Discovery of novel p-arylthio cinnamides as antagonists of leukocyte function-associated antigen-1/intercellular adhesion molecule-1 interaction. 4. Structure - Activity relationship of substituents on the benzene ring of the cinnamide

Article abstract of DOI:10.1021/jm0103108

We have shown that p-arylthio cinnamides can inhibit the interaction of LFA-1 and ICAM-1, which is involved in cell adhesion and the inflammatory process. We now show that 2,3-disubstitution on the aryl portion of the cinnamide results in enhanced activit

Full text of DOI:10.1021/jm0103108

J . Med. Chem. 2001, 44, 4393-4403
4393
Discover y of Novel p-Ar ylth io Cin n a m id es a s An ta gon ists of Leu k ocyte
F u n ction -Associa ted An tigen -1/In ter cellu la r Ad h esion Molecu le-1 In ter a ction . 4.
Str u ctu r e-Activity Rela tion sh ip of Su bstitu en ts on th e Ben zen e Rin g of th e
Cin n a m id e
Martin Winn,* Edward B. Reilly, Gang Liu, J effrey R. Huth, Hwan-Soo J ae, J ennifer Freeman, Zhonghua Pei,
Zhili Xin, J ohn Lynch, J eff Kester, Thomas W. von Geldern, Sandra Leitza, Peter DeVries, Robert Dickinson,
Donna Mussatto, and Gregory F. Okasinski
Metabolic Disease Research, Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064-6098
Received J uly 5, 2001
We have shown that p-arylthio cinnamides can inhibit the interaction of LFA-1 and ICAM-1,
which is involved in cell adhesion and the inflammatory process. We now show that
2,3-disubstitution on the aryl portion of the cinnamide results in enhanced activity over mono
substitution on the ring. The best 2,3-substituents were chlorine and trifluoromethyl groups.
Compounds 39 and 40 which contain two CF3 groups have IC50 values of 0.5 and 0.1 nM,
respectively, in inhibiting J Y8 cells expressing LFA-1 on their surface, from adhering to ICAM-
1. The structure-activity relationship (SAR) was examined using an NMR based model of the
LFA-1 I domain/compound 31 complex. One of our compounds (38) was able to reduce cell
migration in two different in vivo experiments.
Sch em e 1. Synthesis of Thiolsa
In tr od u ction
Inflammation results from a cascade of events that
ultimately leads to leukocyte migration to affected
tissues. Early stages of this process involve leukocytes
rolling, firmly adhering to, and subsequently crossing
the vascular endothelium. The process of attaching to
the vessel wall is mediated through interactions of
leukocyte integrins including LFA-1 (lymphocyte func-
tion-associated antigen-1, CD11a/CD18, RLâ2) with
counter-receptors on the endothelial cells. LFA-1 inter-
acts with the immunoglobulin superfamily member
intercellular adhesion molecule-1 (ICAM-1) on activated
endothelium. The arrested leukocytes then transmigrate
the vascular wall and move toward the lesion along a
chemotactic gradient. The adhesive interaction between
LFA-1 and ICAM-1 is thought to play a critical role in
the inflammatory process, and a drug that would
disrupt this event might be of use in the treatment of
inflammatory diseases, autoimmune diseases, tumor
metastasis, and reperfusion injury. We have discovered
that appropriately substituted cinnamides block the
interaction of LFA-1 and ICAM-1.1-3
Paper 11 of this series described the synthesis and
activity of novel diarylsulfides including 22, 30, and 31,
while paper 22 of this series describes optimization
studies leading to compound 24. These compounds were
moderately potent in inhibiting the interaction of LFA-1
and ICAM-1 with IC50’s in the range of 30-1000 nM.
Paper 2 also describes an NOE-based NMR model of
the LFA-1 I domain and compound 31. We hereby report
the further exploration of the SAR of substituents on
the aryl portion of the cinnamides and report a modi-
a
Reagents: (a) 1. iPr3Si-SH, KH, (PPh3)4Pd, THF, 2. CsF.
fication which provides a dramatic improvement in
potency. The affinity of our compounds can be under-
stood in terms of an NMR-based model of the LFA I
domain and compound 31. We also selected one com-
pound (38) and performed in vivo experiments to show
that this compound indeed slows cell migration into an
area of inflammation.
Ch em istr y
The cinnamic acids sulfides, which are key intermedi-
ates in our work, were synthesized by three different
methods. In Scheme 2 the appropriate sufide aldehydes
4 were made by reacting a benzaldehyde with a fluoro
or triflate in the 4 position, with a substituted ben-
zenethiol. The resulting aldehydes were then converted
to cinnamic acids by treatment with malonic acid.
Alternatively, an aryl iodide such as 14 was reacted with
methyl acrylate in a Heck reaction (Scheme 4). In
another route to preparing the desired compounds, the
4-chloro-3-nitrocinnamide 11 and 2,4-difluorocinnamide
12 were treated with a substituted benzenethiol to give
cinnamides 29-31 and 49 (Scheme 4), which were
subsequently hydrolyzed. The cinnamic acids were
coupled with amines under standard amide forming
conditions to provide the desired analogues.
* To whom correspondence should be addressed. Abbott Laborato-
ries, Department 47H, AP-10-LL, 100 Abbott Park Road, Abbott Park,
IL 60064-6098. Phone: (847)-937-7658. Fax: (847)-938-1674. E-mail:
marty.winn@abbott.com.
10.1021/jm0103108 CCC: $20.00 © 2001 American Chemical Society
Published on Web 10/18/2001

4394 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25
Sch em e 2. Synthesis of Sulfidesa
Winn et al.
Sch em e 4. Synthesis of Cinnamidesa
a
a
Reagents: (a) K2CO3, DMF, 60 °C; (b) Tf2O, pyridine; (c)
Reagents: (a) malonic acid, pyridine, cat. piperidine, 110 °C;
(b) 1. (COCl)2, 2. amine, iPr2NEt; (c) ArSH, K2CO3, DMF, 25 °C;
(d) 2-methoxy-thiophenol, Cs2CO3; (e) 1. tBu-ONO, H2SO4, CH3CN,
2. Kl, urea, 94%; (f) 1. methyl acrylate, Pd(OAc)2, Et3N 82%, 2.
NaOH, EtOH.
iPr2NEt, CH3CN.
Sch em e 3. Synthesis of Aldehydesa
give the sulfide aldehydes (4) which were reacted with
malonic acid to give cinnamic acids and then coupled
with the appropriate amine to give the target com-
pounds.
All the 4-fluorobenzaldehydes were commercially
available except 3e and 3g (Scheme 3). 4-Fluoro-3-
chlorosulfonyl benzoic acid was reacted with dimethyl-
amine to give the sulfonamide. The carboxylic acid was
then reduced to the benzyl alcohol with borane and this
was oxidized to 4-fluoro-3-dimethylaminosulfonyl benz-
aldehyde (3e).
We wished to make the 4-fluoro-2-chloro-3-triflouro-
methyl benzaldehyde starting with 3-trifluoromethyl-
4-fluorobenzoic acid. Bennetau5 had converted 3-chloro-
4-fluorobenzoic acid to 2,3-dichloro-4-fluorobenzoic acid
by dilithiating the acid with sec-butyllithium in the
presence of TMEDA and then treating with hexachlo-
roethane. We did this with 3-trifluoromethyl-4-fluoro-
benzoic acid. The resulting acid was converted to the
aldehyde by reaction with borane followed by MnO2
oxidation. Examination of the NMR spectrum of the
aldehyde showed that the chlorination had taken place
ortho to the fluorine to give 3-trifluoromethyl-4-fluoro-
5-chlorobenzaldehyde (3g). The NMR spectrum of 3-tri-
fluoromethyl-4-fluorobenzaldehyde (from Aldrich) has
a double doublet (J ) 9 Hz, J ) 9 Hz) at 7.40 ppm for
the 5 proton (ortho to the fluorine), a double doublet
(J ) 9 Hz, J ) 2 Hz) at 8.18 ppm for the 2 proton, and
a multiplet of 6 peaks at 8.13 ppm for the 6 proton. Our
aldehyde has no peak at 7.40 ppm which shows that
there is no proton in position 5. There are two double
doublets (J ) 8 Hz, J ) 2 Hz) at 8.05 and 8.15 ppm for
the 2 and 6 protons.
The triflates were synthesized from 4-hydroxybenz-
aldehydes (5h -p ). The 2,3-dichloro (5i),6 2-trifluoro-
methyl-3-chloro (4m ), and 2,3-dimethyl (5j)7 benzalde-
hyes were made from the corresponding phenols by the
Reimer-Tiemann reaction. 1-Naphthol gave 5k by reac-
tion8 with dichloromethyl methyl ether. 2,5-Dichloro-
anisole and dichloromethyl methyl ether gave 2,5-
dichloro-4-methoxybenzaldehyde, which was demethyl-
ated to the known 5p .9 4-Methyl-2,3-di-(trifluoromethy)-
phenol10 was synthesized from 2-methyl furan and
hexafluoro butyne as shown in Scheme 3. The methyl
a
Reagents: (a) 1. Me2NH, 2. BH3 THF, 3. MnO2; (b) CHCl3,
Ca(OH)2; (c) Cl2CHOMe, TiCl4; (d) BBr3; (e) sec-Bu Li, TMEDA,
Cl3CCCl3; (f) 1. BH3 THF, 2. MnO2; (g) 120 °C, 15 h; (h) BF3 Et2O,
25 °C, 16 h; (i) 1. Br-C6H4-SO2Cl, iPr2NEt, 2. NBS, (PhCO)2O2,
CCl4, reflux, 13 h., 3. Me3N-O, DMSO, 25 °C, 2 h.
The thiols we used were commercially available
except for the benzodioxane (1) and indole (2). They
were prepared from the appropriate aryl bromide by
reacting with i-Pr3Si-SH, K salt with Pd(0) catalyst and
removing the i-Pr3Si with CsF4 (Scheme 1). The thiols
were reacted with 4-fluorobenzaldehydes (Scheme 2) to

SAR of Substituents on the Benzene Ring of the Cinnamide
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25 4395
Sch em e 5. Interconversion of Cinnamidesa
An additional boost in potency of 7- to 20-fold came
from adding a second chlorine to position 2 (35-38). The
substitution on the A ring did not seem to make much
of a difference. The 2,3-di-CF3 compounds (39-41) were
equally potent to the 2,3-dichloro compounds in the
biochemical assay but gave another big boost in the cell
adhesion assay when the A ring was 2′-methoxyphenyl
(compare 35 to 40) or a benzodioxane (compare 39 and
37), but no boost when the A ring was a methylindole
(compare 41 and 38). Compound 40 was the most active
compound in the cell adhesion assay with an IC50 of 0.1
nM. The 2-CF3, 3-Cl compounds (42-44) were equi-
potent to the 2,3-dichloro compounds. We could not
make the 2-Cl, 3-CF3 compounds.
a
Reagents: (a) Fe, NH4Cl, EtOH, H2O 97%; (b) 1. tBuONO,
HBF4, CH3CN, 2. CuCl, CuCl2 68%; (c) 1. tBuONO, H2SO4,
CH3CN, 2. H3PO2 50%.
The 2,3 dimethyl compound 45 was 9 times less active
than the corresponding 2,3-dichloro compound 34. The
2,3-difluoro compound 48 was 12 times less active than
the corresponding 2,3-dichloro compound 36. The naph-
thalene compound 47 is 42 times less active than the
corresponding 2,3-dichloro compound 37. These last
three comparisons show that the 2,3-substituents have
to be electron withdrawing. The compounds with one
chlorine, one CF3, or one methyl in the 2 position rather
than the 3 position (compounds 55, 54, and 46) gave
weak to inactive compounds, though no exact compari-
sons are available.
