Design and synthesis of acyclic triaryl (Z)-olefins: A novel class of cyclooxygenase-2 (COX-2) inhibitors

Article abstract of DOI:10.1016/j.bmc.2004.08.021

A group of acyclic 2-alkyl-1,1-diphenyl-2-(4-methylsulfonylphenyl)ethenes was designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition structure-activity studies identified 1,1-diphenyl-2-(4-methylsulfonylphenyl)hex-1-ene as a highly potent (IC ₅₀ = 0.014 μM), and an extremely selective [COX-2 selectivity index (SI) > 7142], COX-2 inhibitor that showed superior anti-inflammatory (AI) activity (ID₅₀ = 2.5 mg/kg) relative to celecoxib (ID ₅₀ = 10.8 mg/kg). This initial study was extended to include the design of a structurally related group of acyclic triaryl (Z)-olefins possessing an acetoxy (OAc) substituent at the para-position of the C-1 phenyl ring that is cis to a C-2 4-methylsulfonylphenyl substituent. COX-1 and COX-2 inhibition studies showed that (Z)-1-(4-acetoxyphenyl)-1-phenyl-2-(4-methylsulfonylphenyl) but-1-ene [(Z)-13b] is a potent (COX-1 IC₅₀ = 2.4 μM; COX-2 IC₅₀ = 0.03 μM), and selective (COX-2 SI = 81), COX-2 inhibitor which is a potent AI agent (ID₅₀ = 4.1 mg/kg) with equipotent analgesic activity to celecoxib. A molecular modeling (docking) study showed that the SO₂Me substituent of (Z)-13b inserts deep inside the 2°-pocket of the COX-2 active site, where one of the O-atoms of SO ₂ group undergoes a H-bonding interaction with Phe⁵¹⁸. The p-OAc substituent on the C-1 phenyl ring is oriented in a hydrophobic pocket comprised of Met⁵²², Gly⁵²⁶, Trp³⁸⁷, Tyr ³⁴⁸, and Tyr³⁸⁵, and the C-2 ethyl substituent is oriented towards the mouth of the COX-2 channel in the vicinity of amino acid residues Arg¹²⁰, Leu⁵³¹, and Val³⁴⁹. Structure-activity data acquired indicate that a (Z)-olefin having cis C-1 4-acetoxyphenyl (phenyl) and C-2 4-methylsulfonylphenyl substituents, and a C-1 phenyl substituent in conjunction with either a C-2 hydrogen or short alkyl substituent provides a novel template to design acyclic olefinic COX-2 inhibitors that, like aspirin, have the potential to acetylate COX-2.

Full text of DOI:10.1016/j.bmc.2004.08.021

Bioorganic & Medicinal Chemistry 12 (2004) 5929–5940
Design and synthesis of acyclic triaryl (Z)-olefins:
a novel class of cyclooxygenase-2 (COX-2) inhibitors
Md. Jashim Uddin, P. N. Praveen Rao and Edward E. Knaus*
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8
Received 22 July 2004; revised 13 August 2004; accepted 13 August 2004
Available online 11 September 2004
Abstract—A group of acyclic 2-alkyl-1,1-diphenyl-2-(4-methylsulfonylphenyl)ethenes was designed for evaluation as selective cyclo-
oxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition structure–activity studies identified 1,1-diphenyl-2-
(4-methylsulfonylphenyl)hex-1-ene as a highly potent (IC50 = 0.014lM), and an extremely selective [COX-2 selectivity index
(SI) >7142], COX-2 inhibitor that showed superior anti-inflammatory (AI) activity (ID50 = 2.5mg/kg) relative to celecoxib
(ID50 = 10.8mg/kg). This initial study was extended to include the design of a structurally related group of acyclic triaryl (Z)-olefins
possessing an acetoxy (OAc) substituent at the para-position of the C-1phenyl ring that is cis to a C-2 4-methylsulfonylphenyl sub-
stituent. COX-1and COX-2 inhibition studies showed that ( Z)-1-(4-acetoxyphenyl)-1-phenyl-2-(4-methylsulfonylphenyl)but-1-ene
[(Z)-13b] is a potent (COX-1IC 50 = 2.4lM; COX-2 IC50 = 0.03lM), and selective (COX-2 SI = 81), COX-2 inhibitor which is a
potent AI agent (ID50 = 4.1mg/kg) with equipotent analgesic activity to celecoxib. A molecular modeling (docking) study showed
that the SO2Me substituent of (Z)-13b inserts deep inside the 2ꢀ-pocket of the COX-2 active site, where one of the O-atoms of SO2
group undergoes a H-bonding interaction with Phe518. The p-OAc substituent on the C-1phenyl ring is oriented in a hydrophobic
pocket comprised of Met522, Gly526, Trp387, Tyr348, and Tyr385, and the C-2 ethyl substituent is oriented towards the mouth of the
COX-2 channel in the vicinity of amino acid residues Arg120, Leu531, and Val349. Structure–activity data acquired indicate that a (Z)-
olefin having cis C-14-acetoxyphenyl (phenyl) and C-2 4-methylsulfonylphenyl substituents, and a C-1phenyl substituent in con-
junction with either a C-2 hydrogen or short alkyl substituent provides a novel template to design acyclic olefinic COX-2 inhibitors
that, like aspirin, have the potential to acetylate COX-2.
ꢁ 2004 Elsevier Ltd. All rights reserved.
1. Introduction
tive COX-2 inhibitors celecoxib (1),4 rofecoxib (2),5
and valdecoxib (3)6 (Fig. 1) having anti-inflammatory
and analgesic activity with less gastrointestinal and renal
toxicity.7,8 For example, the COX-2 binding site pos-
sesses an additional 2ꢀ-pocket that is absent in COX-1,
which is highly relevant to the design of selective
COX-2 inhibitors. This COX-2 2ꢀ-pocket arises due to
a conformational change at Tyr355 that is attributed to
the presence of Ile523 in COX-1relative to Val 523 having
a smaller side chain in COX-2.2 It has also been reported
that replacement of His513 in COX-1by Arg 513 in COX-
2 plays a key role with respect to the H-bond network in
the COX-2 binding site. Access of ligands to the 2ꢀ-
pocket of COX-2 is controlled by histidine (His90), glu-
tamine (Gln192), and tyrosine (Tyr355).9 Interaction of
Arg513 with the bound drug is a requirement for time-
dependent inhibition of COX-2.10 The vast majority of
selective COX-2 inhibitors investigated, or in clinical
use, possess a heterocyclic or carbocyclic central ring
scaffold having two vicinal aryl moieties.11 In a different
context, the nonselective COX inhibitor aspirin (4) is un-
ique because of its ability to inhibit COX isozymes
The constitutive COX-1isozyme catalyzes the biosyn-
thesis of prostaglandins that are necessary for important
physiological maintenance functions that include gastro-
intestinal cytoprotection and vascular homeostasis. In
contrast, inducible COX-2 is expressed predominately
in activated cells, most often in response to mediators
of inflammation. Thus, a selective COX-2 inhibitor
allows the desired synthesis of cytoprotective prosta-
glandins, in conjunction with a simultaneous inhibition
of proinflammatory prostaglandin synthesis, thereby
reducing dyspepsia and ulceration.1 Insights into the dif-
ferences between the binding sites of COX-1and COX-2
obtained from X-ray crystal structure data,2,3 provided
useful guidelines that facilitated the design of the selec-
Keywords: Cyclooxygenase-2; Stereoselective McMurry reaction; Acy-
clic triaryl (Z)-olefins.
*
Corresponding author. Tel.: +1780 492 5993; fax: +1780 492
1217; e-mail: eknaus@pharmacy.ualberta.ca
0968-0896/$ - see front matter ꢁ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2004.08.021

