Structure-based design, synthesis, and biological evaluation of indomethacin derivatives as cyclooxygenase-2 inhibiting nitric oxide donors

Article abstract of DOI:10.1021/jm0611861

Indomethacin, a nonselective cyclooxygenase (COX) inhibitor, was modified in three distinct regions in an attempt both to increase cyclooxygenase-2 (COX-2) selectivity and to enhance drug safety by covalent attachment of an organic nitrate moiety as a nitric oxide donor. A human whole-blood COX assay shows the modifications on the 3-acetic acid part of the indomethacin yielding an amide-nitrate derivative 32 and a sulfonamide-nitrate derivative 61 conferred COX-2 selectivity. Along with their respective des-nitrate analogs, for example, 31 and 62, the nitrates 32 and 61 were effective antiinflammatory agents in the rat air-pouch model. After oral dosing, though, only 32 increased nitrate and nitrite levels in rat plasma, indicating that its nitrate tether served as a nitric oxide donor in vivo. In a rat gastric injury model, examples 31 and 32 both show a 98% reduction in gastric lesion score compared to that of indomethacin. In addition, the nitrated derivative 32 inducing 85% fewer gastric lesions when coadministered with aspirin as compared to the combination of aspirin and valdecoxib.

Full text of DOI:10.1021/jm0611861

J. Med. Chem. 2007, 50, 6367–6382
6367
Structure-Based Design, Synthesis, and Biological Evaluation of Indomethacin Derivatives as
Cyclooxygenase-2 Inhibiting Nitric Oxide Donors§
Shiow-Jyi Wey,* Michael E. Augustyniak, Edward D. Cochran, James L. Ellis, Xinqin Fang, David S. Garvey, David R. Janero,
L. Gordon Letts, Allison M. Martino, Terry L. Melim, Madhavi G. Murty, Steward K. Richardson, Joseph D. Schroeder,
William M. Selig, A. Mark Trocha, Roseanne S. Wexler, Delano V. Young, Irina S. Zemtseva, and Brian M. Zifcak
NitroMed, Inc., 125 Spring Street, Lexington, Massachusetts 02421
ReceiVed October 11, 2006
Indomethacin, a nonselective cyclooxygenase (COX) inhibitor, was modified in three distinct regions in an
attempt both to increase cyclooxygenase-2 (COX-2) selectivity and to enhance drug safety by covalent
attachment of an organic nitrate moiety as a nitric oxide donor. A human whole-blood COX assay shows
the modifications on the 3-acetic acid part of the indomethacin yielding an amide-nitrate derivative 32 and
a sulfonamide-nitrate derivative 61 conferred COX-2 selectivity. Along with their respective des-nitrate
analogs, for example, 31 and 62, the nitrates 32 and 61 were effective antiinflammatory agents in the rat
air-pouch model. After oral dosing, though, only 32 increased nitrate and nitrite levels in rat plasma, indicating
that its nitrate tether served as a nitric oxide donor in vivo. In a rat gastric injury model, examples 31 and
32 both show a 98% reduction in gastric lesion score compared to that of indomethacin. In addition, the
nitrated derivative 32 inducing 85% fewer gastric lesions when coadministered with aspirin as compared to
the combination of aspirin and valdecoxib.
Introduction
means for improving the GI safety of traditional NSAIDs. COX-
inhibiting nitric oxide donors (CINODs) are currently under
laboratory and clinical investigation for using NO to improve
and enhance traditional NSAIDs,13,15–28 as well as for COX-2
selective inhibitors.29,30 Especially in predisposed cardiovascular
patients, the increased cardiovascular risk of COX-2 selective
inhibitors and their gastric toxicity when administered with
aspirin prophylaxis might be ameliorated by supplementary NO.
Common adverse effects of nonsteroidal anti-inflammatory
drugs (NSAIDs) (e.g., aspirin, indomethacin, naproxen, and
ibuprofen) are gastrointestinal (GI) bleeding, ulceration, and
more severely, perforation. Prostaglandins (PGs) synthesized
by the “housekeeping” cyclooxygenase-1 (COX-1) enzyme
mediate many physiological functions, including GI cytopro-
tection. The immediate hypothesis after the discovery of the
“inducible” COX-2 enzyme and its increased expression at the
sites of inflammation was that the proinflammatory PGs
produced by COX-2 caused pain and fever.1–3 Therefore, a
selective COX-2 inhibitor was expected to exert the anti-
inflammatory, analgesic and antipyretic effects of conventional
NSAIDs without the undesired GI side effects associated with
COX-1 inhibition. The subsequent discovery that COX-2 is
constitutively expressed in the brain, the spinal cord, and the
kidneys4,5 suggested that the COX-2 derived PGs have beneficial
effects in, for example, ulcer healing6 and regulation of renal
function.7 The physiological importance of COX-2 was subse-
quently manifested in the clinic as increased cardiovascular and
renal risks associated with COX-2 inhibitors,8,9 particularly,
when administered concurrently with aspirin.10,11 The cardio-
renal liability of COX-2 inhibitor drugs has severely restricted
their use as anti-inflammatory agents, especially for those with
very high selectivity for the COX-2 isoform that may obviate
physiological effects of COX-2 derived PGs and induced a
prothrombotic state.
The crystal structures of the inhibitor-bound COXs show that
the catalytic binding site is a long hydrophobic channel. From
a combination of the information from the 3-D crystal structures,
site-directed mutation studies, and kinetic experiments, the
rationale for inhibitor binding and COX-2 selectivity are
summarized as follows: Arg12031 at the entrance of the catalytic
active site forms a salt bridge with the carboxylic acid end of
the traditional NSAIDs, an interaction important for COX-1
inhibition by traditional NSAIDs, but not crucial for COX-2
inhibition.32,33 Therefore, carboxylic acids are not a structural
requirement for COX-2 selective inhibitors. Other amino acids
involved in the hydrogen-bonding network at the entrance for
binding inhibitors are Tyr355 and Glu524.34 In COX-1, Ile523
blocks the diaryl-heterocycle-type selective inhibitors from
entering the catalytic site.35 Because of the shorter side chain
of Val523 in COX-2, a side-pocket is created (17% increased
size) next to the main catalytic binding site. This side pocket is
referred to as the “selective binding site” because traditional
NSAIDs do not use this space. In the crystal structures of 1CX2
and 6COX, the aryl-sulfonamide group of SC-558, a bromo-
analog of the COX-2 selective inhibitor celecoxib, penetrates
deep into this side pocket and interacts with polar groups His90,
Glu192, and Arg513.36 There is a possibility that the hydrogen-
bonding network extends to nearby Glu524, which is part of
the hydrogen-bonding network at the entrance. In COX-1,
His513’s side chain is shorter, so even if the inhibitor can bypass
Ile523, it likely cannot interact with His513. The use of this
side-pocket and established hydrogen bonding to form a tight-
binding slowly reversible complex was suggested to be the
Nitric oxide (NO) also plays many important physiological
roles, including, vasoregulation, GI tissue protection,12 wound
healing,13 and inhibition of platelet activity.14 Because of its
cyctoprotective effects and its potent antiplatelet and vasore-
laxant properties, adjunctive NO has been considered a plausible
§
A portion of this work was presented in poster form at the 229th ACS
National Meeting (Medicinal Chemistry #194), March 13–17, 2005, San
Diego, CA.
* To whom correspondence should be addressed. Phone: 978-362-1812.
E-mail: swey@comcast.net.
10.1021/jm0611861 CCC: $37.00
2007 American Chemical Society
Published on Web 11/10/2007

6368 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
Scheme 1. Synthesis of Nitrate Tethers As Nitric Oxide
Donorsa
Figure 1. Three regions of modification on indomethacin.
reason for the selectivity. In the report on the modification of
meclofenamic acid, Kalgutkar et al.37 found that Tyr355 showed
a more important role in COX-2 inhibition than did Arg120
from their mutation binding studies. Since Try355 is conserved
in both isoforms, the authors suggest the selectivity must arise
from outside the entrance of the binding site, commonly, referred
to as the “lobby” region. The specific sequence differences
responsible for the selectivity of the amide derivatives of
meclofenamic acid were not identified.
Induced COX conformational changes after binding with
inhibitors caused by the flexibility and sequence differences of
the peptide chain have also been suggested to play a role in
isoform selectivity. For example, one of the sequence differences
between COX-1 and COX-2 is located at the junction of
R-helices C and D, which is the framework in front of the
catalytic binding site.38 As a result of an extra amino acid
inserted between R-helices C and D in COX-2, the R-helix D
that contains Arg120 has more flexibility at the entrance of the
binding site. The combination of these observations with the
kinetic data leads to a possible inhibition profile being proposed:
E + I / [EI] / EI*.39–43 The induced conformational change
resulted a tight-binding, slowly reversible enzyme (E)-inhibitor
(I) complex, EI*. COX-1 inhibition is usually time independent,
whereas COX-2 inhibition is time dependent. Therefore, the
equilibrium between weak complex [EI] and tight complex EI*
can influence selectivity, as may multiple stages of binding
complexes.44,45
There have been several reports of using traditional NSAID
as pharmacophores for the design and syntheses of new COX-2
selective inhibitors, including aspirin,46 meloxicam,47 nime-
sulide,48 meclofenamic acid,37 ketoprofen,49 flurbiprofen,50 and
indomethacin.51–56 Herein, we report the design and synthesis
of a nitric oxide-donating COX-2 selective inhibitor modified
from indomethacin that showed modest COX-2 selectivity in a
human whole-blood assay with improved GI safety, especially
when coadministered with aspirin.
Molecule Design. As shown in Figure 1, three regions of
modifications were preformed with the goal of enhancing the
COX-2 selectivity based on the information just summarized,
and improving its safety profile as a COX-2 selective inhibitor
by attaching a NO donor. From a comparison of the crystal
structures of inhibitor-bound COX-2 enzymes, 4COX (with
indomethacin) and 1CX2 (with SC-558), the 5-methoxy group
and the 6-position of the indomethacin are very close to Val523
and the methoxy group lines up with the sulfonamide group of
SC-558. Thus, the modifications on the 5- or 6-positions of the
indole ring were intended to increase the steric interaction with
Ile523 in COX-1, the probability of establishing a hydrogen-
bond with Arg513 in the selective binding site of COX-2, or
both. The second region of modification was at the N-1 position
of the indole ring. The 4-chlorobenzoyl group of the indometha-
cin, which binds in the apical pocket of the binding site, will
be replaced with cycloalkylalkyl and arylalkyl groups to explore
other hydrophobic residues that can bind in this cavity. Although
the specific sequence differences outside the binding site that
a Reagents and conditions: (a) 90% fuming HNO3, Ac2O, 0°C; (b) 90%
fuming HNO3, Ac2O, EtOAc, 0°C; (c) i. 90% fuming HNO3, Ac2O, AcOH,
0°C; ii. 2 N NaON; iii. HCl/Et2O; (d) AgNO3, acetonitrile.
are responsible for the selectivity were not identified by
Kalgutkar et al.,37 there are two uncharged polar amino acids
just outside the entrance on R-helix D, Tyr115 and Ser119 in
COX-2 instead of Leu115 and Val119 in COX-1,35 that may
influence the inhibitor binding by establishing hydrogen bonds
with a polar-end tether. Finally, since a carboxylic acid-end is
not a structural requirement for COX-2 inhibition, the 3-acetic
acid group of indomethacin was converted to alternative
functional groups and attached with either an alcohol or a nitrate
as a NO donor. These polar-end tethers may also serve to
establish possible hydrogen-bonding with Tyr115, Ser119, or
both outside the binding channel and, hence, may increase the
COX-2 selectivity.
Syntheses. The nitrate tethers for use as potential NO donors
were synthesized either according to or modified from literature
procedures. As shown in Scheme 1, the nitric acid salts of
3-(nitrooxy)propylamine 2 and 2,2-dimethyl-3-(nitrooxy)pro-
pylamine 4 were prepared from the nitration of the correspond-
ing amino alcohols with acetyl nitrate, prepared in situ from
90% fuming nitric acid and acetic anhydride. The free base of
Tris-trinitrate 6 was prepared according to a literature procedure
and was treated with dry hydrochloride in ethyl ether to afford
the salt for storage.57 All amine-nitrate derivatives were not
stable at room temperature for a long period of time and
therefore were kept in the freezer as ammonium salts. 3-(Ni-
trooxy)propan-1-ol58 8 and 4-[(nitrooxy)methyl]benzoic acid 10
were prepared from the corresponding bromo-derivatives and
silver nitrate in acetonitrile.
The 5-O-sulfamate compound 14 was prepared as shown in
Scheme 2. Demethylation of indomethacin with boron tribro-
mide in methylene chloride afforded the phenolic compound
12,59 a possible indomethacin metabolite. The amine-nitrate
tether 2 and 3-aminopropanol 1 were coupled to the 3-acetic
acid in the presence of N-(3-dimethylaminopropyl)-N′-ethyl-
carbodiimide hydrochloride (EDAC) to give examples 13 and
15, respectively. The phenolic group was then transformed to
O-sulfamate 14 by reaction with sulfamoyl chloride in N-methyl-
2-pyrrolidinone.60
The 4- and 6-chloro derivatives of indomethacin were
prepared starting from a Fisher indole synthesis as shown in
Scheme 3. Condensation between 3-chloro-4-methoxyphenyl-
hydrazine 16, which was prepared from 3-chloro-p-anisidine
following a literature procedure,61 and benzyl levulinate in

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6369
Scheme 2. Synthesis of 5-Position Modified Indomethacin and its Derivativesa
a Reagents and conditions: (a) BBr3, CH2Cl2; (b) 2, NEt3, DMAP, EDAC; (c) ClSO2NH2, N-methyl-2-pyrrolidinone; (d) 1, NEt3, DMAP, EDAC.
Scheme 3. Synthesis of 4- and 6-Chloro-indomethacin Derivativesa
a Reagents and conditions: (a) benzyl levulinate, AcOH, reflux; (b) 4-chlorobenzoyl chloride, DMAP, NEt3, CH2Cl2; (c) 10%Pd/C, H2 (30 psi), EtOAc,
MeOH; (d) 2, NEt3, DMAP, EDAC.
refluxing acetic acid gave compounds 17 and 18 in a ratio of
1:2. These two regioisomers were separated by column chro-
matography and were reacted with 4-chlorobenzoyl chloride in
the presence of 4-dimethylaminopyridine (DMAP) to obtain 19
and 20, respectively. 6-Chloro indomethacin 21 was obtained
by hydrogenation of benzyl ester 20 in the presence of 10% Pd
on carbon. The amine-nitrate tether 2 was then coupled to the
carboxylic acid to afford compound 22.
Syntheses to replace the 4-chlorobenzoyl group of in-
domethacin are shown in Scheme 4. Fisher indole synthesis
using 4-methoxyphenylhydrazine and ethyl levulinate in acetic
acid, followed by N-1 alkylation with 4-(bromomethyl)-1-
(methylsulfonyl)benzene62 using potassium t-butoxide as base,
gave compound 24a. After hydrolysis with aqueous sodium
hydroxide in THF, the acid 25a was coupled with amine-nitrate
tether 2 to give example 26a. The N-cyclohexylmethyl deriva-
tives 26b was synthesized using the same procedure as 26a
except (bromomethyl)cyclohexane was used for N-1 alkylation
of compound 23. The nitrate 29b was prepared from the
reduction of ethyl ester 24b with lithium aluminum hydride,
followed by the bromination with hydrobromic acid and then
reaction with silver nitrate.
by coupling with an amine-alcohol or an amine-nitrate in the
presence of EDAC. The amide derivative 34 and hydroxamic
acid 35 were prepared from the reaction of the acyl chloride of
indomethacin63 with Tris-trinitrate 6 or hydroxylamine. Acetyl-
derivatives of hydroxamic acid, examples 36 and 37, were
obtained by controlling the amount of acetic anhydride used in
the reaction. The O-alkyl hydroxamic acid derivatives, examples
38-40, were prepared from the coupling reaction with the
corresponding O-alkyl hydroxylamines. The O-alkyl-hydroxyl-
amines 43 and 44 were prepared from O-alkylation of N-
hydroxyphthalimide with bromoalcohols in the presence of
sodium acetate followed by deprotection with hydrazine.64
Other modifications on the 3-acetic acid of indomethacin started
from borane reduction of indomethacin to give ethanol derivative
45, as shown in Scheme 6. The ethanol derivative 45 was then
transformed to nitrate 47, bromide 48, and azide 54 through a
common intermediate, mesylate 46. The phosphonic acid 50 were
synthesized via an Abuzov reaction by reacting bromide 48 with
trimethyl phosphite, followed by hydrolysis with bromotrimeth-
ylsilane.65 The carboxylsulfamide 51 and carboxylsulfamate 52
were prepared from the reaction of ethanol derivative 45 and
chlorosulfonyl isocyanate followed by the addition of nitrate tethers
2 or 8. Phosgene was used in the preparation of carbamate 53
through the formation of the chloroformate of 45. The amine
As shown in Scheme 5, the amide derivatives of indometha-
cin, compounds 30-33, were all prepared in the same manner