A dramatic effect occurs when a substituent was
added to the other side of ring B. Compare the inactive
3-Cl-5-CF3 compound 50 to the corresponding 3-Cl (25)
and 3-CF3 (28) compounds. Adding a second chlorine
in the 6 position (51) or a methyl in the 6 position (52)
gave inactive compounds. Adding a 6-methyl to a 3-nitro
compound (53) also gave an inactive compound, al-
though no exact comparisons are available.
group was brominated with NBS and the resulting
bromide oxidized to the aldehyde 5n with Me3N-O.11
2-Methyl-4-chloro-5-nitroaniline was a common start-
ing material for the synthesis of the 3-NO2-6-CH3, (53),
3,6-di-Cl (51), and 2-CH3 (46) cinnamides. It was reacted
with 2-methoxybenzenethiol to give 13 (Scheme 4). The
aniline was transformed to the iodo compound 14, and
this was reacted with methyl acrylate via a Heck
reaction to get the cinnamic acid 15 and ester 16. The
nitro group in 16 was reduced to an amino (17) which
was transformed to a chloro (18) and was also removed
to give 19 (Scheme 5).
Str u ctu r e-Activity Rela tion sh ip s
Two experiments were used to measure the activity
of these compounds. In the biochemical interaction
experiment, the wells are coated with LFA-1, and
ICAM-1 is in solution. An active compound will block
the ICAM-1 from binding to the LFA-1. In the cell
adhesion assay, the ICAM-1 coats the wells and the J Y8
cells expressing LFA-1 on their surface are added to the
wells. An active compound prevents the cells from
sticking to the wells.
Three compounds (22, 30, and 31) in Table 1 were
described in our first paper. Compound 22 has a 3-chloro
on the cinnamide (ring B), a 2,4-dichlorophenyl sulfide
(ring A), and an N-acetyl piperazine amide. Compounds
30 and 31 have a 3-nitro on ring B with a 2,3-dichloro
or 2-isopropyl on ring A and are also N-acetyl piperidine
amides. These had moderate activity in both assays.
Compound 24, described in our second paper, in which
ring A is a benzodioxane has better activity in the
biochemical assay but showed no improvement in the
cell adhesion assay. We also used the morpholine and
the 4-carboxypiperidine amides in our series. Examina-
tion of Table 1 (compare 24-25, 26-27, 34-35, and
42-43) shows that interchanging these amides has little
effect on the activity of these compounds. This is
consistent with the results of our third paper.3 A more
dramatic SAR was seen when we varied the substitu-
ents on ring B.
NMR Mod el
In an earlier paper2 we reported an NOE based model
of compound 31 with the LFA-1 I domain (Figure 1A).
This model predicted a hydrophobic pocket next to the
aryl portion of the cinnamides. The 2,3-dichloro com-
pounds were synthesized (35, Figure 1C) and they were
found to have higher affinity than 31. The second
chlorine fills the hydrophobic pocket in the model
without altering the structure of the I domain. For
instance, interactions of the 2-Cl with the side chain of
I306 may account for the increase in potency relative
to compound 31.
Figure 1B shows a model of the inactive sulfonamide
56. This inactivity was surprising since sulfonamide is
also an electron withdrawing group. However, the loss
of potency is explained by the modeling studies. The
sulfonamide is larger than the nitro group of compound
31 or the chlorine group of 35. As a result, the backbone
of the C-terminal helix would have to move to accom-
modate the ligand compared to its position when bound
to compound 31. This indicates that compound 56
cannot fill the B ring pocket without changing the
binding pocket or orientation of the ligand. This reori-
entation could explain the reduction in potency.
Compounds with only hydrogens on ring B (20 and
21) were only weakly active. A 3-CF3 on ring B (26-
28) showed some improvement over chloro and nitro.
Incorporating a sulfonamide in position 3 (56) greatly
reduced activity. This was surprising since a sulfona-
mide is also an electron withdrawing group. The com-
pounds with the electron donating 3-CH3O (32) or the
electronegative but electron donating 2-F (49) have very
little activity.
In Vivo Exp er im en ts
The demonstration that appropriately substituted
cinnamides could block the interaction of LFA-1 and
ICAM-1 in vitro suggested it would be worthwhile to

4396 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25
Winn et al.
Ta ble 1. Structure-Activity Relationships of Cinnamides in the Biochemical ICAM-1/LFA-1 Assay and in the ICAM-1/J Y-8 Cell
Adhesion Assay
biochemical
IC50, nM
(n)
cell adhesion
IC50, nM
(n)
cpd
A ring
2′,4′-di Cl
2′,3′-di Cl
2′,4′-di Cl
B ring
X
(range)
(range)
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
H
H
3-Cl
3-Cl
3-Cl
3-Cl
NCOCH3
O
NCOCH3
O
NCOCH3
CH-COOH
O
NCOCH3
CH-COOH
NCOCH3
NCOCH3
NCOCH3
NCOCH3
NCOCH3
O
CH-COOH
CH-COOH
CH-COOH
CH-COOH
CH-COOH
CH-COOH
CH-COOH
O
4300 (2) (3600-5100)
9100
140 (2) (100-200)
150 (2) (130-170)
40 (2) (30-60)
145 (2) (140-150)
30 (2) (30-30)
55 (2) (50-60)
50 (2) (40-60)
139 (2) (120-140)
105 (2) (100-110)
44 (3) (30-60)
10700 (2) (10400-11300)
7 (2) (6-9)
130 (7) (100-600)
40 (3) (6-100)
80 (3) (30-150)
2′-CH3O
3′,4′-OCH2CH2O
3′,4′-OCH2CH2O
3′,4′-OCH2CH2O
3′,4′-OCH2CH2O
3′,4′-OCH2CH2O
3′,4′-OCH2CH2O
2′,3′-di Cl
2′-CHMe2
2′-CH3O
3′,4′-OCH2CH2O
2′-CH3O
2′-CH3O
3-CF3
3-CF3
3-CF3
3-NO2
3-NO2
3-NO2
3-CH3O
2,3-di Cl
2,3-di Cl
2,3-di Cl
2,3-di Cl
2,3-di Cl
2,3-di Cl
2,3-di CF3
2,3-di CF3
2,3-di CF3
2-CF3, 3-Cl
2-CF3, 3-Cl
2-CF3, 3-Cl
2,3-di CH3
2-CH3
60 (3) (30-170)
100 (6) (30-300)
30 (3) (12-60)
8 (2) (6-10)
6 (1)
8 (3) (2-30)
6 (8) (3-18)
6 (5) (2-9)
4 (12) (1-10)
0.5 (3) (0.08-1.0)
0.1 (4) (0.03-0.5)
5 (3) (2-8)
10 (2) (6-13)
8 (2) (6-12)
2′-CHMe2
10 (4) (6-19)
3′,4′-OCH2CH2O
1-Me-5-indolyl
3′,4′-OCH2CH2O
2′-CH3O
1-Me-5-indolyl
2′-CH3O
2′-CH3O
3,4′-OCH2CH2O
2′-CH3O
2′-CH3O
3′-4′-OCH2CH2O
2′-CHMe2
2′-CH3O
3′,4′-OCH2CH2O
2′-CH3O
7 (2) (6-9)
6 (3) (6-6)
3 (4) (3-6)
5 (2) (4-6)
5 (2) (5-5)
8 (3) (6-10)
5 (3) (3-10)
4 (6) (2-9)
2 (2) (2-2)
CH-COOH
CH-COOH
O
6 (3) (5-8)
5 (2) (4-7)
90 (2) (80-110)
>20000 (2)
CH-COOH
CH-COOH
CH-COOH
NCOCH3
CH-COOH
CH-COOH
CH-COOH
CH-COOH
CH-COOH
CH-COOH
NCOCHe
1,4-naphthalene
2,3-di F
295 (2) (290-300)
115 (2) (110-120)
3900 (3) (2500-11500)
>20000 (2)
2-F
3-Cl, 5-CF3
3,6-di Cl
3-Cl, 6-CH3
3-NO2, 6-CH3
2-CF3
>20000 (2)
2′-CH3O
2′-CH3O
2′-CH3O
2′-CH3O
>20000 (2)
>20000 (2)
265 (2) (260-270)
1400 (2) (760-2620)
3750 (2) (3700-3800)
2-Cl
2′-3′-di Cl
3-SO2NMe2
determine if an active compound could block in vivo cell
trafficking.
fashion at concentrations down to 1 mg/kg. Greater than
60% of eosinophil trafficking was inhibited at the 10 mg/
kg concentration. Neutrophil trafficking was not affected
because the neutrophil influx in the inhaled allergen
model is not an ICAM-1 dependent event.14 It is believed
to be more of a VCAM dependent function. These results
indicate that compound 38 is capable of inhibiting in
vivo cell trafficking by blocking LFA-1/ICAM-1 inter-
actions.
Pharmacokinetic experiments showed that neutral
compounds had very low plasma concentrations when
administered orally to rats. This could be the result of
their very low water solubility. The carboxylic acids had
much greater water solubility and much improved
pharmacokinetics3. The most dramatic case was with
the carboxylic acid compound 38. Its water solubility
(at pH ) 7.4) was >3000 µg/mL, and gave, in rats, an
area under the curve (0-8 h, 5 mg/kg oral dose, n ) 3)
of 14. µg h/mL and an oral bioavailability of 60%. In
contrast, the N-acetyl piperidine amide analogue (not
in table) had a water solubility of 0.21 µg/mL, and an
area under the curve (0-8 h, 5 mg/kg oral dose, n ) 3)
of <0.01 µg h/mL.
Compound 38 was tested in a murine model of
allergen-induced pulmonary inflammation. ICAM-1 de-
pendent eosinophil influx to the lung is a characteristic
feature of this model.13 As shown in Table 2, compared
to the vehicle only control, compound 38 had a signifi-
cant inhibitory effect on eosiniphilia in a dose dependent
Compound 38 was also tested in a staphylococcus
enterotoxin A (SEA)-induced neutrophil trafficking
model in the rat. SEA stimulates macrophages to
produce cytokines that are chemotactic for neutrophils.15
In contrast to the inhaled allergen model, neutrophil
influx is LFA-1/ICAM-1 dependent.16 Results in Table
3 indicate that compound 38 can inhibit neutrophil
migration in an apparent dose responsive manner with
a significant inhibitory effect seen at the 100 mg/kg
concentration. These results confirm that an inhibitor
of LFA-1/ICAM-1 interactions can reduce the severity
of an in vivo inflammatory reaction.

SAR of Substituents on the Benzene Ring of the Cinnamide
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25 4397
Exp er im en ta l Section
Gen er a l. Unless otherwise specified, all solvents and
reagents were obtained from commercial suppliers and used
without further purification. All reactions were performed
under nitrogen atmosphere unless specifically noted. Flash
chromatography was performed using silica gel (230-400
mesh) from E. M. Science. Proton NMR spectra were recorded
on a General Electric QE300 instrument with Me4Si as an
internal standard and are reported as shift (multiplicity,
coupling constants, proton counts). Mass spectral analyses
were accomplished using different techniques, including de-
sorption chemical ionization (DCI), atmospheric pressure
chemical ionization (APCI), and electrospray ionization (ESI),
as specified for individual compounds. Elemental analyses
were performed by Robertson Microlit Laboratories, Madison,
NJ , and are consistent with theoretical values to within 0.4%
unless indicated. Preparative HPLC was performed on an
automated Gilson HPLC system, using an YMC C-18 column,
75 × 30 mm i.d., S-5 µM, 120 Å, and a flow rate of 25 mL/min;
λ ) 214, 245 nm; mobile phase A, 0.05 M NH4OAc or 0.1%
TFA in H2O, and mobile phase B, CH3CN; linear gradient 20-
100% of B in 20 min. The purified fractions were evaporated
to dryness on a Savant SpeedVac.
See p a p er 11 for th e ICAM-1/LF A-1 Bioch em ica l Assa y
a n d ICAM-1/J Y-8 Cell Ad h esion Assa y.
