J ) 8.9, 6.7, 2.0 Hz, 2
H), 4.53 (s, 2 H), 3.89-3.83 (m, 2 H), 3.56-3.50 (m, 6 H),
3.44-3.39 (m, 2 H), 2.22-2.16 (m, 6 H). Anal. (C29H33FNO2Br)
C, H, N, Br. HRMS calcd for (C29H33FNO2) 446.2490, found
446.2489.
1-(2-{[(4-Chlorophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17d). Fol-
lowing the general procedure outlined in 17a, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (30 mg, 0.102 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-4-chlorobenzene (36 mg, 0.143 mmol) in
2CH3CN/3CHCl3 (3.0 mL) were reacted to give the desired product
(17.4 mg, 32%). LC/MS (ES) m/z 462 (M)+. 1H NMR (400 MHz,
MeOD) δ ppm 7.59-7.57 (s, 4 H), 7.35-7.29 (comp, 8 H),
7.26-7.22 (m, 2 H), 4.53 (s, 2 H), 3.90-3.84 (m, 2 H), 3.56-3.50
(m, 6 H), 3.45-3.39 (m, 2 H), 2.23-2.17 (m, 6 H). Anal.
(C29H33ClNO2Br) C, H, N. HRMS calcd for (C29H33ClNO2)
462.2194, found 462.2198.
7.28 Hz, 4 H), 7.36-7.16 (m, 11 H), 5.94 (s, 1 H), 3.39-3.34 (m,
6 H), 3.33-3.29 (m, 2 H), 3.12 -3.06 (m, 2 H), 2.60 (t, J ) 7.28
Hz, 2 H), 2.04-1.94 (m, 6 H), 1.68-1.50 (m, 4 H). HRMS calcd
for (C30H36NO) 426.2791, found 426.2787.
4-[Hydroxy(diphenyl)methyl]-1-[5-(phenyloxy)pentyl]-1-
azoniabicyclo[2.2.2]octane Bromide (14q). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
methanol (10) (52.1 mg, 0.178 mmol) and 5-bromopentyl phenyl
ether (52 mg, 0.214 mmol) in 2CH3CN/3CHCl3 (5.0 mL) were
reacted to give the desired product (0.0725 g, 62.5%). LC/MS (ES)
1
m/z 456 (M)+. H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (d, J
) 7.53 Hz, 4 H), 7.23-7.36 (m, 8 H), 6.94-6.88 (m, 3 H), 5.95
(s, 1 H), 3.96 (t, J ) 6.27 Hz, 2 H), 3.38 (t, J ) 6.78 Hz, 6 H),
3.06 (br. s., 1 H), 3.09 (d, J ) 7.78 Hz, 1 H), 2.00 (t, J ) 6.90 Hz,
6 H), 1.73 (d, J ) 7.78 Hz, 2 H), 1.76 (br s, 2 H), 1.40 (br s, 2 H).
HRMS calcd for (C31H38NO2) 456.2897, found 456.2893.
4-[Cyano(diphenyl)methyl]-1-{2-[(phenylmethyl)oxy]ethyl}-
1-azoniabicyclo[2.2.1]heptane Bromide (15). Following the gen-
eral procedure outlined in 14h, 1-azabicyclo[2.2.1]hept-4-yl(diphe-
nyl)acetonitrile (11) (0.044 g, 0.152 mmol) and 2-bromoethyl
phenylmethyl ether (0.040 mL, 0.253 mmol) in 2CH3CN/3CHCl3
(3.5 mL) were reacted to give the desired product (0.0281 g, 37.0%).
LC/MS (ES) m/z 423 (M)+. 1H NMR (400 MHz, DMSO-d6) δ ppm
7.50-7.43 (m, 6 H), 7.40-7.32 (m, 4 H), 4.55 (s, 2 H), 3.89-3.84
(m, 2 H), 3.79-3.72 (m, 8 H), 2.30-2.23 (m, 2 H), 2.19-2.12
(m, 2 H). HRMS calcd for (C29H31N2O) 423.2431, found 423.2431.
