Alkylsulfone-containing trisubstituted cyclohexanes as potent and bioavailable chemokine receptor 2 (CCR2) antagonists

Article abstract of DOI:10.1016/j.bmcl.2014.02.013

We describe novel alkylsulfones as potent CCR2 antagonists with reduced hERG channel activity and improved pharmacokinetics over our previously described antagonists. Several of these new alkylsulfones have a profile that includes functional antagonism of

Full text of DOI:10.1016/j.bmcl.2014.02.013

Bioorganic & Medicinal Chemistry Letters 24 (2014) 1843–1845
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Alkylsulfone-containing trisubstituted cyclohexanes as potent and
bioavailable chemokine receptor 2 (CCR2) antagonists
a
a
a
a
a
Robert J. Cherney a, , Ruowei Mo , Michael G. Yang , Zili Xiao , Qihong Zhao , Sandhya Mandlekar ,
⇑
Mary Ellen Cvijic a, Israel F. Charo b, Joel C. Barrish a, Carl P. Decicco a, Percy H. Carter a
a Research and Development, Bristol-Myers Squibb Company, Princeton, NJ 08543-4000, United States
b Gladstone Institute of Cardiovascular Disease, J David Gladstone Research Institutes, San Francisco, CA 94158, United States
a r t i c l e i n f o
a b s t r a c t
Article history:
We describe novel alkylsulfones as potent CCR2 antagonists with reduced hERG channel activity and
improved pharmacokinetics over our previously described antagonists. Several of these new alkylsulf-
ones have a profile that includes functional antagonism of CCR2, in vitro microsomal stability, and oral
bioavailability. With this improved profile, we demonstrate that two of these antagonists, 2 and 12,
are orally efficacious in an animal model of inflammatory recruitment.
Received 18 October 2013
Revised 31 January 2014
Accepted 4 February 2014
Available online 21 February 2014
Ó 2014 Elsevier Ltd. All rights reserved.
Keywords:
CCR2
CCR2 antagonist
Chemokine antagonist
GPCR
Monocyte chemoattractant protein-1 (MCP-1 or CCL2) is a CC
chemokine overexpressed in many autoimmune and inflammatory
conditions.1 Its native receptor is CC chemokine receptor 2 (CCR2),
which is a G protein-coupled receptor.2 A primary function of this
pair (MCP-1/CCR2) is the activation and migration of inflammatory
cells to areas of inflammation. MCP-1 and CCR2 have been impli-
cated in several diseases, including rheumatoid arthritis,3 athero-
sclerosis,4 multiple sclerosis5 and insulin resistance.6 This has
resulted in a large effort focused on the design and synthesis of
CCR2 antagonists.7 In this communication, we explore structural
changes to a series of sulfone-containing CCR2 antagonists with
the goal of reducing hERG channel activity and obtaining orally
bioavailable compounds.