1-Meth yl-5-iod oin d ole. To 75 g of 5-iodoindole (0.31 mol)
in 750 mL of dry THF at -78 °C was added 14.85 g of NaH
(60% in mineral oil, 0.37 mol). The suspension was stirred at
-78 °C for 1 h, after which 28.8 mL of CH3I (0.46 mol) was
added. After the mixture was stirred at 25 °C for 16 h, ether
was added, and the mixture was washed with NaCl and dried
(Na2SO4), the ether was evaporated, and the solid was
recrystallized from hexane to give 78.5 g of product (99% yield).
1-Meth yl-S-tr iisop r op ylsilyl-5-in d oleth iol a n d 1-Meth -
yl-5-in d oleth iol (2). KH (12.03 g 35%, in mineral oil, 0.105
mol) was washed with THF and then suspended in 75 mL of
THF at 5 °C. Triisopropylsilylthiol (20.0 g, 0.105 mol) was
added over 15 min with vigorous evolution of hydrogen gas.
The mixture was stirred at 5 °C 1 h and then at 25 °C for 1 h.
This solution was added to a solution of 24.5 g (1.91 mol) of
1-methyl-5-iodoindole and 2.2 g (1.91 mmol) of (Ph3P)4Pd in
100 mL of THF. The yellow suspension was stirred 1 h at 70
°C. After cooling, ether was added, and the solution was
washed with NaCl, dried (Na2SO4), and concentrated. The
residue was chromatographed (silica gel, 3% EtOAc in hexane)
to give 26.7 g (88%) of silylated compound. A solution of the
thiol was made by treating a 10% solution of the silylated
product in N-methyl pyrrolidinone (NMP) with 50% excess
CsF.
F igu r e 1. Interactions of p-arylthiocinnamide antagonists
with the LFA domain. Highlighted in red are atoms on the B
ring that interact with K305, I306, I235, and V233 whose
selected side chain atoms are shown in yellow. (A) NOE based
model of compound 31.2 (B) Model of compound 56 (see
methods). (C) Model of compound 35 (see methods).
Ta ble 2. Compound 38 Inhibits Allergen Induced Cell Influx
in Mice
total cells
(#/µL)
neutrophils
(%)
eosinophils
(%)
treatment
N
naive (- ctrl)
vehicle (+ ctrl)
38 (1 mpk)
38 (3 mpk)
38 (10 mpk)
4
6
7
7
6
70 ( 10
243 ( 25
291 ( 38
147 ( 8b
189 ( 26
2 ( 1
31 ( 4
36 ( 3
31 ( 3
30 ( 2
0 ( 0
22 ( 1
14 ( 2a
10 ( 2b
8 ( 2b
1,4-Ben zod ioxa n e-6-th iol (1). 6-Bromo-1,4-benzodioxane
was reacted with KS-Si(iPr)3 and (Ph3P)4Pd and then with CsF
as described above to give a solution of 1, which was used in
the next step.
a
Significantly different (p, 0.01 from positive control by 1-tail
b
t-test. Significantly different (p, 0.001) from positive control by
1-tail t-test.
4-Flu or o-3-d im eth yla m in osu lfon yl-ben zoic Acid . 4-Flu-
oro-3-chlorosulfonyl-benzoic acid12 (8.00 g), in 20 mL of THF
was added to 60 mL of a cold 15% solution of dimethylamine
in THF and stirred for 1 h at 25 °C. The THF was removed
and the residue treated with water and HCl. The product was
filtered, dissolved in CHCl3, dried (Na2SO4), and concentrated.
Ether and hexane were added to get 6.85 g of product, mp
205-207 °C.
4-F lu or o-3-d im eth yla m in osu lfon ylben zyl Alcoh ol. The
above-described acid (7.47 g, 30.24 mmol) was added in
portions to 75 mL of 1 M BH3 in THF with ice cooling. The
resulting solution was stirred at 25 °C for 90 min. After cooling
in ice, 10 mL of water was added slowly. The resulting solution
was concentrated. The residue was dissolved in CHCl3 and
washed with dilute NaOH, dried (Na2SO4), and concentrated
to give 6.89 g of product (98%).
Ta ble 3. Compound 38 Inhibits SEA-Induced Neutrophil
Trafficking in the Rat
treatmenta
polymorphonuclear cells × 105
2.87 × 105 ( 5.2 × 104 b
negative control (MC/PBS)
positive control (MC/SEA)
38 (50 mg/kg)
10.46 × 105 ( 2.34 × 105
b
7.48 × 105 ( 1.73 × 105 b
38 (100 mg/kg)
4.88 × 105 ( 1.28 × 105 b,c
Ten rats per treatment group. Standard error. c p < 0.052.
a
b
Con clu sion
4-Arylthio-cinnamides that contain a chlorine or a CF3
in both the 2 and 3 positions are potent inhibitors of
the interaction of LFA-1 and ICAM-1. The most potent
compounds (39 and 40) contain two CF3 groups and
have IC50 values of 0.5 and 0.1 nM in inhibiting
adhesion of cells expressing LFA-1 on their surface, to
ICAM-1.
4-F lu or o-3-d im eth yla m in osu lfon ylben za ld eh yd e (3e).
The above-described alcohol (7.00 g, 30.04 mmol) was dissolved
in 140 mL of CH2Cl2 and stirred with 25 g of activated MnO2
(Aldrich) for 16 h at 25 °C. The MnO2 was filtered. The crude

4398 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25
Winn et al.
product was chromatographed (SiO2, 10% EtOAc, 90% CH2-
Cl2) to give 4.66 g (67% yield) of 3e.
mixture was allowed to warm to 25 °C. Water was added
slowly, and the solvents were evaporated. Water was added
and the mixture extracted with ether. The aqueous solution
was acidified with HCl and extracted with EtOAc, back washed
with brine, dried (Na2SO4), and concentrated to give 2.2 g of
crude product.
4-F lu or o-3-ch lor o-5-(tr iflu or om eth yl)ben zyl Alcoh ol.
The above acid (1.4 g, 6.7 mmol) in 25 mL of THF was treated
dropwise at 0 °C with 13.5 mL of 1 M BH3 in THF. After being
stirred at 25 °C for 2 h, the solution was treated with 3 N HCl
at 0 °C. The mixture was extracted with EtOAc to get 1.30 g
of crude benzyl alcohol used in the next step without purifica-
tion.
4-Hyd r oxy-2,3-d im eth ylben za ld eh yd e (5j). 2,3-Dimeth-
oxyphenol (15.0 g, 0.123 mol) was added to 44.83 g of Na2CO3
(0.423 mol) in 230 mL of water. Ca(OH)2 (39.22 g, 0.530 mol)
was added, and the mixture was stirred at 85 °C while CHCl3
(29.37 g, 0.246 mol) was added slowly over a 30 min period.
The mixture was heated for 2 h more at 85 °C. After cooling,
EtOAc was added, and the mixture was acidified with HCl.
The EtOAc was separated, dried (MgSO4), and treated with
charcoal. The solution was concentrated and the residue
crystallized from ether to get 2.567 g; mp 160-171 °C, lit.6
mp 171-172 °C; 14% yield.
3-C h lo r o -4-h y d r o x y -2-(t r iflu o r o m e t h y l)b e n za ld e -
h yd e (5m ). CHCl3 (6.7 g, 2.0 equiv) was added dropwise to a
stirred mixture of Ca(OH)2 (8.95 g, 120 mmol), K2CO3 (13.5 g,
98 mmol), 2-chloro-3-(trifluoromethyl)phenol (5.0 g, 22 mmol),
and 50 mL of water at 65 °C over 2 h. The reaction mixture
was cooled and acidified with concentrated HCl. The product
was extracted into EtOAc and dried (Na2SO4). The crude
product was purified by chromatography (silica gel, hexanes-
EtOAc 3:2) to get 580 mg (10%) of product.
4-(4-Br om oben zen esu lfon yloxy)-2,3-bis(tr iflu or om eth -
yl)ben zyl Br om id e. 4-Methyl-2,3-bis(trifluoromethyl)phenol9
(9) (10.0 g, 40 mmol) was treated with 4-bromobenzenesulfonyl
chloride (11.0 g, 43 mmol) and i-Pr2NEt (5.56 g, 43 mmol) in
100 mL of CH2Cl2 for 2 h. The solution was washed with NaCl
and dried (MgSO4). The solvent was evaporated and replaced
by 100 mL of CCl4. N-Bromosuccinimide (7.3 g, 40 mmol) and
benzoyl peroxide (200 mg) were added, and the mixture was
refluxed 13 h. After cooling, the solid was filtered and washed
with CCl4. The filtrate was concentrated to give the crude
product, which was used in the next step.
4-Hyd r oxy-2,3-bis(tr iflu or om eth yl)ben za ld eh yd e (5n ).
The crude product described above was dissolved in 60 mL of
DMSO and 20 mL of CH2Cl2. Trimethylamine N-oxide (12.0
g) was added, and the mixture was stirred at 25 °C for 2.5 h.
The mixture was poured into 200 mL of cold NaCl solution
and extracted with ether (3 × 100 mL). The ether was dried
(Na2SO4) and concentrated. The product was purified by
chromatography (SiO2, hexanes-EtOAc 3:2) to get 3.00 g of
5n and 4.0 g of recovered 4-(4-bromobenzenesulfonyloxy-2,3-
bis(trifluoromethyl toluene.
4-(2-m eth oxyp h en yth io)-3-ch lor oben za ld eh yd e (4b).
4-Fluoro-3-chlorobenzaldehyde (1.00 g, 6.31 mmol) and 2-meth-
oxybenzenethiol (0.975 g, 6.95 mmol) were dissolved in 4 mL
of DMF. Powdered K2CO3 (0.960 g, 6.96 mmol) was added in
portions. The mixture was stirred at 25° for 15 min and at 55
°C for 1 h. After cooling, cold water, ether, and 0.5 mL of 50%
NaOH were added. The ether phase was washed with dilute
HCl, then NaCl, and dried (Na2SO4). The ether was evapo-
rated, and hexane was added to get 1.471 g; mp 75-77 °C;
84% yield.
4-Meth oxy-3,6-d ich lor oben za ld eh yd e. 2,5-Dichloroani-
sole (3.54 g, 20 mmol) in 50 mL of CH2Cl2 was treated at 0 °C
with 4.38 mL (40 mmol) of TiCl4, followed by 2.30 g (20 mmol)
of CH3OCHCl2 added slowly (30 min). After refluxing for 2 h,
the mixture was cooled and poured onto HCl and ice. The
product was dissolved in EtOAc , washed with water, aqueous
NaHCO3, and brine, and dried (Na2SO4). The solvent was
removed to give 4.00 g (98% yield) of product.
4-Hyr d r oxy-3,5-d ich lor oben za ld eh yd e (5p ). The above
methoxybenzaldehyde was treated with 2 equiv of BBr3 at 0
°C for 1 h, then cooled to -78 °C. Water was added to destroy
the excess BBr3. The CH2Cl2 solution was washed with NaCl
solution, dried, and concentrated to give the title compound.
4-F lu or o-3-ch lor o-5-(tr iflu or om eth yl)ben zoic Acid (7).
To a vigorously stirred solution of s-BuLi (20.34 mL of 1.3 M
in cyclohexane) and TMEDA (4.0 mL, 3.04 mmol) cooled to
-90 °C (liquid N2, pentane/MeOH bath) was added 2.50 g (12.0
mmol) of 4-fluoro-3-(trifluoromethyl) benzoic acid in 80 mL of
THF over a period of 30 min. After being stirred for 30 min at
-90 °C, the solution was then treated with 11.4 g (48.0 mmol)
of hexachloroethane in 100 mL of THF, and the reaction
4-Flu or o-3-ch lor o-5-(tr iflu or om eth yl)ben zaldeh yde (3g).
The above alcohol (200 mg) in 10 mL of CH2Cl2 was stirred
overnight at room temperature with 750 mg of activated MnO2.
