2-(1H-Pyrazol-1-yl)acetic acids as chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes (CRTh2) antagonists

Article abstract of DOI:10.1016/j.ejmech.2013.10.072

In this manuscript, the synthesis and biological activity of a series of pyrazole acetic acid derivatives as CRTh2 antagonists is presented. Biological evaluation in vitro revealed that the pyrazole core showed in several cases a different structure-activity relationship (SAR) to that of related indole acetic acid. A potent series of ortho-sulfonyl benzyl substituents was found, from which compounds 27 and 63 were advanced to in vivo profiling.

Full text of DOI:10.1016/j.ejmech.2013.10.072

European Journal of Medicinal Chemistry 71 (2014) 168e184
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
2-(1H-Pyrazol-1-yl)acetic acids as chemoattractant receptor-
homologous molecule expressed on Th2 lymphocytes (CRTh2)
antagonists
Miriam Andrés a, Mónica Bravo a, Maria Antonia Buil a, Marta Calbet a, Marcos Castillo b,
Jordi Castro a, Peter Eichhorn a, Manel Ferrera, Martin D. Lehner a, Imma Moreno a,
,
a
Richard S. Roberts a , Sara Sevilla
*
a Almirall R&D Centre, Laureano Miró 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
b Almirall-Barcelona Science Park Unit, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
In this manuscript, the synthesis and biological activity of a series of pyrazole acetic acid derivatives as
CRTh2 antagonists is presented. Biological evaluation in vitro revealed that the pyrazole core showed in
several cases a different structureeactivity relationship (SAR) to that of related indole acetic acid. A
potent series of ortho-sulfonyl benzyl substituents was found, from which compounds 27 and 63 were
advanced to in vivo profiling.
Received 18 February 2013
Received in revised form
28 October 2013
Accepted 29 October 2013
Available online 9 November 2013
Ó 2013 Elsevier Masson SAS. All rights reserved.
Keywords:
Pyrazole
CRTh2 antagonists
Structureeactivity relationship (SAR)
1. Introduction
(IgE) production among others. Therefore, molecules that antago-
nize the pro-inflammatory PGD2 effects mediated by CRTh2 on key
Prostaglandin D2 (PGD2) is derived from the metabolism of
arachidonic acid by cyclooxygenases and downstream PGD2 syn-
thases. In the immune system, PGD2 is mainly produced by mast
cells [1] but also although at lower levels, by macrophages and Th2
lymphocytes [2]. PGD2 binds to three different receptors, the
thromboxane type prostanoid receptor (TP) [3], the PGD2 receptor
(DP, also known as DP1) [4] and the chemoattractant receptor ho-
mologous molecule expressed on Th2 lymphocytes (CRTh2, also
known as DP2) [5]. CRTh2 is a Gi coupling GPCR, signalling through
reduction of intracellular cyclic adenosine monophosphate (cAMP)
and calcium mobilization and it is involved in the chemotaxis of
Th2 lymphocytes, eosinophils and basophils [6]. CRTh2 also inhibits
the apoptosis of Th2 lymphocytes [7] and stimulates the production
of IL4, IL5, and IL13 [8], cytokines involved in important biological
responses such as eosinophil recruitment and survival, mucus
secretion, airway hyper-responsiveness and immunoglobulin E
cell types associated with allergic inflammation (basophils, eosin-
ophils and Th2 lymphocytes) should have a potential benefit in
related pathologies.
The search for CRTh2 antagonists is an active field with over 150
articles relating to chemistry and/or biology and around 200 pat-
ents published to date. Many companies are active in this area and
several recent reviews have highlighted the progress and most
advanced series [9e14]. A large proportion of the published
chemical series owe their origins to the observations that the indole
acetic acid indomethacin 1 inhibited the binding of labelled pros-
taglandin PGD2 to CRTh2 (although 1 is in fact a partial agonist of
the receptor) [15], and that the thromboxane inhibitor, the indole
propionic acid Ramatroban 2 was also a fairly potent antagonist of
CRTh2 [16] (Fig. 1).
While robust structural information on the receptor remains
elusive, a clear preference for the arylacetic acid pharmacophore
has emerged. Furthermore, these structures may be conceptually
broken into three areas (Fig. 2) [14]:
* Corresponding author. Drug Discovery Division, Almirall R&D Centre, Laureano
Miró 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain. Tel.: þ34 93 291
7540; fax: þ34 93 291 3420.
1. The acetic acid “head” group. The chain length affects binding
affinity, with acetic acid chains generally best. Alpha-
substitution tends to lose potency and common bioisosteres of
E-mail address: rick.roberts@almirall.com (R.S. Roberts).
0223-5234/$ e see front matter Ó 2013 Elsevier Masson SAS. All rights reserved.
http://dx.doi.org/10.1016/j.ejmech.2013.10.072

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
169
To this end, we therefore first condensed 1-phenylbutane-1,3-
dione with hydrazine and alkylated the resulting pyrazole with
ethyl bromoacetate to give a 90:10 mixture of regioisomers, with
the desired pyrazole 6 as the major product. Again, the electronic
component defining which pyrazole tautomer is deprotonated is
poorly defined, but the steric bulk of the 3-phenyl ring almost
certainly dictated the regiochemistry of the alkylation (Fig. 3) [19].
The two regioisomers 5 and 6 were separable, but required labo-
rious chromatography due to their similar polarities. This separa-
tion of regioisomers was a recurring hindrance throughout much of
the chemistry.
Sulphur containing analogues 9 and 10 were synthesized from 6
first by a sulfenylation reaction (7), followed by oxone-mediated
oxidation as required (8), prior to basic hydrolysis (Scheme 1).
The bicyclic pyrazole compound 16 was synthesized as outlined
in Scheme 2. The pyrazolopiperidine core (12) was synthesized
from N-Boc piperidone using the methodology of Heller and
Natarajan [20]. Using routine methodologies, pyrazole alkylation
(13), de-protection of the Boc group (14) followed by capping with
the desired acid chloride (15) and ester hydrolysis gave 16.
The pyrazole acetic acid examples 27 and 28, containing a
functionalized benzyl tail group, were synthesized according to the
route shown in Scheme 3, exemplified for the case of compound 27.
Further analogues of 27 were synthesized by the choice of appro-
priate, readily available starting materials. The sulfone tail-portions
were synthesized from ortho-fluoro aldehydes 17 which were
smoothly reacted with a range of thiols 18. Complete oxidation to
the sulfone (19 / 20) was achieved with meta-chloroperbenzoic
acid (mCPBA). In this route, we then converted the aldehyde first
to the alcohol 21 and then to the bromide 22. Bromides of structure
22 were then alkylated with the appropriate 1,3-dicarbonyl com-
pound 23 (“Method A”). The alkylation reaction was generally not
purified as the products 24 tended to be oils and existed in a
mixture of keto and enol tautomers. Subsequent condensation with
hydrazine did give solid products 25 which could be purified
adequately. Finally, alkylation with ethyl bromoacetate (25 / 26)
(“Method E”) and basic hydrolysis of the ester gave the desired
pyrazole acetic acid 27.
Fig. 1. Chemical structures of Indomethacin 1 and Ramatroban 2.
carboxylic acids (for example tetrazoles, acyl sulfonamides) are
not well tolerated.
2. The “core” ring. This may be monocyclic or bicyclic and but for a
few exceptions where activity is lost, no clear preference has
emerged in this portion.
3. The “tail” group. This position seems to be the most free in terms
of SAR and a great number of variations in chain length, direc-
tionality and polarity have been published.
We sought to take advantage of known SAR around the indole
acetic acid pharmacophore by applying a conceptual ring expan-
sion of the indole core, revealing a substituted pyrazole (Fig. 2). Two
possible ring-openings were considered: this article addresses our
work on pyrazole-1-acetic acids 4, while the work on pyrazole-4-
acetic acids 3 has been described elsewhere [17].
2. Chemistry
The first compounds 9 and 10 were synthesized from a common
intermediate
6
(Scheme 1). Initially, condensation of 1-
phenylbutane-1,3-dione with ethyl 2-hydrazinylacetate gave an
almost quantitative yield of cyclised material, but as a 95:5 mixture
pyrazoles with the undesired pyrazole 5 as the major product, as
confirmed by NOE experiments (see Supplementary information).
Regioisomer formation in pyrazole condensation is a well-
known problem which is influenced by the substitution of both
the hydrazine and the 1,3-dicarbonyl (Fig. 3). Steric influence will
try and place the large group of the 1,3-dicarbonlyl (Rlarge) in the 3-
position of the newly formed pyrazole. Electronically, the more
nucleophilic nitrogen of the hydrazine reacts first. This is inevitably
the un-substituted NH2 group when Rhydr is aromatic, however it is
more evenly balanced when Rhydr is alkyl and often favouring the
substituted nitrogen. Finally, the electronic preference of the 1,3-
dicarbonyl is for the more reactive carbonyl to be attacked first.
In the case of 1,3-diketones, this is the carbonyl group as drawn in
the preferred enol tautomer form, but this preference is not easily
estimated and less so measured [18].
The route to compound 28 was followed the same steps of
Scheme 3, replacing the alkylating agent of “Method A” (22) with
commercial 2-(bromomethyl)quinoline.
Again, the N-alkylated pyrazoles 26 always required careful
chromatography to separate the other minor regioisomer, typically
formed in about 10% yield [21]. The structures of the desired major
regioisomers were initially all confirmed by weak NOE enhance-
ments observed between the methylene group of the acetate chain
and the methyl group of the pyrazole (see Supplementary
information). In addition, the ortho protons of the pyrazole 3-
phenyl group were typically assigned as a downfield doublet be-
tween 7.5 and 8.0 ppm whereas in the minor, undesired products,
the ortho protons were shifted upfield (see Experimental section
Fig. 2. Conceptual opening of the indole core to reveal the pyrazole acetic acids.

170
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
Scheme 1. Synthetic routes to compounds 9 and 10.
and Supplementary information). Ultimately, we were guided by
the fact that the desired regioisomer of the alkylations was clearly
the major product in the reaction and that it was also the first-
eluting compound by silica.
We next expanded the chemistry of route, exemplified for the
case of compound 35 (Scheme 4). Several 1,3-dicarbonyl com-
pounds were synthesized to test the SAR of the 3-position of the
pyrazole. Also, we had found that the alkylation step of Scheme 3
(“Method A”) was difficult to purify adequately or to achieve in
high yield. In addition, each aldehyde 20 required reduction and
bromination. As an alternative route, we used a Knoevenagel
condensation (“Method K”) between the aldehydes 20 and the 1,3-
dicarbonyls 30. Subsequent reduction was achieved by one of two
methods, according to the functional groups present in 31. In the
Fig. 3. Selectivity considerations in pyrazole condensations and alkylations.

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
171
Scheme 2. Synthesis of compound 16.
Scheme 3. Synthesis of compounds 27 and 28.

172
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
Scheme 4. Alternative route to pyrazoles (e.g 35).
Scheme 5. Synthesis of pyrazoles (e.g. 39) from common intermediate 36.

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
173
Table 1
Lack of broad tail group SAR in the pyrazole series.
Reference compound
Company/reported potency
Pyrazole analogue
GTPg binding
Oxagen
34%
@ 5
Ki 5 nMa
m
M
Novartis
38%
@ 5
Ki 52 nMa
mM
Actelion
23%
@ 5
IC50 1 nMa
mM
Oxagen
IC50
35 nM
ESC hWBb
IC50 5 nM
Oxagen
37%
@ 5
Ki 13 nMa
mM
a
Data taken from Ref. [14] and references therein.
Eosinophil shape change in human whole blood. Data taken from Ref. [13] and references therein.
b
absence of labile halogens, hydrogenation over palladium gave the
desired compounds 32. Alternatively, reduction with zinc metal in
acetic acid also rapidly gave the same products and permitted the
incorporation of halogen substituents which hydrogenation may
have removed.
In this case, we also incorporated an alternative ester (“Method
T”), the tert-butyl ester (34) allowing us the flexibility of either acid
or basic conditions in the final hydrolysis.
Finally, to rapidly expand the SAR of the terminal portion of the
tail, we synthesized common intermediate 36 from 2-iodobenzyl
bromide using methods already described (Scheme 5). This gave
us the advantage of only having to carry out a single purification of
pyrazole regioisomers. The presence of the iodide then allowed us
to introduce thioether, sulfoxide and sulfone groups, first through a
copper catalysed insertion reaction carried our under microwave
irradiation (38) (“Method I”). Under the basic reaction conditions,