Recent reports from this laboratory have described the design
and synthesis of cyclohexane-based CCR2 antagonists.8 The major
focus of these early studies was to explore and define the SAR of
this novel cyclohexyl template, so as to achieve maximum binding
affinity and functional antagonism of CCR2. Unfortunately, the
majority of our high affinity CCR2 antagonists suffered from hERG
channel inhibition: a well known liability within the chemokine
antagonist field.9 In an effort to moderate this hERG liability, we
explored structural changes that would lower our overall lipophil-
icity. As shown in Table 1, when the starting phenyl sulfone 1 was
modified to the methyl sulfone 2, the hERG inhibition was
eliminated as observed via a hERG FLIPR assay. However, as is often
the case in LogP lowering one can sacrifice binding affinity on the
target, as was observed here for the methyl sulfone 2, which lost
almost 2-fold in CCR2 binding affinity10 as compared to 1. Even
though this transformation did eliminate the hERG activity, other
channel binding issues were known to exist with our previous
antagonists, and therefore, we employed a sodium channel binding
assay11 to help monitor this issue. In agreement with the hERG
assessment, methylsulfone 2 also showed very little sodium chan-
nel binding (3% @ 10 lM). Continuing with the modifications, we
added a nitrogen to the trifluoromethylbenzamide to give 3, which
essentially retained the CCR2 binding affinty and channel profile of
2. Compounds 4 and 5 had a tert-butyl group substituted on the
benzamide (instead of a trifluoromethyl), and although they had
improved CCR2 binding affinity versus 2 and 3, respectively, com-
pounds 4 and 5 did display an increase in sodium channel binding
(52% and 46% @ 10 lM, respectively). For other substitutions of the
benzamide, both 6 (4-methyl-3-trifluoromethyl) and 7 (3-triflu-
oromethoxy) had a deleterious effect on CCR2 binding. From here,
we turned to the ethylsulfone, but 8 showed an increase in sodium
channel activity, and 3-phenylbenzamide 9 revealed more hERG
channel activity. The iso-propylsulfone 10 increased the CCR2
binding affinity 6-fold as compared to 2 without displaying hERG
inhibition. However, the combination of 3-tert-butylbenzamide
and iso-propylsulfone to give 11 increased CCR2 binding but also
increased hERG channel binding. tert-Butylsulfones also proved
to be compatible with CCR2 as 12, 13 and 14 all showed excellent
⇑
Corresponding author. Tel.: +1 609 252 3066; fax: +1 609 252 7446.
E-mail address: robert.cherney@bms.com (R.J. Cherney).
http://dx.doi.org/10.1016/j.bmcl.2014.02.013
0960-894X/Ó 2014 Elsevier Ltd. All rights reserved.

1844
R. J. Cherney et al. / Bioorg. Med. Chem. Lett. 24 (2014) 1843–1845
Table 1
Evaluation of alkylsulfone derivatives
R2
4
5
N
O
H
N
1
3
R1
N
X
R
O
S
O
O
Compd #
R
R1
R2
X
CCR2 bindinga IC50 (nM)
hERGb IC50
(
lM)
Na+ bindingc %Inh @10
lM
1
2
3
4
5
6
7
8
Ph
CF3
CF3
CF3
t-Bu
t-Bu
3-CF3
OCF3
CF3
Ph
CF3
t-Bu
CF3
OCF3
3-CF3
—
—
—
—
—
4-CH3
—
—
—
—
—
—
—
C
C
N
C
N
C
C
C
C
C
C
C
C
C
1.0 0.2 (7)
1.8 0.8 (12)
2.2 0.1 (2)
1.2 (1)
0.7 (1)
5.2 (1)
5.0 (1)
1.3 0.02 (2)
1.1 (1)
30
NT
3
0
Me
Me
Me
Me
Me
Me
Et
>80
>80
>80
>80
>80
>80
>80
60
>80
77
>80
>80
>80
52
46
36
32
26
NT
NT
NT
48
61
48
9
Et
10
11
12
13
14
i-Pr
i-Pr
t-Bu
t-Bu
t-Bu
0.3 (1)
0.5 0.2 (2)
0.96 0.26 (19)
1.2 (1)
5-F
1.3 (1)
a
b
c
IC50 values (n) are displayed as mean SD (n = 2) and mean SEM (n > 2).
hERG FLIPR assay (n = 1).
Rat Na+ channel binding assay (n = 1). NT = not tested.
Table 2
Evaluation of alkylsulfone derivatives
CF3
N
O
H
N
N
R
O
S
O
O
IC50 (nM)
Human microsomal
hERGd IC50
(
lM)
Caco-2 PAP-BL (nm/s)
hERG patch clamp
(4 Hz) (% Inh)
Na+ patch clamp
(4 Hz) (% Inh @10 lM)
a
stabilityc (% remaining)
#
R
CCR2 binding
Chemotaxisb
1
2
8
10
12
Ph
Me
Et
i-Pr
t-Bu
1.0 0.2 (7)
1.8 0.8 (12)
1.2 0.07 (4)
0.34 (1)
0.5
2.6
0.6
0.2
0.2
88
30
<15e
<15
<15
<15
30
NT
NT
100
100
100
100
>80
>80
>80
>80
4% @10
3.6% @3
NT
l
lM
M
22%
4.2%
NT
0.96 0.26 (19)
4.2% @10
lM
19%
a
b
c
IC50 values (n) are displayed as mean SD (n = 2) and mean SEM (n > 2).