The MnO2 was filtered, and the solution was concentrated. The
residue was purified by chromatography (hexane: ethyl
acetate 4:1). The fast moving fraction yielded 70 mg of desired
product.
4-(1,4-Ben zod ioxa n e-6-th io)-3-ch lor o-5-(tr iflu or om eth -
yl)ben za ld eh yd e (4g). The fluoroaldehyde 3g (70 mg, 0.31
mmol), 52 mg (0.31 mmol) of 1,4-benzodioxane-6-thiol (in
solution), and 22 mg of K2CO3 were stirred in 3 mL of CH3CN
for 1 h at 25 °C. Water (10 mL) was added, and the mixture
was extracted with ether. The ether was washed with dilute
NaOH, water, and finally dilute HCl. The resulting solution
was dried (Na2SO4) and concentrated. The residue was purified
by chromatography (SiO2, hexanes-EtOAc 4:1) to get 110 mg
(96%) of the desired product.
2-Meth oxyph en yl 4-Am in o-2-n itr o-5-m eth ylph en yl Su l-
fide (13). 2-Methoxybenzenethiol (4.2 mL, 34.4 mmol), 4-chloro-
5-nitro-2-methylaniline (6.43 g, 34.4 mmol) and Cs2CO3 (22.8
g, 70.0 mmol) in 70 mL of DMF were stirred at 60 °C for 16 h.
After cooling, water was added and the solid filtered to get
7.92 g (79%) of product.
2-Meth oxyp h en yl 4-Iod o-2-n itr o-5-m eth ylp h en yl Su l-
fid e (14). tert-Butyl nitrite (2.6 mL, 21.6 mmol) was added to
a solution of 5.97 g (20.6 mmol) of 13 and 33 mL (1.6 equiv) of
3 N aqueous H2SO4 in 50 mL of CH3CN, with ice cooling. After
the mixture was stirred 1 h, a solution of KI (5.81 g, 35.0 mmol)
and urea (0.247 g, 4.12 mmol) in 10 mL of water was added at
0 °C slowly. Gas evolution. After being stirred overnight, the
mixture was filtered to give 7.43 g (90%) of product.
4-(2-Met h oxyp h en ylt h io)-2-m et h yl-5-n it r ocin n a m ic
Acid (15). A solution of 5.00 g (12.5 mmol) of 14, methyl
acrylate (3.4 mL, 37.5 mmol), Et3N (5.2 mL, 37.5 mmol), and
Pd(OAc)2 (0.561 g, 2.5 mmol) was heated at 65 °C for 2 days
in 100 mL of THF. The solvents were evaporated in a vacuum,
and the residue was chromatographed without further treat-
ment (SiO2, hexane-EtOAc 1:1) to get 3.65 g (81%) of cin-
namate ester. The cinnamate ester (400 mg, 1.11 mmol) in 4
mL of EtOH was hydrolyzed at room temperature with NaOH
(1.5 mL of 2 M aqueous solution). After 24 h, the orange
solution was acidified with 1 N HCl, and the resulting
precipitate was filtered to give 360 mg (94%) of the title
compound.
4-(2-Meth oxyp h en ylth io)-3-ch lor ocin n a m ic Acid (10b).
The benzaldehyde 4b (Ar ) 2-methoxyphenyl) (1.45 g, 5.22
mmol) and malonic acid (1.21 g, 11.63 mmol) in 4.2 mL of
pyridine was treated with 90 mg of piperidine. The solution
was heated in a 120 °C bath for 90 min. After cooling, dilute
HCl was added. A goo resulted which crystallized upon adding
2 mL of ether. It was filtered and dried by dissolving in THF
and treating with Na2SO4. The product was crystallized from
heptane and ether (3:1) to get 1.452 g; mp 149-151 °C; 87%
yield.
2-Met h oxyp h en yl 2-Ch lor o-4-[E-(1-m or p h olin o-ca r b -
on yl)eth en yl)p h en yl] Su lfid e (23). The cinnamic acid de-
scribed above (0.250 g) was refluxed with 2 mL of benzene and
1.5 mL of oxalyl chloride for 45 min. The solvents were
evaporated and toluene added and evaporated three times to
remove all of the excess oxalyl chloride. Morpholine (1 mL)
was added to the resulting acid chloride in 2 mL of toluene

SAR of Substituents on the Benzene Ring of the Cinnamide
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25 4399
and the mixture stirred at 25° for 45 min. Toluene was added
and the mixture washed with dilute HCl, water, and finally
KHCO3. After drying (Na2SO4) the solvent was evaporated and
the residue crystallized from ether and hexane (1:2) to get
0.282 g; mp 162-164 °C; 93% yield. 1H NMR (CDCl3, 300 MHz)
δ 3.60-3.78 (m, 8H), 3.84 (s, 3H), 6.72 (d, J ) 9 Hz, 1H), 6.78
(d, J ) 16 Hz, 1H), 6.96-7.04 (m, 2H), 7.16 (dd, J ) 9 Hz, 2
Hz, 1H), 7.40-7.46 (m, 2H), 7.55 (d, J ) 2H, 1H), 7.58 (d, J )
16 Hz, 1H). Anal. (C20H20ClNO3S) C, H, N.
1H, J ) 15.3 Hz), 4.30 (m, 4H), 3.65-3.74 (br m, 8H). MS (ESI)
m/z 452, 474, 925. Anal. (C22H20F3NO4S) C, H, N.
1,4-Ben zod ioxa n -6-yl [2-tr iflu or om eth yl-4-(E-((4-a cet-
ylp ip er a zin -1-yl)ca r b on yl)et h en yl)p h en yl] su lfid e (27)
was prepared (method of compound 23) using the solution of
1,4-benzodioxane-6-thiol in NMP prepared above, 4-fluoro-3-
trifluoromethylbenzaldehyde, and N-acetyl piperazine as start-
ing materials. 1H NMR (CDCl3, 300 MHz) δ 2.15 (s, 3H), 3.46-
3.89 (m, 8H), 4.30 (dd, J ) 2.1, 6.0 Hz, 4H), 6.84 (d, J ) 15.0
Hz, 1H), 6.92 (d, J ) 8.4 Hz, 1H), 6.97-7.10 (m, 3H), 7.42 (d,
J ) 8.4 Hz, 1H), 7.64 (d, J ) 15.0 Hz, 1H), 7.77 (s, 1H). MS
(ESI+) m/z 493 (M+H)+. Anal. (C24H23F3N2O4S) C, H, N.
1,4-Ben zod ioxa n -6-yl [2-tr iflu or om eth yl-4-(E-((4-ca r -
boxypiper idin -1-yl)car bon yl)eth en yl)ph en yl] su lfide (28)
was prepared (methods of compounds 23 and 25) using the
solution of 1,4-benzodioxane-6-thiol in NMP prepared above,
4-fluoro-3-trifluoromethylbenzaldehyde, and 4-carbethoxy-
piperidine as starting materials. The product is a white solid,
mp 88 °C (dec). 1H NMR (DMSO-d6, 300 MHz) δ 1.40 (m, 2H),
1.98 (m, 2H), 2.95 (m, 1H), 3.15 (m, 1H), 3.45 (m, 1H), 4.20
(m, 2H), 4.35 (m, 4H), 7.00 (m, 4H), 7.20 (m, 2H), 7.90 (m,
1H), 8.20 (m, 1H), 12.30 (s, 1H). MS (APCI) m/z 494 (M+H)+.
Anal.(C24H22F3NO5S‚0.3H2O) C, H, N.
1,4-Ben zod ioxa n -6-yl [2-n itr o-4-(E-((4-a cetylp ip er a zin -
1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e (29). To a solution
of 1,4-benzodioxane-6-thiol in NMP prepared above, 1 equiv
of the nitro chloro cinnamide 111 was added along with 1.5
equiv of K2CO3. After the mixture was stirred 1 h at 25 °C,
water was added to precipitate the product as a light-yellow
solid. 1H NMR (DMSO-d6, 300 MHz) δ 2.04 (s, 3H), 3.41-3.80
(m, 8H), 4.28-4.38 (m, 4H), 6.86 (d, J ) 8.4 Hz, 1H), 7.05 (d,
J ) 8.4 Hz, 1H), 7.10 (dd, J ) 2.1, 8.4 Hz, 1H),7.15 (d, J ) 2.1
Hz, 1H), 7.40 (d, J ) 15.6 Hz, 1H), 7.53 (d, J ) 15.6 Hz, 1H),
7.91 (dd, J ) 1.8, 8.4 Hz, 1H), 8.62 (d, J ) 1.8 Hz, 1H). MS
(APCI+) (M+H)+ at m/z 470. Anal. (C23H23N3O6S‚0.17H2O) C,
H, N.
2,4-Dich lor op h en yl [4-(E-((4-a cetylp ip er a zin -1-yl)ca r -
bon yl)eth en yl)p h en yl] su lfid e (20) was prepared (method
of compound 23) using 2,4-dichlorobenzenethiol, 4-fluorobenz-
1
aldehyde, and N-acetyl piperazine as starting materials.. H
NMR (CDCl3, 300 MHz) δ 2.15 (s, 3H), 3.5-3.8 (m, 8H), 6.85
(d, J ) 15 Hz, 1H), 7.10 (d, J ) 9 Hz, 1H), 7.15 (dd, J ) 9 Hz,
2 Hz, 1H), 7.34 (d, J ) 8 Hz, 2H), 7.46 (d, J ) 2 Hz, 1H), 7.50
(d, J ) 8 Hz, 1H), 7.68 (d, J ) 15 Hz, 1H). MS (DCI/NH3)
(M+H) ) 435, 437, 452, 454. Anal. (C21H20Cl2N2O2S 0.5 H2O)
C, H, N.
2,3-Dich lor op h en yl [4-E-((1-m or p h olin o-ca r bon yl)eth -
en yl)p h en yl] su lfid e (21) was prepared (method of com-
pound 23) using 2,3-dichlorobenzenethiol, 4-fluorobenzalde-
hyde, and morpholine as starting materials. 1H NMR (DMSO-
d6, 300 MHz) δ 3.5-3.7 (m, 8H), 6.94 (dd, J ) 8 Hz, 2 Hz,
1H), 7.30 (t, J ) 8 Hz, 1H), 7.33 (d, J ) 15 Hz, 1H), 7.48 (d, J
) 8 Hz, 2H), 7.51 (d, J ) 15 Hz, 1H), 7.54 (dd, J ) 8 Hz, 2 Hz,
1H), 7.83 (d, J ) 8 Hz, 2H). MS (DCI/NH3) (M+H)+ 394, 396,
398. Anal. (C19H17Cl2NO2S) C, H, N.
2,4-Dich lor op h en yl [2-ch lor o-4-(E-((4-a cetylp ip er a zin -
1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (22) was prepared
(method of compound 23) using 2,4-dichlorobenzenethiol,
4-fluoro-3-chlorobenzaldehyde, and N-acetyl piperazine as
1
starting materials. H NMR (CDCl3, 300 MHz) δ 2.15 (s, 3H),
3.50-3.58 (m, 2H), 3.58-3.85 (m, 6H), 6.85 (d, J ) 15.3 Hz,
1H), 6.96 (d, J ) 8.7 Hz, 1H), 7.24-7.36 (m, 3H), 7.54 (d, J )
2.4 Hz, 1H), 7.61 (d, J ) 15.3 Hz, 1H), 7.61 (d, J ) 2.1 Hz,
1H). MS (DCI/NH3) (M+H)+ at m/z 486, 488, 490, 492.
2,3-Dich lor op h en yl [2-n itr o-4-(E-((4-Acetylp ip er a zin -
1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e (30) a n d 2-Isop r o-
pylph en yl [2-Nitr o-4-(E-((4-acetylpiper azin -1-yl)car bon yl)-
eth en yl)p h en yl] Su lfid e (31). See paper 1.1
1,4-Ben zodioxan -6-yl [2-ch lor o-4-(E-((4-acetylpiper azin -
1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (24) was prepared
(method of compound 23) using the solution of 1,4-benzodi-
oxane-6-thiol in NMP prepared above, 4-fluoro-3-chloro-
benzaldehyde, and N-acetylpiperazine as starting materials.