6370 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
Scheme 4. Synthesis of N-Modified Indomethacin and its Derivativesa
a Reagents and conditions: (a) ethyl levulinate, AcONa, AcOH, reflux; (b) t-BuOK, 4-(bromomethyl)-1-(methylsulfonyl)benzene for 24a or (bromom-
ethyl)cyclohexane for 24b; (c) 2 N NaOH, THF; (d) 2, NEt3, EDAC; (e) LiAlH4; (f) HBr; (g) AgNO3, acetonitrile.
Scheme 5. Preparation of Indomethacin Amide and Hydroxamic Acid Derivativesa
a Reagents and conditions: (a) amines, NEt3, DMAP, EDAC; (b) i. (COCl)2, CH2Cl2; ii. 6, NEt3; (c) i. (COCl)2, CH2Cl2; ii. NH2OH·HCl, DMAP; (d)
Ac2O (1.3 equiv), DMAP, DMSO; (e) Ac2O (large excess), DMSO; (f) O-benzylhydroxylamine, EDAC, NEt3, CH2Cl2; (g) 43 or 44, EDAC, NEt3, CH2Cl2;
(h) AcONa, 2-bromoethanol or 3-bromopropan-1-ol, DMSO, 70°C; (i) N2H4 ·H2O, MeOH, 70°C.
derivative 55 was prepared from the hydrogenation of azide 54 in
the presence of acetic acid and was converted to the hydrochloride
salt to prevent possible N-1 benzoyl group transposition to the
primary amine. The benzyl nitrate tether 10 was coupled to the
amine 55 in the presence of triethylamine and EDAC to afford
the inverse amide 56. The urea derivative 57 was prepared through
the formation of the carbamoyl imidazole intermediate of amine
55, followed by the addition of amine-nitrate tether 2. The
sulfonamide derivatives 58 and 60 were obtained from the reaction
of the corresponding sulfonyl chloride with amine 55 and were
converted to their nitrate derivatives, examples 59 and 61, with
silver nitrate in refluxing acetonitrile. Although 4-(bromomethyl)
benzenesulfonyl chloride was used in the preparation of sulfona-
mide derivative 58, the chloromethyl derivative was isolated
because of the halogen exchange in the reaction mixture. Initial
attempts to prepare alcohol 62, not shown in the scheme, through
the conversion of chloride 60 to acetate, followed by hydrolysis,
proved unsuccessful. Under the basic conditions for hydrolysis of
the acetate, a mixture of a cyclic sulfonamide, removal of
4-chlorobenzoyl group product, or both were obtained. The alcohol
derivative 62 was prepared from the hydrogenation of the nitrate
61 using 10% Pd/C as catalyst. Hydrogenation usually will reduce
chlorobenzene, but in our preparation of examples 55 and 62, the
N-1 chlorobenzoyl group remains intact.
Results and Discussion
COX Inhibitory Activity. Compounds were assayed for
COX inhibition using a human whole-blood assay.66,67 After

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6371
Scheme 6. Modifying the 3-Acetic Acid of Indomethacin to Ethanol or Ethyl Amine Derivativesa
a Reagents and conditions: (a) BH3 ·SMe2, THF; (b) CH3SO2Cl, NEt3; (c) (Bu4N)+NO3-, toluene, 100°C; (d) LiBr, acetone, 55°C; (e) P(OMe)3, 110°C;
(f) TMSBr, CH2Cl2; (g) chlorosulfonyl isocyanate, NEt3, 2 or 8; (h) i. phosgene/toluene, K2CO3, THF, 50°C; ii. 2, DMAP, THF; (i) NaN3, DMSO, 50°C;
(j) i. 10% Pd/C, H2 (30 psi), AcOH; ii. Na2CO3 then HCl/Et2O; (k) EDAC, NEt3, DMAP, 10; (l) CDI then 2, NEt3; (m) 4-(bromomethyl)benzenesulfonyl
chloride, NEt3; (n) AgNO3, reflux; (o) 3-chloropropanesulfonyl chloride, NEt3; (p) 10% Pd/C, H2 (35 psi).
Table 1. Selected Examples of COX Inhibitory Activity and Selectivity
sulfamate group might be entering the selective binding site
and interacting with Arg513 as we anticipated, but simulta-
neously lowering the COX inhibitory potency. Both benzyl
esters of 4- and 6-chloro-indomethacin, examples 19 and 20,
showed weak inhibitory activity (data not shown in Table 1).
6-Chloro-indomethacin 21 appears to more favor inhibition of
COX-1 but is not as potent as indomethacin. A chlorine atom
at the 6-position is either not large enough to cause unfavorable
interaction with Ile523 or, perhaps, is too big and causes
indomethacin to adopt another binding mode. As suggested by
Loll et al., another possible conformation for 4′-iodo-indometha-
cin binding in COX-1 is a trans form, as depicted in the crystal
structure of 1PGG.68 Example 22, attaching an amide linker to
6-chloro indomethacin favors COX-2 inhibition by almost
3-fold.
COX-1 IC50
COX-2 IC50
COX-1/
COX-2
examplea
(µM)
(µM)
11
0.5
0.19
15.6
4.7
0.7
0.44
5.0
3.5
26.3
3.0
4.1
5.8
1.2
1.8
1.2
1.2
0.7
10
0.7
0.4
3.1
1.4
>4
1.8
0.4
2.7
2.0
1.8
5.0
2.1
<0.4
0.3
9.1
3.5
11.7
7.6
11b
12
13
14
15
21
22
30
31
32
33
40
57
61
62
>100
5.4
1.6
15.9
2.4
3.3
6.0
2.6
<0.3
3.0
11
3.7
14
6.7
1.2
1.1
1.2
0.87
Replacement of the 4-chlorobenzoyl group of indomethacin
with a 4-bromobenzyl group was reported to give excellent
COX-2 selectivity.51 In our series, replacement of the 4-chlo-
robenzoyl group with a (methylsulfonyl)benzyl, example 25a,
or a cyclohexylmethyl group, example 25b, severely compro-
mised the inhibition of both COX isozymes. The attachment of
an amide-nitrate linker did not improve the inhibitory activity
for the (methylsulfonyl)benzyl derivative, example 26a, but did
cause a minor improvement for the cyclohexylmethyl derivative
26b. The ethanol derivative of cyclohexylmethyl series, example
27b, and its nitrate derivative 29b also show weak inhibitory
activity.
celecoxib
celecoxibb
a See Supporting Information for screening data of all examples. b Values
as reported in ref 67.
initial screening at three concentrations, COX-1 (100 µM) and
COX-2 (1 and 10 µM), the active compounds were selected
for IC50 determination. The complete screening data of all
compounds is available as Supporting Information. The most
promising compounds were further examined using in vivo
experiments for antiinflammatory activity, gastric tolerability,
and NO donor activity.
The indomethacin alkyl-amide derivatives 30-33 increased
COX-2 inhibition from 2- to 5-fold. Decreased selectivity of
compound 33 is most likely caused by the branched side chain
still fitting well in the lobby region of COX-1 and thus exhibiting
better affinity for this subtype. However, this size effect did
not impart a selectivity advantage for COX-2 because the lobby
region of COX-2 has more flexibility.38 An alkyl group with
In our studies, as shown in Table 1, indomethacin (11) slightly
favors COX-1 inhibition and celecoxib showed 11.7-fold COX-2
selectivity. The demethylated indomethacin, example 12, favors
COX-2 inhibition by 3-fold, and incorporation of an amide tether
as in examples 13 and 15 slightly decreases the selectivity. The
5-O-sulfamate group in example 14 does restore COX-2
selectivity by greater than 4-fold. This suggests the 5-O-

6372 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
Figure 2. Anti-inflammatory activity: Rat carrageenan air-pouch model
(intrapouch dosing). Values are means ( SEM (n ) 8–15). Statistical
analysis by ANOVA ,followed by Dunnett’s multiple comparison test
((*) p < 0.05 vs vehicle, (**) p < 0.01 vs vehicle). V: vehicle (0.5%
methylcellulose). Dose for all examples was 45 µmol/kg.
Figure 4. NOx concentration in rat plasma. Values are means ( SEM
(n ) 3). Statistical analysis by ANOVA, followed by Dunnett’s multiple
comparison test ((*) p < 0.05 vs vehicle). V: vehicle (0.5% methyl-
cellulose). Oral dose for all examples was 45 µmol/kg, except for
indomethacin (11), whose dose was 22.5 µmol/kg.
Figure 3. Anti-inflammatory activity: Rat carrageenan air-pouch model
(oral dosing). Values are means ( SEM (n ) 6–22). Statistical analysis
by ANOVA, followed by Dunnett’s multiple comparison test ((*) p <
0.05 vs vehicle, (**) p < 0.01 vs. vehicle). V: vehicle (0.5% meth-
ylcellulose). Dose for all examples was 45 µmol/kg, except for
indomethacin (11), whose dose was 22.5 µmol/kg.
Figure 5. Rat gastric lesion scores. Values are means ( SEM (n )
4–12). Statistical analysis by ANOVA, followed by Dunnett’s multiple
comparison test ((**) p < 0.01 vs indomethacin 11). V: vehicle (0.5%
methylcellulose). Dose concentration for all examples was 45 µmol/
kg.
only example 32 increased rat plasma nitrite plus nitrate (NOx)
concentration, as shown in Figure 4, indicating that the nitrate
tether acted as a NO donor. Since the attachment of a NO donor
to improve the safety profiles of COX-2 inhibitor drugs is the
primary goal of this research, the pair of propoxy-amide
derivatives, examples 31 and 32, were further examined for GI
tolerance.
The amide derivatives, 31 and 32, both show a 98% reduction
in gastric lesion score when compared to equimolar indometha-
cin as shown in Figure 5. Although low-dose aspirin is routinely
used for cardiovascular prophylaxis, concomitant use of aspirin
and a COX-2 inhibitor increases gastric damage when compared
to using either aspirin or the COX-2 inhibitor alone.10,11,69 This
adverse effect was not significant for example 32 when
administered with background aspirin treatment compared to
the valdecoxib and aspirin treatment group as shown in Figure
6. The gastric-sparing effect (85% reduction) is especially
noteworthy given the 4.7-fold greater dose of 32 versus
valdecoxib when coadministered with aspirin.
increased steric bulk, example 34, diminishes the COX-2
selectivity in this series. These results contrast with data from
a purified enzyme assay in which a two-carbon alkyl amide
analogue of compound 31 was reported to have a 290-fold
selectivity for COX-2.54 The derivatives of hydroxamic acid
35-37 showed no COX-2 selectivity. Because the immediate
binding site for the acid group is conserved in both COX
enzymes, a short aliphatic chain most likely will not have a
strong influence on COX selectivity. However, hydroxamic acid
derivatives 38-40 favor COX-1 inhibition as opposed to the
amide derivatives 30-33. Perhaps the preferred binding con-
formation of hydroxamic acid directs the alkyl chain to the
surface of the enzyme instead of in-line with binding channel
to the lobby region.
The nitrate 47, phosphoric acid 50, carboxylsulfamide 51,
carboxylsulfamate 52, carbamate 53, and amine 55 derived from
alcohol 45 lost their ability to inhibit COX isozymes. The inverse
amide 56, urea 57, and aryl-sulfonamide 59 derived from amine
55 also showed no COX-2 selectivity. However, the nitrate of
alkyl-sulfonamides, example 61, showed 9-fold selectivity, and
its alcohol, example 62, showed 4-fold COX-2 selectivity. Both
nitrate derivatives 32 and 61 showed better COX-2 selectivity
than the corresponding alcohols, examples 31 and 62. The
improved selectivity of nitrate derivatives was also reported
previously in pyrazoles derivatives.29
In Vivo Pharmacological Profiling. In the rat air pouch
model, amide derivatives 31 and 32 and alkyl-sulfonamide
derivatives 61 and 62 significantly reduced the PGE2 level when
administered intrapouch by 97%, 99%, 59% and 98%, respec-
tively, as shown in Figure 2. The oral dosing air pouch
experiment, as shown in Figure 3, also showed these four
compounds significantly reduced the PGE2 level as evidence
of their antiinflammatory activity. These two sets of experiments
suggested example 62 has the best bioavailability and least
protein binding affinity followed by 31, 32 and 61. However,
Conclusion
We have identified several modifications of indomethacin
yielding derivatives that increase this NSAID’s COX-2 selectiv-
ity and safety: the 5-phenol 12 and 5-O-sulfamate 14 derivatives,
the alkyl-amide derivatives 30–33, and the inversed alkyl-
sulfonamide derivatives 61 and 62. The 5-O-sulfamate derivative
14 was COX-2 selective but at higher concentration. The nitrated
sulfonamide derivative 61 showed the highest COX-2 selectivity,
but the nitrate tether did not increase plasma NOx concentration
in vivo. With the assumption that the binding mode did not
change because of these modifications, a straight-chain, polar-
end tether might have some influence on COX binding and
selectivity. Potential interactions between the straight-chain polar
group and Tyr115, Ser119, or both in the lobby region would
need to be confirmed through mutation studies. Nevertheless,

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6373
(Kingston or Raleigh). Animal care and use were in accord with
NitroMed’s IACUC guidelines. Rats were randomly housed 5 per
cage and allowed to acclimate on a 12/12 reverse light/dark cycle
with standard chow and water available ad libitum for at least 48 h
before the experiment. Air pouches were produced by subcutaneous
injection of 20 mL of sterile air on day (-6) into the intrascapular
area on the back of the anesthetized rats. An additional 10 mL of
sterile air was injected into the pouch on day (-3) to keep the
pouch open and allow the interior membrane to develop. On day
(-1), rats were fasted 18 h before the experiment (water ad libitum)
in cages equipped with metal floor racks. On day 0, the pulverized
test compounds in 0.5% methocel or vehicle were either injected
into the pouch or dosed orally in blinded fashion, 1 h prior to
carrageenan injection (1 mL of 1.0% carrageenan in saline). After
4 h, PBS/heparin (Invitrogen Corporation, Carlsbad, CA) was
injected into the pouch, which was then massaged gently for 15–20
s. The rat was then quickly sacrificed using carbon dioxide, and
the inflammatory exudate was collected from the pouch. The
exudates were assayed for PGE2 with an enzyme-linked immu-
noassay kit (Cayman).
Figure 6. Aspirin-induced rat gastric lesions. Values are means (
SEM (n ) 3–11). Statistical analysis by ANOVA, followed by
Newman-Keuls multiple comparison test ((**) p < 0.001 vs all other
groups). V1: vehicle (1.0% methylcellulose). V2: vehicle (0.5% meth-
ylcellulose). asp: aspirin (139 µmol/kg). val: valdecoxib (9.5 µmol/
kg). Compound 32 (45 µmol/kg).
we have successfully designed and synthesized a NO-enhanced
COX-2 selective inhibitor, example 32 (IC50 ) 1.2 µM with
5-fold selectivity), from indomethacin which is an effective
antiinflammatory agent in vivo, while being exceptionally well
tolerated without apparent GI liability by itself and, most
notably, when coadministered with aspirin. On the basis of a
prior detailed analysis of indomethacin phenethylamide me-
tabolism in the rat,70 the amide linker of example 32 should be
virtually immune to amidase hydrolysis such that negligible
indomethcin would be generated. Consequently, our approach
toward an NO-enhanced anti-inflammatory agent differs from
the “pro-drug” approach commonly use in the synthesis of
nitrated NSAID esters.
NOx in Rat Plasma. Rat plasma was collected by heart puncher
at the termination of the air-pouch (4 h after oral dosing) described
above. Plasma NOx (the sum of inorganic nitrite and nitrate) was
quantified with a fluorometric kit (Cayman).
Rat Gastric Injury Model. Rats were acclimated as described
for the air pouch model (above) and were fasted 18 h before the
experiment (water ad libitum) in cages equippedwith metal floor
racks. Water was removed 1 h before the experiment and returned
after dosing and removed again 1 h prior to examination of the
stomach. The pulverized test compounds were homogenized with
a glass/Teflon pestle homogenizer in 0.5% methocel and were
prepared immediately before dosing. The test compounds were
administered intragastrically (p.o.) at a dose volume of 1 mL/kg
using an 18-gauge gavage needle. The rats were sacrificed 3 h after
dosing using carbon dioxide. The stomach was removed, opened
along the greater curvature, rinsed, mounted on a Petri dish, and
digitally photographed. The images were analyzed by staff blinded
to drug treatment using Image J Analysis software for visible
hemorrhagic lesions. The length of each lesion was recorded, and
all lesion lengths were summed as the total lesion score. Values
are given as the means ( SEM over 4–12 animals. The significance
of differences between means was evaluated using a one-way
analysis of variance (ANOVA), followed by Dunnett’s multiple
comparison test. P < 0.05 was considered significant.
Aspirin-Induced Rat Gastric Damage Model. A minimum of
72 h was allowed for acclimation of rats, as described above. The
experiment was performed in six groups with 3–11 animals per
group. All test compounds including aspirin were pulverized with
a mortar and pestle and homogenized by vortexing with 2–3 layers
of glass beads in sufficient amount of vehicle. All compounds were
prepared immediately before dosing and were administered intra-
gastrically using gavage needles at a dose volume of 1.0 mL/kg.
Aspirin was suspended in 1.0% methocel, whereas test compounds
were suspended in 0.5% methocel. Four groups of animals were
dosed intragastrically with aspirin (25 mg/kg); then the test
compounds were dosed 2 min later. After 3 h, the rats were
sacrificed and subjected to gastric lesion scoring as described above.
3-(Nitrooxy)propylamine Nitric Acid Salt (2). A solution of
3-amino-1-propanol (6.17 g, 82.2 mmol) was added, dropwise, to
an ice-cooled solution of fuming nitric acid (90%, 12 mL) in acetic
anhydride (50 mL). The reaction was stirred in an ice-bath for 10
min and then at room temperature for 10 min. The solvent was
evaporated under vacuum at 40 °C. The residue was stirred in Et2O
(200 mL) until the product precipitated. The mixture was filtered,
and the white crystalline solid was dried in vacuo to give the title
compound (12.1 g, 80% yield). 1H NMR (DMSO-d6, 300 MHz): δ
4.57 (br. t, 2 H), 2.8–3.0 (m, 2H), 1.98–1.93 (m, 2H). 13C NMR
(DMSO-d6, 75 MHz): δ 70.9, 36.1, 24.5. MS (API-TIS): m/z 121
(M - NO3)+.
Experimental Section
Reagents and solvents were used as obtained from commercial
suppliers. 1H and 13C NMR spectra were recorded on a 300 (Bruker
AMX) or 400 MHz (Bruker AVANCE) spectrometer, and the
chemical shifts are reported in parts per million (ppm) relative to
tetramethylsilane. Mass spectra were recorded on a PE SCIEX, API
150EX instrument using the turbo ion spray atmospheric pressure
ionization method. Melting points were determined on a MEL-
TEMP apparatus and are uncorrected. Elemental analyses were
performed by Robertson Microlit Laboratories (Madison, NJ). Flash
column chromatography was performed using EMD silica gel 60H.
Thin-layer chromatography was carried out on EMD silica gel 60
F254 TLC plates and visualized under UV or by staining with
phosphomolybdate or KMnO4 solution.
Human Whole-Blood COX Inhibition Assay.66 Human whole
blood from consenting donors of either sex who had not taken any
NSAIDs for two weeks were collected in sodium heparin (20 units/
mL). Test compounds at various concentrations, dissolved and
diluted in DMSO at 1000 times the final concentrations, were added
in duplicate to 1 mL per well aliquots of blood in a 24-well plate.
After 15 min of incubation at 37 °C in a CO2 incubator, LPS at 10
µg/mL was added to the appropriate wells to induce COX-2. At
4.5 h after test compound addition, A23187 was added at 25 µM
to other wells to activate COX-1. Vehicle control wells received
equal volumes of DMSO. At 30 min after A23187 activation, that
is, 5 h after LPS addition, reactions were terminated by placing
the 24-well plates on ice and addiing 2 mM EGTA. Plasma was
collected and extracted with methanol overnight at -20 °C. After
evaporation, the thromboxane B2 (TXB2) in each sample was
measured in duplicate with an enzyme-linked immunoassay kit
(Cayman Chemical, Ann Arbor, MI). The results were normalized
against vehicle (control) values and expressed as % control of COX
activity, and an IC50 was determined over the concentration range
tested.
Rat Carrageenan Air Pouch Studies.2 Male Sprague–Dawley
rats (180–200 g) were purchased from Charles River Laboratories