174
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
the ester was also hydrolysed in situ. Appropriate oxidation then
gave the sulfone 39. The iodide 36 could also be functionalized by
other transition metal coupling reactions.
With compound 27 identified, we then set about a structuree
activity relationship (SAR) expansion of the tail group of both the
proximal and the terminal aromatic rings (Table 2).
For the proximal (benzylic) ring, we observed that both the 4-
and 5-methoxy (46 and 51 respectively) maintained potency, while
other changes generally resulted in loss of potency. Of note is the 4-
carboxy group (47). While the potency loss of introduction of this
group was around 10-fold, it should be taken into account however
that the desolvation energy penalty of a carboxylic acid is generally
very high. The only slight loss of potency is indicative that either the
acid is compensating for the desolvation penalty by making an
interaction with the receptor, or that this acid group is free of the
receptor binding site and remains solvated in the bulk water
environment. Both blocking the acid as an ester (48) and replace-
ment of the proximal phenyl ring with a 4-pyridyl (49) lost
considerable potency which overall may indicate a sensitive point
of interaction with the receptor.
For the linker atom, we quickly determined that the sulfone was
optimal, and that a 10-fold loss of potency was observed going from
sulfone to sulphide (57 to 58, and 60e62), showing a contribution
to binding of the S]O bonds. Interestingly, the sulfoxide 61 only
lost 2-fold potency relative to the sulfone 62. Sulfoxides exist as a
mixture of two enantiomers. The 2-fold drop in activity could
indicate that only one of the two enantiomers is active and this in
turn would imply that only one of the sulphone S]O bonds is
3. Results and discussion
All potency data was determined by a [35S]GTP
gS binding assay
[22]. Our first impression was that the tail group of the pyrazoles
would tolerate a wide range of substituents, however this turned
out not to be the case (Table 1) [23]. The first set of pyrazoles
synthesized took advantage of tail groups reportedly used to suc-
cess with corresponding (aza)indole cores. In almost all cases, the
pyrazole analogues were either weakly active or completely inac-
tive. Only in the case of the ortho-sulfonyl benzyl tail 27 did we see
activities in the same range as those reported for the corresponding
bicyclic cores.
The reasons for this discrepancy are not obvious. The indole
cores are all planar, whereas the 3-phenyl ring of the pyrazole
compounds will be twisted with respect to the pyrazole due to the
adjacent tail group in the 4-position. However, this twist should
occur in all of the pyrazole analogues, 27 included.
Table 2
SAR around the sulphone tail.
Table 3
SAR around the pyrazol-3-position.
Compound Synthetic Proximal
methodsa ring
X
Rx substitution
GTPgS IC50
M)
(Rx ¼ Ph unless stated)
(m
(benzylic)
Compound
Synthetic
methods
R3
GTPgS IC50
0.035
(mM)
27
39
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
A, E
I
K, T
K, T
K, T
K, T
K, T
K, T
K, T
I
I
K, T
K, T
I
I
e
SO2
SO2 2-F
SO2
SO2
SO2
e
0.04
0.11
0.45
0.07
0.40
2.5
e
4-CF3
4-OMe
4-CO2H
e
e
e
e
e
e
e
27
A, E
Ph
4-CO2Me SO2
35
D, K, T
0.05
4-(N)
5-F
5-OMe
e
SO2
SO2
SO2
2
0.16
0.06
0.22
0.07
0.20
0.23
1.1
5
0.52
5
72
73
74
K, E
K, T
K, T
Me
OH
OMe
1.6
Inactive
Inactive
SO2 2-Me
SO2 2,6-diMe
SO2 3-F
SO2 3-Cl
SO2 3-CF3
e
e
e
75
D, A, T
0.087
e
e
S
3-OMe
I
I
I
I
e
SO2 3-OMe
SO2 3-CONMe2
S
SO 3,4-diMe
SO2 3,4-diMe
SO2 4-F
SO2 4-Cl
SO2 4-OMe
e
e
3,4-diMe
2.3
76
77
D, A, T
D, K, T
0.3
5
e
0.72
0.38
0.03
0.11
0.20
0.47
0.45
4
I
e
K, T
K, T
K, E
I
e
e
e
e
SO2 4-OCF3
I
e
SO2 4-NMe2
SO2 4-SO2Me
SO2 Rx ¼ Benzyl
SO2 Rx ¼ 8-Quinolinyl
K, E
e
I
I
I
e
0.11
0.27
Inactive
78
79
D, K, T
K, E
inactive
0.44
e
e
e
Rx ¼ 1-Naphthyl
a
Synthetic Methods: A ¼ alkylation of 1e3 diketone (Scheme 3). D ¼ 1,3-
Dicarbonyl synthesized (Scheme 4). E ¼ Ethyl bromoacetate/lithium hydroxide
route (Scheme 3).
I
¼
iodide displacement with nucleophiles (Scheme 5).
K ¼ Knoevenagel/reduction method (Scheme 4). T ¼ tert-butyl bromoacetate/tri-
fluoroacetic acid method (Scheme 4).

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
175
Table 4
Profile of pyrazoles 27 and 63.
Property
27
63
Potency
GTP
GTP
g
g
IC50
(
m
M)
0.04
0.52
0.05
0.24
0. 03
0.07
0.004
0.05
IC50 þ 1% HSAa
(
m
M)
M)
M)
ESCb IC50 (isolated cells,
ESCb IC50 (whole blood,
Physical chemistry
m
m
Caco AB/BA (Papp ꢀ 10ꢁ6 cm/s)
2/2
2/6
Solubility (pH1/7.4, mg/ml)
0.03/0.95
3.5/0.4
99.3%
0.03/0.68
nd/0.5
nd
pKac/logD7.4
d
human plasma protein binding
Oral pharmacokineticse
Cmax (ng/ml)
AUC0-inf (ng*h/ml)
Cl/F (ml/min/kg)
t½ (h)
2340
2238
75
4045
3198
56
5.1
4.0
Foral
40%
50%
a
Human serum albumin.
Eosinophil shape change.
Potentiometric method.
Shake-flask method.
b
c
d
e
10 mg/kg, Wistar rat.
involved in binding. Chiral separation of the racemic sulfoxide
would allow us to confirm this, but it was not carried out due to the
modest activity of these compounds.
should equal the calculated free concentration. However the
whole blood potency data should not be considered in isolation,
but in conjunction with the pharmacokinetic (PK) profile. Just as
high PPB can attenuate the potency of a compound, so it can
also attenuate the clearance of that compound resulting in a
larger exposure, and the two effects effectively cancel each
other out.
To this end, the oral PK profiles were measured in rat. Mem-
brane permeability and solubility at physiological pH were
acceptable for 27 and 63, and as expected both compounds had
acceptable oral bioavailabilities. Clearance was quite high but
encouragingly, both compounds had long terminal half-lives, which
is a requisite for a once-a-day chronic dosing regime. Between the
two compounds, 63 showed a greater exposure, and combined with
the higher potency in the shape change assay, made this the
preferred compound.
For the terminal aromatic ring Rx, we saw that almost every
change we made resulted in a loss of activity, with only 4-
fluorophenyl analogue 63 showing improved potency. Very large
groups (3-CONMe2 in 59 and 4-SO2Me in 68) were clearly too big.
Finally, we replaced the sulphone linker with a rigid structure of the
1-naphthyl 71. Even though the terminal phenyl ring was
conserved, the compound was totally inactive, showing that either
the sulfone linker was again necessary, that the orientation of the
rings was different, or a combination of both.
In parallel, we also carried out a SAR expansion of the 3-position
of the pyrazole (Table 3).
Small substituents were not well tolerated in the R3 position
(72e74). Of the other aromatic rings, ortho-substitution was not
well tolerated (77). The dihedral angle of the pyrazole-aromatic
bond will be greatly increased in these cases and it is possible
that the CRTh2 receptor prefers a planar ring. Again, a very bulk
substitution (78) was completely inactive.
4. Conclusions
The SAR around the pyrazole nucleus showed clear differences
to that reported for the corresponding indole cores. Extensive SAR
investigation showed this pyrazole template to be generally mod-
erate potency. The subset of ortho-substituted benzyl tail groups
led to the identification and characterization of 63 as the lead
compound of the series. CRTh2 has been extensively investigated
since its identification and a number of compounds have been
progressed to clinical trials. In the context of the whole panorama
of CRTh2 antagonists, compounds 63 did not achieve the levels of
potency demonstrated by these clinical candidates, many of which
display low nanomolar potencies. As such, the pyrazole series was
not advanced for further studies, in favour of other more promising
chemical series.
Of all the analogues, we chose to further profile 27 and fluoro-
analogue 63 (Table 4).
Both compounds were of similar potency as measured in the
in vitro binding assay. In the presence of plasma proteins,
notably albumin, 27 lost an order of magnitude of potency
whereas 63 showed little shift, if any. The plasma protein
binding (PPB) for 27 was measured at 99.3%, confirming the role
of albumin in this shift. The pros and cons of plasma protein
binding is a topic of active discussion [24]. The cells that express
the CRTh2 receptor are found predominantly circulating in the
blood and the receptor is expressed on the cell membranes, so
the concentration of antagonist available to bind to the receptor

176
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
5. Experimental section
sodium acetate (8.0 g, 98 mmol) were added and the mixture was
stirred at 70 ꢂC overnight. The mixture was partitioned between
ethyl acetate and water. The aqueous was extracted three times with
ethyl acetate. The organic layer was washed sequentially three times
with dilute potassium carbonate solution and then with brine. The
organics were dried over magnesium sulphate, filtered and evapo-
rated under reduced pressure. The residue was purified using the
SP1 Purification System (ethyl acetateehexane gradient, 0:100 rising
to 30:70) to give 5-methyl-3-phenyl-1H-pyrazole (2.86 g, 18 mmol,
92%) as a pale yellow solid. Purity 98%. 1H NMR (400 MHz, CDCl3)
5.1. Chemistry
5.1.1. General
Reaction products were purified, when necessary, by flash
chromatography on silica gel (40e63 mm) with the solvent system
indicated. Purifications in reverse phase were made in a Biotage
SP1Ò automated purification system equipped with a C18 column
and using a gradient of, unless otherwise stated, water-acetonitrile/
MeOH (1:1) (0.1% v/v ammonium formate both phases) from 0% to
100% acetonitrile/MeOH (1:1) in 80 column volumes. The condi-
tions “formic acid buffer” refer to the use of 0.1% v/v formic acid in
both phases. Preparative HPLC-MS were performed on a Waters
instrument equipped with a 2767 injector/collector, a 2525 binary
gradient pump, a 2996 PDA detector, a 515 pump as a make-up
pump and a ZQ4000 Mass spectrometer detector.
d
ppm 2.27 (s, 3H, Me), 6.34 (s, 1H, pyrazole H(4)), 7.26e7.32 (m, 1H,
para H), 7.33e7.39 (m, 2H, meta H) 7.71 (d, 2H, J ¼ 7.42 Hz, ortho H).
HPLC/MS (9 min) retention time 5.25 min. LRMS: m/z. 159 (M þ 1).
3-Methyl-5-phenyl-1H-pyrazole (1.0 g, 6.3 mmol) and potassium
carbonate (1.92 g, 13.9 mmol) were suspended in 20 ml acetone.
Ethyl bromoacetate (1.44 ml,13.9 mmol) was added and the mixture
was stirred at reflux for 24 h. The mixture evaporated under reduced
pressure and the residue was partitioned between ethyl acetate and
water. The aqueous was extracted three times with ethyl acetate. The
organic layer was washed with brine, dried over magnesium sul-
phate, filtered and evaporated under reduced pressure. The residue
was purified using the SP1 Purification System (ethyl acetateehex-
ane gradient, 0:100 rising to 20:80) to give 6 (0.85 g, 3.5 mmol, 55%).
The chromatographic separations were obtained using a Waters
2795 system equipped with a Symmetry C18 (2.1 ꢀ 50 mm, 3.5
column for methods 1, 2, 3 and 5 and a Symmetry C18 (2.1 ꢀ100 mm,
3.5 M) for method 4. A Waters 2996 diode array was used as a UV
mM)
m
detector. Mass spectra of the chromatograms were acquired using
positive and negative electrospray ionization in a Micromass ZMD or
ina Waters ZQdetectorscoupled totheHPLC. Themobilephaseswere
(A): formic acid (0.5 ml), ammonia (0.125 ml) and water (1000 ml),
(B): formic acid (0.4 ml), ammonia (0.1 ml), methanol (500 ml) and
acetonitrile (500 ml). the following gradients were used.
Method 1 (5 min): 0% B, 0.2 min; 0e95% B, over 3 min; 95% B,
0.8 min.
Purity 98%. 1H NMR (400 MHz, CDCl3)
d
ppm 7.76 (d, 2H, J ¼ 7.0 Hz,
Ph ortho H), 7.37 (t, 2H, J ¼ 7.6 Hz, Ph meta H), 7.28 (t, 1H, J ¼ 7.4 Hz,
Ph para H), 6.39 (s, 1H, pyrazole H(4)), 4.88 (s, 2H, CH2CO), 4.23 (q,
2H, J ¼ 7.3 Hz, OCH2CH3), 2.28 (s, 3H, Me), 1.28 (t, 3H, J ¼ 7.2 Hz,
OCH2CH3). NOE experiments: Irradiation at 2.28 ppm (Me) shows
enhancement at 4.88 ppm (CH2CO) only. Irradiation at 4.88 ppm
(CH2CO) shows enhancement at 2.28 ppm (Me) only. HPLC/MS
(9 min) retention time 6.00 min. LRMS: m/z 245 (M þ 1).
Method 2 (9 min): 0% B, 0.5 min; 0e95% B, over 6.5 min; 95% B,
1 min.
Method 3 (15 min): 0e95% B, over 10.5 min; 95% B, 1.5 min.
Method 4 (30 min): 0e95% B, over 20 min; 95% B, 4 min.
Method 5 (6 min): 0e100% B, over 4.5 min; 100% B, 1.5 min.
1H Nuclear Magnetic Resonance Spectra were recorded on a
Varian Mercury plus operating at a frequency of 400 MHz. Tetra-
5.1.4. 2-(4-(3,4-Dichlorophenylthio)-5-methyl-3-phenyl-1H-
pyrazol-1-yl)acetic acid (9)
N-Chlorosuccinimide (0.52 g, 4.0 mmol) was dissolved in 12 ml
toluene and was cooled in an ice-bath. 3,4-Dichlorobenzene thiol
(0.50 g, 4.0 mmol) was added drop-wise and the mixture was
stirred at room temperature overnight, turning bright yellow. The
solution was filtered and the filtrate was added slowly to a solution
of 6 (0.50 g, 2.1 mmol) in 4 ml acetonitrile at 5 ꢂC and the mixture
was stirred at room temperature overnight. The mixture was
evaporated under reduced pressure and was partially purified us-
ing the SP1 Purification System (ethyl acetateehexane gradient,
0:100 rising to 30:70). The crude product obtained was further
purified by reverse-phase chromatography to give ethyl 2-(4-(3,4-
dichlorophenylthio)-5-methyl-3-phenyl-1H-pyrazol-1-yl) acetate
7 (0.31 g, 0.75 mmol, 36%) as a pale yellow solid. Purity 99%. HPLC/
MS (9 min) retention time 7.68 min. LRMS: m/z 421 (M þ 1).
The ester 7 (75 mg, 0.18 mmol) was dissolved in 2 ml tetrahydro-
furan and 1 ml water. Lithium hydroxide monohydrate (37 mg,
0.89 mmol) was added and the mixture was stirred overnight at room
temperature. The mixture was diluted with dilute hydrochloric acid,
forming a white precipitate. The solid was collected by filtration, was
washed sequentially with water and ether and was dried under vac-
uum to give 9 (61 mg, 0.15 mmol, 87%) as a white solid. Purity 100%. 1H
methylsilane was used as reference. Chemical shifts
d in ppm, the
following abbreviations are used: singlet (s), doublet (d), triplet (t),
quartet (q), double doublet (dd), multiplet (m), broad signal (br. s).
Mass Spectra (m/z) were recorded on a Micromass ZMD or in a
Waters ZQ mass spectrometer using ESI ionization.
5.1.2. Ethyl [(3-methyl-5-phenyl)-1H-pyrazol-1-yl]acetate (5)
1-Phenylbutane-1,3-dione (7.6 g, 47 mmol) was dissolved in
100 ml acetic acid. Ethyl 2-hydrazinylacetate hydrochloride (5.0 g,
31 mmol) and sodium acetate (12.9 g,157 mmol) were added and the
mixture was stirred at 70 ꢂC for 1 h. The mixture was partitioned
between ethyl acetate and water. The aqueous was extracted three
times with ethyl acetate. The organic layer was washed sequentially
three times with 4% w/v sodium bicarbonate solution and then with
brine. The organics were dried over magnesium sulphate, filtered and
evaporated under reduced pressure. The residue was purified using
the SP1 Purification System (ethyl acetateehexane gradient, 0:100
rising to 40:60) to give a 95:5 mixture of 5 and 6 (7.4 g, 30 mmol, 97%)
as a yellow oil. 5. 1H NMR (400 MHz, CDCl3)
d ppm 7.34e7.45 (m, 5H,
ArH), 6.14 (s, 1H, pyrazole H-4), 4.81 (s, 2H, CH2CO), 4.19 (q, 2H,
J ¼ 7.3 Hz, OCH2CH3), 2.32 (s, 3H, Me),1.23 (t, 3H, J ¼ 7.0 Hz, OCH2CH3).
NOE experiments: Irradiation at 7.4 ppm (ArH) shows enhancement
at 4.81 ppm (CH2CO) only. Irradiation at 6.14 ppm (pyrazole H(4))
shows enhancement at 2.32 ppm (Me) only. HPLC/MS (9 min)
retention time 5.98 min. LRMS: m/z 245 (M þ 1).
NMR (400 MHz, DMSO-d6) d ppm 2.22 (s, 3H, Me), 4.71e4.77 (m, 2H,
CH2CO), 6.96 (dd,1H, J ¼ 8.40, 2.15 Hz, SPh H(6)), 7.22 (d,1H, J ¼ 1.95 Hz,
SPh H(2)), 7.29e7.33 (m,1H, Ph para H), 7.36 (t, 2H, J ¼ 7.42 Hz, Ph meta
H), 7.50 (d, 1H, J ¼ 8.60 Hz, SPh H(5)), 7.73e7.79 (m, 2H, Ph ortho H).
HPLC/MS (30 min) retention time 17.52 min. LRMS: m/z 393 (M þ 1).
5.1.5. 2-(4-(3,4-Dichlorophenylsulfonyl)-5-methyl-3-phenyl-1H-
5.1.3. Ethyl [(5-methyl-3-phenyl)-1H-pyrazol-1-yl]acetate (6)
1-Phenylbutane-1,3-dione (4.76 g, 29.4 mmol) was dissolved in
20 ml acetic acid. Hydrazine monohydrate (1.0 g, 19.6 mmol) and
pyrazol-1-yl)acetic acid (10)
Ethyl
2-(4-(3,4-dichlorophenylthio)-5-methyl-3-phenyl-1H-
pyrazol-1-yl) acetate 7 (0.20 g, 0.47 mmol) was dissolved in 5 ml