5930
Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
Me
MeS
O
+
R1
O
6a, R1 = Me
O
6b, R1 = Et
H2NO2S
N
MeO2S
7
6c, R1 = n-Butyl
O
N
6d, R1 = n-Hexyl
6e, R1 = n-Heptyl
6f, R1 = n-Nonyl
6g, R1 = n-Pentadecyl
CF3
Celecoxib (1)
Rofecoxib (2)
a
O
C
N
Me
O
H2NO2S
O
HO2C
MeS
Me
Aspirin (4)
Valdecoxib (3)
R1
O
C
Me
O
8, R1 = Me, Et, n-Butyl, n-Hexyl,
n-Heptyl, n-Nonyl, n-Pentadecyl
S
b
9a, R1 = Me
Me
APHS (5)
9b, R1 = Et
9c, R1 = n-Butyl
9d, R1 = n-Hexyl
9e, R1 = n-Heptyl
9f, R1 = n-Nonyl
9g, R1 = n-Pentadecyl
MeO2S
Figure 1. Representative cyclooxygenase (COX) inhibitors.
irreversibly by transferring its acetyl group to Ser530 as a
covalent modifier.12 The beneficial therapeutic effects of
aspirin can be attributed to the acetylation of COX-2,
while its anti-thrombotic and ulcerogenic effects are
due to acetylation of COX-1. These properties were
exploited in the design of the aspirin analog o-(acetoxy-
phenyl)hept-2-ynyl sulfide (5, APHS) that selectively
acetylated, and irreversibly inactivated, COX-2.13,14 Re-
cently, we designed a new class of highly potent and
selective COX-2 inhibitors having an acyclic triaryl olef-
inic structure (9).15 As part of our ongoing program to
develop new drug design concepts, we now provide com-
plete details of this initial study,15 and also report a
group of related acyclic triaryl (Z)-olefins, possessing a
4-acetoxyphenyl moiety, from which a number of com-
pounds (13) have been identified that exhibit highly po-
tent and selective COX-2 inhibition.
R1
Scheme 1. Reagents and conditions: (a) Zn, TiCl4, THF, reflux 4.5h;
(b) Oxoneꢂ (potassium peroxymonosulfate), MeOH, THF, H2O,
25ꢀC, 15h.
mediate (Z)-olefins 12 (R1 = H, Et, n-butyl, n-heptyl, n-
pentadecyl, R2 = H, OH) were generated in situ using
a (Z)-selective McMurry olefination reaction23 by
Zn–TiCl4 catalyzed reductive cross-coupling of the
respective 4-(methylsulfonyl)alkanophenone (10) with
4-hydroxybenzophenone (11, R2 = OH). Subsequent
acetylation24 of the 4-hydroxyphenyl intermediate 12 af-
forded the target 4-acetoxyphenyl (Z)-olefin product 13
(R1 = H, Et, n-butyl, n-heptyl, n-pentadecyl) in 67–72%
overall yield (Scheme 2). Alternatively, when 4-(methyl-
thio)propiophenone (6, R1 = Et) was used, in place of
4-(methylsulfonyl)propiophenone (10, R1 = Et) which
gave (Z)-13b as the sole product, a mixture of the
isomeric (E)- and (Z)-13b olefins (ratio of 1:4) was
obtained. The structure of the starting 4-methyl-
thiophenyl ketones 6, the cross-coupled products
1,1,2-triaryl-2-alkyl-1-ethenes (9), 4-methylsulfonylphe-
nyl carbonyl compounds 10, the isolated olefins 12a
and 12b, and final target (Z)-1-(4-acetoxyphenyl)-1-phe-
nyl-2-(4-methylsulfonylphenyl)-2-alkyl-1-ethenes (13a–e)
were consistent with their spectral and microanalytical
data. The stereochemistry of (Z)-13e (R1 = n-penta-
decyl) was confirmed by 1H NMR difference nuclear
Overhauser enhancement (NOE) studies (Fig. 2). The
percent NOE enhancements (CDCl3, 22ꢀC) of 6.4%
and 3.2% for the respective H-2 (d 6.84) and H-3 (d
6.76) protons of the 4-acetoxyphenyl substituent upon
irradiation of the H-3 (d 7.74) proton of the 4-methyl-
2. Chemistry
Using a McMurry olefination reaction, intermediate
olefins 8 (R1 = alkyl) were generated in situ by reductive
cross-coupling of the respective ketone 6, prepared by
Friedel–Crafts acylation of thioanisole,16–19 and benzo-
phenone 7.20 Subsequent oxidation of the 4-methyl-
thiophenyl olefins 8 with Oxoneꢂ (potassium peroxy-
monosulfate)21 afforded the target 4-methylsulfonylphe-
nyl olefins 9 (R1 = Me, Et, n-butyl, n-pentyl, n-hexyl,
n-heptyl, n-nonyl, n-pentadecyl) in 62–76% yield
(Scheme 1). On the other hand, carbonyl compounds
10 (R1 = H, Et, n-butyl, n-heptyl, n-pentadecyl) were
prepared by oxidation of the respective methylthio com-
pounds using either Oxoneꢂ or m-CPBA.22 The inter-
21

Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5931
R2
pinacolic intermediate formed by homolytic coupling
of a radical anion species generated from reduction of
the two carbonyl compounds25 prior to subsequent
demetallation and deoxygenation reactions.26 In this re-
gard, the ꢀphenoxy-Ti-sulfoneꢁ induction plays the key
role for (Z)-stereoselection by forcing the phenoxy and
sulfone moieties to be positioned on the same side cis
to each other.23
MeO2S
O
+
R1
O
10a, R1 = H
10b, R1 = Et
10c, R1 = n-Butyl
10d, R1 = n-Heptyl
10e, R1 = n-Pentadecyl
11, R2 = H, OH
3. Results and discussion
In a preliminary study regarding the design of acyclic
triaryl olefins,15 we reported that simple acyclic olefins
exhibit selective COX-2 inhibition when (i) two geminal
unsubstituted phenyl substituents are present at the C-1
position, (ii) a 4-methylsulfonylphenyl substituent is lo-
cated at the C-2 position, and (iii) a n-alkyl substituent
of appropriate chain length is attached to the C-2 posi-
tion. Initial structure–activity studies, where the length
of the C-2 alkyl substituent was varied, showed that
maximal COX-2 potency (IC50 = 0.014lM) and COX-
2 selectivity [selectivity index (SI) > 7142] was exhibited
by compound 9c having a C-2 n-butyl substituent. In
contrast, compound 9g having a longer hydrophobic
C-2 n-pentadecyl substituent did not inhibit COX-1or
COX-2 (IC50 > 1 00lM) (see Table 1).
a
R2
MeO2S
R1
12, R1 = H, Et, n-Butyl, n-Heptyl, n-Pentadecyl;
R2 = H, OH
b
O
C
O
Me
The nonselective COX-2 inhibitor aspirin (4, COX-1
IC50 0.35lM, COX-2 IC50 2.4lM; COX-2 SI = 0.14)
is a 10-fold more potent inhibitor of COX-1 than
COX-2 (see Table 1). Marnett and co-workers reported
the aspirin derivative, o-(acetoxyphenyl)hept-2-ynyl sul-
fide (5, APHS), is a selective inhibitor of COX-2 that
acetylates the hydroxyl group of Ser530 in the COX-2
binding site.13,14 These structure–activity data prompted
us to investigate the effect of an acetoxy substituent on
COX-2 selectivity and potency for a group of 4-acetoxy-
phenyl (Z)-olefins 13 (R1 = H, Me, Et, n-butyl, n-heptyl,
n-pentadecyl), that are analogs of the acyclic triaryl
olefins 9 reported previously as a letter.15 Accordingly,
an initial study showed that the p-acetoxyphenyl olefin
(E,Z)-13a (R1 = H, isomeric ratio = 1:6.4) is a potent
inhibitor of COX-2 (COX-1IC 50 = 11.1lM; COX-2
IC50 = 0.07lM; COX-2 SI = 158), that is 26-fold more
potent and 3-fold more selective than the parent triaryl
olefin 12a (R1 = R2 = H; COX-1IC 50 > 1 00lM; COX-
2 IC50 = 1 .8lM; COX-2 SI > 54). Replacement of the
vinyl hydrogen at the C-2 position of (E,Z)-13a by an
ethyl substituent [(Z)-13b (R1 = Et)], increased COX-2
potency and decreased COX-1selectivity slightly
(COX-1IC 50 = 2.4lM, COX-2 IC50 = 0.03lM; COX-2
SI = 81). In comparison, (Z)-13b was a 40-fold more
potent, and 3-fold more selective, inhibitor of COX-2
than the parent triaryl olefin 9b (R1 = Et; COX-1
13a, R1 = H
13b, R1 = Et
MeO2S
13c, R1 = n-Butyl
13d, R1 = n-Heptyl
13e, R1 = n-Pentadecyl
R1
Scheme 2. Reagents and conditions: (a) Zn, TiCl4, THF, reflux 4.5h;
(b) AcCl, TEA, ether, 25ꢀC, 1.5h.
3.2 %
6.4 %
H
O
C
H
H
H H
MeO2S
O
Me
n-C14H29
H
H
8.2 %
Figure 2. Some NOE determinations to determine the stereochemistry
of the olefinic substituents for (Z)-13e in CDCl3 at 22ꢀC.
sulfonyl moiety indicate that these two aryl moieties are
cis to each other [(Z)-stereoisomer]. This (Z)-stereo-
chemical assignment for 13e is also consistent with the
observation that irradiation of the C@CACH2 (d 2.45)
protons resulted in a 8.2% enhancement of the C-1
ortho-phenyl (d 7.36) protons of the unsubstituted cis
phenyl ring. In regard to the stereochemical aspects of
this (Z)-selective olefination reaction, it has been pro-
posed that the (Z)-isomer arises from a consecutive
induction by the active Tiꢀ surface to the polydentate
IC50 = 31.6lM,
COX-2
IC50 = 1 .2lM;
COX-2
SI = 25). It is noteworthy that the 4-acetoxyphenyl ole-
fin (Z)-13b is about 2.3-fold more potent than celecoxib
(1) and 16-fold more potent than rofecoxib (2) (Table 1).
A comparative study showed that (E,Z-13b) (R1 = Et,
isomeric ratio = 1:4) is a selective inhibitor of COX-2
(COX-1IC 50 > 1 00lM; COX-2 IC50 = 3.2lM; COX-2
SI > 31), but 100-fold less potent than (Z)-13b. Further