1-(2-{[(4-Bromophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17e). Fol-
lowing the general procedure outlined in 17a, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (30 mg, 0.102 mmol) and 1-bromo-
4-{[(2-bromoethyl)oxy]methyl}benzene (42 mg, 0.143 mmol) in
2CH3CN/3CHCl3 (3.0 mL) were reacted to give the desired product
(19.4 mg, 32%). LC/MS (ES) m/z 506 (M)+. 1H NMR (400 MHz,
MeOD) δ ppm 7.58 (d, J ) 7.6 Hz, 4 H), 7.52-7.48 (m, 2 H),
7.34-7.22 (comp, 8 H), 4.51 (s, 2 H), 3.89-3.83 (m, 2 H),
3.56-3.49 (m, 6 H), 3.44-3.38 (m, 2 H), 2.23-2.16 (m, 6 H).
HRMS calcd for (C29H33BrNO2) 506.1689, found 506.1690.
1-(2-{[(4-Cyanophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17f). Fol-
lowing the general procedure outlined in 17a, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (30 mg, 0.102 mmol) and 4-{[(2-
bromoethyl)oxy]methyl}benzonitrile (34 mg, 0.143 mmol) in
2CH3CN/3CHCl3 (3.0 mL) were reacted to give the desired product
4-[Cyano(diphenyl)methyl]-1-{3-[(phenylmethyl)oxy]propyl}-
1-azoniabicyclo[2.2.2]octane Bromide (16). Following the general
procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl(diphenyl)-
acetonitrile (12) (0.0495 g, 0.164 mmol) and 3-bromopropyl
phenylmethyl ether (0.050 mL, 0.283 mmol) in 2CH3CN/3CHCl3
(4.0 mL) were reacted to give the desired product (0.0579 g, 66.6%).
LC/MS (ES) m/z 451 (M)+. 1H NMR (400 MHz, DMSO-d6) δ ppm
7.55-7.49 (m, 4 H), 7.45 (t, J ) 7.45 Hz, 4 H), 7.42-7.27 (m, 7
H), 4.47 (s, 2 H), 3.54-3.47 (m, 8 H), 3.25-3.18 (m, 2 H), 2.13
(t, J ) 7.07 Hz, 6 H), 1.97-1.89 (m, 2 H). HRMS calcd for
(C31H35N2O) 451.2744, found 451.2741.
1
(40 mg, 74%). LC/MS (ES) m/z 453 (M)+. H NMR (400 MHz,
MeOD) δ ppm 7.71 (d, J ) 8.1 Hz, 2 H), 7.60-7.53 (m, 4 H),
7.32 (t, J ) 7.6 Hz, 4 H), 7.24 (t, J ) 7.3 Hz, 2 H), 4.65 (s, 2 H),
3.94-3.92 (m, 2 H), 3.60-3.53 (m, 6 H), 3.48-3.46 (m, 2 H),
2.24-2.18 (m, 6 H). HRMS calcd for (C30H33N2O2) 453.2537,
found 453.2539.
4-[Hydroxy(diphenyl)methyl]-1-[2-({[3-(methyloxy)phenyl]-
methyl}oxy)ethyl]-1-azoniabicyclo[2.2.2]octane Bromide (17a).