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
177
dimethylformamide and the mixture was cooled in an ice-bath.
Oxone (1.05 g, 1.7 mmol) was added portion-wise and the
mixture was stirred at room temperature for 3 d. The mixture was
partitioned between 40% w/v sodium bisulfite solution and ether.
The aqueous phase was extracted three times with ether. The
combined organics were washed with brine, dried over magnesium
sulphate, filtered and evaporated. The residue was purified using
the SP1 Purification System (ethyl acetateehexane gradient, 0:100
rising to 30:70) to give ethyl 2-(4-(3,4-dichlorophenylsulfonyl)-5-
methyl-3-phenyl-1H-pyrazol-1-yl) acetate 8 (0.18 g, 0.40 mmol,
83%) as a colourless oil. Purity 100%. 1H NMR (400 MHz, CDCl3)
colourless oil. Purity 98%. HPLC/MS (6 min) retention time 2.50 min.
LRMS: m/z 286 (M þ 1).
14 (70 mg, 0.24 mmol) was dissolved in 0.5 ml dichloromethane.
Triethylamine (85
ml, 0.35 mmol) and 4-fluorobenzoyl chloride
(42 l, 0.35 mmol) were added and the mixture stirred for 20 min.
m
The mixture diluted with saturated sodium carbonate solution and
was extracted three time with dichloromethane. The combined
organics were washed with brine, dried over magnesium sulphate,
filtered and evaporated under reduced pressure. The residue was
purified by column chromatography (ethyl acetateehexane
gradient, 30:70 rising to 40:60) to give ethyl 2-(5-(4-
fluorobenzoyl)-3-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]
pyridin-1-yl)acetate 15 (59 mg, 0.14 mmol, 59%) as a white solid.
Purity 100%. HPLC/MS (6 min) retention time 4.04 min. LRMS: m/z
408 (M þ 1).
d
ppm 1.30 (t, 3H, J ¼ 7.23 Hz, CH2CH3), 2.66 (s, 3H, Me), 4.26 (q, 2H,
J ¼ 7.16 Hz, CH2CH3), 4.92 (s, 2H, CH2CO), 7.15e7.20 (m, 1H, ArH),
7.23e7.30 (m, 2H, ArH), 7.33e7.44 (m, 5H, ArH). HPLC/MS (9 min)
retention time 7.07 min. LRMS: m/z 453 (M þ 1).
The ester 8 (0.18 g, 0.40 mmol) was dissolved in 3 ml tetrahy-
drofuran and 1 ml water. Lithium hydroxide monohydrate (83 mg,
2.0 mmol) was added and the mixture was stirred overnight at
room temperature. The mixture was diluted with dilute hydro-
chloric acid, forming a white precipitate. The solid was collected by
filtration, was washed sequentially with water and ether and was
dried under vacuum to give 10 (124 mg, 0.29 mmol, 74%) as a white
15 (59 mg, 0.14 mmol) was dissolved in 3 ml of tetrahydrofuran
and 1.5 ml of water. Lithium hydroxide (17 mg, 0.42 mmol) was
added and the mixture was stirred at room temperature for min.
The organics were concentrated under reduced pressure and the
aqueous solution was acidified to pH 1 with 1 N hydrochloric acid.
The aqueous was extracted several times with dichloromethane,
the combined organics were dried over magnesium sulphate,
filtered and evaporated under reduced pressure to give 16 (37 mg,
0.10 mmol, 70%) as a white solid. Purity 99%. 1H NMR (400 MHz,
solid. Purity 100%. 1H NMR (400 MHz, CDCl3)
d ppm 2.63 (s, 3H, Me),
4.94 (s, 2H, CH2CO), 7.24e7.28 (m, 2H, ArH), 7.32e7.40 (m, 4H, ArH),
7.41e7.45 (m, 1H, ArH), 7.47 (d, 1H, J ¼ 1.95 Hz, SPh H(3)). HPLC/MS
(30 min) retention time 15.03 min. LRMS: m/z 425 (M þ 1).
DMSO-d6) d ppm 13.16 (br. s.1H, OH), 7.56e7.71 (m, 2H, Ph ortho H),
7.51 (dd, 2H J ¼ 8.4, 5.7 Hz, PhF H-2 and H-6), 7.44 (m, 2H, ArH),
7.18e7.38 (m, 3H, ArH), 4.92 (s, 2H, CH2CO), 4.79 (m, 1H, C(4)HAHB),
4.56e4.74 (m, 1H, C(4)HAHB), 3.91 (m, 1H, C(6)HAHB), 3.61 (m, 1H,
C(6)HAHB), 2.74 (m, 2H, C(7)H2). HPLC/MS (30 min) retention time
13.65 min. LRMS: m/z 380 (M þ 1).
5.1.6. 2-(5-(4-Fluorobenzoyl)-3-phenyl-4,5,6,7-tetrahydro-1H-
pyrazolo[4,3-c]pyridin-1-yl)acetic acid (16)
tert-Butyl 4-oxopiperidine-1-carboxylate (1.0 g, 5.0 mmol) was
dissolved in 10 ml toluene and was cooled to 0 ꢂC under argon.
Lithium hexamethyldisilazide (1 M in THF, 5.3 ml, 5.3 mmol) was
added and he mixture was stirred for 1 min. Benzoyl chloride
(0.29 ml, 2.5 mmol) was added ad the mixture was stirred at room
temperature for 1 h. The mixture was diluted with 5 ml acetic acid,
20 ml ethanol and 10 ml tetrahydrofuran. Hydrazine hydrate
(4.1 ml, 84 mmol) was added and the mixture was stirred for
15 min. The mixture was basified with 1 N sodium hydroxide and
was extracted five times with ethyl acetate. The organics were dried
over magnesium sulphate, filtered and evaporated. The residue was
purified by column chromatography (ethyl acetateehexane
gradient, 0:100 rising to 100:0) to give tert-butyl 3-phenyl-6,7-
dihydro-1H-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate 12 (0.65 g,
2.17 mmol, 82%) as a white solid. Purity 92%. HPLC/MS (6 min)
retention time 4.18 min. LRMS: m/z 300 (M þ 1).
5.1.7. 2-(Phenylthio)benzaldehyde (19)
2-Fluorobenzaldehyde 17 (9 ml, 90 mmol) and benzenethiol 18
(8.8 ml, 90 mmol) were dissolved in 30 ml dimethylsulfoxide. Po-
tassium carbonate (26 g, 190 mmol) was added and the mixture
was heated at 100 ꢂC for 4 h. The mixture was allowed to cool and
was poured into water. The aqueous layer was extracted with ethyl
acetate. The combined organics were washed with water and brine
and were dried over sodium sulphate. Filtration and evaporation
give 19 (18.5 g, 78 mmol, 95%) as a yellow oil. Used as such without
further purification. Purity 91%. 1H NMR (400 MHz, CDCl3)
d ppm
7.08e7.12 (m, 1H, ArH), 7.29e7.46 (m, 7H, ArH), 7.88 (dd, J ¼ 7.42,
1.56 Hz, 1H, ArH), 10.40 (s, 1H, CHO). HPLC/MS (9 min) retention
time 6.53 min. LRMS: m/z 215 (M þ 1).
12 (0.55 g, 1.83 mmol), caesium carbonate (0.90 g, 2.75 mmol)
and ethyl bromoacetate (2.0 mmoL) were suspended in 5 ml
dimethylformamide and the mixture was stirred for 30 min. The
mixture was partitioned between water and ethyl acetate. The or-
ganics were washed with brine, dried over magnesium sulphate,
filtered and evaporated. The residue was purified by column
chromatography (ethyl acetateehexane gradient, 0:100 rising to
80:20) to give tert-butyl 1-(2-ethoxy-2-oxoethyl)-3-phenyl-6,7-
dihydro-1H-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate 13 (0.50 g,
1.3 mmol, 60%) as a colourless oil. Purity 98%. HPLC/MS (6 min)
retention time 4.23 min. LRMS: m/z 386 (M þ 1).
5.1.8. 2-(Phenylsulfonyl)benzaldehyde (20)
2-(Phenylthio)benzaldehyde (19) (3.5 g, 16.3 mmol) was dis-
solved in 50 ml dichloromethane. 3-Chloroperoxybenzoic acid (77%
max purity, 11 g, 49 mmol) was added in portions and the mixture
was stirred at room temperature overnight. The mixture was
washed sequentially with sodium carbonate 5% solution, water and
brine. The resulting organic layer was dried over sodium sulphate,
filtered and evaporated. The residue was purified using the SP1
Purification System (ethyl acetateehexane gradient, 0:100 rising to
30:70) to give 20 (1.9 g, 7.7 mmol, 47%) as a white solid. Purity 100%.
1H NMR (400 MHz, DMSO-d6)
d
ppm 7.67 (t, 2H, J ¼ 7.62 Hz, PhSO2
13 (495 mg, 1.28 mmol) was dissolved in 4 ml dichloromethane.
1.5 ml Trifluoroacetic acid was added and the mixture was stirred at
room temperature for 90 min. The mixture was evaporated and the
residue partitioned between saturated sodium carbonate solution
and dichloromethane. The aqueous was extracted four times with
dichloromethane and the combined organics were dried over
magnesium sulphate, filtered and evaporated under reduced
pressure to give ethyl 2-(3-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo
[4,3-c]pyridin-1-yl)acetate 14 (338 mg, 1.19 mmol, 93%) as a
meta H), 7.75 (t, 1H, J ¼ 7.42 Hz, PhSO2 para H), 7.88e7.99 (m, 3H,
ArH), 8.02 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho H), 8.20 (d, 1H,
J ¼ 7.82 Hz, ArH), 10.68 (s, 1H, CHO). HPLC/MS (9 min) retention
time 5.47 min. LRMS: m/z 247 (M þ 1).
5.1.9. [2-(Phenylsulfonyl)phenyl]methanol (21)
2-(Phenylsulfonyl)benzaldehyde (20) (2.0 g, 7.74 mmol) was
dissolved in 16 ml methanol. Sodium borohydride (150 mg,
3.86 mmol) was added portion-wise and the mixture was agitated