1H NMR (CDCl3, 300 MHz) δ 2.14 (s, 3H), 3.44-3.57 (m, 2H),
3.57-3.86 (m, 6H), 4.25-4.35 (m, 4H), 6.75 (d, J ) 8.4 Hz,
1H), 6.78 (d, J ) 15.6 Hz, 1H), 6.93 (d, J ) 8.4 Hz, 1H), 7.03
(dd, J ) 2.1, 8.4 Hz, 1H), 7.08 (d, J ) 2.1 Hz, 1H), 7.18 (dd, J
) 2.1, 8.4 Hz, 1H), 7.51 (d, J ) 2.1 Hz, 1H), 7.57 (d, J ) 15.6
Hz, 1H). MS (APCI+) (M+H)+ at m/z 459, 461.
2,3-Dich lor op h en yl [2-d im eth yla m in osu lfon yl-4-(E-((4-
a cetylp ip er a zin -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e
(56) was prepared (method of compound 23) using 2,3-
dichlorobenzenethiol, benzaldehyde 3e, and N-acetyl pipera-
zine as starting materials The product has mp 205-207 °C;
1H NMR (CDCl3, 300 MHz) δ 2.15 (s, 3H), 2.95 (2, 6H), 3.5-
3.8 (broad m, 8H), 6.88 (d, J ) 9 Hz, 1H), 6.92 (d, J ) 16 Hz,
1H), 7.25 (t, J ) 8 Hz, 1H), 7.41 (m, 1H), 7.45 (dd, J ) 8 Hz,
2 Hz, 1H), 7.55 (dd, J ) 8 Hz, 2 Hz, 1H), 7.65 (d, J ) 16 Hz,
1H), 8.20 (s, 1H). Anal. (C23H25Cl2N3O4S2) C, H, N.
4-Tr iflu or om eth a n esu lfon yloxy-2,3-d ich lor oben za ld e-
h yd e (6i). 4-Hydroxy-2,3-dichlorobenzaldehyde (5i)5 (9.10 g,
47.64 mmol) was dissolved in 50 mL of pyridine, and 15.63 g
(55.42 mmol) of (CF3SO2)2O was added with cooling. The
mixture was stirred at 25 °C for 1 h and then poured onto ice,
ether, and 100 mL of concentrated HCl. The ether was
separated and washed with dilute HCl, dried (Na2SO4), and
concentrated. The residue was dissolved in heptane and
filtered from some insoluble material. The heptane was
evaporated giving 8.74 g (57% yield) of 6i as a yellow oil which
solidified in the freezer.
1,4-Ben zod ioxa n -6-yl [2-ch lor o-4-(E-((3-ca r boxyp ip er i-
d in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (25) was pre-
pared (method of compound 23) using the solution of 1,4-
benzodioxane-6-thiol in NMP prepared above, 4-fluoro-3-
chlorobenzaldehyde, and 4-carbethoxy piperidine as starting
materials. The resulting ethyl ester was hydrolyzed by stirring
for 2 h in 1:1 ethanol water containing 4 equiv of NaOH, then
evaporating the ethanol and acidifying with HCl. The resulting
solid was dried by dissolving in CHCl3, filtering from Na2SO4,
and evaporating the CHCl3 to give a white solid. 1H NMR
(CDCl3, 300 MHz) δ 1.64-1.88 (br m, 2H), 1.95-2.09 (br m,
2H), 2.57-2.73 (m, 1H), 2.90-3.17 (m, 1H), 3.17-3.50 (m, 1H),
3.90-4.19 (m, 1H), 4.25-4.36 (m, 4H), 4.39-4.66 (m, 1H), 6.75
(d, J ) 8.4 Hz, 1H), 6.84 (d, J ) 15.3 Hz, 1H), 6.93 (d, J ) 8.7
Hz, 1H), 7.03 (dd, J ) 2.4, 8.7 Hz, 1H), 7.08 (d, J ) 2.4 Hz,
1H), 7.18 (d, J ) 8.4 Hz, 1H), 7.51 (s, 1H), 7.54 (d, J ) 15.3
4-(2-Meth oxyph en ylth io)-2,3-dich lor oben zaldeh yde (4i,
Ar ) 2-m eth oxyp h en yl). The 4-trifloxybenzaldehyde 6i (2.85
g, 8.82 mmol) and 2-methoxybenzenethiol (2.47 g, 17.64 mmol)
were dissolved in 7 mL of CH3CN. With cooling, 2.85 g (22.62
Hz, 1H). MS (ESI+) (M+H)+ at m/z 460, 462. Anal. (C23H22
ClNO5S) C, H, N.
-
i
mmol) of Pr2NEt was added, whereupon a solid formed. The
mixture was stirred at 25 °C 15 min and then at 50 °C for 3
min. Five more milliliters of CH3CN was added, and the mix
was cooled in ice. A solid which formed was filtered. Yield 2.063
g; mp 138-139 °C; 75% yield.
4-(2-Meth oxyph en ylth io)-2,3-dim eth ylben zaldeh yde (4j,
Ar ) 2-m eth oxyp h en yl). 4-Hydroxy-2,3-dimethyl benzalde-
hyde (5j) was converted to the 4-triflate by the method used
with 6i. The triflate (3.29 g, 11.67 mmol), 2-methoxyben-
1,4-Ben zod ioxa n -6-yl [2-tr iflu or om eth yl-4-(E-m or p h o-
lin -1-yl-ca r bon yl)eth en yl)p h en yl] su lfid e (26) was pre-
pared (method of compound 23) using the solution of 1,4-
benzodioxane-6-thiol in NMP prepared above, 4-fluoro-3-
trifluoromethylbenzaldehyde, and morpholine as starting
materials. H NMR (CDCl3, 300 MHz) δ 7.76 (s, 1H), 7.62 (d,
1H, J ) 15.6 Hz), 7.40 (dd, 1H, J ) 1.8, 8.2 Hz), 7.04 (d, 1H,
J ) 2 Hz), 6.98-7.03 (m, 2H), 6.91 (d, 1H, J ) 8 Hz), 6.81 (d,
1

4400 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25
Winn et al.
i
zenethiol (3.29 g, 23.5 mmol) and Pr2NEt (3.73 g, 29.14 mmol)
(m, 1H), 2.88 (brt, J ) 10.5 Hz, 1H), 3.15 (brt, J ) 10.5 Hz,
1H), 3.97 (br d, J ) 13.2 Hz, 1H), 4.11 (br d, J ) 13.2 Hz, 1H),
6.41 (d, J ) 9.0 Hz, 1H), 7.22 (d, J ) 15.6 Hz, 1H), 7.31-7.42
(m, 1H), 7.53 (d, J ) 7.8 Hz, 1H), 7.56-7.64 (m, 2H), 7.71 (d,
J ) 15.6 Hz, 1H), 7.85 (d, J ) 9.0 Hz, 1H). MS (ESI+) (M+H)+
at m/z 478, 480, 482. Anal. Na salt (C24H24Cl2NO3SNa 0.95
H2O) C, H, N.
(1,4-Ben zod ioxa n -6-yl)[2,3-d ich lor o-4-(E-((4-ca r boxyp i-
p er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (37) was
prepared (methods of compounds 34, 25, and 36) using the
solution of 1,4-benzodioxane-6-thiol in NMP prepared above,
4-trifloxy-2,3-dichlorobenzaldehyde, and 4-carbethoxypiperi-
dine as starting materials. 1H NMR (DMSO-d6, 300 MHz) δ
1.33-1.55 (m, 2H), 1.62-1.78 (m, 2H), 1.93-2.07 (m, 1H), 2.90
(br t, J ) 10.5 Hz, 1H), 3.16 (brt, J ) 10.5 Hz, 1H), 3.96 (br d,
J ) 13.5 Hz, 1H), 4.09 (br d, J ) 13.5 Hz, 1H), 4.26-4.42 (m,
4H), 6.60 (d, J ) 9.0 Hz, 1H), 7.04-7.08 (m, 2H), 7.13 (d, J )
1.5 Hz, 1H), 7.22 (d, J ) 15.3 Hz, 1H), 7.70 (d, J ) 15.3 Hz,
1H), 7.86 (d, J ) 9.0 Hz, 1H). MS (ESI+) (M+H)+ at m/z 516,
518, 520. Anal. Na salt (C23H20Cl2NNaO5S‚0.36Et2O): C, H,
N.
were dissolved in 8 mL of CH3CN. In contrast to the fast
reaction with the 2,3-dichloro analogue, this reaction needed
heating at 95 °C for 18 h to go to completion. After cooling,
toluene was added and then washed with dilute HCl, water,
and then NaOH. The product was purified by chromatography
(SiO2, CH2Cl2) to get 1.311 g (59% yield) of 4i mp 102-104
°C. Also isolated (first off the column) was the disulfide of
2-methoxybenzenethiol (1.311 g).
4-(2-Meth oxyp h en ylth io)-3-m eth oxyben za ld eh yd e (4h ,
Ar ) 2-m eth oxyp h en yl). Vanillin was converted to the
4-triflate by the method used with 6i. This triflate (4.50 g,
19.05 mmol), 2-methoxybenzenethiol (6.43 g, 45.92 mmol), and
iPr2NEt (5.00 g, 39.06 mmol) were heated for 5 h at 85 °C in
13 mL of CH3CN. The mixture was cooled, and ether was
added and extracted with dilute HCl, water, and then dilute
NaOH. After drying (Na2SO4 + charcoal), the solution was
concentrated, and the product was chromatographed (SiO2,
CH2Cl2) to get 2.78 g (64% yield) of product. The disulfide of
2-methoxybenzene thiol (faster moving) was also collected.
(2-Meth oxyph en yl) [2,3-Dich lor o-4(E-[(m or ph olin -1-yl)-
ca r bon yl]eth en yl)p h en yl] Su lfid e (34). Aldehyde 4i was
converted to cinnamic acid and then the amide 34 by reaction
with morpholine, using the methods used to prepare 10b and
23, giving a white solid, mp 161-162 °C. 1H NMR (CDCl3 300
MHz) δ 3.83 (s, 3H), 6.55 (d, J ) 9 Hz, 1H), 6.70 (broad d, J )
15 Hz, 1H), 6.99-7.05 (m, 2H), 7.26 (d, J ) 9 Hz, 1H), 7.43-
7.50 (m, 2H), 8.07 (broad d, J ) 15 Hz, 1H) Anal. (C20H19Cl2-
NO3S) C, H, N.
(2-Meth oxyph en yl) [2-m eth oxy-4-(E-((4-acetylpiper azin -
1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (32) was prepared
from the cinnamic acid derivative of aldehyde 4h (Ar )
2-methoxyphenyl) and N-acetylpiperazine using the method
of compound 23. Product has mp 141-143 °C. 1H NMR (CDCl3
300 MHz) δ 2.15 (s, 3H), 3.5-3.8 (br m, 8H), 3.84 (s, 3H), 3.94
(s, 3H), 6.78 (d, J ) 15 Hz, 1H), 7.81 (d, J ) 8 Hz, 1H), 6.90-
7.03 (m, 4H), 7.30 (dd, J ) 8 Hz, 2 Hz, 1H), 7.32-7.39 (m,
1H), 7.65 (d, J ) 15 Hz, 1H). Anal. (C23H26N2O4S) C, H, N.