6374 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
2,2-Dimethyl-3-(nitrooxy)propylamine Nitric Acid Salt (4).
A solution of 3-amino-2,2-dimethylpropanol (6.0 g, 82.2 mmol) in
EtOAc (40 mL) was added, dropwise, to an ice-cooled solution of
fuming HNO3 (90%, 8 mL) in acetic anhydride (50 mL). The
reaction was stirred in an ice-bath for 10 min and an additional 10
min at room temperature. The solvent was evaporated under vacuum
at 40 °C. The residue was stirred in Et2O (200 mL) until the product
precipitated. The mixture was filtered, and the white solid was dried
in vacuo to give the title compound (6.55 g, 53% yield). mp:
114–115 °C. 1H NMR (DMSO-d6, 300 MHz): δ 7.92 (br, 3H), 4.37
(s, 2H), 2.81 (br. s, 2 H), 1.03 (s, 6H). 13C NMR (DMSO-d6, 75
MHz): δ 77.5, 45.6, 33.3, 21.9. MS (API-TIS): m/z 149 (M -
NO3)+.
3-(Nitrooxy)propan-1-ol (8). A solution of 3-bromo-1-propanol
(5.42 g, 39.0 mmol) in acetonitrile (20 mL) was added to a solution
of AgNO3 (10.16 g, 59.8 mmol) in acetonitrile (50 mL) and stirred
at room temperature for 24 h. To the reaction mixture was added
brine (350 mL), and the mixture was stirred for 1 h. The silver
salts were filtered off through Celite, and the filtrate was extracted
with Et2O (200 mL × 3). The organic layer was washed with brine,
dried over Na2SO4, filtered, concentrated, and dried under vacuum
to give the title compound (4.08 g, 86% yield, > 95% purity) that
was used in the next step without purification. 1H NMR (300 MHz,
CDCl3): δ 4.61 (t, J ) 6.4 Hz, 2H), 3.78 (t, J ) 6.4 Hz, 2H), 1.99
(m, 2H). 13C NMR (75 MHz, CDCl3): δ 70.3, 58.5, 29.5.
4-[(Nitrooxy)methyl]benzoic Acid (10). A solution of AgNO3
(17.73 g, 104.4 mmol) and R-bromo-p-toluic acid (10.84 g, 50.4
mmol) in THF (150 mL) and acetonitrile (150 mL) was stirred at
room temperature overnight and then at 50 °C for 1 h. The reaction
mixture was then cooled to room temperature and stirred with brine
(150 mL) for 1 h. The resulting mixture was filtered through Celite
and washed with water. The filtrate was concentrated and then
extracted with ethyl acetate. The combined organic layers were
washed with water, brine, dried over Na2SO4, filtered, concentrated,
and dried under vacuum. The crude product was washed with
CH2Cl2 (50 mL) on a Buchner funnel and then dried under vacuum
to give the title compound as a white solid (7.27 g, 73% yield).
mp: 159–161 °C. 1H NMR (300 MHz, DMSO-d6): δ 8.02 (d, J )
8.1 Hz, 2H), 7.60 (d, J ) 8.1 Hz, 2H), 5.67 (s, 2H). 13C NMR (75
MHz, DMSO-d6): δ 166.9, 137.3, 131.4, 129.7, 129.0, 74.3. MS
(API-TIS): m/z 196 (MH)+.
2-{1-[(4-Chlorophenyl)carbonyl]-5-hydroxy-2-methylindol-3-
yl}acetic Acid (12). A solution of BBr3 (54 mL, 1 M in CH2Cl2,
54 mmol) was added slowly to an ice-cold solution of indomethacin
(9.4 g, 26.3 mmol) in CH2Cl2 (100 mL) and stirred at room
temperature overnight. The resulting mixture was poured onto
crushed ice (250 g) and extracted with EtOAc (200 mL × 3). The
combined organic extracts were washed with water and brine, dried
over Na2SO4, filtered, and concentrated. The resulting solid was
washed with Et2O and dried under vacuum to obtain the title
compound as a yellowish solid (6.49 g, 72% yield). mp: >205 °C
(dec.). 1H NMR (300 MHz, CD3OD): δ 7.65 (d, J ) 8.5 Hz, 2H),
7.53 (d, J ) 8.5 Hz, 2H), 6.89 (d, J ) 2.4 Hz, 1H), 6.82 (d, J )
8.9 Hz, 1H), 6.54 (dd, J ) 8.9, 2.4 Hz, 1H), 3.62 (s, 2H), 2.34 (s,
3H). 13C NMR (75 MHz, CD3OD): δ 175.2, 170.0, 154.6, 140.0,
136.6, 135.9, 132.5, 132.3, 131.8, 130.2, 115.9, 114.6, 113.0, 104.5,
30.8, 13.5. MS (API-TIS): m/z 344 (MH)+. Anal. (C18H14ClNO4)
C, H, N.
2H), 7.61 (d, J ) 8.5 Hz, 2H), 6.88 (d, J ) 8.8 Hz, 1H), 6.84 (d,
J ) 2.1 Hz, 1H), 6.54 (dd, J ) 8.9, 2.4 Hz, 1H), 4.47 (t, J ) 6.4
Hz, 2H), 3.43 (s, 2H), 3.13 (br. q, 2H), 2.19 (s, 3H), 1.79 (m, 2H).
13C NMR (75 MHz, DMSO-d6): δ 169.8, 167.9, 153.4, 137.5,
134.9, 134.5, 131.1, 129.6, 129.1, 114.6, 114.0, 112.0, 103.7, 71.7,
35.3, 31.3, 26.5, 13.4. MS (API-TIS): m/z 446 (MH)+.
1-[(4-Chlorophenyl)carbonyl]-2-methyl-3-({N-[3-(nitrooxy)-
propyl]carbamoyl}methyl)indol-5-yl Aminosulfonate (14). A
solution of sulfamoyl chloride (0.19 g, 1.7 mmol) and 13 (0.19 g,
0.4 mmol) in N-methyl-2-pyrrolidinone (NMP, 3 mL) was stirred
at room temperature for 4 h. The reaction was quenched with brine
and extracted with a mixture of EtOAc (20 mL) and CHCl3 (50
mL). The organic extracts were washed with water and brine, dried
over Na2SO4, filtered, and concentrated. The crude material was
dissolved in CHCl3 (50 mL) and stirred with water (30 mL)
overnight to remove trace amounts of NMP. The white solid
suspended in the CHCl3 layer was collected and dried under vacuum
(0.105 g, 48% yield). mp: 146–148 °C. 1H NMR (300 MHz,
DMSO-d6): δ 8.11 (br. t, 1H), 7.90 (br. s, 2H), 7.71 (d, J ) 8.4
Hz, 2H), 7.65 (d, J ) 8.4 Hz, 2H), 7.46 (d, J ) 2.1 Hz, 1H), 7.11
(d, J ) 8.9 Hz, 1H), 7.01 (dd, J ) 8.9, 2.1 Hz, 1H), 4.47 (t, J )
6.2 Hz, 2H), 3.52 (s, 2H), 3.13 (br. q, 2H), 2.22 (s, 3H), 1.79 (m,
2H). 13C NMR (75 MHz, DMSO-d6): δ 169.8, 167.9, 153.4, 137.5,
134.9, 134.5, 131.1, 129.6, 129.1, 114.6, 114.0, 112.0, 103.7, 71.7,
35.3, 31.3, 26.5, 13.4. MS(API-TIS): m/z 525 (MH)+. Anal.
(C21H21ClN4O8S) C, H, N.
2-{1-[(4-Chlorophenyl)carbonyl]-5-hydroxy-2-methylindol-3-
yl}-N-(3-hydroxypropyl)acetamide (15). A solution of 12 (0.84
g, 2.4 mmol), 3-amino-1-propanol (0.2 mL, 2.6 mmol), DMAP (35
mg, 0.29 mmol), EDAC (0.57 g, 2.97 mmol), and NEt3 (0.37 mL,
2.7 mmol) in CH2Cl2 (100 mL) was stirred at room temperature
overnight. The reaction mixture was partitioned between 3 N HCl
(30 mL) and CH2Cl2 (50 mL × 2). The combined organic extracts
were washed with water and brine, dried over Na2SO4, filtered,
and concentrated. The product was separated by silica gel column
chromatography eluted with MeOH/CHCl3 (gradient from 1:20 to
1
1:15) to obtain the title compound (0.56 g, 57% yield). H NMR
(300 MHz, 10% CD3OD/CDCl3): δ 7.65 (d, J ) 8.5 Hz, 2H), 7.48
(d, J ) 8.5 Hz, 2H), 6.81–6.8 (m, 2H), 6.68 (br. t, 1H), 6.61 (dd,
J ) 8.9, 2.4 Hz, 1H), 3.57 (s, 2H), 3.54 (t, J ) 5.8 Hz, 2H), 3.32
(q, J ) 5.8 Hz, 2H), 2.36 (s, 3H), 1.61 (m, 2H). 13C NMR (75
MHz, 10% CD3OD/CDCl3): δ 171.8, 168.6, 153.1, 139.4, 136.0,
133.6, 131.0, 130.4, 130.3, 129.1, 115.0, 112.5, 102.8, 59.5, 36.9,
31.9, 31.4, 13.0. MS (API-TIS): m/z 401 (MH+).
3-Chloro-4-methoxyphenylhydrazine Hydrochloride (16). A
solution of NaNO2 (4.77 g, 69.1 mmol) in water (15 mL) was added
to an ice-cold mixture of 3-chloro-p-anisidine in 6 N HCl (100
mL) and stirred for 20 min. The resulted solution was added slowly
to a solution of SnCl2 ·2H2O in HCl (conc., 250 mL) at -5 °C.
The reaction mixture was stirred at room temperature for 1 h. The
crude material was collected by filtration, dissolved in MeOH (500
mL), dried over Na2SO4, filtered, and concentrated. The resulting
yellowish solid was washed with Et2O (300 mL) and dried under
vacuum to obtain the title compound (13.62 g, 99% yield). 1H NMR
(300 MHz, DMSO-d6): δ 10.4 (br, 4H), 7.24 (d, J ) 2.1 Hz, 1H),
7.2–7.0 (m, 2H), 3.8 (s, 3H). 13C NMR (75 MHz, DMSO-d6): δ
149.8, 139.6, 121.2, 117.4, 115.4, 113.5, 56.4.
Phenylmethyl 2-(4-chloro-5-methoxy-2-methylindol-3-yl)ac-
etate (17) and Phenylmethyl 2-(6-chloro-5-methoxy-2-methylin-
dol-3-yl)acetate (18). Benzyl levulinate (7.23 g, 35.1 mmol) and
16 (7.53 g, 36.0 mmol) was heated to reflux in acetic acid (100
mL) for 3 h. After the mixture was cooled down to room
temperature, acetic acid was removed under vacuum. The residue
was partitioned between water (100 mL) and EtOAc (100 mL ×
2). The combined organic extracts were washed with saturated
NaHCO3, 3 N HCl, water, and brine, dried over Na2SO4, filtered,
and concentrated. The product was separated by silica gel column
chromatography eluted with EtOAc/hexane (gradient from 1:3 to
1:2, Rf ) 0.2, 0.1). The data for the more-polar compound 17 (1.96
g, 16% yield) follow. mp: 124–125 °C. 1H NMR (300 MHz,
CDCl3): δ 7.93 (br, 1H), 7.4–7.3 (m, 5H), 6.98 (d, J ) 8.7 Hz,
2-{1-[(4-Chlorophenyl)carbonyl]-5-hydroxy-2-methylindol-3-
yl}-N-[3-(nitrooxy)propyl]acetamide (13). A solution of 12 (1.46
g, 4.3 mmol), 2 (0.87 g, 4.8 mmol), DMAP (100 mg, 0.82 mmol),
EDAC (1.07 g, 5.6 mmol), and NEt3 (1.8 mL, 12.9 mmol) in
CH2Cl2 (50 mL) was stirred at room temperature for 4 h. The
reaction mixture was partitioned between 3 N HCl (30 mL) and
CH2Cl2 (50 mL × 2). The combined organic extracts were washed
with water and brine, dried over Na2SO4, filtered, and concentrated.
The crude material was dissolved in EtOAc (5 mL) and CH2Cl2 (5
mL) and triturated with Et2O (80 mL). The solid was collected
and dried under vacuum to obtain the title compound as a white
1
solid (0.89 g, 47% yield). mp: 135–137 °C. H NMR (300 MHz,
DMSO-d6): δ 9.19 (s, 1H), 8.02 (br. t, 1H), 7.67 (d, J ) 8.5 Hz,