178
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
at room temperature for 30 min. Dilute hydrochloric acid (5% v/v
solution) was added and the mixture was concentrated under
reduced pressure. The residue was taken up with water and the
aqueous was extracted with dichloromethane. The combined or-
ganics were washed with brine and were dried over sodium sul-
phate. Filtration and evaporation gave 21 (1.90 g, 7.66 mmol, 98%)
as a yellow solid. Used as such without further purification. Purity
as a white solid. Purity 100%. 1H NMR (400 MHz, CDCl3)
d ppm 1.81
(s, 3H, Me), 4.12 (s, 2H, CH2), 7.00e7.04 (m, 1H, ArH), 7.15e7.24 (m,
5H, ArH), 7.42e7.51 (m, 4H, ArH), 7.53e7.59 (m, 1H, ArH), 7.85e7.91
(m, 2H, ArH), 8.29e8.34 (m, 1H, ArH). HPLC/MS (9 min) retention
time 6.27 min. LRMS: m/z 389 (M þ 1).
5.3. General “Method E”
96%. 1H NMR (400 MHz, CDCl3)
d ppm 3.14 (br. s., 1H, OH), 4.74 (s,
2H, CH2), 7.48e7.58 (m, 4H, ArH), 7.61 (d, 1H, J ¼ 7.42 Hz, 1H), 7.65
(d,1H, J ¼ 7.42 Hz, ArH), 7.90 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho H), 8.15
(d, 1H, J ¼ 7.82 Hz, 1H). HPLC/MS (9 min) retention time 4.97 min.
LRMS: m/z 249 (M þ 1).
5.3.1. Ethyl {5-methyl-3-phenyl-4-[2-(phenylsulfonyl)benzyl]-1H-
pyrazol-1-yl}acetate (26)
5-Methyl-3-phenyl-4-[2-(phenylsulfonyl)benzyl]-1H-pyrazole
(25) (300 mg, 0.77 mmol) was dissolved in 8 ml dimethylforma-
mide. Sodium hydride (60% dispersion in oil, 40 mg, 1 mmol) pre-
viously washed with pentane was added in portions and the
mixture was stirred for 30 min at room temperature. Ethyl 2-
bromoacetate (0.11 ml, 0.95 mmol) dissolved in 2 ml dime-
thylformamide was added and the mixture was agitated overnight.
The mixture was poured into water and the solution was extracted
three times with ethyl acetate. The combined organics were
washed with brine, dried over sodium sulphate and evaporated
under reduced pressure. The residue was purified using the SP1
Purification System (ethyl acetateehexane gradient, 0:100 rising to
50:50) to give 26 (230 mg, 0.48 mmol, 63%) as a white solid. Purity
5.1.10. 1-(Bromomethyl)-2-(phenylsulfonyl)benzene (22)
[2-(Phenylsulfonyl)phenyl]methanol (21) (1.9 g, 7.66 mmol) was
dissolved in 20 ml chlorobenzene. Thionyl bromide (1.46 ml,
18.3 mmol) was slowly added and the mixture was heated at 100 ꢂC
for 1 h. The mixture was concentrated under reduced pressure and
the residue was partitioned between dichloromethane and water.
The aqueous phase was basified with potassium carbonate and
extracted three times with dichloromethane. The combined organics
were washed with water, brine and dried over sodium sulphate and
evaporated. The residue was purified using the SP1 Purification Sys-
tem (ethyl acetateehexane gradient, 0:100 rising to 8:92) to give 22
(1.95 g, 6.27 mmol, 82%) as an oil. Purity 94%. 1H NMR (400 MHz,
100%. 1H NMR (400 MHz, CDCl3)
d
ppm 1.29 (t, 3H, J ¼ 7.03 Hz,
CH2Me), 1.87 (s, 3H, ArMe), 4.14 (s, 2H, ArCH2Ar), 4.24 (q, 2H,
J ¼ 7.03 Hz, CH2Me), 4.90 (s, 2H, COCH2), 7.02e7.22 (m, 6H, ArH),
7.40e7.51 (m, 4H, ArH), 7.52e7.59 (m, 1H, ArH), 7.89 (d, 2H,
J ¼ 7.82 Hz, PhSO2 ortho H), 8.29e8.35 (m,1H, Ar). HPLC/MS (9 min)
retention time 6.70 min. LRMS: m/z 475 (M þ 1).
CDCl3)
d ppm 4.89 (s, 2H, CH2), 7.47e7.67 (m, 6H, ArH), 7.92 (d, 2H,
J ¼ 7.42 Hz, PhSO2 ortho H), 8.19 (d,1H, J ¼ 8.21 Hz). HPLC/MS (9 min)
retention time 6.03 min. LRMS: m/z 311, 313 (M þ 1).
5.2. General “Method A”
5.3.2. {5-Methyl-3-phenyl-4-[2-(phenylsulfonyl)benzyl]-1H-
5.2.1. 1-Phenyl-2-[2-(phenylsulfonyl)benzyl]butane-1,3-dione (24)
Sodium hydride (60% dispersion in oil, 118 mg, 2.95 mmol) was
first washed with hexanes to remove the oil and was then sus-
pended in 10 ml tetrahydrofuran and cooled to 0 ꢂC in an ice-bath. A
solution of 1-phenylbutane-1,3-dione 23 (300 mg, 1.85 mmol)
dissolved in 2 ml tetrahydrofuran was added drop-wise and with
stirring. Upon addition, the mixture was stirred for 1 h at room
temperature. A solution of 1-(bromomethyl)-2-(phenylsulfonyl)
benzene (22) (690 mg, 2.22 mmol) in 3 ml tetrahydrofuran was
added drop-wise with stirring and the mixture was stirred over-
night at room temperature. The organics were concentrated under
reduced pressure and the residue was re-suspended in aqueous
ammonium chloride solution. The solution was extracted three
times with ether and the combined organics were washed with
brine, dried over sodium sulphate and evaporated under reduced
pressure. The residue was purified by reverse-phase chromatog-
raphy using the SP1 Purification System to give 24 (256 mg,
0.65 mmol, 35%) as a colourless oil. Purity 94%. 1H NMR spectrum
complicated by mixtures of tautomers. HPLC/MS (9 min) retention
time 6.47 min. LRMS: m/z 393 (M þ 1).
pyrazol-1-yl}acetic acid (27)
Ethyl
{5-methyl-3-phenyl-4-[2-(phenylsulfonyl)benzyl]-1H-
pyrazol-1-yl}acetate (26) (114 mg, 0.24 mmol) was dissolved in
4 ml of tetrahydrofuran and 4 ml of water. Lithium hydroxide
(50 mg, 1.2 mmol) was added and the mixture was agitated at room
temperature overnight. The mixture was concentrated under
reduced pressure and the residue was acidified with 5 N hydro-
chloric acid to give a white precipitate. The precipitate was filtered
and washed with water. The solid was dried under reduced pres-
sure to give 27 (98 mg, 0.22 mmol, 91%) as a white solid. Purity 99%.
1H NMR (400 MHz, CDCl3)
d ppm 1.79 (s, 3H, Me), 4.11 (s, 2H,
ArCH2Ar), 4.88 (s, 2H, COCH2), 6.95e7.00 (m, 1H, ArH), 7.08e7.14
(m, 2H, ArH), 7.15e7.21 (m, 3H, ArH), 7.39e7.49 (m, 4H, ArH), 7.52e
7.58 (m, 1H, ArH), 7.84e7.88 (m, 2H, ArH), 8.27e8.32 (m, 1H, ArH).
HPLC/MS (30 min) retention time 15.39 min. LRMS: m/z 447
(M þ 1).
5.3.3. 2-(5-Methyl-3-phenyl-4-(quinolin-2-ylmethyl)-1H-pyrazol-
1-yl)acetic acid (28)
Following general methods A, E: White solid. Purity 98%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 2.20 (s, 3H, Me), 4.25 (s, 2H,
5.2.2. 5-Methyl-3-phenyl-4-[2-(phenylsulfonyl)benzyl]-1H-
pyrazole (25)
ArCH2Ar), 4.96 (s, 2H, CH2CO), 7.17 (d, 1H, J ¼ 8.60 Hz, quinoline
H(3)), 7.23e7.29 (m, 1H quinoline H(6)), 7.33 (t, 2H, J ¼ 7.62 Hz, Ph
meta), 7.54 (t, 1H, J ¼ 7.62 Hz, Ph para), 7.64 (d, 2H, J ¼ 7.03 Hz, Ph
ortho), 7.72 (t, 1H, J ¼ 7.62 Hz, quinoline H(7)), 7.89 (d, 1H,
J ¼ 7.82 Hz, quinoline H(5)), 7.95 (d, 1H, J ¼ 8.21 Hz, quinoline H(8)),
8.22 (d, 1H, J ¼ 8.60 Hz, quinoline H(4)). HPLC/MS (30 min) reten-
tion time 8.98 min. LRMS: m/z 358 (M þ 1).
1-Phenyl-2-[2-(phenylsulfonyl)benzyl]butane-1,3-dione
(24)
(254 mg, 0.65 mmol) was dissolved in 5 ml acetic acid. Hydrazine
monohydrate (27 mg, 0.54 mmol) and sodium acetate (221 mg,
2.7 mmol) were added and the mixture was stirred at 70 ꢂC over-
night. The mixture was partitioned between ethyl acetate and
water. The aqueous was extracted three times with ethyl acetate.
The organic layer was washed sequentially with brine, dilute po-
tassium carbonate solution and brine and was dried over sodium
sulphate and evaporated under reduced pressure. The residue was
purified using the SP1 Purification System (ethyl acetateehexane
gradient, 0:100 rising to 40:60) to give 25 (178 mg, 0.46 mmol, 85%)
5.4. General “Method D”
5.4.1. 1-[3-(Trifluoromethyl)phenyl]butane-1,3-dione (30)
Sodium hydride (60% dispersion in oil, 390 mg, 9.75 mmol) was
first washed with hexanes to remove the oil and was then