1-Azabicyclo[2.2.2]oct-4-yl(diphenyl)methanol (10) (30 mg, 0.102
mmol) was added to a solution of 1-{[(2-bromoethyl)oxy]methyl}-
3-(methyloxy)benzene (35 mg, 0.143 mmol) in 2CH3CN/3CHCl3
(3 mL). The reaction was heated at 60 °C for 96 h. The reaction
was concentrated, and the crude product was washed with EtOAc
(3 × 1 mL) and then MeOH (1 × 1 mL). The product was dried
under high vacuum to give the title compound (7.7 mg, 14%). LC/
MS (ES) m/z 458 (M)+. 1H NMR (400 MHz, MeOD) δ ppm 7.58
(d, J ) 7.6 Hz, 4 H), 7.32 (t, J ) 7.6 Hz, 4 H), 7.28-7.23 (comp,
3 H), 6.95-6.90 (m, 2 H), 6.86 (dd, J ) 7.5, 1.89 Hz, 1 H),
3.86-3.82 (m, 2 H), 4.52 (s, 3 H), 3.77 (s, 3 H), 3.53-3.48 (m, 6
H), 3.42-3.36 (m, 2 H), 2.22-2.16 (m, 6 H).
1-(2-{[(3-Fluorophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17g). Fol-
lowing the general procedure outlined in 17a, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (94 mg, 0.321 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-3-fluorobenzene (75 mg, 0.321 mmol) in
2CH3CN/3CHCl3 (4.0 mL) were reacted to give the desired product
1
(50 mg, 30%). LC/MS (ES) m/z 446 (M)+. H NMR (400 MHz,
MeOD) δ ppm 2.24-2.17 (m, 6 H) 3.47-3.41 (m, 2 H) 3.58-3.51
(m, 6 H) 3.92-3.86 (m, 2 H) 4.57 (s, 2 H) 7.02 (td, J ) 8.5, 2.4
Hz, 1 H) 7.11 (d, J ) 9.6 Hz, 1 H) 7.16 (d, J ) 7.6 Hz, 1 H) 7.24
(t, J ) 7.3 Hz, 2 H) 7.37-7.29 (m, 5 H) 7.58 (d, J ) 7.3 Hz, 4 H).
HRMS calcd for (C29H33FNO2) 446.2490, found 446.2493.
1-(2-{[(2-Cyanophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17h). Fol-
lowing the general procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (35.4 mg, 0.121 mmol) and 2-{[(2-
bromoethyl)oxy]methyl}benzonitrile (29 mg, 0.121 mmol) in
2CH3CN/3CHCl3 (1.5 mL) were reacted to give the desired product
(40 mg, 61.5%). LC/MS (ES) m/z 453 (M)+. 1H NMR (400 MHz,
DMSO-d6) δ ppm 7.88 (d, J ) 7.03 Hz, 1 H), 7.74 (t, J ) 7.65
Hz, 1 H), 7.62 (d, J ) 7.78 Hz, 1 H), 7.55 (d, J ) 7.53 Hz, 5 H),
7.32 (t, J ) 7.65 Hz, 4 H), 7.25 (d, J ) 7.03 Hz, 2 H), 5.96 (s, 1
H), 4.68 (s, 2 H), 3.92 (br s, 2 H), 3.49 (t, J ) 7.15 Hz, 6 H), 3.40
1-[2-({[4-(1,1-Dimethylethyl)phenyl]methyl}oxy)ethyl]-4-[hy-
droxy(diphenyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide
(17b). Following the general procedure outlined in 17a, 1-azabicyclo-
[2.2.2]oct-4-yl(diphenyl)methanol (10) (30 mg, 0.102 mmol) and
1-{[(2-bromoethyl)oxy]methyl}-4-(1,1-dimethylethyl)benzene (25
mg, 0.143 mmol) in 2CH3CN/3CHCl3 (3.0 mL) were reacted to
give the desired product (9 mg, 16%). LC/MS (ES) m/z 484 (M)+.
1
Purity by LC: 89%. H NMR (400 MHz, MeOD) δ ppm 7.58 (d,
J ) 7.8 Hz, 4 H), 7.39 (d, J ) 8.3 Hz, 2 H), 7.34-7.24 (comp, 8
H), 4.50 (s, 2 H), 3.85-3.79 (m, 2 H), 3.52-3.46 (m, 6 H),
3.40-3.35 (m, 2 H), 2.21-2.15 (m, 6 H), 1.31 (s, 9 H).