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6375
1H), 6.78 (d, J ) 8.7 Hz, 1H), 5.17 (s, 2H), 3.99 (s, 2H), 3.88 (s,
3H), 2.21 (s, 3H). 13C NMR (75 MHz, CDCl3): δ 173.0, 148.9,
136.0, 135.7, 131.7, 128.4, 128.0, 125.9, 112.7, 109.1, 108.7, 103.9,
66.5, 55.9, 30.7, 11.3. MS (API-TIS): m/z 344 (MH+). The less-
polar compound 18 (4.11 g, 33% yield) can be recrystallized from
with 5% MeOH/Et2O, and dried under vacuum to obtain the title
compound as a yellowish solid (0.61 g, 59% yield). mp: 154–155
°C. 1H NMR (300 MHz, CDCl3): δ 7.66 (d, J ) 8.5 Hz, 2H), 7.51
(d, J ) 8.5 Hz, 2H), 7.15 (s, 1H), 6.92 (s, 1H), 5.73 (br. t, 1H),
4.42 (t, J ) 6.2 Hz, 2H), 3.92 (s, 3H), 3.64 (s, 2H), 3.34 (br. q,
2H), 2.33 (s, 3H), 1.89 (m, 2H). 13C NMR (75 MHz, CDCl3): δ
169.5, 167.8, 151.0, 137.7, 135.5, 133.9, 131.2, 129.7, 129.6, 129.0,
117.2, 115.2, 114.1, 101.6, 71.6, 56.4, 35.2, 31.1, 26.4, 13.5. MS
(API-TIS): m/z 494 (MH)+.
1
Et2O and hexane. mp: 94–95 °C. H NMR (300 MHz, CDCl3): δ
7.74 (br, 1H), 7.3–7.2 (m, 6H), 6.97 (s, 1H), 5.11 (s, 2H), 3.81 (s,
3H), 3.68 (s, 2H), 2.33 (s, 3H). 13C NMR (75 MHz, CDCl3): δ
171.8, 149.3, 135.8, 134.0, 129.6, 128.4, 128.2, 128.0, 117.1, 111.7,
104.1, 100.8, 66.5, 56.5, 30.4, 11.6. MS(API-TIS): m/z 344 (MH)+.
Anal. (C19H18ClNO3) C, H, N.
Ethyl 2-(5-methoxy-2-methylindol-3-yl)acetate (23). A stirred
mixture of 4-methoxyphenylhydrazine hydrochloride (26 g, 0.149
mol), ethyl levulinate (21.5 g, 0.149 mol), and sodium acetate (12.2
g, 0.149 mol) in glacial acetic acid (200 mL) was heated at reflux
for 3 h. The reaction mixture was concentrated to dryness. The
residue was dissolved in ethanol (120 mL), treated with 4 M HCl
in 1,4-dioxane (80 mL), and heated at a gentle reflux for 15 h. The
mixture was concentrated to remove the volatiles, and the residue
was taken up with EtOAc, washed with water, aqueous K2CO3,
and brine. The organic layer was dried over Na2SO4, filtered, and
concentrated. Chromatography of the residue (1:1 EtOAc/hexane,
silica gel) afforded the title compound (28 g, 76% yield) as a viscous
Phenylmethyl 2-{4-Chloro-1-[(4-chlorophenyl)carbonyl]-5-
methoxy-2-methylindol-3-yl}acetate (19). A solution of 17 (1.25
g, 3.6 mmol), 4-chlorobenzoyl chloride (0.55 mL, 4.3 mmol),
DMAP (0.23 g, 1.9 mmol), and NEt3 (2.6 mL, 18.7 mmol) in
CH2Cl2 (20 mL) was stirred at room temperature for 24 h. The
reaction was partitioned between 3 N HCl (50 mL) and CH2Cl2
(100 mL). The organic layer was washed with 3 N HCl, water,
and brine, dried over Na2SO4, filtered, concentrated, and dried under
vacuum. The crude material was dissolved in CH2Cl2 (2 mL) and
triturated with Et2O (70 mL). The off white solid was collected,
washed with Et2O, and dried under vacuum to obtain the title
1
oil. H NMR (300 MHz, CDCl3): δ 7.83 (br. s, 1H), 7.06 (d, J )
1
8.7 Hz, 1H), 7.00 (d, J ) 2.4 Hz, 1H), 6.77–6.73 (m, 1H), 4,12 (q,
J ) 7.1 Hz, 2H), 3.84 (s, 3H), 3.64 (m, 2H), 1.23 (t, J ) 7.1 Hz,
3H). MS (API-TIS): m/z 248 (MH)+.
compound (1.52 g, 87% yield). mp: 147–148 °C. H NMR (300
MHz, CDCl3): δ 7.63 (d, J ) 8.5 Hz, 2H), 7.45 (d, J ) 8.5 Hz,
2H), 7.33 (m, 5H), 6.99 (d, J ) 9.0 Hz, 1H), 6.73 (d, J ) 9.0 Hz,
1H), 5.18 (s, 2H), 4.05 (s, 2H), 3.87 (s, 3H), 2.26 (s, 3H). 13C
NMR (75 MHz, CDCl3): δ 171.2, 168.1, 151.3, 139.6, 137.3, 135.9,
133.6, 132.1, 131.2, 129.2, 128.5, 128.1, 127.6, 113.3, 112.7, 112.2,
108.9, 66.8, 57.2, 31.0, 13.2. MS (API-TIS): m/z 482 (MH)+.
Phenylmethyl 2-{6-Chloro-1-[(4-chlorophenyl)carbonyl]-5-
methoxy-2-methylindol-3-yl}acetate (20). A solution of 18 (0.68
g, 2.0 mmol), 4-chlorobenzoyl chloride (0.28 mL, 2.2 mmol),
DMAP (0.12 g, 1.0 mmol), and NEt3 (1.5 mL, 10.8 mmol) in
CH2Cl2 (20 mL) was stirred at room temperature for 24 h. The
reaction mixture was partitioned between 3 N HCl (10 mL) and
CH2Cl2 (100 mL). The organic layer was washed with 3 N HCl,
water, and brine, dried over Na2SO4, filtered, concentrated, and dried
under vacuum. The product was separated by silica gel column
chromatography, eluted with EtOAc/hexane (1:3, Rf ) 0.3), to
obtain the title compound as a white solid (0.75 g, 79% yield).
mp: 104–105 °C. 1H NMR (300 MHz, CDCl3): δ 7.62 (d, J ) 8.5
Hz, 2H), 7.46 (d, J ) 8.5 Hz, 2H), 7.34–7.2 (m, 5H), 7.20 (s, 1H),
6.94 (s, 1H), 5.13 (s, 2H), 3.81 (s, 3H), 3.69 (s, 2H), 2.28 (s, 3H).
13C NMR (75 MHz, CDCl3): δ 170.2, 167.8, 151.3, 139.2, 135.5,
135.4, 133.3, 130.9, 130.1, 129.0, 128.7, 128.3, 128.2, 128.0, 118.8,
115.6, 112.1, 100.6, 66.6, 56.1, 30.2, 13.3. MS(API-TIS): m/z 482
(MH+). Anal. (C26H21Cl2NO4) C, H, N.
Ethyl 2-(5-Methoxy-2-methyl-1-{[4-(methylsulfonyl)phenyl]meth-
yl}indol-3-yl)acetate (24a). To a stirred solution of 23 (1.45 g, 5.87
mmol) and 4-(bromomethyl)-1-(methylsulfonyl)benzene (1.46 g,
5.87 mmol) in THF (80 mL) was added t-BuOK (1.0 M in THF,
5.87 mL, 5.87 mmol) via syringe at room temperature under N2.
The mixture was heated at a gentle reflux for 16 h. After it was
cooled, the mixture was poured onto ice, neutralized with 1 N HCl,
and extracted with EtOAc twice. The organics were dried over
Na2SO4, filtered, and concentrated. Chromatography of the residue
(1:1 EtOAc/hexane, silica gel) furnished the title compound (2.01
1
g, 82% yield) as a solid. mp: 123–124 °C. H NMR (300 MHz,
CDCl3): δ 7.82 (d, J ) 8.3 Hz, 2H), 7.13–6.99 (m, 4H), 6.78 (m,
1H), 5.34 (s, 2H), 4.14 (q, J ) 7.1 Hz, 2H), 3.86 (s, 3H), 3.71 (s,
2H), 3.00 (s, 3H), 2.31 (s, 3H), 1.25 (t, J ) 7.1 Hz, 3H). MS (API-
TIS): m/z 416 (MH)+.
2-(5-Methoxy-2-methyl-1-{[4-(methylsulfonyl)phenyl]methyl}indol-
3-yl)acetic Acid (25a). To a stirred solution of 24a (2.01 g, 4.84
mmol) in THF (50 mL) was added 2 N NaOH (50 mL). The mixture
was stirred at room temperature for 4 h and concentrated to remove
the volatiles. After acidification to pH 2 with 2 N HCl, the mixture
was extracted with EtOAc twice. The organics were dried over
Na2SO4, filtered, and concentrated to give a solid. Recrystallization
from THF/EtOAc (1:4) afforded the title compound (1.80 g, 95%
yield) as a beige solid. mp: 168 °C. 1H NMR (300 MHz, CDCl3):
δ 7.84 (d, J ) 8.3 Hz, 2H), 7.12 (d, J ) 8.3 Hz, 2H), 7.05–7.00
(m, 1H), 6.81–6.76 (m, 1H), 5.35 (s, 2H), 3.86 (s, 3H), 3.76 (s,
2H), 3.01 (s, 3H), 2.31 (s, 3H). MS (API-TIS): m/z 388 (MH+).
2-(5-Methoxy-2-methyl-1-{[4-(methylsulfonyl)phenyl]methyl}indol-
3-yl)-N-[3-(nitrooxy)propyl]acetamide (26a). To a stirred mixture
of 2 (0.240 g, 1.31 mmol), 25a (0.465 g, 1.20 mmol), and EDAC
(0.251 g, 1.31 mmol) in THF (15 mL) was added triethylamine
(0.366 mL, 2.62 mmol). After 15 h, the mixture was diluted with
EtOAc, washed with 1 N HCl, dried over Na2SO4, filtered, and
concentrated. Chromatography (EtOAc/hexane ) 1:1, neutral
Al2O3) afforded the title compound (106 mg, 18% yield). mp: 106
°C. 1H NMR (300 MHz, CDCl3): δ 7.88 (d, J ) 8.3 Hz, 2H), 7.28
(m, 1H), 7.21 (d, J ) 8.3 Hz, 2H), 7.02 (m, 1H), 6.75–6.70 (m,
1H), 5.53 (s, 2H), 4.63 (t, J ) 6.1 Hz, 2H), 3.79 (s, 3H), 3.66 (s,
2H), 3.19 (s, 3H), 2.94 (m, 2H), 2.54 (m, 1H), 2.31 (m, 3H), 2.01
(m, 2H). MS (API-TIS): m/z 490.0 (MH)+. Anal. (C23H27N3O7S)
C, H, N.
2-{6-Chloro-1-[(4-chlorophenyl)carbonyl]-5-methoxy-2-meth-
ylindol-3-yl}acetic Acid (21). Compound 20 (0.37 g, 0.76 mmol)
was hydrogenated in EtOAc (30 mL) and MeOH (5 mL) in presence
of 10% Pd/C (33 mg) at 30 psi for 2.5 h. The reaction mixture was
filtered through Celite, and the filter cake was washed with EtOAc.
The filtrate was concentrated, and the residue was separated by
silica gel column chromatography eluted with CH2Cl2/MeOH
(20:1, Rf ) 0.1) to obtain the title compound (0.26 g, 87% yield).
1
mp: 69–71 °C. H NMR (300 MHz, CDCl3); δ 7.63 (d, J ) 8.5
Hz, 2H), 7.47 (d, J ) 8.5 Hz, 2H), 7.15 (s, 1H), 6.97 (s, 1H), 3.93
(s, 3H), 3.66 (s, 2H), 2.30 (s, 3H). 13C NMR (75 MHz, CDCl3): δ
176.8, 168.0, 151.6, 139.7, 136.0, 133.2, 131.1, 130.2, 129.2, 128.7,
119.2, 115.8, 111.5, 100.6, 56.5, 30.0, 13.4. MS (API-TIS): m/z
392 (MH+).
2-{6-Chloro-1-[(4-chlorophenyl)carbonyl]-5-methoxy-2-meth-
ylindol-3-yl}-N-[3-(nitrooxy)propyl]acetamide (22). A solution
of 21 (1.11 g, 2.8 mmol), 2 (0.51 g, 3.1 mmol), DMAP (63 mg,
0.5 mmol), EDAC (0.71 g, 3.7 mmol), and NEt3 (1.4 mL, 10.0
mmol) in CH2Cl2 (150 mL) was stirred at room temperature for
5 h. The reaction mixture was partitioned between 3 N HCl (50
mL) and CH2Cl2 (50 mL × 2). The combined organic extracts were
washed with water and brine, dried over Na2SO4, filtered, and
concentrated. The crude material was dissolved in MeOH (5 mL)
and triturated with Et2O (80 mL). The solid was collected, washed
Ethyl 2-[1-(cyclohexylmethyl)-5-methoxy-2-methylindol-3-
yl]acetate (24b). To a stirred solution of 23 (5.40 g, 21.9 mmol)
and (bromomethyl)cyclohexane (3.87 g, 21.9 mmol) in THF at room
temperature was added potassium t-butoxide (1.0 M in THF, 21.9
mL) under N2. The reaction was heated at reflux for 15 h. After it

6376 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
was cooled, the mixture was poured onto ice, acidified to pH 2
with 2 N HCl, and extracted with EtOAc twice. The organics were
dried over Na2SO4, filtered, and concentrated. Chromatography
(2-10% EtOAc in hexane gradient, silica gel) afforded the title
compound (3.88 g, 52% yield) as an oil. 1H NMR (300 MHz,
CDCl3): δ 7.15 (d, J ) 8.8 Hz, 1H), 7.04 (d, J ) 2.4 Hz, 1H),
6.83–6.79 (m, 1H), 4.14 (q, J ) 7.1 Hz, 2H), 3.88 (s, 3H), 3.85
(m, 2H), 3.69 (s, 2H), 2.40 (s, 3H), 1.73–1.67 (m, 6H), 1.26 (t, J
) 7.1 Hz, 3H), 1.23–1.00 (m, 5H). MS (API-TIS): m/z 344 (MH)+.
2-[1-(Cyclohexylmethyl)-5-methoxy-2-methylindol-3-yl]ace-
tic Acid (25b). To a stirred solution of 24b (740 mg, 2.16 mmol)
in 1:1 THF:MeOH (20 mL) was added 2 N NaOH (5 mL). After
the mixture was stirred at room temperature overnight, it was
acidified to pH 1 with 1 N HCl and extracted with EtOAc twice.
The organics were washed with brine, dried over Na2SO4, filtered,
and concentrated to give a tan solid. Recrystalization from EtOAc
(10 mL) afforded the title compound (560 mg, 82% yield) as a
white solid. 1H NMR (300 MHz, CDCl3): δ 11.6–9.5 (br, 1H), 7.13
(d, J ) 8.8 Hz, 1H), 6.97 (d, J ) 2.3 Hz, 1H), 6.78 (dd, J ) 6.4,
2.4 Hz, 1H), 3.84 (s, 3H), 3.82 (m, 2H), 3.69 (s, 2H), 2.35 (s, 3H),
1.7–1.5 (m, 6H), 1.2–0.9 (m, 5H). MS (API-TIS): m/z 316.2 (MH)+.
2-[1-(Cyclohexylmethyl)-5-methoxy-2-methylindol-3-yl]-N-[3-
(nitrooxy)propyl]acetamide (26b). To a stirred solution of 24b
(230 mg, 0.73 mmol), EDAC (280 mg, 1.46 mmol), and 2 (161
mg, 0.88 mmol) in CH2Cl2 was added NEt3 (0.418 mL, 3.00 mmol)
and DMAP (10 mg). After it was stirred at room temperature for
3 h, the reaction mixture was concentrated. The solid residue was
taken up with EtOAc and washed with 2 N HCl and water. The
organic layer was dried over Na2SO4, filtered, and concentrated.
The resulting tan solid was recrystallized from EtOAc/hexane
(1:5) to afford the title compound (282 mg, 92% yield) as a white
solid. mp: 38 °C. 1H NMR (300 MHz, CDCl3): δ 7.17 (d, J ) 8.8
Hz, 1H), 6.9–6.8 (m, 2H), 5.83 (br. t, 1H), 4.35 (t, J ) 6.3 Hz,
2H), 3.85 (d, J ) 7.4 Hz, 2H), 3.82 (s, 3H), 3.65 (m, 2H), 3.25 (m,
2H), 2.33 (m, 3H), 1.84 (t, J ) 6.5 Hz, 2H), 1.8–1.5 (m, 6H),
1.2–1.0 (m, 6H). MS (API-TIS): m/z 418 (MH)+. Anal. (C22
H31N3O5) C, H, N.
treated with brine, and agitated for 10 min. The reaction mixture
was filtered, and the organic layer was separated from the filtrate,
dried over Na2SO4, filtered, and concentrated. Chromatography (1:9
EtOAc/hexane, silica gel) of the residue afforded the title compound
(0.345 g, 81% yield) as a yellow oil. 1H NMR (300 MHz, CDCl3):
δ 7.16 (d, J ) 8.8 Hz, 1H), 6.97 (d, J ) 2.0 Hz, 1H), 6.82 (dd, J
) 8.8, 2.0 Hz, 1H), 4.58 (t, J ) 7.5 Hz, 2H), 3.90 (s, 3H), 3.88–3.84
(m, 2H), 3.12 (t, J ) 7.3 Hz, 2H), 2.36 (s, 3H), 1.74–1.57 (m, 6H),
1.19–1.01 (m, 5H). MS (API-TIS): m/z 347 (MH)+. Anal. (C19
H26N2O4) C, H, N.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-(4-hydroxybutyl)acetamide (30). A solution of indomethacin
(1.6 g, 4.5 mmol), 4-aminobutan-1-ol (1.02 g, 4.7 mmol), DMAP
(0.12 g, 1.0 mmol), EDAC (0.97 g, 5.1 mmol), and NEt3 (1.5 mL,
10.8 mmol) in CH2Cl2 (60 mL) was stirred at room temperature
for 6 h. The reaction was partitioned between 3 N HCl (50 mL)
and CH2Cl2 (100 mL). The organic layer was washed with 3 N
HCl, water, and brine, dried over Na2SO4, filtered, concentrated,
and dried under vacuum. The product was separated by silica gel
column chromatography eluted with MeOH/CHCl3 (1:15, Rf )
0.17). The product was further purified by washing with EtOAc
and Et2O to obtain the title compound as a off-white solid (1.02 g,
53% yield). mp: 134–136 °C. 1H NMR (300 MHz, CDCl3): δ 7.65
(d, J ) 8.3 Hz, 2H), 7.48 (d, J ) 8.3 Hz, 2H), 6.90 (d, J ) 2.0 Hz,
1H), 6.86 (d, J ) 9.0 Hz, 1H), 6.69 (dd, J ) 9.0, 2.0 Hz, 1H), 6.0
(br. t, 1H), 3.81 (s, 3H), 3.62 (s, 2H), 3.55 (t, J ) 5.4 Hz, 2H),
3.23 (br. q, 2H), 2.58 (s, 3H), 1.49 (m, 2H). 13C NMR (75 MHz,
CDCl3): δ 170.0, 168.4, 156.2, 139.6, 136.3, 133.5, 131.2, 130.9,
130.3, 129.2, 115.0, 112.9, 112.1, 101.0, 62.1, 55.7, 39.3, 32.2,
29.6, 26.1, 13.2. MS(API-TIS) m/z 429 (MH)+. Anal. (C23
H25ClN2O4) C, H, N.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-(3-hydroxypropyl)acetamide (31). A solution of indo-
methacin (1.55 g, 4.3 mmol), 3-aminopropan-1-ol (0.35 mL, 4.6
mmol), DMAP (65 mg, 0.5 mmol), EDAC (1.02 g, 5.3 mmol),
and NEt3 (1.2 mL, 8.6 mmol) in CH2Cl2 (70 mL) was stirred at
room temperature overnight. The reaction was partitioned between
3 N HCl (50 mL) and CH2Cl2 (100 mL). The organic layer was
washed with 3 N HCl, water, and brine, dried over Na2SO4, filtered,
concentrated and dried under vacuum. The product was separated
by silica gel column chromatography eluted with MeOH/CHCl3
(1:15, Rf ) 0.25) to obtain the title compound as a off-white solid
(1.23 g, 68% yield). mp: 106–107 °C. 1H NMR (300 MHz, CDCl3):
δ 7.57 (d, J ) 8.4 Hz, 2H), 7.44 (d, J ) 8.4 Hz, 2H), 6.90 (d, J )
2.2 Hz, 1H), 6.85 (d, J ) 9.0 Hz, 1H), 6.66 (dd, J ) 9.0, 2.2 Hz,
1H), 6.48 (br. t, 1H), 3.80 (s, 3H), 3.61 (s, 2H), 3.54 (t, J ) 5.4
Hz, 2H), 3.45 (br, 1H), 3.32 (br. q, 2H), 2.35 (s, 3H), 1.57 (m,
2H). 13C NMR (75 MHz, CDCl3): δ 170.9, 168.2, 156.1, 139.3,
136.2, 133.4, 131.0, 130.7, 130.3, 129.0, 115.0, 112.7, 112.0, 100.8,
59.4, 55.6, 36.6, 31.8, 31.7, 13.1. MS (API-TIS): m/z 415 (MH)+.
Anal. (C22H23ClN2O4) C, H, N.
2-[1-(Cyclohexylmethyl)-5-methoxy-2-methylindol-3-yl]ethan-
1-ol (27b). To a stirred solution of 24b (0.520 g, 1.52 mmol) in
THF (15 mL) was added 1 M LiAlH4 in THF (3 mL, 3 mmol),
and the mixture was stirred at room temperature for 45 min. The
mixture was poured onto solid Na2SO4 ·10H2O and aged for 10
min before filtration. The filter cake was washed several times with
EtOAc. The combined filtrate and EtOAc washings were concen-
trated, and the residue was purified by chromatography (1:2 EtOAc/
hexane, silica gel) to give the title compound (0.450 g, 98% yield)
1
as an oil. H NMR (300 MHz, CDCl3): δ 7.14 (d, J ) 8.8 Hz,
1H), 6.99 (d, J ) 2.4 Hz, 1H), 6.80 (dd, J ) 8.8, 2.4 Hz, 1H), 3.86
(s, 3H), 3.90–3.81 (m, 4H), 2.97 (t, J ) 6.5 Hz, 2H), 2.05 (s, 3H),
1.8–0.99 (m, 12 H). 13C NMR (75 MHz, CDCl3): δ 154.6, 134.7,
131.7, 128.0, 110.1, 110.0, 106.2, 100.1, 62.7, 55.8, 49.7, 38.9,
31.1, 28.0, 26.2, 25.8, 10.5. MS (API-TIS): m/z 302 (MH)+.
3-(2-Bromoethyl)-1-(cyclohexylmethyl)-5-methoxy-2-meth-
ylindole (28b). To a stirred solution of 27b (0.430 g, 1.43 mmol)
in toluene (15 mL) was added 48% aqueous HBr (1.59 mL, 14.3
mmol), and the mixture was heated at reflux for 2 h. After it was
cooled, the mixture was diluted with EtOAc, washed with saturated
aqueous NaHCO3, and water. The organic layer was dried over
Na2SO4, filtered, and concentrated. Chromatography (1:19 EtOAc/
hexane, silica gel) of the residue afforded the title compound (0.45
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-[3-(nitrooxy)propyl]acetamide (32). A solution of in-
domethacin (1.55 g, 4.3 mmol), 2 (0.78 g, 5.0 mmol), DMAP (125
mg, 1.02 mmol), EDAC (1.09 g, 5.7 mmol), and NEt3 (1.6 mL,
11.5 mmol) in CH2Cl2 (60 mL) was stirred at room temperature
for 3.5 h. The reaction was partitioned between 3 N HCl (50 mL)
and CH2Cl2 (100 mL). The organic extract was washed with 3 N
HCl, water, and brine, dried over Na2SO4, filtered, concentrated,
and dried under vacuum. The crude material was dissolved in
CH2Cl2 (3 mL) and triturated with Et2O (60 mL). The solid was
collected and dried under vacuum to obtain the title compound as
1
g, 86% yield) as a foam. H NMR (300 MHz, CDCl3): δ 7.16 (d,
J ) 8.8 Hz, 1H), 6.95 (d, J ) 2.4 Hz, 1H), 6.81 (dd, J ) 8.8, 2.4
Hz, 1H), 3.87 (s, 3H), 3.86–3.83 (m, 2H), 3.52 (m, 2H), 3.26 (t, J
) 8.3 Hz, 2H), 2.36 (s, 3H), 1.8–0.99 (m, 11H). MS (API-TIS):
m/z 364, 366 (MH+ for 79Br and 81Br, respectively).
1
a yellowish solid (1.17 g, 59% yield). mp: 122–124 °C. H NMR
(300 MHz, CDCl3): δ 7.62 (d, J ) 8.5 Hz, 2H), 7.48 (d, J ) 8.5
Hz, 2H), 6.88 (d, J ) 2.3 Hz, 1H), 6.85 (d, J ) 9.0 Hz, 1H), 6.69
(dd, J ) 9.0, 2.3 Hz, 1H), 5.86 (br. t, 1H), 4.39 (t, J ) 6.2 Hz,
2H), 3.82 (s, 3H), 3.65 (s, 2H), 3.31 (br. q, 2H), 2.39 (s, 3H), 1.88
(m, 2H). 13C NMR (75 MHz, CDCl3): δ 170.3, 168.3, 156.3, 139.6,
136.5, 133.5, 131.1, 130.9, 130.2, 129.2, 115.2, 112.5, 112.2, 100.8,
70.9, 55.7, 36.4, 32.2, 28.6, 27.0, 13.2. MS (API-TIS): m/z 460
(MH)+. Anal. (C22H22ClN3O6) C, H, N.
{2-[1-(Cyclohexylmethyl)-5-methoxy-2-methylindol-3-yl]ethyl}
nitrooxy (29b). To a stirred solution of 28b (0.450 g, 1.23 mmol)
in acetonitrile (10 mL) was added AgNO3 (0.419 g, 2.46 mmol).
The mixture was stirred at for 15 h, at which point the bromide
had been completely consumed, as indicated by TLC. Upon
concentration to dryness, the residue was taken up with EtOAc,