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
179
suspended in 7 ml dimethylformamide. A solution of methyl 3-
(trifluoromethyl)benzoate 29 (1.0 g, 4.9 mmol) in 2 ml dime-
thylformamide was added drop-wise and with stirring. Upon
addition, the mixture was stirred for 1 h at room temperature.
as a solid. Used as such without further purification. Purity 100%. 1H
NMR (400 MHz, CDCl3) ppm 8.26e8.33 (m, 1H, ArH), (d, 2H,
J ¼ 7.42 Hz, PhSO2 ortho H), 7.63 (s, 1H, ArH), 7.56 (t, 1H, J ¼ 7.2 Hz,
PhSO2 para H), 7.40e7.52 (m, 5H, ArH), 7.19e7.27 (m, 2H, ArH), 6.97e
7.04 (m, 1H, ArH), 4.13 (s, 2H, CH2), 1.93 (s, 3H, Me). HPLC/MS (9 min)
retention time 6.82 min. LRMS: m/z 457 (M þ 1).
d
Acetone (400 ml, 5.44 mmol) was added drop-wise and the mixture
was stirred overnight at room temperature. The mixture was
poured into water and the aqueous layer was extracted four times
with ether. The aqueous layer was acidified with 2 N hydrochloric
acid and was extracted three times with ether. The combined or-
ganics were dried over sodium sulphate and evaporated under
reduced pressure. The residue was purified using the SP1 Purifi-
cation System (ethyl acetateehexane gradient, 0:100 rising to
10:90) to give 30 (640 mg, 2.78 mmol, 56%) as an oil. Purity 100%. 1H
NMR spectrum complicated by mixtures of tautomers. HPLC/MS
(15 min) retention time 8.53 min. LRMS: m/z 229 (M ꢁ 1).
5.6. General “Method T”
5.6.1. tert-Butyl {5-methyl-4-[2-(phenylsulfonyl)benzyl]-3-[3-
(trifluoromethyl)phenyl]-1H-pyrazol-1-yl}acetate (34)
5-Methyl-4-[2-(phenylsulfonyl)benzyl]-3-[3-(trifluoromethyl)
phenyl]-1H-pyrazole (33) (300 mg, 0.66 mmol) was dissolved in
10 ml dimethylformamide under nitrogen. Sodium hydride (60%
dispersion in oil, 33 mg, 0.86 mmol) previously washed with pentane
was added in portions and the mixture was stirred for 1 h at room
temperature. tert-Butyl 2-bromoacetate (0.12 ml, 0.79 mmol) dis-
solved in 2 ml dimethylformamide was added and the mixture was
stirred at room temperature for 3 h. The mixture was poured into
water and the solution was extracted three times with ether. The
combined organics were washed with water and brine. The organic
layer was dried over sodium sulphate and evaporated under reduced
pressure. The residue was purified using the SP1 Purification System
(ethyl acetateehexane gradient, 0:100 rising to 20:80) to give 34
(228 mg, 0.40 mmol, 61%) of the title compound. Purity 100%. HPLC/
MS (9 min) retention time 7.52 min. LRMS: m/z 571 (M þ 1).
5.5. General “Method K”
5.5.1. 2-[2-(Phenylsulfonyl)benzylidene]-1-[3-(trifluoromethyl)
phenyl]butane-1,3-dione (31)
1-[3-(Trifluoromethyl)phenyl]butane-1,3-dione (30) (635 mg,
2.76 mmol) and 2-(phenylsulfonyl)benzaldehyde (20) (680 mg,
2.76 mmol) were dissolved in 8 ml ethanol. Piperidine (44
ml,
ꢀ
0.44 mmol), acetic acid (210
ml, 3.67 mmol) and a spoonful of 4 A
molecular sieves were added and the mixture was heated at 80 ꢂ
C
overnight. The mixture was filtered and was concentrated under
reduced pressure. The resulting residue was purified using the SP1
Purification System (ethyl acetateehexane gradient, 0:100 rising to
20:80) to give 31 (759 mg, 1.65 mmol, 60%) as a solid. Purity 100%.
5.6.2. {5-Methyl-4-[2-(phenylsulfonyl)benzyl]-3-[3-
(trifluoromethyl)phenyl]-1H-pyrazol-1-yl}acetic acid (35)
1H NMR (400 MHz, CDCl3)
d
ppm 8.37 (s, 1H, C]CH), 8.15 (s, 1H,
tert-Butyl
{5-methyl-4-[2-(phenylsulfonyl)benzyl]-3-[3-(tri-
ArH), 8.10 (d,1H, J ¼ 7.8 Hz, ArH), 7.96 (d, 2H, J ¼ 7.4 Hz, PhSO2 ortho
H), 7.66e7.72 (m, 2H, ArH), 7.58e7.66 (m, 3H, ArH), 7.44 (t, 1H,
J ¼ 7.4 Hz, PhSO2 para H), 7.37e7.41 (m, 1H, ArH), 7.30e7.37 (m, 1H,
ArH), 7.23e7.30 (m, 1H, ArH), 2.47 (s, 3H, Me). HPLC/MS (9 min)
retention time 6.83 min. LRMS: m/z 459 (M þ 1).
fluoromethyl)phenyl]-1H-pyrazol-1-yl}acetate (34) (228 mg,
0.40 mmol) was dissolved in 5 ml dichloromethane. Trifluoroacetic
acid (2.15 ml, 28 mmol) was added and the mixture was stirred at
room temperature overnight. The mixture was concentrated under
reduced pressure. The residue was taken up in a little water, the
mixture frozen and lyophilized overnight to give 35 (146 mg,
0.27 mmol, 67%) as a white solid. Purity 97%. 1H NMR (400 MHz,
5.5.2. 2-[2-(Phenylsulfonyl)benzyl]-1-[3-(trifluoromethyl)phenyl]
butane-1,3-dione (32)
CDCl3)
d ppm 1.94 (s, 3H, Me), 4.18 (s, 2H, ArCH2Ar), 4.88 (s, 2H,
2-[2-(Phenylsulfonyl)benzylidene]-1-[3-(trifluoromethyl)
phenyl]butane-1,3-dione (31) (759 mg,1.66 mmol) was dissolved in
15 ml acetic acid. Zinc dust (670 mg,10.3 mmol)) was added and the
mixture was stirred at 80 ꢂC for 30 min. The mixture was allowed to
cool and was filtered. The solid was washed with ethyl acetate and
the combined organics were concentrated under reduced pressure
to give 32 (762 mg, 1.66 mmol, 100%) as a solid. Used without
further purification. Purity 100%. 1H NMR (400 MHz, CDCl3) keto
COCH2), 6.97 (d, 1H, J ¼ 2.3 Hz, ArH), 7.24e7.28 (m, 1H, ArH), 7.29e
7.45 (m, 6H, ArH), 7.52 (t,1H, J ¼ 7.42 Hz, PhSO2 para H), 7.64 (br s.1H,
ArH), 7.84 (d, 2H, J ¼ 7.82 Hz, PhSO2 ortho H), 8.20 (br. s, 1H, ArH).
HPLC/MS (30 min) retention time 17.27 min. LRMS: m/z 515 (M þ 1).
5.6.3. Ethyl [4-(2-iodobenzyl)-5-methyl-3-phenyl-1H-pyrazol-1-yl]
acetate (36)
Following general methods A, E: White solid. Purity 100%. 1H
tautomer
d
ppm 8.11e8.16 (m, 1H, ArH), 8.09 (s, 1H, CF3Ph-H-2),
NMR (400 MHz, CDCl3)
d
ppm 1.29 (t, 3H, J ¼ 7.2 Hz, CH2Me), 2.09 (s,
8.04 (d, 1H, J ¼ 7.8 Hz, CF3Ph-H-6), 7.82 (d, 2H, J ¼ 7.4 Hz, PhSO2
ortho H), 7.77 (dd, 1H, J ¼ 13.0, 7.4 Hz, ArH), 7.49e7.63 (m, 4H, ArH),
7.32e7.40 (m, 2H, ArH), 7.14e7.19 (m, 1H, ArH), 5.29 (dd, 1H, J ¼ 8.2,
5.9 Hz, COCHCO), 3.56 (dd, 1H, J ¼ 13.9, 5.7 Hz, CHAHB), 3.32 (dd, 1H,
J ¼ 13.7, 8.6 Hz, CHAHB), 2.15 (s, 3H, Me). HPLC/MS (9 min) retention
time 6.97 min. LRMS: m/z 461 (M þ 1).
3H, ArMe), 3.90 (s, 2H, ArCH2Ar), 4.26 (q, 2H, J ¼ 7.23 Hz, CH2Me),
4.95 (s, 2H, COCH2), 6.88e6.95 (m, 2H, ArH), 7.22 (t, 1H, J ¼ 7.52 Hz,
ArH), 7.25e7.34 (m, 3H, ArH), 7.42e7.46 (m, 2H, ArH), 7.88 (dd, 1H,
J ¼ 7.72, 1.27 Hz, Ar). HPLC/MS (6 min) retention time 4.57 min.
LRMS: m/z 461 (M þ 1).
5.7. General “Method I”
5.5.3. 5-Methyl-4-[2-(phenylsulfonyl)benzyl]-3-[3-
(trifluoromethyl)phenyl]-1H-pyrazole (33)
5.7.1. (4-{2-[(2-Fluorophenyl)thio]benzyl}-5-methyl-3-phenyl-1H-
pyrazol-1-yl)acetic acid (38)
Ethyl [4-(2-iodobenzyl)-5-methyl-3-phenyl-1H-pyrazol-1-yl]
acetate (36) (91 mg, 0.20 mmol) potassium hydroxide (22 mg,
0.39 mmol), copper (13 mg, 0.20 mmol) and 2-fluorobenzenethiol
2-[2-(Phenylsulfonyl)benzyl]-1-[3-(trifluoromethyl)phenyl]
butane-1,3-dione (32) (762 mg, 1.6 mmol) was dissolved in 6 ml
acetic acid. Hydrazine monohydrate (0.13 ml, 2.68 mmol) was added
and the mixture was stirred at room temperature overnight. The
mixture was evaporated under reduced pressure and the residue was
partitioned between dichloromethane and water. The aqueous was
extracted twice with dichloromethane. The combined organics were
washed with brine, dried over sodium sulphate, filtered and evap-
orated under reduced pressure to give 33 (755 mg, 1.66 mmol, 100%)
37 (25 ml, 0.20 mmol) were suspended in 1 ml water. The mixture
was heated at 120 ꢂC under microwave irradiation (CEM Discover)
for two cycles of 30 min each. The solution was allowed to cool and
was partitioned between 2 N hydrochloric acid and ethyl acetate.
The aqueous layer was extracted twice with ethyl acetate. The

180
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
combined organics were dried over magnesium sulphate and
evaporated. The resulting residue was purified by reverse-phase
chromatography (formic acid buffer) using the SP1 Purification
system to give 38 (45 mg, 0.10 mmol, 52%) as a white solid. Purity
J ¼ 7.03 Hz, PhSO2 para H), 7.97 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho H),
8.12 (d, 1H, J ¼ 7.82 Hz, proximal Ph H(5)), 8.77 (s, 1H, proximal Ph
H(3)). HPLC/MS (30 min) retention time 16.10 min. LRMS: m/z 505
(M þ 1).
100%. 1H NMR (400 MHz, CDCl3)
d ppm 1.97 (s, 3H, Me), 4.01 (s, 2H,
ArCH2Ar), 4.91 (s, 2H, COCH2), 6.94e6.98 (m, 1H, ArH), 7.00e7.04
(m, 2H, ArH), 7.04e7.10 (m, 1H, ArH), 7.14e7.18 (m, 2H, ArH), 7.18e
7.24 (m, 1H, ArH), 7.25e7.29 (m, 3H, ArH), 7.31e7.34 (m, 1H, ArH),
7.37e7.42 (m, 2H, ArH), 9.03 (s, 1H, OH). HPLC/MS (6 min) retention
time 4.65 min. LRMS: m/z 433 (M þ 1).
5.7.7. (5-Methyl-3-phenyl-4-{[3-(phenylsulfonyl)pyridin-4-yl]
methyl}-1H-pyrazol-1-yl)acetic acid (49)
Following general methods K, T: White solid. Purity 99%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.85 (s, 3H, Me), 4.06 (s, 2H,
ArCH2Ar), 4.98 (s, 2H, COCH2), 6.89 (d, 1H, J ¼ 5.08 Hz, Pyr H(5)),
7.02e7.14 (m, 4H, ArH), 7.14e7.21 (m, 1H, ArH), 7.67 (t, 2H,
J ¼ 7.82 Hz, PhSO2 meta H), 7.77 (t, 1H, J ¼ 7.42 Hz, PhSO2 para H),
8.04 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho H), 8.70 (d, 1H, J ¼ 5.08 Hz, Pyr
H(6)), 9.26 (s, 1H, Pyr H(2)), 13.15 (br. s., 1H, OH). HPLC/MS (30 min)
retention time 14.26 min. LRMS: m/z 448 (M þ 1).
5.7.2. (4-{2-[(2-Fluorophenyl)sulfonyl]benzyl}-5-methyl-3-phenyl-
1H-pyrazol-1-yl)acetic acid (39)
(4-{2-[(2-Fluorophenyl)thio]benzyl}-5-methyl-3-phenyl-1H-
pyrazol-1-yl)acetic acid (38) (65 mg, 0.13 mmol) was dissolved in
2 ml dichloromethane and the mixture was cooled in an ice-bath.
3-Chloroperoxybenzoic acid (50% max purity, 90 mg, 0.26 mmol)
was added and the mixture was stirred at room temperature for 2 h.
The mixture was evaporated under reduced pressure. The resulting
residue was purified by reverse-phase chromatography (formic
acid buffer) using the SP1 Purification system to give 39 (15 mg,
0.032 mmol, 32%) as a white solid. Purity 94%. 1H NMR (400 MHz,
5.7.8. {4-[5-Fluoro-2-(phenylsulfonyl)benzyl]-5-methyl-3-phenyl-
1H-pyrazol-1-yl}acetic acid (50)
Following general methods K, T: White solid. Purity 94%. 1H
NMR (400 MHz, CDCl3)
d ppm 1.85 (s, 3H, Me), 4.09 (s, 2H,
ArCH2Ar), 4.88 (s, 2H, COCH2), 6.67 (d, 1H, J ¼ 10.16 Hz, proximal Ph
H(6)), 7.03e7.22 (m, 5H, ArH), 7.42e7.51 (m, 3H, ArH), 7.56 (t, 1H,
J ¼ 6.90 Hz, proximal Ph H(4)), 7.85 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho
H), 8.33 (dd, 1H, J ¼ 8.79, 5.67 Hz, proximal Ph H(3)). HPLC/MS
(30 min) retention time 15.85 min. LRMS: m/z 465 (M þ 1).
CDCl3)
d
ppm 8.32e8.38 (m, 1H, ArH), 8.11 (td, 1H, J ¼ 7.3, 1.2 Hz,
terminal Ph H(3)), 7.51e7.59 (m, 1H, ArH), 7.45 (dd, 2H, J ¼ 5.0,
3.9 Hz, ArH), 7.20e7.27 (m, 1H, ArH), 7.14e7.19 (m, 3H, ArH), 7.06e
7.14 (m, 3H, ArH), 7.00 (d, 1H, J ¼ 3.3 Hz, ArH), 4.90 (s, 2H, COCH2),
4.07 (s, 2H, ArCH2Ar), 1.83 (s, 3H, Me). HPLC/MS (30 min) retention
time 15.54 min. LRMS: m/z 465 (M þ 1).
5.7.9. {4-[5-Methoxy-2-(phenylsulfonyl)benzyl]-5-methyl-3-
phenyl-1H-pyrazol-1-yl}acetic acid (51)
Following general methods K, T: Pale yellow solid. Purity 98%. 1H
5.7.3. {5-Methyl-3-phenyl-4-[2-(phenylsulfonyl)-4-
NMR (400 MHz, DMSO-d6) d ppm 1.81 (s, 3H, ArMe), 3.68 (s, 3H,
(trifluoromethyl)benzyl]-1H-pyrazol-1-yl}acetic acid (45)
OMe), 3.96 (s, 2H, ArCH2Ar), 4.97 (s, 2H, COCH2), 6.38 (d, 1H,
J ¼ 1.95 Hz, proximal Ph H(6)), 7.01e7.25 (m, 6H, ArH), 7.63 (t, 2H,
J ¼ 7.82 Hz, PhSO2 meta H), 7.69 (t, 1H, J ¼ 7.42 Hz, PhSO2 para H),
7.88 (d, 2H, J ¼ 7.42 Hz, PhSO2 ortho H), 8.21 (d, 1H J ¼ 8.99 Hz,
proximal Ph H(3)). HPLC/MS (30 min) retention time 15.35 min.
LRMS: m/z 477 (M þ 1).
Following general methods K, T: White solid. Purity 99%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.80 (s, 3H, Me), 4.08 (s, 2H,
ArCH2Ar), 4.97 (s, 2H, COCH2), 7.01e7.24 (m, 6H, ArH), 7.67 (t, 2H,
J ¼ 7.62 Hz, PhSO2 meta H), 7.77 (t, 1H, J ¼ 7.42 Hz, PhSO2 para H),
7.96e8.08 (m, 3H, ArH), 8.48 (s, 1H, proximal Ph H(3)), 13.14 (br. s.,
1H, OH). HPLC/MS (30 min) retention time 17.47 min. LRMS: m/z
515 (M þ 1).
5.7.10. (5-Methyl-4-{2-[(2-methylphenyl)sulfonyl]benzyl}-3-
phenyl-1H-pyrazol-1-yl)acetic acid (52)
5.7.4. {4-[4-Methoxy-2-(phenylsulfonyl)benzyl]-5-methyl-3-
phenyl-1H-pyrazol-1-yl}acetic acid (46)
Following general method I: Yellow solid. Purity 90%. 1H NMR
(400 MHz, CDCl3)
d ppm 1.79 (s, 3H, pyrazole Me), 2.36 (s, 3H,
Following general methods K, T: Yellow solid. Purity 96%. 1H
PhMe), 3.99 (s, 2H, ArCH2Ar), 4.87 (s, 2H, COCH2), 6.94e6.99 (m, 1H,
ArH), 7.09e7.19 (m, 5H, ArH), 7.20e7.24 (m, 1H, ArH), 7.31 (t, 1H,
J ¼ 7.52 Hz, ArH), 7.37 - 7.46 (m, 3H, ArH), 8.18 (dd, 1H, J ¼ 7.91,
1.07 Hz, ArH), 8.23e8.28 (m, 1H, ArH). HPLC/MS (30 min) retention
time 16.38 min. LRMS: m/z 461 (M þ 1).
NMR (400 MHz, DMSO-d6)
d ppm 1.77 (s, 3H, ArMe), 3.85 (s, 3H,
OMe), 3.92 (s, 2H, ArCH2Ar), 4.95 (s, 2H, COCH2), 6.82 (d, 1H,
J ¼ 8.60 Hz, proximal Ph H(5)), 7.04e7.23 (m, 6H, ArH), 7.64 (t, 2H,
J ¼ 7.42 Hz, PhSO2 meta H), 7.68e7.84 (m, 2H, ArH), 7.95 (d, 2H,
J ¼ 7.42 Hz, PhSO2 ortho H), 13.10 (br. s., 1H, OH). HPLC/MS (30 min)
retention time 15.57 min. LRMS: m/z 477 (M þ 1).
5.7.11. (4-{2-[(2,6-Dimethylphenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (53)
5.7.5. 4-{[1-(Carboxymethyl)-5-methyl-3-phenyl-1H-pyrazol-4-yl]
methyl}-3-(phenylsulfonyl)benzoic acid (47)
Following general method I: White solid. Purity 94%. 1H NMR
(400 MHz, CDCl3)
d
ppm 1.80 (s, 3H, pyrazole Me), 2.52 (s, 6H, 2ꢀ
Following general methods K, T: White solid. Purity 93%. 1H NMR
PhMe), 3.93 (s, 2H, ArCH2Ar), 4.89 (s, 2H, COCH2), 6.94e6.98 (m, 1H,
ArH), 7.07 (d, 2H, J ¼ 7.62 Hz, PhSO2 meta H), 7.15e7.23 (m, 5H,
ArH), 7.24 (d, 1H, J ¼ 7.42 Hz, PhSO2 para H), 7.34e7.39 (m, 2H, ArH),
8.06e8.11 (m, 1H, ArH). HPLC/MS (30 min) retention time
17.05 min. LRMS: m/z 475 (M þ 1).
(400 MHz, DMSO-d6)
d ppm 1.79 (s, 3H, Me), 4.06 (s, 2H, ArCH2Ar),
4.96 (s, 2H, COCH2), 7.05 (d, 1H, J ¼ 8.21 Hz, ArH), 7.08e7.22 (m, 5H,
ArH), 7.65 (t, 2H, J ¼ 7.62 Hz, PhSO2 meta H), 7.74 (t, 1H, J ¼ 7.42 Hz,
PhSO2 para H), 7.96 (d, 2H, J ¼ 7.82 Hz, PhSO2 ortho H), 8.09 (d, 1H,
J ¼ 7.82 Hz, proximal Ph H(5)), 8.75 (s, 1H, proximal Ph H(3)). HPLC/
MS (30 min) retention time 14.53 min. LRMS: m/z 491 (M þ 1).
5.7.12. (4-{2-[(3-Fluorophenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (54)
5.7.6. {4-[4-(Methoxycarbonyl)-2-(phenylsulfonyl)benzyl]-5-
methyl-3-phenyl-1H-pyrazol-1-yl}acetic acid (48)
Following general methods K, T: White solid. Purity 99%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.84 (s, 3H, Me), 4.05 (s, 2H,
Following general methods K, T: White solid. Purity 90%. 1H
ArCH2Ar), 4.91 (s, 2H, COCH2), 6.97 (d, 1H, J ¼ 7.42 Hz, proximal Ph
H(6)), 7.04e7.23 (m, 5H, ArH), 7.52e7.63 (m, 3H, ArH), 7.63e7.80
(m, 3H, ArH), 8.23 (d, 1H, J ¼ 7.42 Hz, terminal Ph H(2)). HPLC/MS
(30 min) retention time 16.05 min. LRMS: m/z 465 (M þ 1).
NMR (400 MHz, DMSO-d6)
d ppm 1.79 (s, 3H, ArMe), 3.91 (s, 3H,
OMe), 4.06 (br. s., 2H, ArCH2Ar), 4.97 (s, 2H, COCH2), 7.01e7.15 (m,
6H, ArH), 7.65 (t, 2H, J ¼ 7.42 Hz, PhSO2 meta H), 7.75 (t, 1H,