1-Azoniabicyclo[2.2.2]octane mAChR Antagonists
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8 2503
(br s, 2 H), 2.01 (t, J ) 7.03 Hz, 6 H). HRMS calcd for
(C30H33N2O2) 453.2537, found 453.2532.
in 2CH3CN/3CHCl3 (5.0 mL) were reacted to give the desired
1
product (40.6 mg, 13.1%). LC/MS (ES) m/z 442 (M)+. H NMR
(400 MHz, DMSO-d6) δ ppm 7.55 (d, J ) 7.53 Hz, 4 H), 7.35-7.28
(m, 5 H), 7.25 (d, J ) 7.28 Hz, 2 H), 7.22-7.17 (m, 3 H), 5.95 (s,
1 H), 4.50 (s, 2 H), 3.87-3.80 (m, 2 H), 3.46 (t, J ) 7.40 Hz, 6
H), 3.39-3.35 (m, 2 H), 2.26 (s, 3 H), 2.00 (t, J ) 7.28 Hz, 6 H).
Anal. (C30H36NO2Br·1.2H2O) C, H, N, Br. HRMS calcd for
(C30H36NO2) 442.2741, found 442.2737.
1-(2-{[(3-Bromophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17i). Fol-
lowing the general procedure outlined in 14h, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (61.9 mg, 0.211 mmol) and 2-bromoethyl
(3-bromophenyl)methyl ether (62 mg, 0.211 mmol) in 2CH3CN/
3CHCl3 (1.5 mL) were reacted to give the desired product (17 mg,
13.72%). LC/MS (ES) m/z 506 (M)+. 1H NMR (400 MHz, DMSO-
d6) δ ppm 7.58-7.49 (m, 6 H), 7.36-7.29 (m, 6 H), 7.27-7.22
(m, 2 H), 5.99 (br s, 1 H), 4.50 (s, 2 H), 3.82 (br s, 2 H), 3.52-3.43
(m, 6 H), 3.42-3.31 (m, 2 H), 2.08-1.90 (m, 6 H). HRMS calcd
for (C29H33BrNO2) 506.1689, found 506.1683.
1-(2-{[(2-Fluorophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17j). Fol-
lowing the general procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (177 mg, 0.602 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-2-fluorobenzene (169 mg, 0.602 mmol)
in 2CH3CN/3CHCl3 (5.0 mL) were reacted to give the desired
product (36 mg, 10.8%). LC/MS (ES) m/z 446 (M)+. 1H NMR (400
MHz, DMSO-d6) δ ppm 7.55 (d, J ) 7.53 Hz, 4 H), 7.45 (t, J )
7.53 Hz,1 H), 7.39 (d, J ) 7.53 Hz, 1 H), 7.33 (t, J ) 7.65 Hz, 4
H), 7.27-7.20 (m, 4 H), 5.95 (s, 1 H), 4.56 (s, 2 H), 3.85 (d, J )
4.02 Hz, 2 H), 3.46 (t, J ) 7.40 Hz, 6 H), 3.40-3.34 (m, 2 H),
2.00 (t, J ) 7.28 Hz, 6 H). HRMS calcd for (C29H33FNO2)
446.2490, found 446.2485.
4-[Hydroxy(diphenyl)methyl]-1-(2-{[(3-methylphenyl)meth-
yl]oxy}ethyl)-1-azoniabicyclo[2.2.2]octane Bromide (17k). Fol-
lowing the general procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (119 mg, 0.407 mmol) and 2-bromoethyl
(3-methylphenyl)methyl ether (153 mg, 0.407 mmol) in 2CH3CN/
3CHCl3 (5.0 mL) were reacted to give the desired product (33 mg,
14.7%). LC/MS (ES) m/z 442 (M)+. 1H NMR (400 MHz, DMSO-
d6) δ ppm 7.55 (d, J ) 7.28 Hz, 4 H), 7.33 (t, J ) 7.53 Hz, 4 H),
7.24 (t, J ) 7.15 Hz, 3 H), 7.14-7.10 (m, 3 H), 5.95 (s, 1 H), 4.46
(s, 2 H), 3.82-3.78 (m, 2 H), 3.46 (t, J ) 7.53 Hz, 6 H), 3.40-3.29
(m, 2 H), 2.29 (s, 3 H), 2.00 (t, J ) 7.40 Hz, 6 H). Anal.