Chemotaxis in human monocytes (n = 1) with 0.1 M BSA.
Percent remaining after 10 min incubation in human hepatic microsomes.
hERG FLIPR assay (n = 1). NT = not tested.
d
e
<15 is limit of detection for this assay.
CCR2 binding affinity with no hERG channel activity and only mod-
erate sodium channel binding. From this data set, an increase in
CCR2 binding affinity trended with the alkylsulfone group in this
order: Me < Et < t-Bu < i-Pr.
exposure across the four species with dog being the best (F% = 51).
Compound 2 showed a wide disparity in clearance (iv) with high
clearance recorded in mouse (CL = 70 mL/min/kg) and low clear-
ance recorded in dog (CL = 3 mL/min/kg). As shown in Table 4,
the tert-butylsulfone 12 had more consistent oral bioavailability
across the four species than the methylsulfone 2. This improved
bioavailability for 12 may be a reflection of improved permeability
as noted in the Caco-2 value. Compound 12 also had low clearance
values across three species with rat being the outlier.
With both 2 and 12 showing oral bioavailability, it was our de-
sire to test these CCR2 antagonists in a mouse model of inflamma-
tory cellular recruitment. The MCP-1/CCR2 pair plays a major role
in mediating the egress of inflammatory monocytes (defined as
Ly6C+F4/80+) from bone marrow to blood,14 and this can be emu-
lated with the thioglycollate (TG)-induced peritonitis model.15
However, 2 and 12 have poor activity versus mouse CCR2, hence
our TG model had to be performed in a human-CCR2 knock-in
mouse (we did dose 12 in a TG-induced peritonitis model using
wild-type mice, however 12 did not show any activity—data not
shown). As shown in Table 5 with human-CCR2 knock-in mice,
As shown in Table 2, four alkylsulfones (2, 8, 10, and 12) were
selected for chemotaxis, in vitro microsomal incubation, Caco-2,
hERG patch-clamp12 and sodium patch-clamp13 evaluation. All
four alkylsulfones displayed excellent chemotaxis values, hence
confirming their ability to operate as potent functional antagonists.
Another benefit of the alkylsulfone was observed in the in vitro
microsomal stability assay, as all four alkylsulfones were extre-
mely stable as compared to phenylsulfone 1. In addition, although
permeability was universally poor, as measured by Caco-2, the
tert-butylsulfone 12 did show a measurable value. Three of these
compounds (2, 8, and 12) were also taken into hERG and sodium
patch-clamp assays. The patch-clamp values were in-line with
the in vitro assessment and indicated a low to moderate liability.
With promising antagonists in hand, we selected two com-
pounds for further evaluation in four species pharmacokinetic
(PK) studies. As shown in Table 3, compound 2 displayed some oral

R. J. Cherney et al. / Bioorg. Med. Chem. Lett. 24 (2014) 1843–1845
1845
Table 3
BocHN
a
BocHN
BocHN
b
Pharmacokinetic data for compound 2
NHCbz
NHCbz
NHCbz
a
Species
Dose
F%a
CLiv (mL/min/kg)
HO
S
S
(mpk) iv/po
O
O
15
17
16
Mouse
Rat
Cyno
Dog
3/54
6/72
1/14
1/14
16
1
9
70
42
14
51
3
BocHN
BocHN
O
O
c
d
a
NHCbz
NHCbz
SMe
Values are an average from two animals.