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
181
5.7.13. (4-{2-[(3-Chlorophenyl)sulfonyl]benzyl}-5-methyl-3-
5.7.19. (4-{2-[(3,4-Dimethylphenyl)sulfinyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (61)
phenyl-1H-pyrazol-1-yl)acetic acid (55)
Following general methods K, T: White solid. Purity 99%. 1H
Following general method I: Yellow solid. Purity 93%. 1H NMR
NMR (400 MHz, DMSO-d6)
d
ppm 1.85 (s, 3H, Me), 4.04 (s, 2H,
(400 MHz, CDCl3)
d
ppm 8.04 (d, 1H, J ¼ 7.2 Hz, ArH), 8.01 (s, 1H,
ArCH2Ar), 4.96 (s, 2H, COCH2), 6.96 (d, 1H, J ¼ 7.03 Hz, ArH), 7.07e
7.15 (m, 4H, ArH), 7.14e7.22 (m, 1H, ArH), 7.53e7.72 (m, 3H, ArH),
7.81 (d, 1H, J ¼ 7.82 Hz, terminal Ph H(6)), 7.87e7.95 (m, 2H, ArH),
8.26 (d, 1H, J ¼ 1.56 Hz, terminal Ph H(2)). HPLC/MS (30 min)
retention time 16.79 min. LRMS: m/z 481 (M þ 1).
terminal Ph H(2)), 7.45 (t, 1H, J ¼ 7.4 Hz, ArH), 7.32e7.36 (m, 1H,
ArH), 7.26 (m, 6H, ArH), 7.14 (d, 1H, J ¼ 8.0 Hz), 6.97 (d, 1H,
J ¼ 7.6 Hz, proximal Ph H(6)), 4.90 (s, 2H, COCH2), 4.05 (d, 1H,
J ¼ 17.4 Hz, ArCHAHBAr), 3.76 (d,1H, J ¼ 17.6 Hz, ArCHAHBAr), 2.25 (s,
3H, PhMe), 2.20 (s, 3H, PhMe), 1.91 (s, 3H, pyrazole Me). HPLC/MS
(30 min) retention time 15.81 min. LRMS: m/z 459 (M þ 1).
5.7.14. [5-Methyl-3-phenyl-4-(2-{[3-(trifluoromethyl)phenyl]
sulfonyl}benzyl)-1H-pyrazol-1-yl]acetic acid (56)
5.7.20. (4-{2-[(3,4-Dimethylphenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (62)
Following general method I: Purity 100%. 1H NMR (400 MHz,
CDCl3)
d
ppm 8.32 (dd, 1H, J ¼ 7.5, 1.7 Hz, terminal Ph H(6)), 8.11
Following general method I: White solid. Purity 99%. 1H NMR
(s, 1H, terminal Ph H(2)), 8.07 (d, 1H, J ¼ 8.2 Hz, ArH), 7.80 (d,
1H, J ¼ 7.8 Hz, ArH), 7.60 (t, 1H, J ¼ 7.8 Hz, ArH), 7.50 (td, 1H,
J ¼ 7.6, 1.5 Hz, ArH), 7.47 (t, 1H, J ¼ 7.6 Hz, ArH), 7.03e7.18 (m,
6H, ArH), 4.88 (s, 2H, COCH2), 4.10 (s, 2H, ArCH2Ar), 1.92 (s, 3H,
Me). HPLC/MS (30 min) retention time 17.04 min. LRMS: m/z 515
(M þ 1).
(400 MHz, CDCl3)
d
ppm 8.27 (dd, 1H, J ¼ 5.6, 3.6 Hz, proximal Ph
H(3)), 7.60 (s, 1H, terminal Ph H(2)), 7.57 (d, 1H, J ¼ 7.8 Hz, terminal
Ph H(6)), 7.41 (dd, 2H, J ¼ 5.7, 3.5 Hz, ArH), 7.16e7.21 (m, 2H, ArH),
7.13 (d, 2H, J ¼ 7.5 Hz, ArH), 7.06 (t, 2H, J ¼ 7.5 Hz, pyrazole Ph meta
H), 6.98 (dd, 1H, J ¼ 5.0, 3.5 Hz, proximal Ph H(6)), 4.90 (2 H, s,
COCH2), 4.14 (2 H, s, ArCH2Ar), 2.28 (s, 3H, PhMe), 2.21 (s, 3H,
PhMe), 1.88 (s, 3H, pyrazole Me). HPLC/MS (30 min) retention time
16.81 min. LRMS: m/z 475 (M þ 1).
5.7.15. (4-{2-[(3-Methoxyphenyl)thio]benzyl}-5-methyl-3-phenyl-
1H-pyrazol-1-yl)acetic acid (57)
Following general method I: White solid. Purity 100%. 1H NMR
5.7.21. (4-{2-[(4-Fluorophenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (63)
(400 MHz, CDCl3) d ppm 9.14 (br. s. 1H, OH), 7.40e7.44 (m, 1H, ArH),
7.34e7.40 (m, 2H, ArH), 7.22e7.28 (m, 3H, ArH), 7.09e7.20 (m, 3H,
ArH), 6.96 (d, 1H, J ¼ 4.1 Hz, ArH), 6.74 (d, 2H, J ¼ 7.0 Hz, ArH), 6.70
(s, 1H, terminal Ph H(2)), 4.89 (s, 2H, COCH2), 3.97 (s, 2H, ArCH2Ar),
3.72 (s, 3H, OMe), 1.93 (s, 3H, ArMe). HPLC/MS (6 min) retention
time 4.66 min. LRMS: m/z 445 (M þ 1).
Following general methods K, T: White solid. Purity 99%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.86 (s, 3H, ArMe), 4.01 (s, 2H,
ArCH2Ar), 4.97 (s, 2H, COCH2), 6.95 (d, 1H, J ¼ 7.03 Hz, proximal Ph
H(6)), 7.01e7.16 (m, 4H, ArH), 7.15e7.25 (m, 1H, ArH), 7.45 (t, 2H,
J ¼ 8.79 Hz, terminal Ph H(3) and H(5)), 7.56 (t,1H, J ¼ 7.42 Hz, ArH),
7.60 (td, 1H, J ¼ 7.42, 1.56 Hz, ArH), 8.00 (dd, 2H, J ¼ 8.60, 5.08 Hz,
terminal Ph H(2) and H(6)), 8.25 (d, 1H, J ¼ 7.42 Hz, proximal Ph
H(3)), 13.15 (br. s., 1H, OH). HPLC/MS (30 min) retention time
15.87 min. LRMS: m/z 465 (M þ 1).
5.7.16. (4-{2-[(3-Methoxyphenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (58)
Following general method I: White solid. Purity 100%. 1H
NMR (400 MHz, CDCl3)
d ppm 8.25e8.32 (m, 1H, ArH), 7.39e7.45
(m, 3H, ArH), 7.33e7.38 (m, 2H, ArH), 7.20 (t, 1H, J ¼ 7.0 Hz, ArH),
7.18 (d, 2H, J ¼ 7.0 Hz, ArH), 7.12 (m, 2H, ArH), 7.06 (dd, 1H,
J ¼ 7.7, 1.9 Hz), 7.00 (dd, 1H, J ¼ 5.0, 4.0 Hz, ArH), 4.89 (s, 2H, s,
COCH2), 4.14 (s, 2H, ArCH2Ar), 3.75 (s, 3H, OMe), 1.85 (s, 3H,
ArMe). HPLC/MS (30 min) retention time 15.71 min. LRMS: m/z
477 (M þ 1).
5.7.22. (4-{2-[(4-Chlorophenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (64)
Following general methods K, T: White solid. Purity 99%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.87 (s, 3H, ArMe), 4.00 (s, 2H,
ArCH2Ar), 4.98 (s, 2H, COCH2), 6.95 (d, 1H, J ¼ 7.42 Hz, proximal Ph
H(6)), 7.00e7.14 (m, 4H, ArH), 7.13e7.27 (m, 1H, ArH), 7.51e7.66 (m,
2H, ArH), 7.68 (d, 2H, J ¼ 8.60 Hz, terminal Ph H(3) and H(5)), 7.92
(d, 2H, J ¼ 8.60 Hz, terminal Ph H(2) and H(6)), 8.25 (dd, 1H, J ¼ 7.4
and 1.3 Hz, proximal Ph H(3)), 13.13 (br. s., 1H, OH). HPLC/MS
(30 min) retention time 16.89 min. LRMS: m/z 481 (M þ 1).
5.7.17. {4-[2-({3-[(Dimethylamino)carbonyl]phenyl}sulfonyl)
benzyl]-5-methyl-3-phenyl-1H-pyrazol-1-yl}acetic acid (59)
Following general method I: Pale yellow solid. Purity 97%. 1H
NMR (400 MHz, CDCl3)
d
ppm 8.30 (dd, 1H, J ¼ 7.1, 2.1 Hz, terminal
Ph (H(6)), 7.91 (s, 1H, terminal Ph H(3)), 7.90 (d, 1H, J ¼ 7.5 Hz,
terminal Ph H(4)), 7.63 (d, 1H, d, J ¼ 7.6 Hz, proximal Ph H(3)), 7.53
(t, 1H, J ¼ 7.8 Hz, terminal Ph H(5)), 7.37e7.49 (m, 2H, ArH), 7.14e
7.25 (m, 5H, ArH), 7.05 (d, 1H, J ¼ 2.0 Hz ArH), 4.87 (s, 2H, COCH2),
4.12 (s, 2H, ArCH2Ar), 3.08 (s, 3H, NMeAMeB), 2.81 (s, 3H, NMeAMeB),
1.76 (s, 3H, ArMe). HPLC/MS (30 min) retention time 13.84 min.
LRMS: m/z 518 (M þ 1).
5.7.23. (4-{2-[(4-Methoxyphenyl)sulfonyl]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (65)
Following general methods K, E: White solid. Purity 99%. 1H
NMR (400 MHz, CDCl3)
d
ppm 8.26 (dd,1H, J ¼ 5.5, 3.5 Hz, ArH), 7.78
(d, 2H, J ¼ 8.6 Hz terminal Ph H(2) and H(6)), 7.40 (dd, 2H, J ¼ 5.7,
3.3 Hz, ArH), 7.04e7.23 (m, 5H, ArH), 6.97 (d, 1H, J ¼ 5.5 Hz, prox-
imal Ph H(6)), 6.89 (d, 2H, J ¼ 9.0 Hz, terminal Ph H(3) and H(5)),
4.91 (s, 2H, COCH2), 4.12 (s, 2H, ArCH2Ar), 3.81 (s, 3H, OMe), 1.87 (s,
3H, ArMe). HPLC/MS (30 min) retention time 15.56 min. LRMS: m/z
477 (M þ 1).
5.7.18. (4-{2-[(3,4-Dimethylphenyl)thio]benzyl}-5-methyl-3-
phenyl-1H-pyrazol-1-yl)acetic acid (60)
Following general method I: White solid. Purity 99%. 1H NMR
(400 MHz, CDCl3)
d
ppm 7.42 (dd, 2H, J ¼ 6.3, 2.8 Hz, ArH), 7.26e
5.7.24. [5-Methyl-3-phenyl-4-(2-{[4-(trifluoromethoxy)phenyl]
sulfonyl}benzyl)-1H-pyrazol-1-yl]acetic acid (66)
7.31 (m, 3H, ArH), 7.23e7.25 (m, 1H, ArH), 7.10e7.14 (m, 1H, ArH),
7.09 (s, 1H, terminal Ph H(2)), 7.06 (d, 1H, J ¼ 7.5 Hz, terminal Ph
H(5)), 7.00 (dd, 1H, J ¼ 7.7, 1.5 Hz, terminal Ph H(6)), 6.91 (dd, 1H,
J ¼ 5.0, 4.0, Hz, proximal Ph H(6)), 6.01 (br. s., 1H, ArH), 4.91 (s, 2H,
COCH2), 3.99 (s, 2H, ArCH2Ar), 2.24 (s, 3H, PhMe), 2.21 (s, 3H,
PhMe), 2.01 (s, 3H, pyrazole Me). HPLC/MS (30 min) retention time
20.49 min. LRMS: m/z 443 (M þ 1).
Following general method I: White solid. Purity 97%. 1H NMR
(400 MHz, CDCl3)
d
ppm 8.30 (dd, 1H, J ¼ 7.1, 2.1 Hz, terminal Ph
H(2) and H(6)), 7.91 (d, 2H, J ¼ 8.8 Hz, terminal Ph H(3) and H(5)),
7.42e7.54 (m, 2H, ArH), 7.25e7.30 (m, 2H, ArH), 7.22 (t, 1H,
J ¼ 7.1 Hz, ArH), 7.09e7.19 (m, 4H, ArH), 7.03 (d, 1H, J ¼ 2.0 Hz,
proximal Ph H(6)), 4.92 (s, 2H, COCH2), 4.11 (s, 2H, ArCH2Ar), 1.89 (s,