(C30H36NO2 ·0.5H2O) C, H, N, Br. HRMS calcd for (C30H36NO2)
442.2741, found 442.2736.
1-(2-{[(2-Bromophenyl)methyl]oxy}ethyl)-4-[hydroxy(diphe-
nyl)methyl]-1-azoniabicyclo[2.2.2]octane Bromide (17l). Fol-
lowing the general procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (136 mg, 0.464 mmol) and 2-bromoethyl
(2-bromophenyl)methyl ether (192 mg, 0.464 mmol) in 2CH3CN/
3CHCl3 (5.0 mL) were reacted to give the desired product (48 mg,
16.75%). LC/MS (ES) m/z 506 (M)+. 1H NMR (400 MHz, DMSO-
d6) δ ppm 7.62 (d, J ) 1.00 Hz, 1 H), 7.55 (d, J ) 7.53 Hz, 4 H),
7.51-7.46 (m, 1 H), 7.41 (t, J ) 6.90 Hz, 1 H), 7.35-7.29 (m, 4
H), 7.25 (q, J ) 7.11 Hz, 3 H), 5.95 (s, 1 H), 4.55 (s, 2 H),
3.94-3.87 (m, 2 H), 3.49 (t, J ) 7.40 Hz, 6 H), 3.43-3.38 (m, 2
H), 2.00 (t, J ) 7.40 Hz, 6 H). Anal. (C29H33NO2Br2 ·1.5H2O) C,
H, N, Br. HRMS calcd for (C29H33BrNO2) 506.1689, found
506.1683.
4-[Bis(4-fluorophenyl)(hydroxy)methyl]-1-{2-[(phenylmethyl)-
oxy]ethyl}-1-azoniabicyclo[2.2.2]octane Bromide (18a). A solu-
tion of 4-fluorophenylmagnesiumbromide (1.0 M in THF, 4.4 mL,
4.4 mmol) was chilled down to 0 °C under Ar. Ethyl 1-azabicyclo-
[2.2.2]octane-4-carboxylate (8) (0.1973 g, 1.08 mmol) in THF (4
mL) was slowly added to the reaction mixture at 0 °C over 20
min. The reaction was allowed to warm up to room temperature
and then heated at 60 °C for 16 h. The reaction was chilled in an
ice bath, quenched with saturated NH4Cl, and concentrated under
vacuum. The resulting residue was treated with H2O and extracted
with EtOAc. The combined organic layers were dried with MgSO4,
filtered,andconcentratedundervacuumtoyield1-azabicyclo[2.2.2]oct-
4-yl[bis(4-fluorophenyl)]methanol (0.3152 g, 88.9%). LC/MS (ES)
m/z 330 (M + H)+. Following the general procedure outlined in
14h, 1-azabicyclo[2.2.2]oct-4-yl[bis(4-fluorophenyl)]methanol (0.0489
g, 0.148 mmol) and 2-bromoethyl phenylmethyl ether (0.0352 mL,
0.222 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were reacted to give
the desired product (0.0534 g, 66.1%). LC/MS (ES) m/z 464 (M)+.
1H NMR (400 MHz, DMSO-d6) δ ppm 7.56 (dd, J ) 8.84, 5.56
Hz, 4 H), 7.40-7.28 (m, 5 H), 7.19-7.12 (m, 2 H), 7.15 (t, J )
8.84 Hz, 2 H), 6.09 (s, 1 H), 4.50 (s, 2 H), 3.85-3.785 (m, 2 H),
3.47 (t, J ) 7.33 Hz, 6 H), 3.40-3.35 (m, 2 H), 1.97 (t, J ) 7.20
Hz, 6 H). HRMS calcd for (C29H32F2NO2) 464.2396, found
464.2398.