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6377
N-[2,2-Dimethyl-3-(nitrooxy)propyl]-2-{1-[(4-chlorophenyl)-
carbonyl]-5-methoxy-2-methylindol-3-yl}acetamide (33). A solu-
tion of indomethacin (1.15 g, 3.2 mmol), 4 (0.70 g, 3.3 mmol),
EDAC (0.74 g, 3.9 mmol), and NEt3 (0.95 mL, 6.8 mmol) in
CH2Cl2 (40 mL) was stirred at room temperature for 2 h. The
reaction was partitioned between 3 N HCl (50 mL) and CH2Cl2
(100 mL). The organic layer was washed with 3 N HCl, water,
and brine, dried over Na2SO4, filtered, concentrated, and dried under
vacuum. The crude material was dissolved in CH2Cl2 (3 mL) and
triturated with Et2O (60 mL). The solid was collected, washed with
MeOH, and dried under vacuum to obtain the title compound as a
white solid (0.57 g, 37% yield). mp: 148 °C (dec.). 1H NMR (300
MHz, CDCl3): δ 7.66 (d, J ) 8.5 Hz, 2H), 7.49 (d, J ) 8.5 Hz,
2H), 6.90 (d, J ) 2.4 Hz, 1H), 6.86 (d, J ) 9.0 Hz, 1H), 6.69 (dd,
J ) 9.0, 2.4 Hz, 1H), 5.80 (br. t, 1H), 4.08 (s, 2H), 3.81 (s, 3H),
3.67 (s, 2H), 3.16 (br. d, 2H), 2.42 (s, 3H), 0.89 (s, 6H). 13C NMR
(75 MHz, CDCl3): δ 170.3, 168.2, 156.3, 139.5, 136.4, 133.5, 131.1,
130.9, 130.1, 129.1, 115.2, 112.5, 112.3, 100.7, 79.1, 55.6, 46.6,
35.7, 32.1, 22.2, 13.1. MS (API-TIS): m/z 488 (MH)+.
N-{1,1-Bis[(nitrooxy)methyl]-2-(nitrooxy)ethyl}-2-{1-[(4-chlo-
rophenyl)-carbonyl]-5-methoxy-2-methylindol-3-yl}acetamide
(34). Oxalyl chloride (0.19 mL, 2.2 mmol) was added to an ice-
cold solution of indomethacin (0.6 g, 1.7 mmol) in CH2Cl2 (50
mL) and DMF (10 µL). The reaction was stirred in the ice-bath
for 15 min then at room temperature for 2 h. The reaction mixture
was evaporated to dryness under reduced pressure, and the resulting
crude material was dissolved in CH2Cl2 (50 mL). Compound 6 was
added to the above solution followed by the addition of NEt3 (0.5
mL, 3.6 mmol) and stirred at room temperature for 3 h. The reaction
was partitioned between 3 N HCl (50 mL) and CH2Cl2 (100 mL ×
2). The combined organic extracts were washed with water,
saturated NaHCO3, and brine, dried over Na2SO4, filtered, and
concentrated. The product was separated by silica gel column
chromatography eluted with EtOAc/hexane (1:3, Rf ) 0.2). The
resulting yellowish solid, after evaporation of the solvents, was
washed with Et2O and dried under vacuum to obtain the title
compound as a white solid (0.16 g, 16% yield). mp: >122 °C (dec.).
1H NMR (300 MHz, acetone-d6): δ 7.75 (d, J ) 8.4 Hz, 2H), 7.72
(br, 1H), 7.62 (d, J ) 8.4 Hz, 2H), 7.10 (d, J ) 2.4 Hz, 1H), 7.02
(d, J ) 9.0 Hz, 1H), 6.70 (dd, J ) 9.0, 2.4 Hz, 1H), 5.04 (s, 6H),
3.82 (s, 3H), 3.70 (s, 2H), 2.31 (s, 3H). 13C NMR (75 MHz,
acetone-d6): δ 171.9, 168.9, 157.2, 139.2, 136.7, 133.6, 132.1, 131.9,
131.8, 129.9, 115.7, 114.1, 112.6, 102.0, 70.8, 57.2, 55.9, 32.5,
13.6. MS (API-TIS): m/z 596 (MH)+.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}ethanehydroxamic Acid (35). Oxalyl chloride (0.8 mL, 9.2
mmol) was added to an ice-cold solution of indomethacin (2.51 g,
7.0 mmol) in CH2Cl2 (50 mL) and DMF (20 µL). The reaction
was stirred in the ice-bath for 30 min then at room temperature for
2 h. The reaction mixture was evaporated to dryness under reduced
pressure, and the resulting crude acid chloride was dissolved in
CH2Cl2 (50 mL). Hydroxylamine hydrochloride (0.51 g, 7.3 mmol)
and DMAP (1.71 g, 14.0 mmol) were added to the above solution
and stirred at room temperature overnight. To the reaction mixture
was added 3 N HCl (100 mL), and the solid precipitating out from
the solution was collected, washed with CH2Cl2 and Et2O, and then
dried under vacuum to obtain a white solid (1.04 g, 40% yield).
1H NMR (300 MHz, DMSO-d6): δ 10.6 (s, 1H), 8.7 (br., 1H),
7.68–7.65 (m, 4H), 7.15 (d, J ) 2.3 Hz, 1H), 6.92 (d, J ) 9.0 Hz,
1H), 6.71 (dd, J ) 9.0, 2.3 Hz, 1H), 3.77 (s, 3H), 3.40 (s, 2H),
2.25 (s, 3H). 13C NMR (75 MHz, DMSO-d6): δ 167.9, 166.4, 155.5,
137.6, 135.3, 134.2, 131.2, 130.8, 130.3, 129.1, 114.5, 113.8, 111.2,
102.1, 55.5, 28.4, 13.3. MS (API-TIS): m/z 373 (MH)+.
(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-
3-yl}acetylamino) Acetate (36). A solution of 35 (0.49 g, 1.3
mmol), DMAP (20 mg), and acetic anhydride (0.16 mL, 1.7 mmol)
in DMSO (5 mL) was stirred at room temperature for 3 days. The
solvents were evaporated under vacuum. The residue was dissolved
in EtOAc (60 mL), washed with 3 N HCl, water, and brine, dried
over Na2SO4, filtered, and concentrated. The product was separated
by silica gel column chromatography eluted with MeOH/CHCl3
(1:20, Rf ) 0.3). The crude purified material was washed with
MeOH to obtain the title compound as a solid (0.24 g, 44% yield).
mp: 153–156 °C. 1H NMR (300 MHz, CDCl3): δ 9.1 (br, 1H),
7.62 (d, J ) 8.5 Hz, 2H), 7.46 (d, J ) 8.5 Hz, 2H), 6.99 (d, J )
2.3 Hz, 1H), 6.90 (d, J ) 9.0 Hz, 1H), 6.69 (dd, J ) 9.0, 2.3 Hz,
1H), 3.84 (s, 3H), 3.73 (s, 2H), 2.38 (s, 3H), 2.16 (s, 3H). 13C
NMR (75 MHz, CDCl3): δ 168.4, 168.3, 156.2, 139.4, 136.4, 133.4,
131.1, 130.8, 130.1, 129.1, 115.0, 112.3, 111.1, 100.9, 55.6, 29.4,
18.0, 13.2. MS(API-TIS): m/z 415 (MH)+. Anal. (C21H19ClN2O5)
C, H, N.
(N-Acetyl-2-{1-[(4-chlorophenyl)carbonyl]-5-methoxy-2-me-
thylindol-3-yl}acetylamino) Acetate (37). A solution of 35 (0.42
g, 1.13 mmol) in a mixture of THF (10 mL), DMSO (2 mL), and
acetic anhydride (5 mL) was stirred at room temperature overnight.
The solvents were evaporated under vacuum. The residue was
dissolved in EtOAc (100 mL), washed with saturated NaHCO3, 3
N HCl, water, and brine, dried over Na2SO4, filtered, and
concentrated. The residue was triturated with Et2O, and the solid
was collected and dried under vacuum to obtain the title compound
(0.32 g, 61% yield). mp: 156–158 °C. 1H NMR (300 MHz, CDCl3):
δ 7.67 (d, J ) 8.4 Hz, 2H), 7.46 (d, J ) 8.4 Hz, 2H), 6.87 (d, J )
9.0 Hz, 1H), 6.84 (d, J ) 2.3 Hz, 1H), 6.66 (dd, J ) 9.0, 2.3 Hz,
1H), 4.06 (br. s, 2H), 3.82 (s, 3H), 2.42 (s, 3H), 2.33 (s, 3H), 2.27
(s, 3H). 13C NMR (75 MHz, CDCl3): δ 168.2, 167.9, 167.4, 155.1,
139.2, 136.4, 133.8, 131.2, 130.8, 130.5, 129.1, 115.0, 111.8, 111.2,
101.0, 55.7, 32.2, 24.3, 17.9, 13.4. MS (API-TIS): m/z 457 (MH)+.
Anal. (C23H21ClN2O6) C, H, N.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-(phenylmethoxy)acetamide (38). A solution of indomethacin
(4.01 g, 11.2 mmol), O-benzylhydroxylamine (0.70 g, 3.3 mmol),
EDAC (2.76 g, 14.4 mmol), and NEt3 (3.6 mL, 25.8 mmol) in
CH2Cl2 (100 mL) was stirred at room temperature overnight. The
reaction was partitioned between 3 N HCl (100 mL) and CH2Cl2
(100 mL). The organic layer was washed with 3 N HCl, water,
and brine, dried over Na2SO4, filtered, concentrated, and dried under
vacuum. The product was separated by silica gel column chroma-
tography eluted with EtOAc/hexane (1:1, Rf ) 0.2). The resulting
yellowish solid, after evaporation of solvents, was washed with Et2O
and dried under vacuum to obtain the title compound as a white
1
solid (1.98 g, 38% yield). mp: 152–153 °C (dec.). H NMR (300
MHz, CDCl3): δ 8.3 (br, 1H), 7.57 (d, J ) 8.5 Hz, 2H), 7.45 (d, J
) 8.5 Hz, 2H), 7.40–7.20 (m, 5H), 6.88 (d, J ) 2.4 Hz, 1H), 6.83
(d, J ) 9.0 Hz, 1H), 6.69 (dd, J ) 9.0, 2.4 Hz, 1H), 4.84 (s, 2H),
3.80 (s, 3H), 3.58 (s, 2H), 2.28 (s, 3H). 13C NMR (75 MHz, CDCl3):
δ 168.2, 167.3, 156.2, 139.5, 136.1, 134.7, 133.5, 131.1, 130.8,
129.3, 129.1, 128.7, 128.5, 115.0, 112.1, 111.5, 100.9, 78.2, 55.7,
29.2, 13.2. MS(API-TIS): m/z 463 (MH)+.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-(2-hydroxyethoxy)acetamide (39). A solution of indometha-
cin (6.23 g, 17.4 mmol), 43 (1.35 g, 17.5 mmol), EDAC (4.32 g,
22.5 mmol), and NEt3 (5.6 mL, 40.2 mmol) in CH2Cl2 (100 mL)
was stirred at room temperature for 2 h. The reaction was partitioned
between 3 N HCl (100 mL) and CH2Cl2 (100 mL × 2). The
combined organic extracts were washed with 3 N HCl, water, and
brine, dried over Na2SO4, filtered, and concentrated. The resulting
crude material was washed with methanol, filtered, and dried under
vacuum to obtain the title compound as a yellowish solid (5.32 g,
73% yield). mp: 146–148 °C. 1H NMR (300 MHz, CDCl3): δ 8.69
(br. s, 1H), 7.62 (d, J ) 8.5 Hz, 2H), 7.46 (d, J ) 8.5 Hz, 2H),
6.90 (d, J ) 2.4 Hz, 1H), 6.84 (d, J ) 9.0 Hz, 1H), 6.69 (dd, J )
9.0, 2.4 Hz, 1H), 3.90–3.70 (m, 2H), 3.80 (s, 3H), 3.60–3.50 (m,
4H), 2.29 (s, 3H). 13C NMR (75 MHz, 20% CD3OD/CDCl3): δ
169.2, 168.4, 155.8, 139.2, 136.0, 133.4, 130.9, 130.6, 130.2, 128.9,
114.7, 111.8, 111.4, 101.0, 77.6, 59.0, 55.3, 28.6, 12.8. MS(API-
TIS): m/z 417 (MH)+. Anal. (C21H21ClN2O5) C, H, N.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}-N-(3-hydroxypropoxy)acetamide (40). A solution of indo-
methacin (2.1 g, 5.9 mmol), 44 (0.64 g, 7.1 mmol), EDAC (1.45
g, 22.5 mmol), and NEt3 (1.6 mL, 11.5 mmol) in CH2Cl2 (50 mL)
was stirred at room temperature overnight. The reaction was
partitioned between 3 N HCl (50 mL) and CH2Cl2 (50 mL × 2).