182
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
3H, ArMe). HPLC/MS (30 min) retention time 17.42 min. LRMS: m/z
531 (M þ 1).
the mixture stirred at 90 ꢂC overnight. The mixture was filtered
through Celite and the filtrate was evaporated under reduced
pressure. The residue was partitioned between ethyl acetate and
water. The organics were washed with brine, dried over magne-
sium sulphate, filtered and evaporated under reduced pressure. The
residue was purified using the SP1 Purification System (ethyl ace-
tateehexane gradient, 0:100 rising to 20:80). to give ethyl 2-(5-
methyl-4-(2-(naphthalen-1-yl)benzyl)-3-phenyl-1H-pyrazol-1-yl)
acetate (54 mg, 0.12 mmol, 69%) as a pale yellow solid. HPLC/MS
(9 min) retention time 7.68 min. LRMS: m/z 461 (M þ 1).
5.7.25. [4-(2-{[4-(Dimethylamino)phenyl]sulfonyl}benzyl)-5-
methyl-3-phenyl-1H-pyrazol-1-yl]acetic acid (67)
Following general method I gave, upon mCPBA oxidation, 64 mg
of the crude N-oxide [4-(2-{[4-(dimethylnitroryl)phenyl]sulfonyl}
benzyl)-5-methyl-3-phenyl-1H-pyrazol-1-yl]acetic acid. HPLC/MS
(6 min) retention time 3.68 min. LRMS: m/z 506 (M þ 1).
The N-oxide was dissolved in 4 ml methanol. Palladium (10% on
carbon, 50 mg) was added and the mixture was stirred at room
temperature for 1 h under a hydrogen atmosphere at 50 psi. The
mixture was filtered and evaporated under reduced pressure. The
resulting residue was purified by reverse-phase chromatography
(formic acid buffer) using the SP1 Purification system to give 67
(8 mg, 0.016 mmol, 12% over two steps) as a white solid. Purity 98%.
The ester (52 mg, 0.11 mmol) was dissolved in 1 ml tetrahy-
drofuran and 1 ml water. Lithium hydroxide monohydrate (24 mg,
0.57 mmol) was added and the mixture was stirred for 2 h. The
organics were evaporated under reduced pressure and the mixture
was acidified to pH 4 with dilute hydrochloric acid, forming a white
precipitate. The solid was collected by filtration, was washed with
water and was dried under vacuum to give 71 (34 mg, 0.079 mmol,
70%) as a white solid. Purity 100%. 1H NMR (400 MHz, DMSO-d6)
1H NMR (400 MHz, CDCl3)
d ppm 1.87 (s, 3H, ArMe), 3.00 (s, 6H,
NMe2), 4.18 (s, 2H, ArCH2Ar), 4.86 (s, 2H, COCH2), 6.57 (d, 2H,
J ¼ 9.18 Hz, terminal Ph H(3) and H(5)), 6.92e6.98 (m, 1H, proximal
Ph H(6)), 7.05e7.11 (m, 2H, ArH), 7.11e7.20 (m, 3H, ArH), 7.32e7.36
(m, 2H, ArH), 7.66 (d, 2H, J ¼ 8.99 Hz, terminal Ph H(2) and H(6)),
8.19e8.23 (m, 1H, proximal Ph H(3)). HPLC/MS (30 min) retention
time 15.82 min. LRMS: m/z 490 (Mþ1).
d
ppm 13.13 (br. s. 1H, OH), 8.00 (d, 1H, J ¼ 7.4 Hz, ArH), 7.96 (d, 1H,
J ¼ 8.2 Hz, ArH), 7.60 (t, 1H, J ¼ 7.6 Hz, ArH), 7.49e7.57 (m, 2H, ArH),
7.43e7.49 (m, 2H, ArH), 7.33e7.40 (m, 2H, ArH), 7.17e7.30 (m, 6H,
ArH), 6.97e7.04 (m, 1H, ArH), 4.94 (s, 2H, CH2CO), 3.55 (d, 1H,
J ¼ 17.0 Hz, ArCHACHBAr), 3.37 (d, 1H, J ¼ 17.0 Hz, ArCHACHBAr), 2.02
(s, 3H, Me). HPLC/MS (30 min) retention time 19.65 min. LRMS: m/z
433 (M þ 1).
5.7.26. [5-Methyl-4-(2-{[4-(methylsulfonyl)phenyl]sulfonyl}
benzyl)-3-phenyl-1H-pyrazol-1-yl]acetic acid (68)
Following general methods K, E: white solid. Purity 92%. 1H NMR
5.7.30. {3,5-Dimethyl-4-[2-(phenylsulfonyl)benzyl]-1H-pyrazol-1-
yl}acetic acid (72)
(400 MHz, CDCl3)
d
ppm 8.33 (d, 1H, J ¼ 7.0 Hz, proximal Ph H(3)),
8.03 (s, 4H, terminal Ph), 7.51 (br. s., 2H, ArH), 7.19e7.28 (m, 2H,
ArH), 7.08e7.16 (m, 4H, ArH), 7.05 (d, 1H, J ¼ 6.6 Hz, proximal Ph
H(6)), 4.90 (s, 2H, COCH2), 4.06 (s, 2H, ArCH2Ar), 3.01 (s, 3H,
SO2Me), 1.91 (s, 3H, ArMe). HPLC/MS (30 min) retention time
14.35 min. LRMS: m/z 525 (M þ 1).
Following general methods K, E: White solid. Purity 98%. 1H
NMR (400 MHz, CDCl3)
d
ppm 8.25 (d, 1H, J ¼ 7.4 Hz, proximal Ph
H(3)), 7.88 (d, 2H, J ¼ 7.8 Hz, PhSO2 ortho H), 7.58 (t, 1H, J ¼ 7.4 Hz,
PhSO2 para H), 7.51 (t, 2H, J ¼ 7.6 Hz, PhSO2 meta H), 7.44 (t, 1H,
J ¼ 7.4 Hz, proximal Ph H(5)), 7.40 (t, 1H, J ¼ 7.4 Hz, proximal Ph
H(4)), 6.89 (d, 1H, J ¼ 7.4 Hz, proximal Ph H(6)), 4.73 (s, 2H, COCH2),
3.94 (br. s., 2H, ArCH2Ar), 1.86 (s, 3H, pyrazole-3-Me), 1.80 (s, 3H,
pyrazole-5-Me). HPLC/MS (30 min) retention time 13.45 min.
LRMS: m/z 385 (M þ 1).
5.7.27. {4-[2-(Benzylsulfonyl)benzyl]-5-methyl-3-phenyl-1H-
pyrazol-1-yl}acetic acid (69)
Following general method I: White solid. Purity 99%. 1H NMR
(400 MHz, CDCl3)
d
ppm 7.73 (d, 1H, J ¼ 7.8 Hz, proximal Ph H(3)),
7.37e7.45 (m, 3H, ArH), 7.28e7.34 (m, 3H, ArH), 7.20e7.28 (m, 4H,
ArH), 7.05 (d, 1H, J ¼ 7.8 Hz, proximal Ph H(6)), 7.02 (d, 2H,
J ¼ 7.0 Hz, terminal Ph ortho H), 4.94 (s, 2H, COCH2), 4.30 (s, 2H,
SO2CH2Ar), 4.20 (s, 2H, ArCH2Ar), 1.99 (s, 3H, ArMe). HPLC/MS
(30 min) retention time 15.64 min. LRMS: m/z 461 (M þ 1).
5.7.31. 2-(3-Hydroxy-5-methyl-4-(2-(phenylsulfonyl)benzyl)-1H-
pyrazol-1-yl)acetic acid (73)
Following general methods K, T: White solid. Purity 100%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.62 (s, 3H, Me), 3.76 (s, 2H,
ArCH2Ar), 4.56 (s, 2H, CH2CO), 7.17 (d, 1H, J ¼ 6.64 Hz, proximal Ph
H(6)), 7.48e7.54 (m, 1H, ArH), 7.55e7.60 (m, 1H, ArH), 7.61e7.67 (m,
2H, ArH), 7.70e7.75 (m, 1H, ArH), 7.86e7.91 (m, 2H, ArH), 8.15 (dd,
1H, J ¼ 7.82, 1.56 Hz, proximal Ph H(3)), 11.52 (s, 1H, OH, possibly as
NH tautomer). HPLC/MS (30 min) retention time 11.25 min. LRMS:
m/z 387 (M þ 1).
5.7.28. {5-Methyl-3-phenyl-4-[2-(quinolin-8-ylsulfonyl)benzyl]-
1H-pyrazol-1-yl}acetic acid (70)
Following general method I: White solid. Purity 94%. 1H NMR
(400 MHz, CDCl3)
d
ppm 8.82 (dd, 1H, J ¼ 4.1, 1.6 Hz quinoline H(2)),
8.69 (dd, 1H, J ¼ 7.4, 1.0 Hz, quinoline H(5)), 8.63 (d, 1H, J ¼ 8.0 Hz,
ArH), 8.19 (dd, 1H, J ¼ 8.3, 1.5 Hz, quinoline H(4)), 8.01 (d, 1H,
J ¼ 7.4 Hz, ArH), 7.59 (t, 1H, J ¼ 7.7 Hz, ArH), 7.45 (dd, 1H, J ¼ 8.3,
4.1 Hz quinoline H(3)), 7.44 (d, 1H, J ¼ 8.0 Hz, ArH), 7.36 (t, 1H,
J ¼ 7.0 Hz, ArH), 7.04 (t,1H, J ¼ 7.4 Hz, ArH), 7.00 (d, 2H, J ¼ 7.4 Hz, Ph
ortho), 6.89 (d, 1H, J ¼ 7.6 Hz, proximal Ph H(6)), 6.79 (t, 2H,
J ¼ 7.7 Hz Ph meta), 4.82 (s, 2H, COCH2), 4.10 (s, 2H, ArCH2Ar), 1.74
(s, 3H, Me). HPLC/MS (30 min) retention time 14.49 min. LRMS: m/z
498 (Mþ1).
5.7.32. 2-(3-Methoxy-5-methyl-4-(2-(phenylsulfonyl)benzyl)-1H-
pyrazol-1-yl)acetic acid (74)
Following general methods K, T: The methoxy group was
introduced as follows:
Prior to deprotection to give 73, tert-butyl 2-(3-hydroxy-5-
methyl-4-(2-(phenylsulfonyl)benzyl)-1H-pyrazol-1-yl)acetate
(36 mg, 0.08 mmol) was dissolved in 5 ml acetone. Potassium
carbonate (23 mg, 0.16 mmol) and dimethyl sulphate (8
ml,
0.08 mmol) were added and the mixture was stirred at reflux
overnight. The mixture evaporated under reduced pressure and the
residue was partitioned between ethyl acetate and water. The or-
ganics were washed with brine, dried over magnesium sulphate,
filtered and evaporated under reduced pressure. The residue was
purified using the SP1 Purification System (ethyl acetateehexane
gradient, 0:100 rising to 100:0) to give tert-butyl 2-(3-methoxy-5-
methyl-4-(2-(phenylsulfonyl)benzyl)-1H-pyrazol-1-yl)acetate
5.7.29. Ethyl 2-(5-methyl-4-(2-(naphthalen-1-yl)benzyl)-3-phenyl-
1H-pyrazol-1-yl)acetate (71)
A mixture of 36 (78 mg, 0.17 mmol), naphthylen-1-ylboronic
acid (44 mg, 0.26 mmol), [1,10-bis(diphenylphosphino)ferrocene]
palladium(II) dichloride (7 mg, 0.01 mmol) and caesium carbonate
solution (2 M, 0.25 ml, 0.5 mmol) were suspended in 3.5 ml dioxane
in a pressure tube. The solution was degassed, the tube sealed and