(1-Meth ylin d ol-5-yl) [2,3-d ich lor o-4-(E-((4-ca r boxyp i-
p er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (38) was
prepared (methods of compounds 34, 25, and 36) using the
solution of 1-methyl-5-indolethiol in NMP prepared above,
4-trifloxy-2,3-dichlorobenzaldehyde, and 4-carbethoxypiperi-
dine as starting materials. 1H NMR (DMSO-d6, 300 MHz) δ
1.31-1.53 (m, 2H), 1.62-1.76 (m, 2H), 1.94-2.09 (m, 1H), 2.88
(brt, J ) 10.5 Hz, 1H), 3.13 (brt, J ) 10.5 Hz, 1H), 3.86 (s,
3H), 3.93 (br d, J ) 13.2 Hz, 1H), 4.09 (br d, J ) 13.2 Hz, 1H),
6.41 (d, J ) 8.7 Hz, 1H), 6.53 (dd, J ) 0.9, 3.0 Hz, 1H), 7.04
(d, J ) 15.3 Hz, 1H), 7.32 (dd, J ) 2.1, 8.7 Hz, 1H), 7.48 (d, J
) 3.0 Hz, 1H), 7.64 (d, J ) 8.7 Hz, 1H), 7.69 (d, J ) 15.3 Hz,
1H), 7.73 (d, J ) 8.7 Hz, 1H), 7.88 (d, J ) 2.1 Hz, 1H). MS
(ESI+) (M+H)+ at m/z 489, 491, 493. Anal. Na salt (C24H21
Cl2N2NaO3S), C, H, N.
-
(2-Meth oxyp h en yl) [2,3-Bis(tr iflu or om eth yl)-4-(E-((4-
ca r boxyp ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e
(40). 4-Hydroxy-2,3-bis(trifluoromethyl)benzaldehyde (5n ) was
converted to the 4-triflate 6n by the same methods used to
prepare the 2,3-dichloro analogue 6i. This triflate was reacted
with 2-methoxybenzenethiol by the same method used to
prepare the 2,3-dichloro analogue (4i, Ar ) 2-methoxyphenyl)
to give 4-(2-methoxyphenylthio)-2,3-bis(trifluoromethyl)-
benzaldehyde (4n , Ar ) 2-methoxyphenyl). Reaction of 4n with
malonic acid gave the cinnamic acid 10, which was converted
to the acid chloride. This was reacted with 4-carbethoxypip-
eridine and the resulting ester hydrolyzed to give the desired
(1,4-Ben zod ioxa n -6-yl) [2,3-d ich lor o-4-(E-((4-a cetylp ip -
er a zin -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (33) was
prepared (method of compound 34) using the solution of 1,4-
benzodioxane-6-thiol in NMP prepared above, 4-trifloxy-2,3-
dichlorobenzaldehyde, and N-acetyl piperazine as starting
1
materials. The product is a white solid. H NMR (CDCl3, 300
MHz) δ 2.17 (s, 3H), 3.50-3.94 (m, 8H), 4.26-4.40 (m, 4H),
6.61 (d, J ) 8.7 Hz, 1H), 6.71 (d, J ) 15.6 Hz, 1H), 6.95 (d, J
) 8.4 Hz, 1H), 7.04 (dd, J ) 2.4, 8.4 Hz, 1H), 7.09 (d, J ) 2.4
Hz, 1H), 7.30 (d, J ) 8.7 Hz, 1H), 7.99 (d, J ) 15.6 Hz, 1H).
1
MS (ESI+) (M+Na)+ at m/z 515, 517, 519. Anal. (C23H22
-
product (methods of compound 23 and 25). H NMR (CD3OD,
300 MHz) δ 1.65 (br s, 2H), 1.94-2.03 (m, 2H), 2.57-2.67 (m,
1H), 2.95-3.05 (m, 1H), 3.23-3.32 (m, 1H), 3.75 (s, 3H), 4.12
(br s, 1H), 4.40 (br s, 1H), 7.00 (d, J ) 15 Hz, 1H), 7.03-7.20
(m, 3H), 7.47-7.53 (m, 2H), 7.68 (d, J ) 9 Hz, 1H), 7.77 (dd,
Cl2N2O4S 0.52 CH2Cl2) C, H, N.
(2-Met h oxyp h en yl)-[2,3-d ich lor o-4(E-[(4-ca r b oxyp ip -
er id in -1-yl)ca r bon yl]eth en yl)p h en yl] su lfid e (35) was
prepared (methods of compounds 34 and 25) using 2-meth-
oxybenzenethiol, 4-trifloxy-2,3-dichlorobenzaldehyde, and 4-car-
bethoxypiperidine as starting materials. 1H NMR (CDCl3 300
MHz) δ 1.66-1.83 (m, 2H), 1.95-2.09 (m, 2H), 2.57-2.69 (m,
1H), 2.94-3.08 (m, 1), 3.15-3.31 (m, 1H), 3.72 (s, 3H), 3.90-
4.05 (m, 1H), 4.41-4.55 (m, 1H), 6.55 (d, J ) 9 Hz, 1H), 6.73
(d, J ) 15 Hz, 1H), 7.00-7.05 (m, 2H), 7.27 (d, J ) 8 Hz, 1H),
7.44-7.50 (m, 2H), 7.92 (d, J ) 15 Hz, 1H). Anal. (C22H21Cl2-
NO4S) C, H, N.
J ) 15 Hz, 1H). MS (ESI) m/z 534 (M+H)+. Anal. (C24H21
NF6O4S) C, H, N.
-
(1,4-Ben zod ioxa n -6yl) [2,3-bis(tr iflu or om eth yl)-4-(E-
((4-ca r boxyp ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su l-
fid e (39) was prepared (method of compound 40) using a
solution of 1,4-benzodioxane-6-thiol in NMP prepared above,
4-trifloxy-2,3-bis(trifluoromethyl)benzaldehyde, and 4-carbe-
1
thoxypiperidine as starting materials. H NMR (CD3OD, 300
MHz) δ 1.65(br s, 2H),1.93-2.04 (m, 2H), 2.57-2.65 (m, 1H),
2.95-3.05 (m, 1H), 3.25 (m, 1H), 4.12 (m, 1H), 4.28 (m, 4H),
4.41 (m, 1H), 6.92-7.03 (m, 4H), 7.25 (d, J ) 9 Hz, 1H), 7.72
(d, J ) 9 Hz, 1H), 7.72-7.81 (m, 1H). MS (ESI) m/e 562
(M+H)+. Anal. (C25H21NO5F6S) C, H, N.
(1-Meth ylin d ol-5-yl) [2,3-bis(tr iflu or om eth yl)-4-(E-((4-
ca r boxyp ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e
(41) was prepared (method of 40) using the solution of
1-methylindole-5-thiol in NMP prepared above, 4-trifloxy-2,3-
bis(trifluoromethyl)benzaldehyde, and 4-carbethoxypiperidine
as starting materials. 1H NMR (CD3OD, 300 MHz) δ 1.52-
1.68 (m, 2H), 1.92-2.03 (m, 2H), 2.55-2.65 (m, 1H), 2.93-
3.04 (m, 1H), 3.20-3.28 3.84 (s, 3H), (m, 1H), 4.01-4.12 (m,
(2-Isop r op ylp h en yl) [2,3-d ich lor o-4-(E-((4-ca r boxyp i-
p er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (36) was
prepared (methods of compounds 34 and 25) using 2-isopro-
pylbenzenethiol, 4-trifloxy-2,3-dichlorobenzaldehyde, and 4-car-
bethoxypiperidine as starting materials. The sodium salt was
prepared as follows. The acid was dissolved in methanol. One
equivalent of NaOH was carefully weighed out and dissolved
in methanol. The solutions of acid and NaOH were mixed, and
the methanol was evaporated in a vacuum. Toluene was added
and then evaporated to remove all of the methanol. Ether was
added and the mixture stirred to give the sodium salt as a
white powder. 1H NMR (DMSO-d6, 300 MHz) δ 1.16 (d, J )
7.2 Hz, 6H), 1.33-1.53 (m, 2H), 1.64-1.78 (m, 2H), 1.97-2.10

SAR of Substituents on the Benzene Ring of the Cinnamide
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25 4401
1H), 4.32-4.43 (m, 1H), 6.52 (dd, J ) 4 Hz, 2 Hz, 1H), 7.04 (d,
J ) 15 Hz, 1H), 7.09 (d, J ) 9 Hz, 1H), 7.25-7.30 (m, 2H),
7.50 (d, J ) 8 Hz, 1H), 7.61 (d, J ) 9 Hz, 1H), 7.70-7.80 (octet,
1H), 8.20-8.45 (m, 3H). MS(ESI+) m/z 476 (M+H)+. Anal.
(C27H25NO5S‚0.67H2O) C, H, N.
(2-Isop r op ylp h en yl) [2,3-Diflu or o-4-(E-((4-ca r boxyp i-
p er id in -1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e (48). 2,3,4-
Trifluorocinnamic acid (Aldrich) was converted to the methyl
ester. This compound was reacted with 1 equiv of 2-isopropyl-
benzenethiol, and 2.5 equiv of K2CO3 in CH3CN at 25 °C for
16 h. The product was purified by chromatography (hexanes-
EtOAc 5:1) to get methyl 4-(2-isopropylthio) 2,3-difluoro cin-
namate in 27% yield. This was hydrolyzed to the acid with
NaOH, coupled with 4-carbethoxypiperidine, and then hydro-
J
) 15 Hz, 4 Hz, 1H), 7.82 (d, J ) 2 Hz, 1H). Anal.
(C26H22F6N2O3S). C, H, N.
(2-Meth oxyp h en yl) [2-Ch lor o-3-tr iflu or om eth yl-4-(E-
((m or p h olin -1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e (42).
4-Hydroxy-3-chloro-2-trifluoromethylbenzaldehyde (5m ) was
converted to the 4-triflate 6m by the same methods used to
prepare the 2,3-dichloro analogue 6i. This triflate was reacted
with 2-methoxybenzenethiol by the same method used to
prepare the 2,3-dichloro analogue (4i, Ar ) 2-methoxyphenyl)
to give 4-(2-methoxyphenylthio)-2-chloro-3-(trifluoromethy)-
benzaldehyde (4m , Ar ) 2-methoxyphenyl). Reaction of 4m
with malonic acid gave the cinnamic acid 10 which was
converted to the acid chloride. This was reacted with morpho-
1
lyzed with NaOH to the title compound. H NMR (DMSO-d6,
300 MHz) δ 1.18 (d, J ) 6.8 Hz, 6H); 1.30-1.91 (br m, 4H);
2.50-3.50 (br m, 4H); 4.02-4.34 (br m, 2H); 6.62-6.72 (m,
1H); 7.23-7.73 (m, 7H). MS (APCI) (M+H)+ at m/z 446. Anal.
(C24H25F2NO3S) C, H, N.