6378 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
The combined organic extracts were washed with 3 N HCl, water,
and brine, dried over Na2SO4, filtered, and concentrated. The
resulting crude material was dissolved in ethyl acetate and triturated
with hexane. The solid was collected and dried under vacuum to
obtain the title compound as a yellowish solid (2.40 g, 95% yield).
mp: 112–114 °C. 1H NMR (300 MHz, CDCl3): δ 9.15 (br. s, 1H),
7.62 (d, J ) 8.5 Hz, 2H), 7.47 (d, J ) 8.5 Hz, 2H), 6.92 (d, J )
2.4 Hz, 1H), 6.84 (d, J ) 9.0 Hz, 1H), 6.67 (dd, J ) 9.0, 2.4 Hz,
1H), 3.99 (t, J ) 5.7 Hz, 2H), 3.81 (s, 3H), 3.74 (t, J ) 5.7 Hz,
2H), 3.59 (s, 2H), 2.37 (s, 3H), 1.80–1.73 (m, 2H). 13C NMR (75
MHz, CDCl3) δ 168.3, 168.2, 156.0, 139.3, 136.3, 133.4, 131.1,
130.7, 130.2, 129.0, 114.9, 111.7, 101.1, 74.5, 59.4, 55.6, 30.4,
29.2, 13.2. MS(API-TIS): m/z 431 (MH)+.
2-(2-Hydroxyethoxy)benzo[c]azolidine-1,3-dione (41). A solu-
tion of sodium acetate (33.21 g, 0.4 mol), N-hydroxyphthalimide
(22.0 g, 0.135 mol), and 2-bromoethanol (50.6 g, 0.4 mol) in DMSO
(400 mL) was heated to 70 °C for 6 h. After it was cooled down
to room temperature, water (400 mL) was added to the reaction
mixture, and it was extracted with CH2Cl2 (250 mL × 3). The
combined organic extracts were washed with water (250 mL × 2),
3 N HCl (150 mL), and brine, dried over Na2SO4, filtered, and
concentrated. The resulting crude material was washed with 50%
ethanol in water (120 mL), filtered, and dried under vacuum to
obtained the title compound as a white solid (17.76 g, 64% yield).
mp: 82–84 °C. 1H NMR (300 MHz, CD3OD): δ 7.9–7.8 (m, 4H),
4.30–4.25 (m, 2H), 3.90–3.82 (m, 2H). 13C NMR (75 MHz,
CD3OD): δ 165.2, 135.8, 130.2, 124.3, 80.5, 60.8. MS(API-TIS):
m/z 208 (MH)+.
2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}ethyl Methylsulfonate (46). Triethylamine (0.22 mL, 1.6 mmol)
and methanesulfonyl chloride (0.15 mL, 1.9 mmol) were added to
a solution of 45 (0.44 g, 1.3 mmol) in CH2Cl2 (15 mL), and the
mixture was stirred at room temperature for 2 h. The reaction was
partitioned between 3 N HCl (10 mL) and CH2Cl2 (30 mL). The
organic extract was washed with water and brine, dried over
Na2SO4, filtered, concentrated, and dried under vacuum. The
product, >95% purity from NMR analysis, was used in the next
step without purification. 1H NMR (300 MHz, CDCl3): δ 7.64 (d,
J ) 8.5 Hz, 2H), 7.47 (d, J ) 8.5 Hz, 2H), 6.95 (d, J ) 2.4 Hz,
1H), 6.89 (d, J ) 9.0 Hz, 1H), 6.67 (dd, J ) 9.0, 2.4 Hz, 1H), 4.39
(t, J ) 7.0 Hz, 2H), 3.83 (s, 3H), 3.13 (t, J ) 7.0 Hz, 2H), 2.92 (s,
3H), 2.35 (s, 3H). 13C NMR (75 MHz, CDCl3): δ 168.1, 155.9,
139.1, 135.6, 133.7, 131.0, 130.7, 130.3, 129.0, 114.9, 113.7, 111.4,
100.8, 68.5, 55.6, 37.2, 24.4, 13.1. MS(API-TIS): m/z 422 (MH)+.
4-Clorophenyl 5-methoxy-2-methyl-3-[2-(nitrooxy)ethyl]-in-
dolyl Ketone (47). The crude product of 46 and tetrabutylammo-
nium nitrate (0.47 g, 1.54 mmol) was heated to 100 °C overnight
in toluene (15 mL). After it was cooled to room temperature, the
reaction mixture was dissolved in EtOAc (100 mL), washed with
water and brine, dried over Na2SO4, filtered, and concentrated. The
product was separated by silica gel column chromatography eluted
with EtOAc/hexane (1:5, Rf ) 0.25) to obtain the title compound
1
as a sticky oil (0.12 g, 24% yield). H NMR (300 MHz, CDCl3):
δ 7.65 (d, J ) 8.6 Hz, 2H), 7.45 (d, J ) 8.6 Hz, 2H), 6.92 (d, J )
2.5 Hz, 1H), 6.88 (d, J ) 9.0 Hz, 1H), 6.68 (dd, J ) 9.0, 2.5 Hz,
1H), 4.62 (t, J ) 7.1 Hz, 2H), 3.83 (s, 3H), 3.09 (t, J ) 7.1 Hz,
2H), 2.36 (s, 3H). 13C NMR (75 MHz, CDCl3): δ 168.2, 156.1,
139.3, 135.8, 133.8, 131.1, 130.9, 130.3, 129.1, 115.1, 113.5, 111.6,
100.7, 71.6, 55.7, 22.1, 13.1. MS (API-TIS): m/z 389 (MH)+.
3-(2-Bromoethyl)-5-methoxy-2-methylindolyl 4-chlorophenyl
Ketone (48). To the crude product of 46 (1.03 g 3.0 mmol) was
added LiBr (0.55 g, 6.4 mmol) and heated to 55 °C in acetone
(100 mL) for 24 h. After the mixture was cooled to room
temperature, the acetone was evaporated under vacuum. The residue
was dissolved in CH2Cl2 (100 mL), washed with water and brine,
dried over Na2SO4, filtered, and concentrated. The product was
separated by silica gel column chromatography eluted with EtOAc/
hexane (1:10, Rf ) 0.25) to obtain the title compound (0.96 g, 79%
yield). The product can be recrystallized from Et2O and hexane.
2-(3-Hydroxypropoxy)benzo[c]azolidine-1,3-dione (42). The
title compound was prepared as a white solid (70% yield) from
3-bromopropan-1-ol by following the procedure for 41. mp: 78–80
°C. 1H NMR (300 MHz, CDCl3): δ 7.9–7.75 (m, 4H), 4.39 (t, J )
6.0 Hz, 2H), 3.93 (t, J ) 6.0 Hz, 2H), 3.04 (br. s, 1H), 2.02 (m,
2H). 13C NMR (75 MHz, CDCl3): δ 163.7, 134.5, 128.6, 123.5,
75.8, 58.8, 30.7. MS (API-TIS): m/z 222 (MH)+.
2-(Aminooxy)ethan-1-ol (43). A solution of 41 (15.57 g, 75.2
mmol) and hydrazine hydrate (5.4 mL, 0.11 mol) in MeOH (150
mL) was heated to 70 °C for 1.5 h. After the mixture was cooled
down to room temperature, CHCl3 (100 mL) was added to the
reaction mixture. The resulting slurry was filtered and washed with
CHCl3 (100 mL × 2). The filtrate was concentrated, and the residue
was distilled under vacuum (0.025 mmHg) at 75-80 °C to obtain
1
mp: 92–93 °C. H NMR (300 MHz, CDCl3): δ 7.63 (d, J ) 8.5
1
a colorless oil (4.54 g, 78% yield). H NMR (300 MHz, CDCl3):
Hz, 2H), 7.44 (d, J ) 8.5 Hz, 2H), 6.90 (d, J ) 2.5 Hz, 1H), 6.90
(d, J ) 8.9 Hz, 1H), 6.66 (dd, J ) 8.9, 2.5 Hz, 1H), 3.82 (s, 3H),
3.56 (t, J ) 7.6 Hz, 2H), 3.21 (t, J ) 7.6 Hz, 2H), 2.34 (s, 3H).
13C NMR (75 MHz, CDCl3): δ 168.1, 155.9, 139.1, 135.4, 133.9,
131.0, 130.9, 130.2, 129.0, 116.6, 115.0, 111.3, 100.9, 55.7, 31.4,
27.9, 13.3. MS (API-TIS): m/z 406 (MH)+.
δ 3.78 (s, 4H). 13C NMR (75 MHz, CDCl3): δ 76.3, 60.7.
3-(Aminooxy)propan-1-ol (44). The title compound was pre-
pared as a colorless oil (87% yield), by following the procedure
for 43, and was distilled under vacuum (0.05 mmHg) at 90–95 °C.
1H NMR (300 MHz, CDCl3): δ 6.0–5.0 (br, 3H), 3.79 (t, J ) 6.1
Hz, 2H), 3.67 (t, J ) 6.1 Hz, 2H), 1.81 (m, 2H). 13C NMR (75
MHz, CDCl3): δ 73.0, 59.2, 31.2.
(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-
3-yl}ethyl)-dimethoxyphosphino-1-one (49). A solution of 48
(0.43 g, 1.1 mmol) in P(OMe)3 (3 mL) was heated to 110 °C for
2 days. The reaction mixture was evaporated to dryness under
vacuum. The product was separated by silica gel column chroma-
tography eluted with MeOH/ EtOAc (1:10, Rf ) 0.3) to obtain the
title compound (0.32 g, 70% yield). 1H NMR (300 MHz, CDCl3):
δ 7.63 (d, J ) 8.5 Hz, 2H), 7.46 (d, J ) 8.5 Hz, 2H), 6.92 (d, J )
2.5 Hz, 1H), 6.89 (d, J ) 9.0 Hz, 1H), 6.66 (dd, J ) 9.0, 2.5 Hz,
1H), 3.83 (s, 3H), 3.76 (d, JPH) 10.7 Hz, 6H), 2.96 (m, 2H), 2.35
(s, 3H), 2.06 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 168.0, 155.8,
4-Chlorophenyl 3-(2-hydroxyethyl)-5-methoxy-2-methylin-
dolyl Ketone (45). A solution of BH3 ·SMe2 in THF (2 M, 15 mL,
30 mmol) was added slowly to an ice-cold solution of indomethacin
(10.2 g, 28.6 mmol) in THF (150 mL). The reaction was warmed
up slowly from the ice-bath and stirred at room temperature
overnight. Excess BH3 was destroyed by the slow addition of MeOH
(2 mL). The reaction mixture was evaporated to dryness under
reduced pressure. The crude material was dissolved in CH2Cl2 (200
mL), washed with saturated NaHCO3, water, 3 N HCl, water, and
brine, dried over Na2SO4, filtered, and concentrated. The residue
was dissolved in Et2O (50 mL) and triturated with hexane (200
mL). The yellowish solid was collected and dried under vacuum
to obtain the title compound (8.01 g, 81% yield). mp: 111–113 °C.
1H NMR (300 MHz, CDCl3): δ 7.63 (d, J ) 8.5 Hz, 2H), 7.45 (d,
J ) 8.5 Hz, 2H), 6.94 (d, J ) 2.4 Hz, 1H), 6.87 (d, J ) 9.0 Hz,
1H), 6.65 (dd, J ) 9.0, 2.4 Hz, 1H), 3.86 (t, J ) 6.7 Hz, 2H), 3.83
138.9, 134.0, 133.9, 130.9, 130.8, 130.1, 128.9, 118.2 (d, JCP
)
16.7 Hz), 114.9, 111.1, 100.9, 55.6, 52.2 (d, JCP ) 6.5 Hz), 24.5
(d, JCP ) 137.4 Hz), 16.84 (d, JCP ) 4.3 Hz), 13.0. MS (API-TIS):
m/z 436 (MH)+.
4-Chlorophenyl 5-methoxy-2-methyl-3-(2-phosphonoethyl)in-
dolyl Ketone (50). Bromotrimethylsilane (0.65 mL, 4.9 mmol) was
added to an ice-cold solution of 49 (0.96 g, 2.2 mmol) in CH2Cl2
(30 mL) and stirred at room temperature overnight. The reaction
mixture was partitioned between 1 N HCl (80 mL) and CH2Cl2
(100 mL × 2). The combined organic extracts were washed with
water and brine, dried over Na2SO4, filtered, concentrated, and dried
under vacuum. The residue was dissolved in CHCl3 (5 mL) and
(s, 3H), 2.94 (t, J ) 6.7 Hz, 2H), 2.35 (s, 3H), 1.81 (br., 1H). 13
C
NMR (75 MHz, CDCl3): δ 168.3, 156.0, 139.1, 135.4, 134.0,
131.08, 131.04, 130.97, 129.0, 116.0, 115.0, 111.3, 101.3, 62.1,
55.7, 27.6, 13.3. MS (API-TIS): m/z 344 (MH)+. Anal.
(C19H18ClNO3) C, H, N.

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6379
1
triturated with Et2O (100 mL). The off-white solid was collected,
washed with Et2O, and then dried under vacuum (0.51 g, 57%
yield). mp: 165–167 °C. 1H NMR (300 MHz, CD3OD): δ 7.62 (d,
J ) 8.4 Hz, 2H), 7.52 (d, J ) 8.4 Hz, 2H), 7.01 (d, J ) 2.1 Hz,
1H), 6.92 (d, J ) 9.0 Hz, 1H), 6.64 (dd, J ) 9.0, 2.1 Hz, 1H), 3.81
(s, 3H), 2.95 (m, 2H), 2.27 (s, 3H), 1.99 (m, 2H). 13C NMR (75
MHz, CD3OD): δ 169.9, 157.7, 140.0, 135.9, 134.9, 132.4, 132.2,
131.8, 130.2, 120.5 (d, JCP ) 18 Hz), 116.1, 112.5, 102.1, 55.1,
28.4 (d, JCP ) 134.3 Hz), 18.5 (d, JCP ) 3.8 Hz), 13.4. MS (API-
TIS): m/z 408 (MH)+.
(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-3-
yl}ethoxy)-N-({[3-(nitrooxy)propyl]amino}sulfonyl)carboxamide
(51). Chlorosulfonyl isocyanate (115 µL, 1.3 mmol) and NEt3 (180
µL, 1.3 mmol) were added to an ice-cold solution of 45 (0.40 g,
1.2 mmol) in CH2Cl2 (15 mL) and stirred in the ice-bath for 30
min. Compound 2 (0.26 g, 1.4 mmol) and NEt3 (250 µL, 1.8 mmol)
were added to the reaction, and the temperature allowed to warm
slowly in the ice-bath to room temperature. After 3 h, the reaction
mixture was diluted with CH2Cl2 (80 mL), washed with 3 N HCl,
water, and brine, and dried over Na2SO4, filtered, and concentrated.
The products were separated by silica gel column chromatography
eluted with EtOAc/hexane (1:1, Rf ) 0.32) to obtain the title
compound (0.15 g, 23% yield). The product can be recrystallized
from CHCl3/hexane. mp: 127–129 °C. 1H NMR (300 MHz, DMSO-
d6): δ 7.66 (d, J ) 8.6 Hz, 2H), 7.60 (d, J ) 8.6 Hz, 2H), 7.09 (d,
J ) 2.4 Hz, 1H), 6.99 (d, J ) 9.0 Hz, 1H), 6.70 (dd, J ) 9.0, 2.4
Hz, 1H), 4.54 (t, J ) 6.3 Hz, 2H), 4.31 (t, J ) 6.9 Hz, 2H), 3.80
(s, 3H), 3.03–2.97 (m, 4H), 2.23 (s, 3H), 1.86 (m, 2H). 13C NMR
(75 MHz, 5% CDCl3/DMSO-d6): δ 168.0, 155.9, 151.8, 137.8,
135.2, 134.3, 131.3, 130.7, 130.6, 129.2, 115.0, 114.8, 111.5, 101.5,
71.0, 64.4, 55.5, 39.8, 26.2, 23.4, 13.2. MS (API-TIS): m/z 569
(MH)+.
recrystallized from CHCl3 /hexane. mp: 51–52 °C. H NMR (300
MHz, CDCl3): δ 7.61 (d, J ) 8.5 Hz, 2H), 7.43 (d, J ) 8.5 Hz,
2H), 6.96 (d, J ) 2.1 Hz, 1H), 6.87 (d, J ) 9.0 Hz, 1H), 6.64 (dd,
J ) 9.0, 2.1 Hz, 1H), 5.15 (br, 1H), 4.44 (t, J ) 5.9 Hz, 2H), 4.23
(t, J ) 6.7 Hz, 2H), 3.81 (s, 3H), 3.24 (br. q, 2H), 2.96 (t, J ) 6.7
Hz, 2H), 2.32 (s, 3H), 1.88 (m, 2H). 13C NMR (75 MHz, CDCl3):
δ 168.1, 156.4, 155.8, 138.9, 135.1, 133.9, 130.9, 130.7, 128.9,
115.3, 114.8, 111.0, 101.2, 70.6, 55.5, 37.3, 27.2, 23.9, 13.0. MS
(API-TIS): m/z 490 (MH)+.
3-(2-Azidoethyl)-5-methoxy-2-methylindolyl 4-chlorophenyl
Ketone (54). To the crude product 46 (1.51 g, 4.4 mmol), was
added NaN3 (0.58 g, 8.9 mmol), and the mixture was heated to 70
°C in DMSO (50 mL) for 2 h. After the mixture was cooled to
room temperature, the DMSO was evaporated under vacuum. The
residue was dissolved in CH2Cl2 (150 mL), washed with water and
brine, dried over Na2SO4, filtered, concentrated, and dried under
vacuum to obtain the title compound. The product, >95% purity
from NMR analysis, was used in the next step without purification.
An analytical sample was obtained by silica gel column chroma-
tography eluted with EtOAc/hexane (1:5, Rf ) 0.45). 1H NMR (300
MHz, CDCl3): δ 7.64 (d, J ) 8.5 Hz, 2H), 7.45 (d, J ) 8.5 Hz,
2H), 6.91 (d, J ) 2.5 Hz, 1H), 6.89 (d, J ) 9.0 Hz, 1H), 6.67 (dd,
J ) 9.0, 2.5 Hz, 1H), 3.83 (s, 3H), 3.49 (t, J ) 7.0 Hz, 2H), 2.94
(t, J ) 7.0 Hz, 2H), 2.37 (s, 3H). 13C NMR (75 MHz, CDCl3): δ
168.2, 155.9, 139.1, 135.4, 133.9, 131.1, 130.9, 130.5, 129.0, 115.5,
115.0, 111.2, 101.0, 55.7, 50.7, 24.1, 13.1.
3-(2-Aminoethyl)-5-methoxy-2-methylindolyl 4-chlorophenyl
Ketone Hydrochloride (55). The crude product 54 was hydroge-
nated in EtOAc (30 mL) in the presence of 10% Pd/C (0.14 g) and
acetic acid (0.5 mL) at 30 psi for 2 h. The reaction mixture was
filtered through Celite, and the filter cake was washed with MeOH
(100 mL). The filtrate was concentrated, and the residue was
partitioned between CH2Cl2 (200 mL) and water (100 mL). The
organic layer was washed with saturated Na2CO3, water, and brine,
dried over Na2SO4, filtered, concentrated, and dried under vacuum.
The product was dissolved in Et2O and treated with HCl/Et2O. The
brown solid was collected, washed with Et2O, and then dried under
3-(Nitrooxy)propyl [(2-{1-[(4-chlorophenyl)carbonyl]-5-meth-
oxy-2-methylindol-3-yl}ethoxy)carbonylamino]sulfonate (52). Chlo-
rosulfonyl isocyanate (130 µL, 1.5 mmol) and NEt3 (210 µL, 1.5
mmol) were added to an ice-cold solution of 45 (0.52 g, 1.5 mmol)
in CH2Cl2 (20 mL) and stirred in the ice-bath for 30 min. Compound
8 (0.25 g, 2.1 mmol) and NEt3 (210 µL, 1.5 mmol) were added to
the reaction; the temperature allowed to increase slowly in the ice-
bath to room temperature, and the mixture was stirred overnight.
The reaction mixture was partitioned between 3 N HCl (20 mL)
and CH2Cl2 (50 mL). The organic extract was washed with water
and brine, dried over Na2SO4, filtered, and concentrated. The
products were separated by silica gel column chromatography eluted
with EtOAc/hexane (1:1, Rf ) 0.1) to obtain the title compound as
1
vacuum (1.21 g, 73% yield for 4 steps). mp: >200 °C. H NMR
(300 MHz, DMSO-d6): δ 8.30 (br, 3H), 7.71 (d, J ) 8.7 Hz, 2H),
7.63 (d, J ) 8.7 Hz, 2H), 7.26 (d, J ) 2.1 Hz, 1H), 6.96 (d, J )
9.0 Hz, 1H), 6.71 (dd, J ) 9.0, 2.1 Hz, 1H), 3.80 (s, 3H), 3.00 (m,
4H), 2.23 (s, 3H). 13C NMR (75 MHz, DMSO-d6): δ 168.0, 155.7,
137.6, 134.9, 134.2, 131.2, 130.5, 130.3, 129.0, 114.7, 111.5, 101.5,
55.6, 38.5, 21.6, 13.1. MS (API): m/z 343 (M - Cl)+.
N-(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-
3-yl}ethyl){4-[(nitrooxy)methyl]phenyl}carboxamide (56). A mix-
ture of 55 (1.01 g, 2.7 mmol), 10 (0.59 g, 3.0 mmol), DMAP (0.4
g, 3.3 mmol), EDAC (0.67 g, 3.5 mmol), and NEt3 (1.6 mL, 11.5
mmol) in CH2Cl2 (30 mL) and THF (20 mL) was stirred at room
temperature for 2 days. The reaction mixture was partitioned
between 3 N HCl (30 mL) and EtOAc (50 mL × 2). The combined
organic extracts were washed with water and brine, dried over
Na2SO4, filtered, and concentrated. The product was separated by
silica gel column chromatography eluted with EtOAc/hexane (2:3,
Rf ) 0.25 in 1:1) to obtain the title compound (0.28 g, 20% yield).
The product can be recrystallized from Et2O and hexane. mp:
141–144 °C. 1H NMR (300 MHz, CDCl3): δ 7.70 (d, J ) 8.2 Hz,
2H), 7.61 (d, J ) 8.5 Hz, 2H), 7.43 (d, J ) 8.5 Hz, 2H), 7.41 (d,
J ) 8.2 Hz, 2H), 6.98 (d, J ) 2.5 Hz, 2H), 6.89 (d, J ) 9.0 Hz,
1H), 6.67 (dd, J ) 9.0, 2.5 Hz, 1H), 6.4 (br. t, 1H), 5.43 (s, 2H),
3.74 (s, 3H), 3.67 (br. q, 2H), 3.00 (t, J ) 6.6 Hz, 2H), 2.30 (s,
3H). 13C NMR (75 MHz, CDCl3): δ 168.2, 166.8, 156.0, 139.1,
136.0, 135.3, 135.0, 133.8, 131.0, 130.88, 130.85, 129.0, 128.8,
127.4, 116.6, 115.0, 111.5, 101.0, 55.6, 39.9, 23.9, 13.2. MS (API-
TIS): m/z 522 (MH)+. Anal. (C27H24ClN3O6) C, H, N.
1
a solid (0.143 g, 17% yield). mp: 44–46 °C. H NMR (300 MHz,
CDCl3): δ 7.61 (d, J ) 8.5 Hz, 2H), 7.43 (d, J ) 8.5 Hz, 2H), 6.94
(d, J ) 2.3 Hz, 1H), 6.89 (d, J ) 9.0 Hz, 1H), 6.65 (dd, J ) 9.0,
2.3 Hz, 1H), 4.48 (t, J ) 6.0 Hz, 2H), 4.36 (t, J ) 6.9 Hz, 2H),
4.31 (t, J ) 6.0 Hz, 2H), 3.82 (s, 3H), 3.02 (br. t, 2H), 2.31 (s,
3H), 2.07 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 168.5, 156.0,
150.9, 139.2, 135.6, 133.6, 131.1, 130.9, 130.6, 129.0, 115.0, 114.5,
111.3, 101.2, 69.0, 68.5, 66.1, 55.7, 26.3, 23.4, 13.1. MS (API-
TIS): m/z 570 (MH)+.
(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-
3-yl}ethoxy)-N-[3-(nitrooxy)propyl]carboxamide (53). A solution
of 45 (0.39 g, 1.1 mmol) in THF (5 mL) was added to a mixture
of phosgene (20% in toluene, 10 mL) and K2CO3 (0.16 g, 1.2
mmol). The reaction was stirred at room temperature for 1 h then
heated to 50 °C for an additional 0.5 h. The reaction was cooled
down to room temperature. The excess phosgene was removed by
evaporation of the reaction mixture to half the volume under reduced
pressure. The resulting crude intermediate was dissolved in THF
(20 mL), and 2 (0.20 g, 1.1 mmol) and DMAP (0.44 g, 3.6 mmol)
were added and stirred at room temperature for 1.5 h. The reaction
was quenched with 3 N HCl (100 mL) and extracted with EtOAc
(50 mL × 2). The combined organic layers were washed with 3 N
HCl, water, and brine, dried over Na2SO4, filtered, and concentrated.
The product was separated by silica gel column chromatography
eluted with EtOAc/hexane (2:3, Rf ) 0.25) to obtain the title
compound as a solid (0.47 g, 83% yield). The product can be
N-(2-{1-[(4-Chlorophenyl)carbonyl]-5-methoxy-2-methylindol-
3-yl}ethyl){[3-(nitrooxy)propyl]amino}carboxamide (57). N,N′-
Carbonyldiimidazole (79 mg, 0.49 mmol) and 55 (0.16 g, 0.46
mmol) in CH2Cl2 (10 mL) were stirred at room temperature for
45 min. Compound 2 (85 mg, 0.46 mmol) and NEt3 (0.07 mL,
0.5 mmol) in THF (5 mL) was added to the resulting solution, and