N
N
H
S
S
O
O
O
O
18
19
Table 4
Pharmacokinetic data for compound 12
a
Species
Dose (mpk) iv/po
F%a
CLiv (mL/min/kg)
CF3
N
Mouse
Rat
Cyno
Dog
5/100
4/43
1/10
1/10
13
14
26
74
25
54
12
5
O
e then f
H
N
N
O
S
O
O
12
a
Values are an average from two animals.
Scheme 1. Reagents and conditions: (a) (i) MsCl, TEA, DCM, 0 °C, quant; (ii) NaS-t-
Bu, DMF, 78%; (b) oxone, IPA, H2O, 79%; (c) H2, Pd/C, MeOH; (ii) BOP, NMM, N-Cbz-
L-
Met-OH, DMF, 95% (two steps); (d) (i) Mel; (ii) Cs2CO3, DMF, 76%; (e) (i) H2, Pd/C,
MeOH; (ii) BOP, NMM, 3-trifluoromethylbenzoic acid, DMF, 90% (2 steps); (f) (i)
TFA, DCM, quant; (ii) acetone, NaBH(OAc)3, DCM; (iii) 37% HCHO, NaBH(OAc)3,
DCM, 96% (two steps).
Table 5
6-h TG model in human-CCR2 knock-in mice with 2 and 12
12
Acknowledgment
8
4
0
We thank our colleagues in the Department of Chemical Syn-
thesis at Biocon Bristol-Myers Squibb Research Center (BBRC) for
the preparation of the precursor to compound 15.
No
Vehicle
2
12
References and notes
challenge
TG challenge
1. Daly, C.; Rollins, B. J. Microcirculation 2003, 10, 247; For chemokine
nomenclature, see: Murphy, P. M.; Baggiolini, M.; Charo, I. F.; Hebert, C. A.;
Horuk, R.; Matsushima, K.; Miller, L. H.; Oppenheim, J. J.; Power, C. A.
Pharmacol. Rev. 2000, 52, 145.
2. Feria, M.; Diaz-Gonzalez, F. Expert Opin. Ther. Pat. 2006, 16, 49.
3. Tak, P. P. Best Pract. Res. Clin. Rheumatol. 2006, 20, 929.
(n=5 per group)
Dose informaꢀon: 2 dosed at 50 mpk po
12 dosed at 100 mpk po
a % of Ly6C+F4/80+ cells vs. TG control in peripheral blood.
4. (a) Coll, B.; Alonso-Villaverde, C.; Joven, J. Clin. Chim. Acta 2007, 383, 21; (b)
Peters, W.; Charo, I. F. Curr. Opin. Lipidol. 2001, 12, 175.
5. Mahad, D. J.; Ransohoff, R. M. Semin. Immunol. 2003, 15, 23.
6. Kamei, N.; Tobe, K.; Suzuki, R.; Ohsugi, M.; Watanabe, T.; Kubota, N.; Ohtsuka-
Kowatari, N.; Kumagai, K.; Sakamoto, K.; Kobayashi, M.; Yamauchi, T.; Ueki, K.;
Oishi, Y.; Nishimura, S.; Manabe, I.; Hashimoto, H.; Ohnishi, Y.; Ogata, H.;
Tokuyama, K.; Tsunoda, M.; Ide, T.; Murakami, K.; Nagai, R.; Kadowaki, T. J. Biol.
Chem. 2006, 281, 26602.
7. (a) Carter, P. H. Expert Opin. Ther. Pat. 2013, 23, 549; (b) Struthers, M.;
Pasternak, A. Curr. Top. Med. Chem. 2010, 10, 1278; (c) Xia, M.; Sui, Z. Expert
Opin. Ther. Pat. 2009, 19, 295; (d) Carter, P. H.; Cherney, R. J.; Mangion, I. K.
Annu. Rep. Med. Chem. 2007, 42, 211.