1
(2-Meth oxyp h en yl) [3-F lu or o-4-(E-((4-a cetylp ip er a zin -
1-yl)ca r bon yl)eth en yl)p h en yl] Su lfid e (49). 2,4-Difluoro-
cinnamic acid and N-acetyl piperazine were coupled to form
the cinnamide 12. This was reacted with 2-methoxyben-
zenethiol by the method of compound 48 to give the title
compound. 1H NMR (DMSO-d6, 300 MHz) δ 2.02 (s, 3H), 3.45-
3.75 (br m, 8H), 3.80 (s, 3H), 6.90 (dd, J ) 10 Hz, 2 Hz, 1H),
6.98 (dd, J ) 8 Hz, 2 Hz, 1H), 7.02 (t, J ) 7 Hz, 1H), 7.18 (d,
J ) 7 Hz, 1H), 7.25 (d, J ) 15 Hz, 1H), 7.38 (d, J ) 7 Hz, 1H),
7.47 (dt, J ) 8 Hz, 2 Hz, 7.55 (d, J ) 15 Hz, 1H), 7.86 (t, J )
8 Hz, 1H). Anal. (C22H23FN2O3S) C, H, N.
1,4-Ben zod ioxa n -6-yl [2-Ch lor o-6-tr iflu or om eth yl-4-(E-
((3-ca r boxyp ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] Su l-
fid e (50). The aldehyde 4g was converted to the cimnnamic
acid 10g (Ar ) 1,4-benzodioxane) by reaction with malonic acid
(see compound 10b, Ar ) 2-methoxypheny), and then coupling
with 4-carbethoxypiperidine, and finally hyrolysis with NaOH
to give the title compound. 1H NMR (CD3OD, 300 MHz) δ
1.55-1.70 (m, 2H), 1.93-2.04 (m, 2H), 2.55-2.67 (m, 1H),
2.92-3.04 (m, 1H), 3.22-3.31 (m, 1H), 4.25-4.35 (m, 1H),
4.36-4.47 (m, 4H), 4.55-4.66 (m, 1H), 6.58 (d, J ) 2 Hz, 1H),
6.63 (dd, J ) 2 Hz, 9 Hz, 1H), 6.75 (d, J ) 9 Hz, 1H), 7.37 (d,
J ) 15 Hz, 1H), 7.52 (d, J ) 15 Hz, 1H), 8.02 (d, J ) 2 Hz,
1H), 8.10 (d, J ) 2 Hz). Anal. (C24H21ClF3NO5S) C, H, N.
line to give the desired product (method of compound 23). H
NMR (CDCl3, 300 MHz) δ 3.56-3.62 (br m, 2H), 3.67-3.77
(br m, 6H), 3.85 (s, 3H), 6.45 (d, J ) 15 Hz, 1H), 6.73 (d, J )
9 Hz, 1H), 7.03 (d, J ) 9 Hz, 2H), 7.09 (t, J ) 9 Hz, 1H), 7.52
(d, J ) 9 Hz, 2H), 2.93 (dd, J ) 6 Hz, 1H). MS (DCI/NH3) m/z
458 (M+H)+. Anal. (C21H19ClF3NO3S) C, H, N.
(2-Met h oxyp h en yl) [2-ch lor o-3-t r iflu or om et h yl-4-(E-
((4-ca r b oet h oxyp ip er id in -1-yl)ca r b on yl)et h en yl)p h en -
yl] su lfid e (43) was prepared (methods of compounds 42 and
25) by using 2-methoxybenzenethiol, 4-trifloxy-3-chloro-2-
(trifluoromethyl)benzaldehyde, and 4-carbethoxypiperidine as
starting materials. 1H NMR (DMSO, 300 MHz) δ 1.37-1.52
(br. 2H), 1.78-1.86 (br. 2H), 2.45-2.55 (m, 1H), 2.83 (t, J )
12 Hz, 1H), 3.17 (t, J ) 13.5 Hz, 1H), 3.80 (s, 3H), 4.07 (d, J
) 12 Hz, 1H), 4.26 (d, J ) 13.5 Hz, 1H), 6.75 (d, J ) 9 Hz,
1H), 6.98 (d, J ) 15 Hz, 1H), 7.11(t, J ) 9 Hz, 1H), 7.26 (d, J
) 9 Hz, 1H), 7.53 (d, J ) 7.5 Hz, 1H), 7.62 (d, J ) 9 Hz, 2H),
7.70 (dd, J ) 4.5 Hz, 1H). MS (DCI/NH3) m/e 500 (M+H)+.
Anal. (C23H21ClF3NO4S) C, H, N.
1,4-Ben zod ioxa n -6-yl [2-ch lor o-3-t r iflu or om et h yl4-
(E-((3-ca r b oxyp ip er id in -1-yl)ca r b on yl)et h en yl)p h en yl]
su lfid e (44) was prepared (methods of compounds 42 and 25)
by using the solution of 1,4-benzodioxane-6-thiol in NMP
prepared above, 4-trifloxy-3-chloro-2-(trifluoromethyl)benz-
aldehyde, and 4-carbethoxypiperidine as starting materials.
1H NMR (CD3OD, 300 MHz) δ 1.55-1.70 (m, 2H), 1.93-2.04
(m, 2H), 2.55-2.67 (m, 1H), 2.92-3.04 (m, 1H), 3.22-3.31 (m,
1H), 4.05-4.15 (m, 1H), 4.26-4.37 (m, 4H), 4.35-4.46 (m, 1H),
6.85 (d, J ) 15 Hz, 1H), 6.89 (d, J ) 8 Hz, 1H), 6.95-7.08 (m,
3H), 7.41 (d, J ) 8 Hz, 1H), 7.84 (octet, J ) 15 Hz, 4 Hz, 1H).
Anal. (C24H21ClF3NO5S) C, H, N.
(2-Meth oxyp h en yl) [2,5-Dich lor o-4(E-[(4-ca r boxyp ip -
er id in -1-yl)ca r bon yl]eth en yl)p h en yl] Su lfid e (51). 4-Hy-
droxy-3,6-dichlorobenzaldehyde (5p ) was converted to the
4-triflate (6p ) by the method used with the 2,3-dichloro
analogue (5i), and then this was reacted with 2-methoxyben-
zenethiol to give 4p (Ar ) 2-methoxyphenyl) and then on to
the title compound also using the same method used to make
1
the 2,3-dichloro analogue 35. H NMR (CD3OD, 300 MHz) δ
(2-Met h oxyp h en yl)-[2,3-d im et h yl-4(E-[(m or p h olin -1-
yl)ca r bon yl]eth en yl)p h en yl] Su lfid e (45). 4-(2-Methoxy-
phenylthio)-2,3-dimethylbenzaldehyde (4j) was converted to
the cinnamic acid with malonic acid (method of compound
10b), and this was converted to the acid chloride with (COCl)2
and reacted with morpholine to give the title compound. 1H
NMR (CDCl3 300 MHz) δ 2.39 (s, 3H), 2.42 (s, 3H), 3.60-3.80
(m, 8H), 3.90 (s, 3H), 6.69 (d, J ) 15 Hz, 1H), 6.82-6.94 (m,
3H), 7.05 (d, J ) 9 Hz, 1H), 7.20-7.30 (m, 2H), 8.06 (d, J ) 5
Hz, 1H). Anal.(C22H25NO3S) C, H, N.
1.57-1.67 (m, 2H), 1.93-2.07 (m, 2H), 2.58-2.69 (m, 1H),
2.95-3.06 (m, 1H), 3.32-3.4 1 (m, 1H), 3.82 (s, 3H), 4.25-
4.35 (m, 1H), 4.36-4.45-4.56 (m, 1H), 6.55 (s, 1H), 7.08 (t, J
) 8 Hz, 1H), 7.18 (, J ) 9 Hz, 1H), 7.22 (d, J ) 15 Hz, 1H),
7.49-7.59 (m, 1H), 7.80 (d, J ) 15 Hz, 1H), 7.94 (s, 1H). Anal.
(C22H21Cl2NO4S) C, H, N.
(2-Meth oxyp h en yl) [2-Nitr o-5-m eth yl-4(E-[(4-ca r boxy-
piper idin -1-yl)car bon yl]eth en yl)ph en yl] Su lfide (53). 4-(2-
Methoxyphenylthio)-2-methyl-5-nitrocinnamic acid (15) and
4-carbethoxypiperidine were converted to the title compound
(methods of compounds 23 and 25); mp 206-208 °C. 1H NMR
(DMSO-d6, 300 MHZ) δ 1.35-1.45 (m, 2H), 1.80-1.90 (m, 2H),
2.39 (s, 3H), 2.45-2.55 (m, 1H), 2.75-2.85 (m,1H), 3.05-3.15
(m, 1H), 3.60-3.70 (m, 1H), 3.77 (s, 3H), 4.15-4.25 (m, 1H),
6.47 (d, J ) 15 Hz, 1H), 6.89 (s, 1H), 7,11 (t, J ) 7 Hz, 1H),
7.24 (d, J ) 8 Hz, 1H), 7.47-7.62 (m, 3H), 8.14 (s, 1H). Anal.
(C23H24N2O6S), C, H, N.
(2-Met h oxyp h en yl) [2-Ch lor o-5-m et h yl-4-(E-[(4-ca r -
boxypiper idin -1-yl)car bon yl]eth en yl)ph en yl] Su lfide (52).
The ethyl ester of cinnamic acid 16 (3.12 g, 8.70 mmol) was
added to powdered iron (2.43 g, 43.5 mmol) and NH4Cl (0.558
g, 10.4 mmol) in 20 mL of water and 20 mL of ethanol and
heated at 105 °C for 1 h. The mixture was filtered and the
solid washed with EtOAc. The filtrate was washed with brine
and dried (MgSO4) and the solvents evaporated to give 2.76 g
of the amino compound, methyl ester intermediate (17). This
(1,4-Ben zod ioxa n -6-yl) [4-(E-((4-Ca r boxyp ip er id in -1-
yl)ca r bon yl)eth en yl)n a p h th yl] Su lfid e (47). 4-Hydroxy-1-
naphthaldehyde7 was converted to the triflate by the method
used to prepare 6i. This was reacted with a solution of 1,4-
benzodioxane-6-thiol in NMP prepared above, by the method
used to prepare 4j (Ar ) 2-methoxyphenyl) to give 4-(1,4-
benzodioxane-6-thio)-1-naphthaldehyde (4k , Ar ) 1,4-benzo-
dioxane-6-yl). This was converted to the cinnamic acid with
malonic acid. The cinnamic acid was converted to the acid
chloride with oxalyl chloride, which was reacted with 4-car-
bethoxypiperidine, and the resulting ester was hydrolyzed with
NaOH to give the title compound. 1H NMR (DMSO-d6, 300
MHz) δ 1.50 (br s, 2H), 1.83-1.92 (m, 2H), 2.5-2.6 (m, 1H),
2.85-2.95 (m, 1H), 3.18-3.29 (m, 1H), 4.22 (br s, 5H), 4.30-
4.38 (m, 1H), 6.87-6.92 (m, 3H), 7.38 (d, J ) 15 Hz, 1H), 7.45
(d, J ) 7.5 Hz, 1H), 7.64-7.70 (m, 2H), 7.93 (d, J ) 7.5 Hz,

4402 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25
Winn et al.
compound (330 mg, 1.00 mmol), in 15 mL of CH3CN containing
0.19 mL (1.30 mmol) of 60% HBF4, was treated with tert-butyl
nitrite (0.155 mL, 1.30 mmol) at 0 °C. After 2 h, 45 mL of
saturated NH4Cl was added. And the mixture was extracted
with EtOAc. The EtOAc was washed with NH4Cl, water, and
brine and dried (MgSO4), and the solvents were evaporated.
The product was purified by chromatography (SiO2, hexanes-
EtOAc 7:3) to get 0.236 g (68%) of the methyl ester of 18. This
was hydrolyzed to 18 with NaOH in water-ethanol. The
cinnamic acid 18 and 4-carbethoxypiperidine were converted
24 h later for the determination of total cell number using a
particle counter (Coulter Corp.) and percent leukocytes using
Diff-Quik differential stains (Dade AG).
In the second model of in vivo trafficking, neutrophil
migration in the rat was induced by injection of Staphlococcus
Enterotoxin A (SEA) (Sigma S-9399) in an air pouch. The
dosing vehicle was 0.2% methylcellulose (MC) in phosphate
buffered saline (PBS). Animals were injected subcutaneously
with 20 cm3 sterile air on day 0 and again on day 3 to induce
an air pouch. On day 6, compound 38 was administered orally,
and 1 h later SEA was injected into the air pouch. Four hours
later, animals were sacrificed, the air pouches lavaged,
cytospins collected, and differential cell counts determined
with Wright Giemsa staining.
NMR m od elin g. Procedures used to generate the NOE
based model of compound 31 bound to the LFA-1 I domain
are described in ref 2. A model of compound 56 bound to LFA-1
I domain was obtained by positioning the compound near the
C-terminus of the I domain followed by energy minimization
with XPLOR as described in ref 2. Nineteen intermolecular
and one intraligand distance restraints were used that mimic
the NOEs observed for the complex of LFA-1 and compound
31. The six lowest energy structures out of 100 calculations
were selected for a comparison with the compound 31/LFA-1
complex. Similarly, the binding of compound 35 was modeled
using 19 intermolecular and one intraligand distance re-
straints. The seven lowest energy structures out of 100
calculations were selected for a comparison with the compound
31/LFA-1 complex.