M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
183
(15 mg, 0.03 mmol, 41%) as a colourless oil. HPLC/MS (9 min)
retention time 6.77 min. LRMS: m/z 457 (M þ 1).
HPLC/MS (30 min) retention time 12.62 min. LRMS: m/z 484
(M þ 1).
Deprotection according to general method T gave 74. White
solid. Purity 98%. 1H NMR (400 MHz, CDCl3)
d ppm 1.84 (s, 3H, Me),
5.8. CRTh2 GTPgS antagonism binding assay
3.59 (s, 3H, OMe), 3.91 (s, 2H, ArCH2Ar), 4.63 (s, 2H, CH2CO), 7.18 (d,
1H, J ¼ 7.42 Hz, proximal Ph H(6)), 7.35e7.42 (m, 1H, ArH), 7.43e
7.54 (m, 3H, ArH), 7.54e7.62 (m, 1H, ArH), 7.83e7.90 (m, 2H, ArH),
8.13e8.26 (m, 1H, proximal Ph H(3)). HPLC/MS (30 min) retention
time 11.95 min. LRMS: m/z 401 (M þ 1).
The assay was performed by pre-incubating 4e8
m
g of mem-
branes (obtained from CHO.K1 cells stably overexpressing the
CRTh2 receptor) per well with the compound to be tested for 1 h,
followed by incubation with 50 nM PGD2 and 0.1 nM [35S]-GTP
g
S in
incubation buffer (20 mM HEPES, 10 mM MgCl2, 100 mM NaCl,
10 M GDP, 10 g/ml Saponine and 0.2% BSA) for 2 h at room
5.7.33. {5-Methyl-4-[2-(phenylsulfonyl)benzyl]-3-pyrimidin-5-yl-
1H-pyrazol-1-yl}acetic acid (75)
m
m
temperature. The reaction was terminated by filtering in GF/C
plates pre-treated with 20 mM HEPES, 10 mM MgCl2, 100 mM NaCl
and 0.1% BSA and washing 6 times with wash buffer (20 mM
NaH2PO4, 20 mM Na2HPO4). After washing, the plates were dried
and scintillation buffer Optiphase was added. The radioactivity
retained in the filter was counted using a Microbeta liquid scintil-
lation counter. Compound IC50s were determined using Excel XL-fit
for calculations.
Following general methods D, A, T: White solid. Purity 95%. 1H
NMR (400 MHz, DMSO-d6)
d ppm 1.84 (s, 3H, Me), 4.07 (s, 2H,
ArCH2Ar), 5.01 (s, 2H, COCH2), 6.91e6.96 (m, 1H, proximal Ph H(6)),
7.55e7.60 (m, 2H, ArH), 7.60e7.65 (m, 2H, ArH), 7.68e7.74 (m, 1H,
ArH), 7.88e7.92 (m, 2H, ArH), 8.20e8.24 (m, 1H, ArH), 8.53 (s, 2H,
pyrimidine H(4) and H(6)), 9.01 (s, 1H, pyrimidine H(2)), 12.71e
13.25 (br. s, 1H, OH). HPLC/MS (30 min) retention time 12.75 min.
LRMS: m/z 449 (M þ 1).
5.9. CRTh2 radioligand binding serum shift assay
5.7.34. {5-Methyl-4-[2-(phenylsulfonyl)benzyl]-3-pyridin-4-yl-1H-
pyrazol-1-yl}acetic acid (76)
Following general methods D, A, T: White solid. Purity 98%. 1H
The assay was performed as above, replacing 0.2% BSA of the
incubation buffer with 1% HSA.
NMR (400 MHz, DMSO-d6)
d ppm 1.87 (s, 3H, Me), 4.08 (s, 2H,
ArCH2Ar), 5.01 (s, 2H, COCH2), 6.85e6.89 (m, 1H, proximal Ph H(6)),
6.99e7.02 (m, 2H, ArH), 7.55e7.59 (m, 2H, ArH), 7.63e7.69 (m, 2H,
ArH), 7.71e7.77 (m, 1H, ArH), 7.93e7.97 (m, 2H, ArH), 8.23e8.29 (m,
3H, ArH), 13.24 (s, 1H, OH). HPLC/MS (30 min) retention time
10.21 min. LRMS: m/z 448 (M þ 1).
5.10. CRTh2 isolated cell eosinophil cell shape assay
Citrated whole blood was obtained from consenting donors and
polymorphonuclear (OMN) leukocytes were obtained by gradient
centrifugation on Polymorphprep for 40 min at 500G brake off. The
PMN fraction was re-suspended in calcium free buffer (10 mM
HEPES, 10 mM glucose, 0.1% BSA in calcium free PBS) and centri-
fuged for 10 min at 400G at room temperature. Red blood cells were
lysed by adding 20 ml of 0.2% saline buffer (0.2% NaCl) for 40 s and
stopped by adding 20 ml of 1.6% saline buffer (1.6% NaCl). For
5.7.35. {3-(2,5-Dichlorophenyl)-5-methyl-4-[2-(phenylsulfonyl)
benzyl]-1H-pyrazol-1-yl}acetic acid (77)
Following general methods D, K, T: White solid. Purity 97%. 1H
NMR (400 MHz, CDCl3)
d
ppm 8.19 (d, 1H, J ¼ 7.4 Hz, proximal Ph
H(3)), 7.78 (d, 2H, J ¼ 7.4 Hz, terminal Ph ortho), 7.54 (t, 1H,
J ¼ 7.4 Hz, terminal Ph para), 7.44 (t, 2H, J ¼ 7.8 Hz, terminal Ph
meta), 7.33e7.43 (m, 2H, ArH), 7.22 (d, 1H, J ¼ 8.4 Hz, Cl2Ph H(3)),
7.17 (dd, 1H, J ¼ 8.4, 2.5 Hz, Cl2Ph H(4)), 7.04 (d, 1H, J ¼ 2.3 Hz, Cl2Ph
H(6)), 6.96 (d, 1H, J ¼ 7.4 Hz, proximal Ph H(6)), 4.89 (s, 2H, COCH2),
3.97 (s, 2H, ArCH2Ar), 1.94 (s, 3H, ArMe). HPLC/MS (30 min)
retention time 16.71 min. LRMS: m/z 515 (M þ 1).
compound treatment, 90
ml of PMNs cells (re-suspended at a
density of 5 ꢀ 106 cells/ml in 10 mM HEPES, 10 mM glucose, 0.1%
BSA in calcium containing PBS) were incubated for 10 min with
10 ml of compound to be tested followed by incubation with 10 ml of
500 nM PGD2 for exactly 4 min at 37 ꢂC. Fixation was performed by
addition of 0.2 ml of ice-cold 1:5 diluted CellFix (BD Biosciences)
and samples were immediately analysed on a FACSCalibur (BD
Biosciences). Eosinophils were gated on the basis of auto-
fluorescence in the FL2 channels and shape change of 600 cells
was assayed by forward scatter and side scatter analysis. Com-
pound IC50s were determined using Excel XL-fit for calculations.
5.7.36. 2-(3-(4-(Dimethylcarbamoyl)phenyl)-5-methyl-4-(2-
(phenylsulfonyl)benzyl)-1H-pyrazol-1-yl)acetic acid (78)
Following general methods D, K, T: White solid. Purity 98%.
1H NMR (400 MHz, CDCl3)
d ppm 8.27e8.33 (m, 1H, proximal Ph
H(3)), 7.87 (d, 2H, J ¼ 7.8 Hz, terminal Ph ortho), 7.60 (t, 1H,
J ¼ 7.4 Hz, terminal Ph para), 7.50 (t, 2H, J ¼ 7.6 Hz, terminal Ph
meta), 7.42e7.46 (m, 2H, ArH), 7.24 (d, 2H, J ¼ 7.0 Hz, PhCO H(3) and
H(5)), 7.20 (d, 2H, J ¼ 7.0 Hz, PhCO H(2) and H(6)), 6.93e7.01 (m,1H,
proximal Ph H(6)), 4.87 (s, 2H, CH2CO), 4.13 (s, 2H, ArCH2Ar), 3.11 (s,
3H, CONMeAMeB), 2.94 (s, 3H, CONMeAMeB), 1.86 (s, 3H, Me).).
HPLC/MS (30 min) retention time 13.88 min. LRMS: m/z 518
(M þ 1).
5.10.1. CRTh2 whole blood eosinophil cell shape assay
Whole blood obtained from consenting donors was mixed with
heparin and kept in rotation until use. For compound treatment,
90
incubated for 10 min at room temperature followed by addition of
10
l of 500 nM PGD2 for exactly 4 min at 37 ꢂC. The reaction was
ml of blood was mixed with 10 ml of compound to be tested and
m
stopped by placing the tubes on ice and adding of 0.25 ml of ice-
cold 1:5 diluted CellFix (BD Biosciences). Red blood cells were
lysed in two steps by adding 2 ml of lysis solution (150 mM
ammonium chloride, 10 mM potassium hydrogencarbonate),
incubating for 20 and 10 min respectively and centrifuging at 300G
for 5 min at 6 ꢂC. The pellet was re-suspended in 0.2 ml fixative
solution and immediately analysed on a FACSCalibur (BD Bio-
sciences). Eosinophils were gated on the basis of auto-fluorescence
in the FL2 channels and shape change of 600 cells was assayed by
forward scatter and side scatter analysis. Compound IC50s were
determined using Excel XL-fit for calculations.
5.7.37. {5-Methyl-3-(morpholin-4-ylcarbonyl)-4-[2-
(phenylsulfonyl)benzyl]-1H-pyrazol-1-yl}acetic acid (79)
Following general methods K, E: White solid. Purity 99%. 1H
NMR (400 MHz, CDCl3)
d
ppm 8.11 (d, 1H, J ¼ 7.9 Hz, proximal Ph
H(3)), 7.86 (d, 2H, J ¼ 7.6 Hz, terminal Ph ortho), 7.63e7.54 (m,
1H, ArH), 7.51 (t, 2H, J ¼ 7.3 Hz, terminal Ph meta), 7.47e7.39 (m,
1H, ArH), 7.34 (t, 1H, J ¼ 7.4 Hz, ArH), 7.03 (d, 1H, J ¼ 7.0 Hz,
proximal Ph H(6)), 4.68 (s, 2H, COCH2), 4.06 (s, 2H, ArCH2Ar),
3.49 (s, 4H, NCH2CH2O), 3.33 (s, 4H, NCH2CH2O), 1.86 (s, 3H, Me).

184
M. Andrés et al. / European Journal of Medicinal Chemistry 71 (2014) 168e184
[11] P. Norman, Expert Opin. Investig. Drugs 19 (2010) 947.
Acknowledgements
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The authors thank the following for their valuable assistance in
the experimental procedures: Manel de Luca, José Luís Gómez,
Encarna Jiménez, Francisco Jiménez, Juan Navarro, Isabel Pagan and
Sílvia Petit.
Appendix A. Supplementary data
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Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2013.10.072.
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