4-(Hydroxy{bis[3-(methyloxy)phenyl]}methyl)-1-{2-[(phenyl-
methyl)oxy]ethyl}-1-azoniabicyclo[2.2.2]octane Bromide (18b).
Following the general procedure outlined in 18a, ethyl 1-azabicyclo-
[2.2.2]octane-4-carboxylate (8) (0.1608 g, 0.877 mmol) and 3-(me-
thyloxy)phenylmagnesiumbromide (1.0 M in THF, 3.3 mL, 3.3
mmol) in THF (4.0 mL) were reacted to give 1-azabicyclo[2.2.2]oct-
4-yl{bis[3-(methyloxy)phenyl]}methanol (0.2881 g, 92.9%). LC/
MS (ES) m/z 354 (M + H)+. Following the general procedure
outlined in 14h, 1-azabicyclo[2.2.2]oct-4-yl{bis[3-(methyloxy)-
phenyl]}methanol (0.0538 g, 0.152 mmol) and 2-bromoethyl
phenylmethyl ether (0.0361 mL, 0.228 mmol) in 2CH3CN/3CHCl3
(4.0 mL) were reacted to give the desired product (0.0292 g, 33.8%).
LC/MS (ES) m/z 488 (M)+. 1H NMR (400 MHz, DMSO-d6) δ ppm
7.37-7.30 (m, 5 H), 7.25 (t, J ) 8.08 Hz, 2 H), 7.14 (d, J ) 8.59
Hz, 2 H), 7.08 (t, J ) 2.02 Hz, 2 H), 6.84 (dd, J ) 7.96, 2.40 Hz,
2 H), 5.96 (s, 1 H), 4.50 (s, 2 H), 3.84-3.79 (m, 2 H), 3.73 (s, 6
H), 3.50-3.42 (m, 6 H), 3.39-3.33 (m, 2 H), 2.03 - 1.96 (m, 6
H). HRMS calcd for (C31H38NO4) 488.2795, found 488.2796.
4-[Bis(3-fluorophenyl)(hydroxy)methyl]-1-{2-[(phenylmethyl)-
oxy]ethyl}-1-azoniabicyclo[2.2.2]octane Bromide (18c). Following
the general procedure outlined in 18a, ethyl 1-azabicyclo-
[2.2.2]octane-4-carboxylate (8) (0.1756 g, 0.958 mmol) and 3-fluo-
rophenylmagnesiumbromide (1.0 M in THF, 3.3 mL, 3.3 mmol)
in THF (4.0 mL) were reacted to give 1-azabicyclo[2.2.2]oct-4-
yl[bis(3-fluorophenyl)]methanol (0.242 g, 76.7%). LC/MS (ES) m/z
330 (M + H)+. Following the general procedure outlined in 14h,
1-azabicyclo[2.2.2]oct-4-yl[bis(3-fluorophenyl)]methanol (0.0507 g,
0.154 mmol) and 2-bromoethyl phenylmethyl ether (0.0365 mL,
0.230 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were reacted to give
the desired product (0.0362 g, 43.2%). LC/MS (ES) m/z 464 (M)+.
1H NMR (400 MHz, DMSO-d6) δ ppm 7.43-7.30 (m, 11 H),
7.17-7.11 (m, 2 H), 6.27 (s, 1 H), 4.50 (s, 2 H), 3.85-3.79 (m, 2
H), 3.48 (t, J ) 7.45 Hz, 6 H), 3.40-3.35 (m, 2 H), 1.98 (t, J )
7.20 Hz, 6 H). HRMS calcd for (C29H32F2NO2) 464.2396, found
464.2396.