Table 1. In vitro COX-1/COX-2 enzyme inhibition assay data for 9a–g, 12a–b, 13a–e, 14, and in vivo anti-inflammatory and analgesic activity assay data for 9c–d, 13b, and 14
R2
MeO2S
R1
R1
14
9a-g or 12a-b or 13a-e
COX-2 IC50 (lM)b
3 a
˚
Vol (A )
Compound
R1
R2
COX-1IC (lM)b
COX-2 SIc
AI activityd ID50 (mg/kg)
Analgesic activitye
%Inhibition (30min) %Inhibition (1h)
50
9a
9b
Me
Et
H
319
337
369
403
420
453
555
303
343
347
380
380
414
464
599
318
298
266
153
0.47
31.6
>100
1.7
0.63
1.2
0.74
25
––
––
––
––
––
––
H
9c
9d
n-C4H9
n-C6H13
n-C7H15
n-C9H19
n-C15H31
H
H
0.014
0.03
0.15
1.1
>7142
54
2.5
1.6
––
49.3 9.0
52.4 6.0
54.3 7.5
61.9 12.5
H
9e
H
>100
>100
>100
>100
31.6
11.1
2.4
>666
91
––
––
––
––
––
––
––
––
––
––
––
––
9f
9g
H
––
––
H
>100
1.8
1.9
1
12a
H
>54
16
––
––
(Z)-12b
(E,Z)-13af
(Z)-13b
(E,Z)-13bg
(Z)-13c
(Z)-13d
(Z)-13e
14
Et
OH
OAc
OAc
OAc
OAc
OAc
OAc
––
H
Et
0.07
0.03
3.2
158
814.1
>31
0.14
––
43.0 7.0
––
––
62.7 9.7
Et
>100
4.6
––
––
––
––
n-C4H9
n-C7H15
n-C15H31
n-C4H9
––
31.6
3.17.9
>50
0.39
>50
7.9
––
––
––
1––
––
––
>100
33.1
>100
0.35
>12
472
22.3
10.8
––
55.5 6.8
69.3 12.1h
44.4 6.8
79.5 2.0h
––
Celecoxib
Rofecoxib
Aspirin
––
––
0.07
0.50
2.4
––
––
>200
0.14
––
––
––
––
––
a The volume of the molecule, after minimization using PM3 geometry optimization, was calculated using the ALCHEMY 2000 program.
b The in vitro test compound concentration required to produce 50% inhibition of COX-1or COX-2. The result (IC 50, lM) is the mean of two determinations.
c Selectivity Index (SI) = COX-1IC 50/COX-2 IC50
.
d Inhibitory activity in a carrageenan-induced rat paw edema assay. The results are expressed as the ID50 value (mg/kg) at 3h after oral administration of the test compound.
e Inhibitory activity in the rat 4% NaCl-induced abdominal constriction assay. The results are expressed as the mean % inhibition value SEM (n = 4) following a 5mg/kg oral dose of the test compound.
f Ratio (E):(Z) = 1:6.4.
g Ratio (E):(Z) = 1:4.
h Oral dose (50mg/kg).

Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5933
elongation of the alkyl substituent chain length at C-2 to
n-butyl [(Z)-13c] and n-heptyl [(Z)-13d] decreased COX-
potency and selectivity. The C-2 n-pentadecyl
2
compound (Z)-13e was an inactive inhibitor of both
COX-1and COX-2 (IC 50 > 50lM). It is noteworthy that
replacement of the C-1phenyl substituent in compound
9c (R1 = n-Bu) and 9e (R1 = n-heptyl) by a 4-acetoxy-
phenyl substituent in the respective compounds (Z)-
13c and (Z)-13d reduced COX-2 potency and selectivity
dramatically. On the other hand, the C-14-acetoxyphe-
nyl compound (Z)-13b was a more potent and selective
COX-2 inhibitor than the corresponding C-14-hydroxy-
phenyl compound (12b). These structure-activity data
suggest that the acyclic olefin (Z)-13b, which possesses
the best combination of COX-2 potency and selectivity
among the group of compounds 13, should inhibit the
synthesis of inflammatory prostaglandins via the COX
pathway at sites of induced inflammation.
Aspirin treatment of human prostaglandin endoperox-
ide H synthase (hPGHS-1, hCOX-1) expressed in cos-1
cells causes a time-dependent inactivation of oxygenase
activity. In contrast, treatment of PGHS-2 (COX-2)
produced an enzyme that retained oxygenase activity,
but which formed the unnatural (15R)-hydroxy-
5,8,11,13-eicosatetraenoic acid [(15R)-HETE] exclu-
sively that is a precursor of leukotrienes via the 5-lip-
oxygenase (5-LO) pathway rather than prostaglandin
H2 (PGH2) produced via the cyclooxygenase pathway.
The Km values for arachidonate of native and aspirin-
treated hPGHS-2 were similar suggesting that arachido-
nate binds to both aspirin-treated and native hPGHS-2
in a similar manner.27 A recent study has shown that
(15R)-HETE inhibits the release of the potent inflamma-
tory mediator LTB4 from blood polymorphonuclear
cells via the 5-LO pathway.28 Based on these reports,
it is possible that the 4-acetoxyphenyl (Z)-olefins 13a–
b, in addition to inhibiting COX-2, could also acetylate
COX-2 to produce (15R)-HETE that would prevent the
formation of inflammatory leukotrienes such as LTB4
via the 5-LO pathway. Since the 4-acetoxyphenyl olefin
(Z)-13b may undergo in vivo bioconversion by esterases
to the 4-hydroxylphenyl olefin (Z)-12b (R1 = Et,
R2 = OH), the COX-1and COX-2 enzyme inhibition
activities of (Z)-12b were determined where the assay
showed a reduction in potency (COX-1IC 50 = 31.6lM,
COX-2 IC50 = 1 .9lM; COX-2 SI = 16) (Table 1). The
combined volume of the COX-2 primary and secondary
Figure 3. Docking of (Z)-13b in the binding site of murine COX-2.
Hydrogen atoms of the amino acid residues have been removed to
improve clarity.
His90. One of the O-atoms of SO2Me moiety forms a H-
bond with an amide hydrogen (NH) of Phe518 (dis-
˚
tance = 2.06A), whereas the other O-atom is closer to
the NH2 of Arg513 (distance of 5.54A). The C-14-acet-
˚
oxyphenyl substituent, that is cis to the C-2 4-methyl-
sulfonylphenyl substituent is oriented toward a hydro-
phobic pocket comprised of Met522, Gly526, Trp387
,
Tyr348, and Tyr385 at the apex of the binding site.
The distance between the center of C-14-acetoxyphenyl
ring at the olefinic C-1position and the OH of Ser530 is
˚
about 6.19A, and this moiety is within van der Waalꢁs
384
˚
contact range (distance less than 5A) of Leu
and
Tyr385. The OH of Ser530 is about 6.55A from the C-
˚
atom of the C@O, and the C@O oxygen atom forms a
H-bond with the OH of Tyr385 (distance = 3.08A). This
˚
H-bonding of Tyr385 with the C@O oxygen atom could
be beneficial for the acetylation of Ser530 in the
active site of COX-2. This possibility is based on the
facts that (i) Tyr385 hydrogen bonds to the acetyl group
of aspirin, it orients the acetoxy substituent of aspirin,
which it acetylates, and (ii) this H-bonding interaction
increases its reactivity by stabilizing the incipient nega-
tive charge of the tetrahedral intermediate of acetyla-
tion.30 The unsubstituted C-1phenyl ring that is cis to
the C-2 ethyl substituent is oriented toward the mouth
3
˚
binding site is 394A , which is 25% larger than the
3
COX-1binding site (316A ).29 In this regard, it is possi-
˚
ble that (Z)-13b (R1 = Et) with a molecular volume of
3
3
˚
˚
380A may easily enter the COX-2 active site (394A )
with a favorable orientation to induce COX-2 inhibitory
activity. In contrast, the 4-acetoxyphenyl olefin (Z)-13e
(R1 = n-pentadecyl) having a molecular volume of
3
599A is likely too large to insert into the COX-2 active
of the channel comprised of Ser530, Leu531, and Ala527
The distance between the center of the C-1phenyl ring
.
˚
site resulting in a loss of COX-2 inhibitory activity. A
molecular modeling study of the 4-acetoxyphenyl olefin
(Z)-13b docked in the COX-2 active site (Fig. 3) shows
that (Z)-13b binds in the primary binding-site such that
the p-SO2Me substituent on the C-2 phenyl ring inserts
cis to the C-2 ethyl substituent and the OH of Ser530 is
˚
about 4.58A. The C-2 ethyl substituent is oriented
towards a pocket comprised of Tyr355, Arg120, Leu531
,
and Val349 at the mouth of the COX-2 active site. This
computational study shows that the stereochemical dis-
position of aryl, alkyl, or acetoxy substituents about the
˚
into the 2ꢀ-pocket present in COX-2 (distance = 1.76A)
undergoing interactions with Phe518, Arg513, Gln192, and