8. (a) Cherney, R. J.; Mo, R.; Meyer, D. T.; Voss, M. E.; Yang, M. G.; Santella, J. B.;
Duncia, J. V.; Lo, Y. C.; Yang, G.; Miller, P. B.; Scherle, P. A.; Zhao, Q.; Mandlekar,
S.; Cvijic, M. E.; Barrish, J. C.; Decicco, C. P.; Carter, P. H. Bioorg. Med. Chem. Lett.
2010, 20, 2425; (b) Cherney, R. J.; Mo, R.; Meyer, D. T.; Voss, M. E.; Lo, Y. C.;
Yang, G.; Miller, P. B.; Scherle, P. A.; Tebben, A. J.; Carter, P. H.; Decicco, C. P.
Bioorg. Med. Chem. Lett. 2009, 19, 3418.
compounds 2 and 12 were orally dosed in separate experiments
one hour before thioglycollate challenge, and both 2 and 12
showed a significant reduction of inflammatory monocytes in
blood as compared to vehicle (similar findings were observed with
these monocytes in the peritoneal cavity—data not shown). Hence,
these results validate the in vivo activity of compounds 2 and 12.
The synthesis of compound 12, shown in Scheme 1, is used as a
representative example of these alkylsulfone antagonists. The syn-
thesis commenced with mesylation of the homochiral alcohol 15.16
The resulting mesylate was used, without purification, in a dis-
placement reaction to give 16, which was subsequently oxidized
to sulfone 17. The carbamate of 17 was then removed prior to cou-
pling with a methionine derivative to yield 18. The lactam was
formed under our modified Freidinger17 conditions (MeI and then
Cs2CO3 in DMF) to give 19. Final elaboration was performed by
way of benzamide installation followed by tertiary amine forma-
tion to afford 12.
9. Shamovsky, I.; Connolly, S.; David, L.; Ivanova, S.; Norden, B.; Springthorpe, B.;
Urbahns, K. J. Med. Chem. 2008, 51, 1162.
10. For biological assay details, see: Carter, P. H.; Cherney, R. J. Diamines as
Modulators of Chemokine Receptor Activity. WO 2002050019, 2002.
11. Rat sodium channel (site 2) binding assay from MDS Pharma Services.
12. Zhou, Z.; Gong, Q.; Ye, B.; Fan, Z.; Makielski, J. C.; Robertson, G. A.; January, C. T.
Biophys. J. 1998, 74, 230.
In summary, we have demonstrated that trisubstituted cyclo-
hexanes containing alkylsulfones are potent functional antagonists
of CCR2 that have an improved hERG channel profile as compared
to our previously described antagonists. Two of these alkylsulfone
antagonists, 2 and 12, also displayed in vitro microsomal stability
and oral bioavailability. With this improved profile, we established
that these CCR2 antagonists are orally efficacious in an animal
model of monocyte recruitment, one of the hallmarks of autoim-
mune disease.
13. Balser, J. R. Cardiovasc. Res. 1999, 42, 327.
14. Serbina, N. V.; Pamer, E. G. Nat. Immunol. 2006, 7, 311.
15. Melnicoff, M. J.; Horan, P. K.; Morahan, P. S. Cell. Immunol. 1989, 118, 178. In the
TG-induced peritonitis model from Table 5, compounds are dosed one hour
before TG. The cells were then harvested 6-hours after the TG dose. We used
monocyte staining of the peripheral blood to quantify the Ly6C+F4/80+ cells.
16. Campbell, C. L.; Hassler, C.; Ko, S. S.; Voss, M. E.; Guaciaro, M. A.; Carter, P. H.;
Cherney, R. J. J. Org. Chem. 2009, 74, 3638.
17. (a) Freidinger, R. M.; Veber, D. F.; Perlow, D. S.; Brooks, J. R.; Saperstein, R.
Science 1980, 210, 656; (b) Freidinger, R. M.; Perlow, D. S.; Veber, D. F. J. Org.
Chem. 1982, 47, 104.