6380 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
the mixture was stirred for an additional 5 h. The reaction mixture
was partitioned between 3 N HCl (30 mL) and CH2Cl2 (50 mL).
The organic extract was washed with water and brine, dried over
Na2SO4, filtered, and concentrated. The product was separated by
silica gel column chromatography eluted with EtOAc/hexane
(gradient from 2:1 to 4:1, Rf ) 0.33 in 2:1) to obtain the title
compound (0.081 g, 40% yield). The product can further purified
by washing with Et2O. mp: 112–114 °C. 1H NMR (300 MHz,
CDCl3): δ 7.60 (d, J ) 8.4 Hz, 2H), 7.44 (d, J ) 8.4 Hz, 2H), 6.94
(d, J ) 2.1 Hz, 1H), 6.87 (d, J ) 9.0 Hz, 1H), 6.66 (dd, J ) 9.0,
2.1 Hz, 1H), 4.58 (br, 2H), 4.46 (t, J ) 6.0 Hz, 2H), 3.83 (s, 3H),
3.40 (br. q, 2H), 3.23 (br. q, 2H), 2.86 (t, J ) 6.6 Hz, 2H), 2.30 (s,
3H), 1.87 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 168.4, 158.0,
156.1, 139.3, 135.1, 133.9, 131.1, 131.0, 129.1, 128.8, 116.8, 115.0,
111.2, 101.4, 71.0, 55.7, 40.1, 36.9, 27.8, 24.8, 13.2. MS (API-
TIS): m/z 489 (MH)+.
139.0, 135.2, 133.7, 130.9, 130.5, 128.9, 115.4, 114.9, 111.3, 101.0,
55.6, 49.7, 42.6, 26.6, 25.5, 13.2. MS (API-TIS): m/z 483 (MH)+.
Anal. (C22H24Cl2N2O4S) C, H, N.
4-Chlorophenyl 5-methoxy-2-methyl-3-[2-({[3-(nitrooxy)-pro-
pyl]sulfonyl}-amino)ethyl]indolyl Ketone (61). A solution of 60
(3.08 g, 6.4 mmol) and AgNO3 (3.14 g, 18.5 mmol) in acetonitrile
(100 mL) was heated to reflux for 3 days. The reaction was cooled
down to room temperature and stirred with brine (50 mL) for 30
min. The silver salts were filtered off through Celite, and the filtrate
was extracted with CH2Cl2. The organic extracts were washed with
brine, dried over Na2SO4, filtered, concentrated, and dried under
vacuum. The product was separated by silica gel column chroma-
tography eluted with EtOAc/hexane (2:3, Rf ) 0.19) to obtain the
title compound as a yellowish solid (1.96 g, 60% yield). 1H NMR
(300 MHz, CDCl3): δ 7.61 (d, J ) 8.5 Hz, 2H), 7.45 (d, J ) 8.5
Hz, 2H), 6.97 (d, J ) 2.4 Hz, 1H), 6.89 (d, J ) 9.0 Hz, 1H), 6.67
(dd, J ) 9.0, 2.4 Hz, 1H), 4.73 (t, J ) 6.3 Hz, 1H), 4.47 (t, J ) 6.2
Hz, 2H), 3.83 (s, 3H), 3.36 (br. q, 2H), 2.92–3.0 (m, 4H), 2.34 (s,
3H), 2.10 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 168.3, 156.0,
139.3, 135.5, 133.7, 131.1, 130.9, 130.5, 129.1, 115.3, 115.0, 101.1,
70.5, 55.7, 49.0, 42.8, 25.6, 21.6, 13.3. MS (API-TIS): m/z 510
(MH)+. Anal. (C22H24ClN3O7S) C, H, N.
4-Chlorophenyl 3-(2-{[(3-hydroxypropyl)sulfonyl]amino}ethyl)-
5-methoxy-2-methylindolyl Ketone (62). Compound 61 (0.36 g,
0.71 mmol) was hydrogenated in EtOAc (20 mL) in presence of
10% Pd/C (55 mg) at 35 psi for 3.5 h. The reaction mixture was
filtered through Celite, and the filter cake was washed with EtOAc.
The filtrate was concentrated, and the residue was separated by
silica gel column chromatography eluted with EtOAc/hexane (2:1,
Rf ) 0.1) to obtain the title compound (0.27 g, 80% yield). mp:
116–118 °C. 1H NMR (400 MHz, CDCl3): δ 7.65 (d, J ) 8.0 Hz,
2H), 7.47 (d, J ) 8.0 Hz, 2H), 6.97 (d, J ) 2.4 Hz, 1H), 6.89 (d,
J ) 8.8 Hz, 1H), 6.67 (dd, J ) 8.8, 2.4 Hz, 1H), 4.64 (br. t, 1H),
3.84 (s, 3H), 3.67 (t, J ) 6.0 Hz, 2H), 3.37 (br. q, 2H), 3.07 (m,
2H), 2.96 (t, J ) 6.8 Hz, 2H), 2.36 (s, 3H), 2.00–1.90 (m, 2H),
1.80–1.70 (br, 1H). 13C NMR (100 MHz, CDCl3): δ 168.4, 156.1,
139.4, 135.5, 133.8, 131.2, 131.0, 130.6, 129.1, 115.5, 115.0, 111.5,
101.2, 60.6, 55.8, 49.8, 42.8, 26.8, 25.6, 13.4. MS (API-TIS): m/z
465 (MH)+. Anal. (C22H25ClN2O5S) C, H, N.
3-[2-({[4-(Chloromethyl)phenyl]sulfonyl}amino)ethyl]-5-meth-
oxy-2-methylindolyl 4-chlorophenyl Ketone (58). 4-(Bromom-
ethyl)benzenesulfonyl chloride (1.15 g, 4.3 mmol) and NEt3 (1.0
mL, 7.2 mmol) were added to 55 in CH2Cl2 (50 mL), and the
mixture was stirred at room temperature overnight. The reaction
was partitioned between 3 N HCl (30 mL) and CH2Cl2 (50 mL ×
3). The combined organic extracts were washed with 3 N HCl,
saturated NaHCO3, water, and brine, dried over Na2SO4, filtered,
and concentrated. The product was separated by silica gel column
chromatography eluted with EtOAc/hexane (1:2, Rf ) 0.25) to
1
obtain the title compound (0.83 g, 53% yield). mp: 58–60 °C. H
NMR (300 MHz, CDCl3): δ 7.73 (d, J ) 8.3 Hz, 2H), 7.57 (d, J
) 8.4 Hz, 2H), 7.43 (d, J ) 8.4 Hz, 2H), 7.42 (d, J ) 8.3 Hz, 2H),
6.86 (d, J ) 9.0 Hz, 1H), 6.85 (d, J ) 2.4 Hz, 1H), 6.64 (dd, J )
9.0, 2.4 Hz, 1H), 5.15 (br. t, 1H), 4.57 (s, 2H), 3.80 (s, 3H), 3.21
(br. q, 2H), 2.88 (t, J ) 6.9 Hz, 2H), 2.25 (s, 3H). 13C NMR (75
MHz, CDCl3): δ 168.2, 155.9, 142.0, 139.7, 139.1, 135.3, 133.7,
131.0, 130.8, 130.4, 129.0, 128.95, 127.2, 115.3, 115.0, 111.4,
100.9, 55.6, 44.8, 42.5, 24.8, 13.2. MS (API-TIS): m/z 531 (MH)+.
4-Chlorophenyl 5-methoxy-2-methyl-3-{2-[({4-[(nitrooxy)
methyl]phenyl}-sulfonyl)amino]ethyl}indolyl Ketone (59). A
solution of 58 (0.83 g, 1.6 mmol) and AgNO3 (0.61 g, 3.95 mmol)
in acetonitrile (60 mL) was heated to 70 °C for 6 h. The reaction
was cooled down to room temperature and stirred with brine (50
mL) for 1 h. The silver salts were filtered off through Celite, and
the filtrate was extracted with CH2Cl2. The organic layer was
washed with brine, dried over Na2SO4, filtered, concentrated, and
dried under vacuum. The product was separated by silica gel column
chromatography eluted with EtOAc/hexane (1:2, Rf ) 0.15) to
obtain the title compound. The product was washed with 10%
EtOAc/hexane to obtain a light yellowish solid (0.50 g, 57% yield).
Supporting Information Available: COX inhibition screening
data of all compounds and combustion analyses results. This
material is available free of charge via the Internet at http://
pubs.acs.org.
References
1
(1) Mitchell, J. A.; Akarasereenont, P.; Thiemermann, C.; Flower, R. J.;
Vane, J. R. Selectivity of nonsteroidal antiinflammatory drugs as
inhibitors of constitutive and inducible cyclooxygenase. Proc. Natl.
Acad. Sci. U.S.A. 1993, 90, 11693–11697.
(2) Masferrer, J. L.; Zweifel, B. S.; Manning, P. T.; Hauser, S. D.; Leahy,
K. M.; et al. Selective inhibition of inducible cyclooxygenase-2 in
ViVo is antiinflammatory and nonulcerogenic. Proc. Natl. Acad. Sci.
U.S.A. 1994, 91, 3228–3232.
(3) Seibert, K.; Zhang, Y.; Leahy, K.; Hauser, S.; Masferrer, J.; et al.
Pharmacological and biochemical demonstration of the role of
cyclooxygenase 2 in inflammation and pain. Proc. Natl. Acad. Sci.
U.S.A. 1994, 91, 12013–12017.
(4) Smith, W. L.; Garavito, R. M.; DeWitt, D. L. Prostaglandin endo-
peroxide H synthase (cyclooxygenase)-1 and -2. J. Biol. Chem. 1996,
271, 33157–33160.
mp: 143–146 °C. H NMR (300 MHz, DMSO-d6): δ 7.9–7.7 (m,
3H), 7.7–7.6 (m, 6H), 6.99 (d, J ) 2.4 Hz, 1H), 6.97 (d, J ) 9.0
Hz, 1H), 6.71 (dd, J ) 9.0, 2.4 Hz, 1H), 5.65 (s, 2H), 3.78 (s, 3H),
3.01 (br. q, 2H), 2.79 (t, J ) 6.6 Hz, 2H), 2.15 (s, 3H). 13C NMR
(75 MHz, CDCl3): δ 167.8, 155.6, 141.2, 137.6, 136.9, 134.5, 134.2,
131.2, 130.5, 130.4, 129.5, 129.0, 126.8, 116.1, 114.7, 111.3, 101.2,
73.8, 55.4, 42.4, 24.4, 13.2. MS (API-TIS): m/z 558 (MH)+. Anal.
(C26H24ClN3O7S) C, H, N.
4-Chlorophenyl 3-(2-{[(3-chloropropyl)sulfonyl]amino}ethyl)-
5-methoxy-2-methylindolyl Ketone (60). 3-Chloropropanesulfonyl
chloride (0.24 mL, 2.0 mmol) and NEt3 (0.5 mL, 3.6 mmol) was
added to 55 in CHCl3 (20 mL), and the mixture was stirred at room
temperature overnight. The reaction mixture was partitioned
between 3 N HCl (30 mL) and CH2Cl2 (50 mL × 2). The combined
organic extracts were washed with 3 N HCl, saturated NaHCO3,
water, and brine, dried over Na2SO4, filtered, and concentrated. The
product was separated by silica gel column chromatography eluted
with EtOAc/hexane (1:2, Rf ) 0.12) to obtain the title compound
(0.55 g, 77% yield). mp: 108–111 °C. 1H NMR (300 MHz, CDCl3):
δ 7.59 (d, J ) 8.4 Hz, 2H), 7.43 (d, J ) 8.4 Hz, 2H), 6.98 (d, J )
2.4 Hz, 1H), 6.90 (d, J ) 9.0 Hz, 1H), 6.65 (dd, J ) 9.0, 2.4 Hz,
1H), 5.00 (t, J ) 6.3 Hz, 1H), 3.82 (s, 3H), 3.55 (t, J ) 6.0 Hz,
2H), 3.35 (br. q, 2H), 3.06 (m, 2H), 2.94 (t, J ) 6.9 Hz, 2H), 2.33
(s, 3H), 2.12 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 168.2, 155.9,
(5) Hoffmann, C. COX-2 in brain and spinal cordsImplications for
therapeutic use. Curr. Med. Chem. 2000, 7, 1113–1120.
(6) Tibble, J.; Sigthorsson, G.; Caldwell, C.; Palmer, R. H.; Bjarnason, I.
Effects of NSAIDs on cryoprobe-induced gastric ulcer healing in rats.
Aliment. Pharmacol. Ther. 2001, 15, 2001–2008.
(7) Rodriguez, F.; Llinas, M. T.; Gonzalez, J. D.; Rivera, J.; Salazar, F. J.
Renal changes induced by a cyclooxygenase-2 inhibitor during normal
and low sodium intake. Hypertension 2000, 36, 276–281.
(8) Zhang, J.; Ding, E. L.; Song, Y. Adverse effects of cyclooxygenase 2
inhibitors on renal and arrhythmia events: Meta-analysis of randomized
trials. J. Am. Med. Assoc. 2006, 296, 1619–1632.
(9) McGettigan, P.; Henry, D. Cardiovascular risk and inhibition of
cyclooxygenase: A systematic review of the observational studies of