5934
Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
C@C bond controls the optimal protein–ligand binding
interactions in the active site of COX-2.
CDCl3 was dried using molecular sieves (type 3A, 1.6mm
pellets), treated with neutral alumina to remove acidic
impurities, and degassed by passage of dry argon gas at
22ꢀC just prior to use. Molecular tumbling time was not
altered. Elemental analysis (EA) were performed for C,
H (Micro-analytical Service Laboratory, Department of
Chemistry, University of Alberta). Silica gel column chro-
matography was performed using Merck silica gel 60
ASTM (70–230mesh). The starting carbonyl compounds
6a–c (R1 = Me, Et, n-butyl)16–18 and 10a–b (R1 = H,
Et)22,23 were prepared using literature methods. All the
other reagents were purchased from the Aldrich Chemical
Company (Milwaukee, WI) and used without further
purification. Male Sprague–Dawley rats, used in the
anti-inflammatory-analgesic screens, were purchased from
Animal Health Services at the University of Alberta, and
experiments were carried out using protocols approved
by the Animal Welfare Committee, University of Alberta.
Pharmacological studies were carried out to assess the
in vivo anti-inflammatory (AI) and analgesic activity of
some of the most potent and selective COX-2 inhibitors
[9c,d, (Z)-13b] based on in vitro enzyme inhibition data
(Table 1). In a carrageenan-induced rat paw edema assay
model, the hex-1-ene (9c, ID50 = 2.5mg/kg) and oct-1-ene
(9d, ID50 = 1.6mg/kg) compounds having a C-1 phenyl
substituent, and the but-1-ene having a C-1 4-acetoxyphe-
nyl moiety [(Z)-13b, ID50 = 4.1mg/kg] all exhibited supe-
rior AI activity relative to the reference drug celecoxib
(ID50 = 10.8mg/kg). It is also noteworthy that the parent
compound 1,1,2-triphenylhex-1-ene 14, lacking the tradi-
tional MeSO2 COX-2 pharmacophore, also exhibited
moderate AI potency (ID50 = 22.3mg/kg). In a rat model
4% NaCl-induced abdominal constriction assay, a 5mg/
kg po dose of 9c,d, or (Z)-13b exhibited good analgesic
activities (43–63% range), that are comparable to celec-
oxib, at 30 or 60min post drug administration.
5.1. General procedure for the synthesis of 4-(methyl-
thio)alkanophenones (6d–h)
The alkanoyl chloride (14.4mmol) was added drop wise
to a stirred suspension of AlCl3 (1.76g, 13.2mmol) in
chloroform (10mL). Thioanisole (1.38g, 11.1mmol)
was added at 0ꢀC and the reaction was allowed to pro-
ceed with stirring for 1.5h at 25ꢀC. Water (10mL) was
added slowly at 0ꢀC, the organic layer was separated,
and the aqueous layer was extracted with EtOAc
(3 · 10mL). The combined organic fractions were
washed with water (10mL), the organic fraction was
dried (Na2SO4), and the solvent was removed in vacuo.
The residue was recrystallized from CH2Cl2–n-hexane
(1:9, v/v) to afford the respective product 6d–h. Some
physical, spectroscopic and microanalytical data for
products 6d–h are listed below.
4. Conclusions
Novel acyclic 2-alkyl-1,1-diphenyl-2-(4-methylsulfonyl-
phenyl)ethenes having a short 2-alkyl substituent,
such as 1,1-diphenyl-2-(4-methylsulfonylphenyl)hex-1-
ene (9c), exhibit optimal COX-2 inhibitory potency
(IC50 = 0.014lM) and selectivity (SI) > 7142]. A group
of structurally related acyclic (Z)-1,1,2-triarylethenes
(13) was also designed in which a C-14-acetoxyphenyl
substituent is cis to a C-2 4-methylsulfonylphenyl substit-
uent. Compounds having a C-2 hydrogen (13a), or ethyl
(13b), substituent exhibited optimal COX-2 inhibitory
potency (IC50 = 0.03–0.07lM range) and selectivity
(SI = 81–158 range). A molecular modeling study
showed that the SO2Me moiety of (Z)-13b inserts deep
inside the COX-2 2ꢀ-pocket and that the C@O oxy-
gen atom of the acetoxy substituent is H-bonding to
Tyr385, which could potentially enhance its ability to
acetylate Ser530 like aspirin. The structure–activity rela-
tionships acquired show that appropriately substituted
acyclic (Z)-olefins have the necessary geometry to pro-
vide potent and selective inhibition of the COX-2 iso-
zyme, and to exhibit excellent AI and analgesic activities.
5.2. 4-(Methylthio)hexanophenone (6d)
Yield, 60%; white plates; mp 70–72ꢀC; IR (film): 1677
(C@O) cmÀ1
;
1H NMR (CDCl3): d 0.91(t, 3H,
J = 7.0Hz, CH2CH3), 1.31–1.38 [m, 4H, (CH2)2], 1.70–
1.75 (m, 2H, CH2), 2.52 (s, 3H, SCH3), 2.91(t, 2H,
J = 7.3Hz, COCH2), 7.26 (d, 2H, J = 8.5Hz, 4-methyl-
thiophenyl H-3, H-5), 7.87 (d, 2H, J = 8.5Hz, 4-methyl-
thiophenyl H-2, H-6). Anal. Calcd for C13H18OS: C,
70.22; H, 8.16. Found: C, 70.03; H, 8.33.
5. Experimental
5.3. 4-(Methylthio)heptanophenone (6e)
Melting points were determined using a Thomas–Hoover
capillary apparatus and are uncorrected. Infrared (IR)
spectra were recorded as films on NaCl plates using a Nic-
Yield, 96%; white needles; mp 58–60ꢀC; IR (film): 1667
(C@O) cmÀ1
;
1H NMR (CDCl3): d 0.81(t, 3H,
J = 7.0Hz, CH2CH3), 1.21–1.26 [m, 6H, (CH2)3], 1.59–
1.67 (m, 2H, CH2), 2.45 (s, 3H, SCH3), 2.84 (t, 2H,
J = 7.3Hz, COCH2), 7.19 (d, 2H, J = 8.5Hz, 4-methyl-
thiophenyl H-3, H-5), 7.80 (d, 2H, J = 8.5Hz, 4-methyl-
thiophenyl H-2, H-6). Anal. Calcd for C14H20OS: C,
71.14; H, 8.53. Found: C, 71.07; H, 8.76.
1
olet 550 Series II Magna FT-IR spectrometer. H NMR
and 13C NMR spectra were recorded on a Bruker AM-
300 spectrometer, where J (coupling constant) values are
estimated in Hz. 13C NMR spectra were acquired using
the J modulated spin echo technique where methyl and
methine carbons appear as positive peaks and methylene
and quaternary carbon resonances appear as negative
peaks. The NOE studies were performed under steady-
state conditions using the Bruker NOE DIFF.AU soft-
ware program (signal:noise ratio of 136 for a single pulse).
5.4. 4-(Methylthio)octanophenone (6f)
Yield, 72%; white solid; mp 66–68ꢀC; IR (film): 1682
(C@O) cmÀ1
;
1H NMR (CDCl3): d 0.80 (t, 3H,

Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5935
J = 7.0Hz, CH2CH3), 1.15–1.35 [m, 8H, (CH2)4], 1.60–
1.70 (m, 2H, CH2), 2.45 (s, 3H, SCH3), 2.84 (t, 2H,
J = 7.3Hz, CH2), 7.19 (d, 2H, J = 8.5Hz, 4-methylthio-
phenyl H-3, H-5), 7.80 (d, 2H, J = 8.5Hz, 4-methylthio-
phenyl H-2, H-6). Anal. Calcd for C15H22OS: C, 71.95;
H, 8.86. Found: C, 71.48; H, 8.97.
ane–EtOAc (2:1, v/v) as eluant to afford the respective
4-methylsulfonylphenyl olefin 9a–g. The physical, spect-
roscopic, and microanalytical data for products 9a–g are
listed below.
5.8. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)prop-1-ene
(9a)
5.5. 4-(Methylthio)decanophenone (6g)
Yield, 62%; white solid; mp 154–156ꢀC; IR (film): 1143,
1316 (SO2) cmÀ1 1H NMR (CDCl3): d 2.16 (s, 3H,
;
Yield, 72%; white needles; mp 80–82ꢀC; IR (film): 1682
(C@O) cmÀ1
;
1H NMR (CDCl3): d 0.88 (t, 3H,
CH3), 3.02 (s, 3H, SO2CH3), 6.85–6.88 (m, 2H, phenyl
hydrogens), 7.04–7.07 (m, 3H, phenyl hydrogens),
7.23–7.38 (m, 7H, phenyl hydrogens and 4-methylsulfon-
ylphenyl H-2, H-6), 7.72 (d, 2H, J = 8.5Hz, 4-methyl-
sulfonylphenyl H-3, H-5). Anal. Calcd for
C22H20O2SÆ1/3H2O: C, 74.54; H, 5.83. Found: C,
74.31; H, 5.62.
J = 7.0Hz, CH2CH3), 1.27–1.33 [m, 12H, (CH2)6],
1.67–1.74 (m, 2H, CH2), 2.53 (s, 3H, SCH3), 2.91(t,
2H, J = 7.3Hz, COCH2), 7.27 (d, 2H, J = 8.5Hz, 4-
methylthiophenyl H-3, H-5), 7.88 (d, 2H, J = 8.5Hz, 4-
methylthiophenyl H-2, H-6). Anal. Calcd for
C17H26OS: C, 73.33; H, 9.41. Found: C, 73.15; H, 9.54.
5.6. 4-(Methylthio)hexadecanophenone (6h)
5.9. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)but-1-ene
(9b)
Yield, 69%; white solid; mp 88–90ꢀC; IR (film): 1663
(C@O) cmÀ1
;
1H NMR (CDCl3): d 0.88 (t, 3H,
Yield, 70%; white solid; mp 124–126ꢀC; IR (film): 1155,
J = 7.0Hz, CH2CH3), 1.26–1.33 [m, 24H, (CH2)12],
1.69–1.74 (m, 2H, CH2), 2.53 (s, 3H, SCH3), 2.91(t,
2H, J = 7.3Hz, COCH2), 7.27 (d, 2H, J = 8.5Hz, 4-
methylthiophenyl H-3, H-5), 7.87 (d, 2H, J = 8.5Hz, 4-
methylthiophenyl H-2, H-6). Anal. Calcd for
C23H38OSÆ1/2H2O: C, 74.33; H, 10.50. Found: C,
74.06; H, 10.89.
1334 (SO2) cmÀ1 1H NMR (CDCl3): d 0.95 (t, 3H,
;
J = 7.3Hz, CH2CH3), 2.53 (q, 2H, J = 7.3Hz,
CH2CH3), 3.03 (s, 3H, SO2CH3), 6.86–6.88 (m, 2H, phe-
nyl hydrogens), 7.01–7.16 (m, 3H, phenyl hydrogens),
7.24–7.32 (m, 7H, phenyl hydrogens and 4-methylsulfon-
ylphenyl H-2, H-6), 7.73 (d, 2H, J = 8.4Hz, 4-methyl-
sulfonylphenyl H-3, H-5); 13C NMR (CDCl3): d 13.5
(CH2C3), 28.8 (C2CH3), 44.5 (SO2C3), 126.4, 126.9,
127.0, 127.6, 128.2, 129.2, 130.5, 130.6 (Carom–H),
137.9, 140.2, 141.1, 141.9, 142.6, 148.6 (Carom–C;
Colefin–C; Carom–S). Anal. Calcd for C23H22O2SÆ1/
4H2O: C, 75.26; H, 6.13. Found: C, 75.48; H, 6.01.
5.7. General procedure for the synthesis of 1,1-diphenyl-2-
(4-methylsulfonylphenyl)alkyl-1-enes (9a–g)
TiCl4 (1.83mL, 13mmol) was added dropwise to a stir-
red suspension of Zn powder (1.7g, 26.5mmol) in dry
THF (30mL), under Ar, at À10ꢀC, and after the addi-
tion was completed the reaction mixture was refluxed
for 2h. A solution of the respective 4-(methylthio)alk-
anophenone (6a–g, 3.3mmol) and benzophenone (7,
0.61g, 3.3mmol) in THF (65mL) were added to a
cooled suspension of the titanium reagent at 0ꢀC, and
the reaction mixture was refluxed for 2.5h. After cooling
to 25ꢀC, the reaction mixture was poured into a 10%
aqueous K2CO3 solution (100mL), this mixture was stir-
red vigorously for 5min, and the dispersed insoluble
material was removed by vacuum filtration through a
pad of Celite 545. The organic layer was separated
and the aqueous layer was extracted with EtOAc
(3 · 50mL). The combined organic fractions were
washed with water (10mL), the organic fraction was
dried (Na2SO4), and the solvent was removed in vacuo
to afford the respective 4-methylthiophenyl olefinic
intermediate 8a–g, which was dissolved in THF–MeOH
(1:1, v/v; 10mL). A solution of Oxoneꢂ (potassium per-
oxymonosulfate) (4.06g, 6.6mmol) in water (20mL) was
added drop wise at 0ꢀC, the reaction was allowed to
proceed for 15h at 25ꢀC with stirring, and the solvent
was removed in vacuo. Water (20mL) was added to
the residue, this mixture was extracted with EtOAc
(3 · 30mL), the combined organic fractions were
washed with water (10mL). The organic fraction was
dried (Na2SO4), and the residue obtained was purified
by silica gel flash column chromatography using n-hex-
5.10. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)hex-1-ene
(9c)
Yield, 72%; white solid; mp 79–81ꢀC; IR (film): 1153,
1327 (SO2) cmÀ1 1H NMR (CDCl3): d 0.79 (t, 3H,
;
J = 7.0Hz, CH2CH3), 1.24–1.27 [m, 4H, (CH2)2], 2.48
(t, 2H, J = 7.3Hz, C@CACH2), 3.03 (s, 3H, SO2CH3),
6.84–6.87 (m, 2H, phenyl hydrogens), 7.02–7.04 (m,
3H, phenyl hydrogens), 7.23–7.31(m, 7H, phenyl hydro-
gens and 4-methylsulfonylphenyl H-2, H-6), 7.72 (d, 2H,
J = 8.4Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C25H26O2SÆ1/8H2O: C, 76.44; H, 6.68. Found:
C, 76.28; H, 6.86.
5.11. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)oct-1-ene
(9d)
Yield, 66%; white solid; mp 104–106ꢀC; IR (film): 1159,
1308 (SO2) cmÀ1 1H NMR (CDCl3): d 0.65 (t, 3H,
;
J = 7.3Hz, CH2CH3), 0.96–1.08 [m, 8H, (CH2)4], 2.29
(t, 2H, J = 7.3Hz, C@CACH2), 2.85 (s, 3H, SO2 CH3),
6.66–6.69 (m, 2H, phenyl hydrogens), 6.84–6.86 (m,
3H, phenyl hydrogens), 7.05–7.18 (m, 7H, phenyl hydro-
gens and 4-methylsulfonylphenyl H-2, H-6), 7.55 (d, 2H,
J = 8.4Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C27H30O2S: C, 77.47; H, 7.22. Found: C,
77.55; H, 6.92.

5936
Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5.12. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)non-1-ene
(9e)
5.16. 4-(Methylsulfonyl)pentanophenone (10c)
Yield, 94%; white needles; mp 85–87ꢀC; IR (film): 1142,
1
Yield, 68%; white solid; mp 64–66ꢀC; IR (film): 1143,
1320 (SO2), 1698 (C@O) cmÀ1; H NMR (CDCl3): d
1318 (SO2) cmÀ1
;
1H NMR (CDCl3): d 0.85 (t, 3H,
0.97 (t, 3H, J = 7.3Hz, CH2CH3), 1.36–1.49 (m, 2H,
CH2CH3), 1.69–1.76 (m, 2H, COCH2CH2), 3.01(t,
2H, J = 7.3Hz, COCH2), 3.09 (s, 3H, SO2CH3), 8.05
(d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5),
8.13 (d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-2,
H-6). Anal. Calcd for C12H16O3SÆ1/6H2O: C, 59.23; H,
6.71. Found: C, 59.45; H, 6.67.
J = 7.0Hz, CH2CH3), 1.17–1.40 [m, 10H, (CH2)5], 2.47
(t, 2H, J = 7.3Hz, C@CACH2), 3.02 (s, 3H, SO2CH3),
6.84–6.87 (m, 2H, phenyl hydrogens), 7.01–7.04 (m,
3H, phenyl hydrogens), 7.23–7.43 (m, 7H, phenyl hydro-
gens and 4-methylsulfonylphenyl H-2, H-6), 7.72 (d, 2H,
J = 8.4Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C28H32O2S: C, 77.74; H, 7.46. Found: C,
77.86; H, 7.41.
5.17. 4-(Methylsulfonyl)octanophenone (10d)
Yield, 75%; while needles; mp 105–107ꢀC; IR (film):
1148, 1313 (SO2), 1691 (C@O) cmÀ1; 1H NMR (CDCl3):
d 0.89 (t, 3H, J = 7.0Hz, CH2CH3), 1.29–1.45 [m, 8H,
(CH2)4CH3], 1.70–1.77 (m, 2H, COCH2CH2), 3.0 (t,
2H, J = 7.3Hz, COCH2) 3.09 (s, 3H, SO2CH3), 8.04
(d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5),
8.13 (d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-2,
H-6). Anal. Calcd for C15H22O3S: C, 63.80; H, 7.85.
Found: C, 63.61; H, 7.86.
5.13. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)undec-1-
ene (9f)
Yield, 68%; white solid; mp 65–67ꢀC; IR (film): 1157,
1315 (SO2) cmÀ1 1H NMR (CDCl3): d 0.88 (t, 3H,
;
J = 7.0Hz, CH2CH3), 1.17–1.29 [m, 14H, (CH2)7], 2.47
(t, 2H, J = 7.3Hz, C@CACH2), 3.03 (s, 3H, SO2CH3),
6.85–6.87 (m, 2H, phenyl hydrogens), 7.00–7.04 (m,
3H, phenyl hydrogens), 7.23–7.38 (m, 7H, phenyl hydro-
gens and 4-methylsulfonylphenyl H-2, H-6), 7.72 (d, 2H,
J = 8.4Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C30H36O2S: C, 78.22; H, 7.88. Found: C,
78.08; H, 7.91.
5.18. 4-(Methylsulfonyl)hexadecanophenone (10e)
Yield, 65%; white plates; mp 108–110ꢀC; IR (film):
1143, 1327 (SO2), 1685 (C@O) cmÀ1; 1H NMR (CDCl3):
d 0.88 (t, 3H, J = 7.0Hz, CH2CH3), 1.26–1.40 [m, 24H,
(CH2)12CH3], 1.70–1.85 (m, 2H, COCH2CH2), 3.00 (t,
2H, J = 7.3Hz, COCH2), 3.09 (s, 3H, SO2CH3), 8.06
(d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5),
8.13 (d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl H-2,
H-6). Anal. Calcd for C23H38O3S: C, 70.00; H, 9.71.
Found: C, 69.91; H, 9.96.
5.14. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)heptadec-1-
ene (9g)
Yield, 76%; white solid; mp 68–70ꢀC; IR (film): 1143,
1316 (SO2) cmÀ1 1H NMR (CDCl3): d 0.89 (t, 3H,
;
J = 7.0Hz, CH2CH3), 1.26–1.40 [m, 26H, (CH2)13],
2.46 (t, 2H, J = 7.3Hz, C@CACH2), 2.69 (s, 3H,
SO2CH3), 6.84–6.87 (m, 2H, phenyl hydrogens), 7.00–
7.05 (m, 3H, phenyl hydrogens), 7.23–7.40 (m, 7H, phe-
nyl hydrogens and 4-methylsulfonylphenyl H-2, H-6),
7.44 (d, 2H, J = 8.4Hz, 4-methylsulfonylphenyl H-3,
H-5). Anal. Calcd for C36H48O2S: C, 79.36; H, 8.88.
Found: C, 79.20; H, 9.16.
5.19. 1,1-Diphenyl-2-(4-methylsulfonylphenyl)ethene
(12a)
TiCl4 (1.83mL, 13mmol) was added drop wise to a stir-
red suspension of Zn powder (1.7g, 26.5mmol) in dry
THF (30mL) under an argon atmosphere at À10ꢀC,
and after the addition was completed this mixture was
refluxed for 2h to produce the titanium reagent. A solu-
tion of 4-(methylsulfonyl)benzaldehyde (10a, 0.60g,
3.3mmol) and benzophenone (7, 0.61g, 3.3mmol) in
THF (65mL) was added to the cooled suspension of
the titanium reagent at 0ꢀC, and the reaction mixture
was refluxed for 2.5h. After cooling to 25ꢀC, the reac-
tion mixture was poured onto a 10% aqueous K2CO3
solution (100mL), this mixture was stirred vigorously
for 5min, and the dispersed insoluble material was re-
moved by vacuum filtration using a Celite 545 pad.
The organic layer was separated, the aqueous layer
was extracted with EtOAc (3 · 50mL), the combined
organic fractions were washed with water, the organic
fraction was dried (Na2SO4), and the solvent was re-
moved in vacuo to give a residue that was purified by
silica gel flash column chromatography. Elution with
n-hexane–EtOAc (2:1, v/v) as eluant afforded 12a
(0.75g, 70%); mp 131–133 0C; IR (film): 1155, 1313
(SO2) cmÀ1; 1H NMR (CDCl3) d 3.02 (s, 3H, SO2CH3),
5.15. General procedure for the synthesis of 4-(methyl-
sulfonyl)alkanophenones (10c–e)
A solution of Oxoneꢂ (potassium peroxymonosulfate)
(4.06g, 6.6mmol) in water (20mL) was added to a stir-
red solution of the 4-(methylthio)alkanophenone (6c,d,
or 6e, 3.3mmol) in THF–MeOH (1:1, v/v; 10mL) at
0ꢀC, and the reaction was allowed to proceed with stir-
ring for 15h at 25ꢀC. Removal of the solvent in vacuo
gave a residue to which water (20mL) was added.
Extraction with EtOAc (3 · 30mL), washing the com-
bined extracts with water (10mL), drying the organic
fraction (Na2SO4), and removal of the solvent in vacuo
gave a white solvent which was purified by recrystalliza-
tion from CH2Cl2–n-hexane (1:9, v/v) to afford the
respective product 10c,d, or 10e. Physical, spectroscopic,
and microanalytical data products 10d–e are listed
below.

Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5937
6.98 (s, 1H, @CH), 7.16–7.37 (m, 12H, phenyl hydro-
gens, 4-methylsulfonylphenyl H-2, H-6), 7.68 (d, 2H,
J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C21H18O2SÆ1/4H2O: C, 74.41; H, 5.45. Found:
C, 74.67; H, 5.54.
silica gel flash column chromatography using n-hex-
ane–EtOAc (3:1, v/v) as eluant to afford the respective
product 13a–e. Physical, spectroscopic and microanaly-
tical data for products 13a–e are listed below.
5.22. (E,Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methyl-
sulfonylphenyl)ethene (13a)
5.20. (Z)-1-(4-Hydroxyphenyl)-1-phenyl-2-(4-methyl-
sulfonylphenyl)but-1-ene (12b)
Yield, 67%; isolated as a mixture of (E) and (Z) isomers
(the isomeric ratio = 1:6.4 as determined from the inte-
grals for the CH3SO2 resonances at d 3.03 and 3.02,
respectively); mp 158–160ꢀC; IR (film): 1153, 1309
Reaction of 4-(methylsulfonyl)propanophenone (10b)
and 4-hydroxybenzophenone (11) with the titanium rea-
gent, following the procedure described for the synthesis
and silica gel flash column purification of 12a, gave 12b
in 60% yield as a white solid; mp 188–190ꢀC; IR (film):
1148, 1320 (SO2), 3381(OH) cm À1; 1H NMR (CDCl3) d
0.92 (t, 3H, J = 7.3Hz, CH2CH3), 2.50 (q, 2H,
J = 7.3Hz, CH2CH3), 3.05 (s, 3H, SO2CH3), 4.56 (br
s, 1H, OH), 6.49 (d, 2H, J = 8.5Hz, 4-hydroxyphenyl
H-3, H-5), 6.70 (d, 2H, J = 8.5Hz, 4-hydroxyphenyl
H-2, H-6), 7.10–7.39 (m, 7H, phenyl hydrogens, 4-meth-
ylsulfonylphenyl H-2, H-6), 7.74 (d, 2H, J = 8.5Hz, 4-
methylsulfonylphenyl H-3, H-5). Anal. Calcd for
C23H22O3SÆ1/4H2O: C, 72.12; H, 5.87. Found: C,
72.05; H, 5.86.
1
(SO2), 1768 (C@O) cmÀ1; H NMR (CDCl3) for (Z)-
13a: d 2.32 (s, 3H, COCH3), 3.02 (s, 3H, SO2CH3),
6.96 (s, 1H, @CH), 7.06 (d, 2H, J = 8.5Hz, 4-acetoxy-
phenyl H-3, H-5), 7.15 (d, 2H, J = 8.5Hz, 4-acetoxy-
phenyl H-2, H-6), 7.27–7.38 (m, 7H, phenyl hydrogens,
and 4-methylsulfonylphenyl H-2, H-6), 7.68 (d, 2H,
J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5). Anal.
Calcd for C23H20O4S: C, 70.39; H, 5.14. Found: C,
70.14; H, 5.25.
5.23. (Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methylsulfon-
ylphenyl)but-1-ene (13b)
5.21. General procedure for the synthesis of 1-(4-acet-
oxyphenyl)-1-phenyl-2-(4-methylsulfonylphenyl)alkenes
(13a–e)
Yield, 72%; colorless crystals; mp 140–142ꢀC; IR (film):
1153, 1318 (SO2), 1759 (C@O) cmÀ1; 1H NMR (CDCl3):
d 0.93 (t, 3H, J = 7.3Hz, CH2CH3), 2.23 (s, 3H,
COCH3), 2.52 (q, 2H, J = 7.3Hz, CH2CH3), 3.04 (s,
3H, SO2CH3), 6.77 (d, 2H, J = 8.5Hz, 4-acetoxyphenyl
H-3, H-5), 6.85 (d, 2H, J = 8.5Hz, 4-acetoxyphenyl
H-2, H-6), 7.23–7.39 (m, 7H, phenyl hydrogens, and
TiCl4 (1.83mL, 13mmol) was added drop wise to a stir-
red suspension of Zn powder (1.7g, 26.5mmol) in dry
THF (30mL) under an argon atmosphere at À10ꢀC,
and this mixture was heated at reflux for 2h to produce
the titanium reagent. A cooled suspension of this titanium
reagent was added to a solution of the respective 4-(meth-
ylsulfonyl)alkanophenone [4-(methylsulfonyl)benzalde-
hyde, 10a, R1 = H; 4-(methylsulfonyl)propanophenone,
10b, R1 = Et; 4-(methylsulfonyl)pentanophenone, 10c,
R1 = n-Bu; 4-(methylsulfonyl)octanophenone, 10d,
R1 = n-heptyl; or 4-(methylsulfonyl)hexadecanophen-
one, 10e, R1 = pentadecyl] (3.3mmol) and 4-hydroxy-
benzophenone (11, R2 = 4-HO-C6H4-; 0.65g, 3.3mmol)
in THF (65mL) at 0ꢀC, and the reaction was allowed
to proceed at reflux for 2.5h. After cooling to 25ꢀC,
the reaction mixture was poured into a 10% aqueous
K2CO3 solution (100mL), this mixture was stirred vigor-
ously for 5min, and the dispersed insoluble material was
removed by vacuum filtration through a Celite 545 pad.
The organic fraction was separated, the aqueous layer
was extracted with EtOAc (3 · 50mL), and the com-
bined organic fractions were dried (Na2SO4). Removal
of the solvent in vacuo afforded the respective 4-
hydroxyphenyl olefinic intermediate (12, R1 as indicated
above; R2 = OH), which was dissolved in ether (10mL),
and triethylamine (0.5g, 5.0mmol) was added. Acetyl
chloride (0.39g, 5.0mmol) was added drop wise at
0ꢀC, and the reaction was allowed to proceed at 25ꢀC
for 1.5h prior to quenching with water (20mL). The
organic layer was separated, the aqueous layer was ex-
tracted with EtOAc (3 · 30mL), the combined organic
fractions were washed with water (10mL), and the
organic fraction was dried (Na2SO4). Removal of the
solvent in vacuo gave a residue that was purified by
4-methylsulfonylphenyl
H-2,
H-6),
7.75
(d,
2H, J = 8.5Hz, 4-methylsulfonylphenyl H-3, H-5);
13C NMR (CDCl3): d 13.4 (CH2C3), 21.1 (COC3),
29.7
(C2CH3),
44.4
(SO2C3),
120.6,
126.9,
127.1, 128.2, 129.1, 130.5, 131.4 (Carom–H), 138.0,
139.3, 140.1, 140.7, 142.2, 148.3, 148.9 (Carom–C,
Colefin–C, Carom–O, Carom–S), 169.2 (C@O). Anal. Calcd
for C25H24O4S: C, 71.40; H, 5.75. Found: C, 71.30; H,
5.89.
5.24. (E,Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methyl-
sulfonylphenyl)but-1-ene [(E,Z)-13b]
The title compound was synthesized as an isomeric mix-
ture using a McMurry reductive cross-coupling reaction
of 4-(methylthio)propiophenone (6b) and 4-hydroxy-
benzophenone (11, R2 = OH)) to give an (E) and (Z)
mixture of 1-(4-hydroxyphenyl)-1-phenyl-2-(4-methyl-
thiophenyl)but-1-ene, that was then oxidized using
Oxoneꢂ to give the corresponding 1-(4-hydroxyphenyl)-
1-phenyl-2-(4-methylsulfonylphenyl)but-1-ene. A subse-
quent acetylation of the (E,Z)-1-(4-hydroxyphenyl)-
1-phenyl-2-(4-methylsulfonylphenyl)but-1-ene
using
acetyl chloride gave the target (E,Z)-1-(4-acetoxyphen-
yl)-1-phenyl-2-(4-methylsulfonylphenyl)but-1-ene (13b,
isomeric ratio = 1:4) in 65% yield. The (E):(Z) ratio
was calculated from the integrals for the respective
CH3SO2 resonances at d 3.03 and 3.04, respectively.
The purification method used was identical to the proce-
1
dure described above to purify (Z)-13a. The H NMR
spectral data for the (Z)-13b isomer is the same as that