4-[Hydroxy(diphenyl)methyl]-1-(2-{[(4-methylphenyl)meth-
yl]oxy}ethyl)-1-azoniabicyclo[2.2.2]octane Bromide (17m). Fol-
lowing the general procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-
4-yl(diphenyl)methanol (10) (171 mg, 0.583 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-4-methylbenzene (167 mg, 0.583 mmol)
in 2CH3CN/3CHCl3 (5.0 mL) were reacted to give the desired
product (72.7 mg, 22.67%). LC/MS (ES) m/z 442 (M)+. 1H NMR
(400 MHz, DMSO-d6) δ ppm 7.55 (d, J ) 7.53 Hz, 4 H), 7.33 (t,
J ) 7.65 Hz, 4 H), 7.28-7.20 (m, 4 H), 7.19-7.14 (m, 2 H), 5.95
(s, 1 H), 4.44 (s, 2 H), 3.82-3.75 (m, 2 H), 3.46 (t, J ) 7.40 Hz,
6 H), 3.38-3.34 (m, 2 H), 2.29 (s, 3 H), 2.00 (t, J ) 7.40 Hz, 6
H). Anal. (C30H36NO2Br·1.1H2O) C, H, N, Br. HRMS calcd for
(C30H36NO2) 442.2741, found 442.2736.
4-[Hydroxy(diphenyl)methyl]-1-(2-{[(2-methylphenyl)meth-
yl]oxy}ethyl)-1-azoniabicyclo[2.2.2]octane (17n). Following the
general procedure outlined in 14c, 1-azabicyclo[2.2.2]oct-4-yl-
(diphenyl)methanol (10) (174 mg, 0.593 mmol) and 1-{[(2-
bromoethyl)oxy]methyl}-2-methylbenzene (194 mg, 0.593 mmol)
4-(Hydroxy{bis[4-(methyloxy)phenyl]}methyl)-1-{2-[(phenyl-
methyl)oxy]ethyl}-1-azoniabicyclo[2.2.2]octane Bromide (18d).
Following the general procedure outlined in 18a, ethyl 1-azabicyclo-
[2.2.2]octane-4-carboxylate (8) (0.1587 g, 0.866 mmol) and 4-(me-

2504 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 8
Laine´ et al.
thyloxy)phenylmagnesiumbromide (0.5 M in THF, 6.5 mL, 3.25
mmol) in THF (4.0 mL) were reacted to give 1-azabicyclo[2.2.2]oct-
4-yl{bis[4-(methyloxy)phenyl]}methanol (0.273 g, 89.0%). LC/MS
(ES) m/z 354 (M + H)+. Following the general procedure outlined
in 14h, 1-azabicyclo[2.2.2]oct-4-yl{bis[4-(methyloxy)phenyl]}-
methanol (0.0498 g, 0.141 mmol) and 2-bromoethyl phenylmethyl
ether (0.0334 mL, 0.211 mmol) in 2CH3CN/3CHCl3 (4.0 mL) were
reacted to give the desired product (0.0374 g, 46.7%). LC/MS (ES)
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m/z 488 (M)+. H NMR (400 MHz, MeOD) δ ppm 7.48 (t, J )
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(m, 9 H), 7.21 (t, J ) 7.6 Hz, 2 H), 7.06 (d, J ) 6.8 Hz, 2 H), 5.86
(s, 1 H), 4.51 (s, 2 H), 3.82 (br. S, 2 H), 3.46 (br s, 6 H), 3.36 (br.
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Supporting Information Available: The general method of
preparation of the noncommercially available alkylating agents to
prepare the compounds 17a-17o (Table 3). The elemental analyses
data for compounds 10, 14j, 14o, 17c, 17d, 17k, 17l, 17m, and
17n. The general methods for the in vitro and in vivo assays (Tables
1-6, Figure 6). The pA2 data at the M1 and M2 receptors for
compounds 14k and 14o. This material is available free of charge
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