Indomethacin DeriVatiVes as COX-2 Inhibiting NO Donors
Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25 6381
selective and nonselective inhibitors of cyclooxygenase 2. J. Am. Med.
Assoc. 2006, 296, 1633–1644.
(10) Silverstein, F. E.; Faich, G.; Goldstein, J. L.; Simon, L. S.; Pincus,
T.; et al. Gastrointestinal toxicity with celecoxib vs nonsteroidal anti-
inflammatory drugs for osteoarthritis and rheumatoid arthritis. J. Am.
Med. Assoc. 2000, 284, 1247–1255.
(11) Goldstein, J. L.; Lowry, S. C.; Lanza, F. L.; Schwartz, H. I.; Dodge,
W. E. The impact of low-dose aspirin on endoscopic gastric and
duodenal ulcer rates in users of a non-selective non-steroidal anti-
inflammatory drug or a cyclo-oxygenase-2-selective inhibitor. Aliment.
Pharmacol. Ther. 2006, 23, 1489–1498.
(12) Wallace, J. L.; Miller, M. J. S. Nitric oxide in mucosal defense: A
little goes a long way. Gastroenterology 2000, 119, 512–520.
(13) Elliott, S. N.; McKnight, W.; Cirino, G.; Wallace, J. L. A nitric oxide-
releasing nonsteroidal anti-inflammatory drug accelerates gastric ulcer
healing in rats. Gastroenterology 1995, 109, 524–530.
(14) Radomski, M. W.; Palmer, R. M.; Moncada, S. The role of nitric oxide
and cGMP in platelet adhesion to vascular endothelium. Biochem.
Biophys. Res. Commun. 1987, 148, 1482–1489.
(15) Bandarage, U. K.; Chen, L.; Fang, X.; Garvey, D. S.; Glavin, A.; et
al. Nitrosothiol esters of diclofenac: Synthesis and pharmacological
characterization as gastrointestinal-sparing prodrugs. J. Med. Chem.
2000, 43, 4005–4016.
(16) Mizoguchi, H.; Hase, S.; Tanaka, A.; Takeuchi, K. Lack of small
intestinal ulcerogenecity of nitric oxide-releasing indomethacin, NCX-
530, in rats. Aliment. Pharmacol. Ther. 2001, 15, 257–267.
(17) Lolli, M. L.; Cena, C.; Medana, C.; Lazzarato, L.; Morini, G.; et al.
A new class of ibuprofen derivatives with reduced gastrotoxicity.
J. Med. Chem. 2001, 44, 3463–3468.
(18) Takeuchi, K.; Mizoguchi, H.; Araki, H.; Komoike, Y.; Suzuki, K. Lack
of gastric toxicity of nitric oxide-releasing indomethacin, NCX-530,
in experimental animals. Dig. Dis. Sci. 2001, 46, 1805–1818.
(19) Minuzi, P.; Degani, M.; Gainol, S.; Meneguzzii, A.; Zuliani, V.; et
al. NCX4016 (NO-aspirin) inhibits thromboxane biosynthesis and
tissue factor expression and activity in human monocytes. Med. Sci.
Monit. 2001, 7, 573–577.
(20) Muscará, M. N.; Lovren, F.; McKnight, W.; Dicay, M.; Soldato, P. D.;
et al. Vasorelaxant effects of a nitric oxide-releasing aspirin derivative
in normotensive and hypertensive rats. Br. J. Pharmacol. 2001, 133,
1314–1322.
(21) Keeble, J.; Al-Swayeh, O. A.; Moore, P. K. Vasorelaxant effect of
nitric oxide releasing steroidal and nonsteroidal anti-inflammatory
drugs. Br. J. Pharmacol. 2001, 133, 1023–1028.
(22) Kartasasmita, R. E.; Laufer, S.; Lehmann, J. NO-Donors (VII [I]):
Synthesis and cyclooxygenase inhibitory properties of N- and S-
nitrooxypivaloyl-cysteine derivatives of naproxensA novel type of
NO-NSAID. Arch. Pharm. Pharm. Med. Chem. 2002, 8, 363–366.
(23) Napoli, C.; Ackah, E.; Nigris, F. D.; Soldato, P. D.; D’Armiento, F. P.;
et al. Chronic treatment with nitric oxide-releasing aspirin reduces
plasma low-density lipoprotein oxidation and oxidative stress, arterial
oxidation-specific epitopes, and atherogenesis in hypercholesterolemic
mice. Proc. Natl. Acad. Sci. U.S.A. 2002, 99, 12467–12470.
(24) Hawkey, C. J.; Jones, J. I.; Atherton, C. T.; Skelly, M. M.; Bebb,
J. R.; et al. Gastrointestinal safety of AZD3582, a cyclooxygenase
inhibiting nitric oxide donator: Proof of concept study in humans. Gut
2003, 52, 1537–1542.
(25) Fiorucci, S.; Santucci, L.; Wallace, J. L.; Sardina, M.; Romano, M.;
et al. Interaction of a selective cyclooxygenase-2 inhibitor with aspirin
and NO-releasing aspirin in the human gastric mucosa. Proc. Natl.
Acad. Sci. U.S.A. 2003, 100, 10937–10941.
(26) Cena, C.; Lolli, M. L.; Lazzarato, L.; Guaita, E.; Morini, G.; et al.
Antiinflammatory, gastrosparing, and antiplatelet properties of new
NO-donor esters of aspirin. J. Med. Chem. 2003, 46, 747–754.
(27) Huledal, G.; Jonzon, B.; Malmenas, M.; Hedman, A.; Andersson, L. I.;
et al. Renal effects of the cyclooxygenase-inhibiting nitric oxide
donator AZD3582 compared with rofecoxib and naproxen during
normal and low sodium intake. Clin. Pharmacol. Ther. 2005, 77, 437–
450.
(28) Muscará, M. N.; Wallace, J. L. COX-inhibiting nitric oxide donors
(CINODs): Potential benefits on cardiovascular and renal function.
CardioVasc. Hematol. Agents Med. Chem. 2006, 4, 155–164.
(29) Ranatunge, R. R.; Augustyniak, M.; Bandarage, U. K.; Earl, R. A.;
Ellis, J. L.; et al. Synthesis and selective cyclooxygenase-2 inhibitory
activity of a series of novel, nitric oxide donor-containing pyrazoles.
J. Med. Chem. 2004, 47, 2180–2193.
(33) Greig, G. M.; Francis, D. A.; Falgueyret, J.-P.; Ouellet, M.; Percival,
M. D.; et al. The interaction of arginine 106 of human prostaglandin
G/H synthase-2 with inhibitors is not a universal component of
inhibition mediated by nonsteroidal anti-inflammatory drugs. Mol.
Pharmacol. 1997, 52, 829–838.
(34) Bhattacharya, D. K.; Lecomte, M.; Rieke, C. J.; Garavito, R. M.; Smith,
W. L. Involvement of arginine 120, glutamate 524, and tyrosine 355
in the binding of arachidonate and 2-phenylpropionic acid inhibitors
to the cyclooxygenase active site of ovine prostaglandin endoperoxide
H synthase-1. J. Biol. Chem. 1996, 271, 2179–2184.
(35) Gierse, J. K.; McDonald, J. J.; Hauser, S. D.; Rangwala, S. H.; Koboldt,
C. M.; et al. A single amino acid difference between cyclooxygenase-1
(COX-1) and -2 (COX-2) reverses the selectivity of COX-2 specific
inhibitors. J. Biol. Chem. 1996, 271, 15810–15814.
(36) Kurumbail, R. G.; Stevens, A. M.; Gierse, J. K.; McDonald, J. J.;
Stegeman, R. A.; et al. Structural basis for selective inhibition of
cycloxygenase-2 by anti-inflammatory agents. Nature 1996, 384, 644–
648.
(37) Kalgutkar, A. S.; Rowlinson, S. W.; Crew, B. C.; Marnett, L. J. Amide
derivatives of meclofenamic acid as selective cyclooxygenase-2
inhibitors. Bioorg. Med. Chem. Lett. 2002, 12, 521–524.
(38) Luong, C.; Miller, A.; Barnett, J.; Chow, J.; Ramesha, C.; et al.
Flexibility of the NSAID binding site in the structure of human
cyclooxygenase-2. Nat. Struct. Biol. 1996, 3, 927–933.
(39) Copeland, R. A.; Williams, J. M.; Giannaras, J.; Nurnberg, S.;
Covington, M.; et al. Mechanism of selective inhibition of the inducible
isoform of prostaglandin G/H synthase. Proc. Natl. Acad. Sci. U.S.A.
1994, 91, 11202–11206.
(40) Callan, O. H.; So, O.-Y.; Swinney, D. C. The kinetic factors that
determine the affinity and selectivity for slow binding inhibition of
human prostaglandin H synthase 1 and 2 by indomethacin and
flurbiprofen. J. Biol. Chem. 1996, 271, 3548–3554.
(41) Houtzager, V.; Ouellet, M.; Falgueyret, J.-P.; Passmore, L. A.; Bayly,
C.; et al. Inhibitor-induced changes in the intrinsic fluorescence of
human cyclooxygenase-2. Biochemistry 1996, 35, 10974–10984.
(42) Gierse, J. K.; Koboldt, C. M.; Walker, M. C.; Seibert, K.; Isakson,
P. C. Kinetic basis for selective inhibition of cyclo-oxygenases.
Biochem. J. 1999, 339, 607–614.
(43) Timofeevski, S. L.; Prusakiewicz, J. J.; Rouzer, C. A.; Marnett, L. J.
Isoform-selective interaction of cyclooxygenase-2 with indomethacin
amides studied by real-time fluorescence, inhibition kinetics, and site-
directed mutagenesis. Biochemistry 2002, 41, 9654–9662.
(44) So, O.-Y.; Scarafia, L. E.; Mak, A. Y.; Callan, O. H.; Swinney, D. C.
The dynamics of prostaglandin H synthases. Studies with prostaglandin
H synthase 2 Y355F unmask mechanisms of time-dependent inhibition
and allosteric activation. J. Biol. Chem. 1998, 273, 5801–5807.
(45) Walker, M. C.; Kurumbail, R. G.; Kiefer, J. R.; Moreland, K. T.;
Koboldt, C. M.; et al. A three-step kinetic mechanism for selective
inhibition of cyclo-oxygenase-2 by diarylheterocyclic inhibitors.
Biochem. J. 2001, 357, 709–718.
(46) Kalgutkar, A. S.; Kozak, K. R.; Crews, B. C.; Hochgesang, G. P. J.;
Marnett, L. J. Covalent modification of cyclooxygenase-2 (COX-2)
by 2-acetoxyphenyl alkyl sulfides, A new class of selective COX-2
inactivators. J. Med. Chem. 1998, 41, 4800–4818.
(47) Lazer, E. S.; Miao, C. K.; Cywin, C. L.; Sorcek, R.; Wong, H.-C.; et
al. Effect of structure modification of enol-carboxamide-type nonste-
roidal antiinflammatory drugs on COX-2/COX-1 selectivity. J. Med.
Chem. 1997, 40, 980–989.
(48) Julémont, F.; Leval, X. D.; Michaux, C.; Renard, J.-F.; Winum, J.-
Y.; et al. Design, synthesis, and pharmacological evaluation of
pyridinic analogues of nimesulide as cyclooxygenase-2 selective
inhibitors. J. Med. Chem. 2004, 47, 6749–6759.
(49) Palomer, A.; Pascual, J.; Cabré, M.; Borràs, L.; González, G.; et al.
Structure-based design of cyclooxygenase-2 selectivity into ketoprofen.
Bioorg. Med. Chem. Lett. 2002, 12, 533–537.
(50) Bayly, C. I.; Black, W. C.; Léger, S.; Ouimet, N.; Ouellet, M.; et al.
Structure-based design of COX-2 selectivity into flurbiprofen. Bioorg.
Med. Chem. Lett. 1999, 9, 307–312.
(51) Black, W. C.; Bayly, C.; Belly, M.; Chan, C. C.; Charleson, S.; et al.
From indomethacin to a selective COX-2 inhibitor: Development of
indolalkanoic acids as potent and selective cyclooxygenase-2 inhibitors.
Bioorg. Med. Chem. Lett. 1996, 6, 725–730.
(52) Leblanc, Y.; Black, W. C.; Chan, C. C.; Charleson, S.; Delorme, D.;
et al. Synthesis and biological evaluation of both enantiomers of
L-761,000 as inhibitors of cyclooxygenase-1 and -2. Bioorg. Med.
Chem. Lett. 1996, 6, 731–736.
(53) Woods, K. W.; McCroskey, R. W.; Michaelides, M. R.; Wada, C. K.;
Hulkower, K. I.; et al. Thiazole analogues of the NSAID indomethacin
as selective COX-2 inhibitors. Bioorg. Med. Chem. Lett. 2001, 11,
1325–1328.
(30) Engelhardt, F. C.; Shi, Y.-J.; Cowden, C. J.; Conlon, D. A.; Pipik, B.;
et al. Synthesis of a NO-releasing prodrug of rofecoxib. J. Org. Chem.
2006, 71, 480–491.
(31) COX-1 numbering was used.
(32) Mancini, J. A.; Riendau, D.; Falgueyret, J.-P.; Vickers, P. J.; O’Neill,
G. P. Arginine 120 of prostaglandin G/H synthase-1 is required for
the inhibition by nonsteroidal anti-inflammatory drugs containing a
carboxylic acid moiety. J. Biol. Chem. 1995, 270, 29372–29377.
(54) Kalgutkar, A. S.; Marnett, A. B.; Crew, B. C.; Remmel, R. P.; Marnett,
L. J. Ester and amide derivatives of the nonsteroidal antiinflammatory

6382 Journal of Medicinal Chemistry, 2007, Vol. 50, No. 25
Wey et al.
drug, indomethacin, as selective cyclooxygenase-2 inhibitors. J. Med.
Chem. 200043, 2860–2870.
(55) Kalgutkar, A. S.; Crews, B. C.; Rowlinson, S. W.; Marnett, A. B.;
Kozak, K. R.; et al. Biochemically based design of cyclooxygenase-2
(COX-2) inhibitors: Facile conversion of nonsteroidal antiinflammatory
drugs to potent highly selective COX-2 inhibitors. Proc. Natl. Acad.
Sci. U.S.A. 2000, 97, 925–930.
(56) Kozak, K. R.; Prusakiewicz, J. J.; Rowlinson, S. C.; Marnett, L. J.
Enantiospecific, selective cyclooxygenase-2 inhibitors. Bioorg. Med.
Chem. Lett. 2002, 12, 1315–1318.
inhibitors of both cyclooxygenase and 5-lipoxygenase. J. Med. Chem.
1990, 33, 2070–2072.
(64) Sebesta, D. P.; O’Rourke, S. S.; Martinez, R. L.; Pieken, W. A.;
McGee, D. P. C. 2′-Deoxy-2′-alkoxylaminouridine: Novel 2′-sub-
stituted uridines prepared by intramolecular nucleophilic ring opening
of 2,2′-O-anhydrouridines. Tetrahedron 1996, 52, 14385–14402.
(65) McKenna, C. E.; Higa, M. T.; Cheung, N. H.; McKenna, M.-C. The
facile dealkylation of phosphonic acid dialkyl esters by bromotrim-
ethylsilane. Tetrahedron Lett. 1977, 155–158.
(66) Young, J. M.; Panah, S.; Satchawatcharaphong, C.; Cheung, P. S.
Human whole blood assays for inhibition of prostaglandin G/H
synthases-1 and -2 using A23187 and lipopolysaccharide stimulation
of thromboxane B2 production. Inflamm. Res. 1996, 45, 246–253.
(67) Riendeau, D.; Percival, M. D.; Brideau, C.; Charleson, S.; Dube, D.;
et al. Etoricoxib (MK-0663): Preclinical profile and comparison with
other agents that selectively inhibit cyclooxygenase-2. J. Pharmacol.
Exp. Ther. 2001, 296, 558–566.
(68) Loll, P. J.; Picot, D.; Ekabo, O.; Garavito, R. M. Synthesis and use of
iodinated nonsteroidal antiinflammatory drug analogs as crystal-
lographic probes of the prostaglandin H2 synthase cyclooxygenase
active site. Biochemistry 1996, 35, 7330–7340.
(69) Hawkey, C. J.; Skelly, M. M. Gastrointestinal safety of selective
COX-2 inhibitors. Curr. Pharm. Des. 2002, 8, 1077–1089.
(70) Remmel, R. P.; Crews, B. C.; Kozak, K. R.; Kalgutkar, A. S.; Marnett,
L. J. Studies on the metabolism of the novel, selective cyclooxyge-
nase-2 inhibitor indomethacin phenethylamide in rat, mouse, and
human liver microsomes: Identification of active metabolites. Drug
Metab. Dispos. 2004, 32, 113–122.
(57) Myers, G. S.; Winthrop, S. O. Poly-nitrate esters and salts thereof.
U.S. Patent 2, 975, 208, 1961.
(58) Kawashima, Y.; Ikemoto, T.; Horiguchi, A.; Hayashi, M.; Matsumoto,
K.; et al. Synthesis and pharmacological evaluation of (nitrooxy)alkyl
apovincaminates. J. Med. Chem. 1993, 36, 815–819.
(59) McOmie, J. F. W.; Watts, M. L.; West, D. E. Demethylation of aryl
methyl ethers by boron tribromide. Tetrahedron 1968, 24, 2289–2292.
(60) Okada, M.; Iwashita, S.; Koizumi, N. Efficient general method for
sulfamoylation of a hydroxyl group. Tetrahedron Lett. 2000, 41, 7047–
7051.
(61) Blair, J. B.; Kurrasch-Orbaugh, D.; Marona-Lewicka, D.; Cumbay,
M. G.; Watts, V. J.; et al. Effect of ring fluorination on the
pharmacology of hallucinogenic tryptamines. J. Med. Chem. 2000,
43, 4701–4710.
(62) Kelley, J. L.; Linn, J. A.; Selway, J. W. T. Synthesis and antirhinovirus
activity of 6-(dimethylamino)-2-(trifluoromethyl)-9-(substituted ben-
zyl)-9H-purines. J. Med. Chem. 1989, 32, 1757–1763.
(63) Flynn, D. L.; Capiris, T.; Cetenko, W. J.; Connor, D. T.; Dyer, R. D.;
et al. Nonsteroidal antiinflammatory drug hydroxamic acids. Dual
JM0611861