5938
Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
1
listed above. The H NMR spectral data for (E)-13b is
listed below. 1H NMR (CDCl3): d 0.87 (t, 3H,
J = 7.2Hz, CH2CH3), 2.32 (s, 3H, COCH3), 2.51(q,
2H, J = 7.2Hz, CH2CH3), 3.03 (s, 3H, SO2CH3), 6.76
(d, 2H, J = 8.5Hz, 4-acetoxyphenyl H-3, H-5), 6.84 (d,
2H, J = 8.5Hz, 4-acetoxyphenyl H-2, H-6), 7.02–7.39
(m, 7H, phenyl hydrogens, 4-methylsulfonylphenyl H-
2, H-6), 7.74 (d, 2H, J = 8.5Hz, 4-methylsulfonylphenyl
H-3, H-5).
was added to a cooled suspension of this titanium rea-
gent at 0ꢀC, and the reaction was allowed to proceed
at reflux for 2.5h. After cooling to 25ꢀC, the reaction
mixture was poured into 10% aqueous K2CO3 solution
(100mL), and after vigorous stirring for 5min, the dis-
persed insoluble matters were removed by vacuum filtra-
tion using Celite 545. The organic layer was separated
and the aqueous layer was extracted with EtOAc
(3 · 50mL). The combined organic fractions were
washed with water, and the organic fraction was dried
(Na2SO4). Purification by flash silica gel column chro-
matography using n-hexane–EtOAc (3:1, v/v) as eluent
afforded the olefin 14 (0.69g, 67%) as a white solid,
mp 90–92ꢀC (lit. mp 91ꢀC);31 1H NMR (CDCl3, 300
MHz) d 0.78 (t, 3H, J = 7.0Hz, CH2CH3), 1.18–1.55
[m, 4H, (CH2)2CH3], 2.44 (t, 2H, J = 7.0Hz,
C@CACH2) 6.86–7.38 (m, 15H, phenyl hydrogens).
5.25. (Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methylsulfon-
ylphenyl)hex-1-ene (13c)
Yield, 68%; white plates; mp 115–117ꢀC; IR (film):
1150, 1315 (SO2), 1750 (C@O) cmÀ1; 1H NMR (CDCl3):
d 0.79 (t, 3H, J = 7.0Hz, CH2CH3), 1.18–1.35 [m, 4H,
(CH2)2CH3], 2.23 (s, 3H, COCH3), 2.47 (t, 2H,
J = 7.3Hz, C@CACH2), 3.04 (s, 3H, SO2CH3), 6.76
(d, 2H, J = 8.5Hz, 4-acetoxyphenyl H-3, H-5), 6.85 (d,
2H, J = 8.5Hz, 4-acetoxyphenyl H-2, H-6), 7.21–7.39
(m, 7H, phenyl hydrogens, and 4-methylsulfonylphenyl
H-2, H-6), 7.74 (d, 2H, J = 8.5Hz, 4-methylsulfonylphe-
nyl H-3, H-5). Anal. Calcd for C27H28O4S: C, 72.29; H,
6.29. Found: C, 72.53; H, 6.04.
6. Molecular modeling (docking) study
Docking experiment was performed using INSIGHT II
software Version 2000.1(Accelrys Inc.) running on a Sil-
icon Graphics Octane 2 R14000A workstation. The
coordinates for the X-ray crystal structure of the enzyme
COX-2 were obtained from the RCSB Protein Data
Bank and hydrogens were added. The ligand molecules
were constructed using the Builder module and energy
minimized for 1000 iterations reaching a convergence
5.26. (Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methylsulfon-
ylphenyl)non-1-ene (13d)
Yield, 67%; colorless syrup; IR (film): 1157, 1315 (SO2),
1757 (C@O) cmÀ1; H NMR (CDCl3): d 0.84 (t, 3H,
of 0.01kcal/molA. The docking experiment on COX-2
1
˚
J = 7.0Hz, CH2CH3), 1.12–1.57 [m, 10H, (CH2)5CH3],
2.23 (s, 3H, COCH3), 2.44 (t, 2H, J = 7.3Hz,
C@CACH2), 3.04 (s, 3H, SO2CH3), 6.76 (d, 2H,
J = 8.5Hz, 4-acetoxyphenyl H-3, H-5), 6.84 (d, 2H,
J = 8.5Hz, 4-acetoxyphenyl H-2, H-6), 7.22–7.39 (m,
7H, phenyl hydrogens, 4-methylsulfonylphenyl H-2, H-
6), 7.74 (d, 2H, J = 8.4Hz, 4-methylsulfonylphenyl H-
3, H-5). Anal. Calcd for C30H34O4SÆ1/6H2O: C, 72.98;
H, 6.95. Found: C, 72.94; H, 9.91.
was carried out by superimposing the energy minimized
ligand on SC-558 in the PDB file 1cx2 after which SC-
558 was deleted. The resulting ligand–enzyme complex
was subjected to docking using the Affinity command
in the Docking module of INSIGHT II after defining sub-
˚
sets of the enzyme such that residues within 10A of the
ligand were allowed to relax, while the remainder of the
enzyme residues were fixed. The consistent valence force
field (CVFF) was employed for all docking purposes.
The ligand–enzyme assembly was then subjected to a
molecular dynamics (MD) simulation using the Dis-
cover module Version 2.98 at a constant temperature
of 300K with a 100 step equilibration for over 1000 iter-
ations and a time step of 1fs using a distance dependent
dielectric constant 4r. The optimal binding orientation
of the ligand–enzyme assembly obtained after docking
was further minimized for 1000 iterations using the con-
5.27. (Z)-1-(4-Acetoxyphenyl)-1-phenyl-2-(4-methylsulfon-
ylphenyl)heptadec-1-ene (13e)
Yield, 70%; colorless oil; IR (film): 1155, 1313 (SO2),
1
1753 (C@O) cmÀ1; H NMR (CDCl3): d 0.88 (t, 3H,
J = 7.0Hz, CH2CH3), 1.12–1.56 [m, 26H, (CH2)13CH3],
2.23 (s, 3H, COCH3), 2.45 (t, 2H, J = 7.3Hz,
C@CACH2), 3.04 (s, 3H, SO2CH3), 6.76 (d, 2H,
J = 8.5Hz, 4-acetoxyphenyl H-3, H-5), 6.84 (d, 2H,
J = 8.5Hz, 4-acetoxyphenyl H-2, H-6), 7.22–7.39 (m,
7H, phenyl hydrogens, 4-methylsulfonylphenyl H-2, H-
6), 7.74 (d, 2H, J = 8.4Hz, 4-methylsulfonylphenyl H-
3, H-5). Anal. Calcd for C38H50O4SÆ1/6H2O: C, 75.32;
H, 8.30. Found: C, 75.28; H, 7.91.
jugate gradient method until
˚
0.001kcal/molA was reached.
a
convergence of
7. Volume determination
The ALCHEMY 2000 program32 was used to calculate
3
the molecular volume (A ) of compounds in the
˚
5.28. 1,1,2-Triphenylhex-1-ene (14)
Table 1 after minimization using PM3.
TiCl4 (1.83mL, 13mmol) was added drop-wise to a stir-
red suspension of Zn powder (1.7g, 26.5mmol) in dry
THF (30mL), under Ar at À10ꢀC. After the addition
was completed, the reaction mixture was refluxed for
2h. A solution of valerophenone (0.54g, 3.3mmol)
and benzophenone (0.61g, 3.3mmol) in THF (65mL)
8. In vitro cyclooxygenase inhibition assays
The ability of the test compounds listed in the Table 1 to
inhibit ovine COX-1and COX-2 (IC values, lM) was
determined using an enzyme immuno assay (EIA) kit
50

Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
5939
(catalog number 560101, Cayman Chemical, Ann Ar-
10. Analgesic assay
bor, MI, USA) according to the manufacturerꢁs instruc-
tions. Cyclooxygenase catalyzes the first step in the
biosynthesis of arachidonic acid (AA) to PGH2. PGF2a,
produced from PGH2 by reduction with stannous chlor-
ide, is measured by enzyme immunoassay (ACETM com-
petitive EIA). Stock solutions of test compounds were
dissolved in a minimum volume of DMSO. Briefly, to
a series of supplied reaction buffer solutions (960lL,
0.1M Tris–HCl pH8.0 containing 5mM EDTA and
2mM phenol) with either COX-1or COX-2 (10 lL) en-
zyme in the presence of heme (10lL) were added 10lL
of various concentrations of test drug solutions (0.01,
0.1, 1, 10, 50, and 100lM in a final volume of 1mL).
These solutions were incubated for a period of 5min
at 37ꢀC after which 10lL of AA (100lM) solution were
added and the COX reaction was stopped by the addi-
tion of 50lL of 1M HCl after 2min. PGF2a, produced
from PGH2 by reduction with stannous chloride was
measured by enzyme immunoassay. This assay is based
on the competition between PGs and a PG-acetylcholi-
nesterase conjugate (PG tracer) for a limited amount
of PG antiserum. The amount of PG tracer that is able
to bind to the PG antiserum is inversely proportional to
the concentration of PGs in the wells since the concen-
tration of PG tracer is held constant while the concen-
tration of PGs varies. This antibody–PG complex
binds to a mouse anti-rabbit monoclonal antibody that
had been previously attached to the well. The plate is
washed to remove any unbound reagents and then Ell-
manꢁs reagent, which contains the substrate to acetyl-
choline esterase, is added to the well. The product of
this enzymatic reaction produces a distinct yellow color
that absorbs at 405nm. The intensity of this color, deter-
mined spectrophotometrically, is proportional to the
amount of PG tracer bound to the well, which is inver-
sely proportional to the amount of PGs present in the
well during the incubation: Absorbance a [Bound PG
Tracer] a1/PGs. Percent inhibition was calculated by
the comparison of compound treated to various control
incubations. The concentration of the test compound
causing 50% inhibition (IC50, lM) was calculated from
the concentration–inhibition response curve (duplicate
determinations).
Analgesic activity was determined using the 4% sodium
chloride-induced writhing (abdominal constriction) as-
say described by Fukawa et al.34
Acknowledgements
We are grateful (i) to the Canadian Institutes of Health
Research (CIHR) (MOP-14712) for financial support of
this research, (ii) to the Alberta Heritage Foundation for
Medical Research (AHFMR) for a postdoctoral fellow-
ship award (to M.J.U.), and a graduate scholarship (to
P.R.)
References and notes
1. Meade, E. A.; Smith, W. L.; DeWitt, D. L. J. Biol. Chem.
1993, 268, 6610.
2. Kurumbail, R. G.; Stevens, A. M.; Gierse, J. K.;
McDonald, J. J.; Stegemen, R. A.; Pak, J. Y.; Gildehaus,
D.; Miyashiro, J. M.; Penning, T. D.; Seibert, K.; Isakson,
P. C.; Stallings, W. C. Nature 1996, 384, 644.
3. Picot, D.; Loll, P. J.; Garavito, R. M. Nature 1994, 367,
243.
4. Penning, T. D.; Talley, J. J.; Bertenshaw, S. R.; Carter, J.
S.; Collins, P. W.; Docter, S.; Graneto, M. J.; Lee, L. F.;
Malecha, J. W.; Miyashiro, J. M.; Rogers, R. S.; Rogier,
D. J.; Yu, S. S.; Anderson, G. D.; Burton, E. G.; Cogburn,
J. N.; Gregory, S. A.; Koboldt, C. M.; Perkins, W. E.;
Seibert, K.; Veenhuizen, A. W.; Zhang, Y. Y.; Isakson, P.
C. J. Med. Chem. 1997, 40, 1347.
5. Prasit, P.; Wang, Z.; Brideau, C.; Chan, C. C.; Charleson,
S.; Cromlish, W.; Ethier, D.; Evans, J. F.; Ford-Hutchin-
son, A. W.; Gauthier, J. Y.; Gordon, R.; Guay, J.;
Gresser, M.; Kargman, S.; Kennedy, B.; Leblanc, Y.;
Leger, S.; Mancini, J.; OꢁNeill, G. P.; Ouellet, M.; Percival,
M. D.; Perrier, H.; Riendeau, D.; Rodger, I.; Zamboni,
R.; Boyce, S.; Rupniak, N.; Forrest, M.; Visco, D.;
Patrick, D. Bioorg. Med. Chem. Lett. 1999, 9, 1773.
6. Talley, J. J.; Brown, D. L.; Carter, J. S.; Graneto, M. J.;
Koboldt, C. M.; Masferrer, J. L.; Perkins, W. E.; Rogers,
R. S.; Shaffer, A. F.; Zhang, Y. Y.; Zweifel, B. S.; Seibert,
K. J. Med. Chem. 2000, 43, 775.
7. Silverstein, F. E.; Faich, G.; Goldstein, J. L.; Simon, L. S.;
Pincus, T.; Whelton, A.; Makuch, R.; Eisen, G.; Agrawal,
N. M.; Stenson, W. F.; Burr, A. M.; Zhao, W. W.; Kent, J.
D.; Lefkowith, J. B.; Verburg, K. M.; Geis, G. S. JAMA
2000, 284, 1247.
9. Anti-inflammatory assay
8. Whelton, A.; Schulman, G.; Wallemark, C. M.; Drower,
E. J.; Isakson, P. C.; Verburg, K. M.; Geis, G. S. Arch. Int.
Med. 2000, 160, 1465.
9. Llorens, O.; Perez, J. L.; Palomer, A.; Mauleon, D.
Bioorg. Med. Chem. Lett. 1999, 9, 2779.
10. Garavito, R. M.; DeWitt, D. L. Biochem. Biophys. Acta
1999, 1441, 278.
11. Dannhardt, G.; Kiefer, W. Eur. J. Med. Chem. 2001, 36,
109, and references cited therein.
12. DeWitt, D. L.; El-Harith, E. A.; Kraemer, S. A.; Andrews,
M. J.; Yao, E. F.; Armstraong, R. L.; Smith, W. L. J. Biol.
Chem. 1990, 265, 5192.
13. Kalgutkar, A. S.; Crews, B. C.; Rowlinson, S. W.; Garner,
C.; Seibert, K.; Marnett, L. J. Science 1998, 280, 1268.
14. Kalgutkar, A. S.; Kozak, K. R.; Crews, B. C.; Hochge-
sang, G. P.; Marnett, L. J. J. Med. Chem. 1998, 41, 4800.
Anti-inflammatory activity was measured using a car-
rageenan-induced rat paw edema assay described by
Winter et al.33 Briefly, four male Sprague Dawley rats
weighing 100–110g were used in each group. Test com-
pounds suspended in water containing 1% methyl cellu-
lose, were administered orally at different doses
(0.5–30mg/kg range) 1h prior to a 0.05mL subcutane-
ous injection of 1% carrageenan in 0.9% NaCl solution
under the planter skin of the right hind paw. Control
experiments were identical except that the vehicle did
not contain a test compound. The volume of the injected
paw was measured at 0 and 3h using a UGO Basile 7141
Plethysmometer (Ser. No 43201) for calculation of %
inhibition of inflammation.

5940
Md. J. Uddin et al. / Bioorg. Med. Chem. 12 (2004) 5929–5940
15. Uddin, M. J.; Rao, P. N. P.; Knaus, E. E. Bioorg. Med.
Chem. Lett. 2004, 14, 1953.
24. Strazzolini, P.; Verardo, G.; Giumanini, A. G. J. Org.
Chem. 1988, 53, 3321.
16. Huang, H.-C.; Li, J. J.; Garland, D. J.; Chamberlain, T.
S.; Reinhard, E. J.; Manning, R. E.; Seibert, K.; Koboldt,
C. M.; Gregory, S. A.; Anderson, G. D.; Veenhuizen, A.
W.; Zhang, Y.; Perkins, W. E.; Burton, E. G.; Cogburn, J.
N.; Isakson, P. C.; Reitz, D. B. J. Med. Chem. 1996, 39,
253.
25. McMurry, J. E. Chem. Rev. 1989, 89, 1513.
26. McMurry, J. E.; Fleming, M. P.; Kees, K. L.; Krepski, L.
R. J. Org. Chem. 1978, 43, 3255.
27. Lecomte, M.; Laneuville, O.; Ji, C.; DeWitt, D. L.; Smith,
W. L. J. Biol. Chem. 1994, 269, 13207.
28. Vachier, I.; Chanez, P.; Bonnans, C.; Godard, P.; Bous-
quet, J.; Chavis, C. Biochem. Biophys. Res. Commun. 2002,
290, 219.
´
17. Buu-Hoi, N. P.; Hoan, N. J. Org. Chem. 1952, 17,
350.
18. Wagner, P. J.; Kemppainen, A. E.; Schott, H. N. J. Am.
Chem. Soc. 1973, 95, 560.
19. Rahim, M. A.; Rao, P. N. P.; Knaus, E. E. Bioorg. Med.
Chem. Lett. 2002, 12, 2753.
29. Luong, C.; Miller, A.; Barnett, J.; Chow, J.; Ramesha, C.;
Browner, M. F. Nat. Struct. Biol. 1996, 3, 927.
30. Hochgesang, G. P.; Rowlinson, S. W.; Marnett, L. J.
J. Am. Chem. Soc. 2000, 122, 6514.
20. Rubin, V. N.; Ruenitz, P. C.; Boudinot, F. D.; Boyd, J. L.
Bioorg. Med. Chem. 2001, 9, 1579.
31. Melamed, U.; Feit, B. A. J. Chem. Soc., Perkin Trans. 1
1978, 1228.
21. Habeeb, A. G.; Rao, P. N. P.; Knaus, E. E. J. Med. Chem.
2001, 44, 2921.
32. Alchemy 2000 (program), Version 2.0; Tripos Inc.; St.
Louis, MO, USA.
22. Fringuelli, F.; Pellegrino, R.; Piermatti, O.; Pizzo, F.
Synth. Commun. 1994, 18, 2665.
33. Winter, C. A.; Risley, E. A.; Nuss, G. W. Proc. Soc. Exp.
Biol. Med. 1962, 111, 544.
23. Uddin, M. J.; Rao, P. N. P.; Knaus, E. E. Synlett 2004,
1513.
34. Fukawa, K.; Kawano, O.; Hibi, M.; Misaka, N.; Ohba, S.;
Hatanaka, Y. J. Pharmacol. Methods 1980, 4, 251.