1
to the title compound (methods of compounds 23 and 25). H
NMR (DMSO-d6, 300 MHz) δ 1.35-1.45 (m, 2H), 1.80-1.89
(m, 2H), 2.38 (s, 3H), 2.75-2.85 (m, 1H), 3.05-3.15 (m, 1H),
3.50-3670 (m, 1H), 3.84 (s, 3H), 3.95-4.05 (m, 1H), 4.22-
4.31 (m, 1H), 6.76 (d, J ) 7 Hz, 1H), 6.93 (t, J ) 8 Hz, 1H),
6.99 (d, J ) 15 Hz, 1H), 7.11 (d, J ) 9 Hz, 1H), (t, J ) 7 Hz,
1H), 7.54 (s, 1H), 7.58 (d, J ) 15 Hz, 1H), 7.71 (s, 1H). Anal.
(C23H24ClNO4S‚0.25H2O) C, H, N.
(2-Meth oxyp h en yl) [3 -Meth yl-4(E-[(4-ca r boxyp ip er i-
d in -1-yl)ca r bon yl]eth en yl)p h en yl] Su lfid e (46). The amino
cinnamate intermediate 17 in the synthesis of 52 (1.95 g, 5.92
mmol) in 25 mL of CH3CN containing 3.16 mL of 3 M aqueous
H2SO4, 9.47 mmol) was treated with 0.820 mL of tert-butyl
nitrite (6.22 mmol) at 0 °C. After 30 min, a 50% aqueous
solution of hypophosphorus acid (H3PO2, 12.3 mL, 118 mmol)
was added. The mixture was stirred at 25 °C for 16 h. The
product was purified by chromatography (SiO2, hexane-
ETOAc 85:15) to get 0.905 (49%) of methyl ester of the
cinnamic acid 19. This was hydrolyzed to 19 (LiOH) which was
coupled with 4-carbethoxypiperidine and the resulting ester
hydrolyzed to the title compound (methods of compounds 23
Refer en ces
1
(1) Liu, G.; Link, J . T.; Pei, Z.; Reilly, E. B.; Leitza, S.; Nguyen, B.;
Marsh, K.; Okasinski, G. F.; von Geldern, T. W.; Ormes, M.;
Fowler, K.; Gallatin, M. Discovery of Novel p-Arylthio Cinna-
mides as Antagonists of Leukocyte Function-Associated Antigen-
1/Intracellular Adhesion Molecule-1 Interaction 1. Identification
of an Additional Binding Pocket Based on an Anilino Diaryl
Sulfide Lead. J . Med. Chem. 2000, 43, 4025-4044.
and 35). H NMR (DMSO-d6, 300 MHz) δ 1.35-1.45 (m, 2H),
1.80-1.89 (m, 2H), 2.37 (s, 3H), 2.78-2.88 (m, 1H), 3.15-3.25
(m, 1H), 3.50-3.60 (m, 1H), 3.82 (s, 3H), 4.15-4.22 (m, 1H),
4.32-4.41 (m, 1H), 6.83-6.92 (m, 2H), 7.08 (d, J ) 8 Hz, 1H),
7.15-7.28 (m, 3H), 7.22 (d, J ) 15 Hz, 1H), 7.66 (d, J ) 15
Hz, 1H), 7.88 (s, 1H). Anal. (C23H25NO4S 0.5 H2O) C, H, N.
(2) Liu, G.; Huth, J . R.; Olejniczak, E. T.; Mendoza, R.; DeVries,
P.; Leitza, S.; Reilly, E. B.; Okasinski, G. F.; von Geldern, T.
W., Fesik, S W. Novel p-Arylthio Cinnamides as Antagonists of
LFA-1/ICAM-1 Interaction. 2 Determination of the Mechanism
of Inhibition and Structure-based SAR Approach for Improved
Pharmaceutical Properties. J . Med. Chem. 2001, 44, 1202-1210
(3) Pei, Z.; Xin, Z.; Liu, G.; Li, Y.; Link, J . T.; Huth, J .; von Geldern,
T. W.; Reilly, E. B.; Leitz, S.; Marsh, K. C.; Okasinski, G. F.
Discovery of Potent Antagonists of Leukocyte Function Associ-
ated Antigen-1/Intracellular Adhesion Molecule-1 Interaction.
3. SAR of the Amide Portion (C-ring) of the Molecules. J . Med.
Chem., 2001, 44, 1202-1210.
(4) Miranda, E. I.; Diaz. M. J .; Rosario, I.; Soderquist, J . A. Thiols,
Unsymmetrical Sulfides and Thioacetals From the New Re-
agent: Triisopropylsilanethiol. Tetrahedron Lett. 1994, 35,
3221-3224.
(5) Bennetau, B.; Mortier, J .; Moyroud, J .; Guesnet, J . Directed
Lithiation of Unprotected Benzoic Acids. J . Chem. Soc., Perkin
Trans. 1, 1995, 1265-1271.
(2-Meth oxyp h en yl) [3-tr iflu or om eth yl-4-(E-((4-ca r bo-
eth oxyp ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e
(54) was prepared (methods of compounds 23 and 25) using
2-methoxybenzenethiol, 4-fluoro-2-(trifluoromethyl)benzalde-
hyde, and 4-carbethoxypiperidine as starting materials. 1H
NMR (DMSO-d6, 300 MHz) δ 1.40-1.55 (m, 2H), 1.80-1.90
(m, 2H), 2.80-2.92 (m, 1H), 3.14-3.26 (m, 2H), 3.79 (s, 3H),
4.11-4.30 (m, 2H), 7.04 (dt, J ) 8 Hz, 2 Hz, 1H), 7.19 (dd, J
) 8 Hz, 1H), 7.33 (d, J ) 15, 1H), 7.36-7.41 (m, 2H), 7.49 (dt,
J ) 8 Hz, 2 Hz, 1H), 7.65 (octet, J ) 15 Hz, 2 Hz, 1H), 8.06 (d,
J ) 8 Hz, 1H), MS (APCI) (M+ H) 466 Anal. (C23H22F3NO4S)
C, H, N.
(2-Met h oxyp h en yl) [3-ch lor o-4-(E-((4-ca r b oet h oxy-
p ip er id in -1-yl)ca r bon yl)eth en yl)p h en yl] su lfid e (55) was
prepared (methods of compounds 23 and 25) using 2-meth-
oxybenzenethiol, 4-fluoro-2-chlorobenzaldehyde, and 4-carbe-
thoxypiperidine as staring materials. The reaction between
2-methoxybenzenethiol and 4-fluoro-2-chloro-benzaldehyde
was carried out at 25 °C instead of at 55 °C. 1H NMR (DMSO-
d6, 300 MHz) δ 1.35-1.50 (m, 2H), 1.84-1.93 (m, 2H), 2.50-
2.60 (m, 1H), 2.80-2.90 (m, 1H), 3.15-3.25 (m, 1H), 4.10-
4.20 (m, 1H), 4.22-4.35 (m 1H), 7.02 (t, J ) 8 Hz, 1H), 7.10
(dd, J ) 8 Hz, 1 Hz),7.15 (d, J ) 2 Hz, 1H), 7.18 (d, J ) 8 Hz,
1H), 7.26 (d, J ) 15 Hz, 1H), 7.35 (d, J ) 8 Hz, 1H), 7.48 (t, J
) 8 Hz, 1H), 7.70 (d, J ) 15 Hz, 1H), 7.96 (d, J ) 8 Hz, 1H).
Anal. (C22H22ClNO4S 0.5 H2O) C, H, N.
In Vivo Cell Tr a ffick in g Mod els. The in vivo efficacy of
compound 38 was evaluated in two separate rodent cell
trafficking models. In the first model, eosinophil migration into
the lung was induced by inhaled allergen. The dosing vehicle
was 1.7% dextrose in water. On day 0 mice were sensitized
with ovalbumin (OA) adsorbed to aluminum hydroxide (AlOH)
intraperitoneally (ip) and boosted on day 6 with OA-AlOH ip
and OA in PBS intranasally. Mice were aerosol challenged
twice on day 20 with OA in PBS, and compound 38 was
administered orally at -1 h and +7 h relative to the first
aerosol challenge. Lungs from sacrificed animals were lavaged
(6) Bicking, J . B.; Holtz, W. J .; Watson, L. S.; Cragoe, E. T.
(Vinylaryloxy)acetic Acids. A New Class of Diuretic Agents. 1.
(Diacylvinyloxy)acetic Acids J . Med. Chem. 1976, 19, 530.
(7) Auwers, K.. V.; Mauss, W. A Study of the Friedel Crafts, Fries
and Gattermann Reactions. Chem. Ber. 1928, 61, 1495.
(8) Buzzetti, F.; Vittorio, B.; Brasca, M. G.; Crugnola, A.; Fustinoni,
S.; Longo, A. Synthesis and Configuration of Some New Bicyclic
3-Arylidene- and 3-Hetroarylidene-2-oxoindoles. Gazetta Chim.
Ital. 1995, 125, 69-76.
(9) Knuutinen, J . S.; Kolehmainen, E. Synthesis and Spectroscopic
Data of Chlorinated 4-Hydroxybenzaldehydes. J . Chem. Eng.
Data 1983, 28, 139-141.
(10) Chambers, R. D.; Roche, A. J .; Rock, M. H. Polyhalogenated
Heterocyclic Compounds. Part 41 Cycloaddition Reactions In-
volving Hexafluorobut-2-yne and 1,1,1,2,4,4,4-Heptafluorobut-
2-ene. J . Chem. Soc., Perkin Trans.1. 1996, 11, 1095-1100.
(11) Godfrey, A. G.; Ganem, B. Ready Oxidation of Halides to
Aldehydes Using Trimethylamine N-Oxide in Dimethyl sulfox-
ide. Tetrahedron Lett. 1990, 31, 4825-4826.
(12) J ucker, E.; Lindemann, A. Diuretic activity of Benzoic Acid
Derivatives. Helv. Chim. Acta 1962, 45, 2316.
(13) Gonzalo, J . A.; Lloyd, C. M.; Kremer, L.; Finger, E.; Martinez,
A. C.; Siegelman, M. H.; Cybulsky, M.; Guitierrez-Ramos, J . C.
Eosinophil Recruiyment to the Lung in a Murine Model of
Allergic Inflammation: The Role of T Cells, Chemokines, and
Adhesion Receptors. J . Clin. Inves. 1996, 98, 2332-2345.

SAR of Substituents on the Benzene Ring of the Cinnamide
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 25 4403
(14) Gundel, R. H.; Wegner, C. D.; Torcellini, C. A.; Clarke, C. C.;
Haynes, N.; Rothlein, R.; Smith, C. W.; Letts, L. G. Endothelial
Leukocyte Adhesion Molecule-1 Mediates Antigen-induced Acute
Airway Inflammation and Late-phase Airway Obstruction in
Monkeys. J . Clin. Invest. 1991, 88 (4), 1407-1411.
(15) Miller, E. J .; Cohen, A. B.; Peterson, B. T. Peptide Inhibitor of
Interleukin-8 (IL-8) Reduces Staphylococcal Enterotoxin-A (SEA)
Induced Neutrophil Trafficking to the Lung. Inflamm. Res. 1996,
45, 393-397.
(16) Tessier, P. A.; Naccache, P. H.; Diener, K, R.; Gladue, R. P.;
Neote, K. S.; Clark-Lewis, I.; McColl, S. R. Induction of Acute
Inflammation in vivo by Staphylococcal Superantigens II. Criti-
cal Role for Chemokines, ICAM-1 and TNF-alpha. J . Immunol.
1998, 161 (3), 1204-1211.
J M0103108