Antileukotrienic N-arylethyl-2-arylacetamides in the treatment of ulcerative colitis

Article abstract of DOI:10.1016/j.ejmech.2007.01.014

A series of arylacetic acid derivatives bearing methyl(arylethyl)amino groups were prepared and their antileukotrienic activities involving LTB₄ were evaluated. Regression analysis has shown a strong dependence of these activities on lipophilic

Full text of DOI:10.1016/j.ejmech.2007.01.014

European Journal of Medicinal Chemistry 42 (2007) 1084e1094
http://www.elsevier.com/locate/ejmech
Original article
Antileukotrienic N-arylethyl-2-arylacetamides in the treatment of
ulcerative colitis
a
a
b
Richard Junek , Bohumila Brunova , Miloslav Kverka , Vladimıra Panajotova ,
c
´
Antonın Jandera , Miroslav Kuchar
´
´
˚
c
´
ˇ a,
*
a Zentiva VUFB, a.s., 102 01 Prague 10, Czech Republic
b Institute of Microbiology, Academy of Sciences, 142 00 Prague 4, Czech Republic
c REaD VUFB, Ltd., 180 66 Prague 9, Czech Republic
Received 26 May 2006; received in revised form 5 January 2007; accepted 18 January 2007
Available online 27 January 2007
Abstract
A series of arylacetic acid derivatives bearing methyl(arylethyl)amino groups were prepared and their antileukotrienic activities involving
LTB4 were evaluated. Regression analysis has shown a strong dependence of these activities on lipophilicity for both LTB4 receptor binding
and inhibition of LTB4 biosynthesis; parabolic relationships were derived. The values of slopes of the ascending linear parts of these depen-
dences indicate various types of hydrophobic binding at the site of ligand interaction with relevant biomacromolecules. The anti-inflammatory
effect of the compounds under study was also evaluated in three animal models of inflammation and their possible utilization in the treatment of
ulcerative colitis (UC) was followed. The importance of antileukotrienic activities for the anti-inflammatory effect, especially in the model of UC
was discussed, but further experiments are necessary to confirm the respective relations.
Ó 2007 Elsevier Masson SAS. All rights reserved.
Keywords: N-Phenethyl-2-arylacetamides; Antileukotrienic activity; QSAR; Regression analysis; Lipophilicity; Treatment of ulcerative colitis
1. Introduction
a significant role in the amplification of many other inflamma-
tory disease states [4,5] including psoriasis, gout, rheumatoid
arthritis and asthma. In addition, LTB4 is a mediator of inflam-
matory pain [6] and binds to peroxisome proliferator-
activated receptor (PPARa), which could affect the duration
of an inflammatory response to LTB4 [7].
The majority of antileukotrienics share common structural
features expressed by the following rules [8]: (i) a hydrophobic
region in the proximity of a polar group is in the ‘‘western’’
part; (ii) the ‘‘eastern’’ part is a carrier of an acid group (car-
boxyl or equivalent); (iii) a flexible spacer of various lengths
connecting both parts. The lipophilic fragments bearing phe-
nethylamino [9e12] or ethyl(methyl)amino [13] groups are
frequently used. It was found out that the presence of the eth-
yl(methyl)amino group has a positive influence on binding
activity and oral efficiency in in vivo experiments [14]. The
present work represents the continuation of our previous con-
tributions [15e17] to the study of substituted arylalkanoic
Inflammatory bowel diseases (IBD) such as ulcerative coli-
tis (UC) and Crohn’s disease (CD) are largely of unknown eti-
ology and are among the most challenging human diseases [1].
There is evidence of an intense local immune response associ-
ated with recruitment of lymphocytes and macrophages fol-
lowed by release of soluble cytokines. Excessive production
of leukotrienes (LT) has been implicated in the pathogenesis
of various immune and inflammatory diseases including IBD
[2]. LTB4 is a 5-lipoxygenase (5-LO) derived metabolite of
arachidonic acid which is synthesized by a number of cell
types, including eosinophils, neutrophils (PMNs), and macro-
phages [3]. It is a potent pro-inflammatory mediator playing
* Corresponding author. Tel.: þ420 267243703.
ˇ
E-mail address: kuchar@zentiva.cz (M. Kuchar).
0223-5234/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2007.01.014

R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1085
acids with antileukotrienic activities. Our effort was focused
on the preparation of arylacetic acid derivatives bearing
N-arylethyl-2-arylacetamido group through N-methyl-N-aryle-
thylamides of (4-hydroxyphenyl)acetic acid as key inter-
mediates. The series of new compounds 1e9 (Table 1) was
generated, characterized by 1H, 13C NMR and elemental
analysis and subjected to the evaluation of both in vitro
antileukotrienic and in vivo anti-inflammatory activities in-
cluding the treatment of ulcerative colitis. We have tried
to elucidate the role of lipophilicity in antileukotrienic activi-
ties of the compounds studied using QSAR methodology
[18,19].
preparation of acids 9. From these intermediates, the esters
40a and 40b were prepared in higher yields and purity and
in shorter reaction time. N-Methyl-N-phenethylamide of 13e15
was prepared from the corresponding 2-phenethylamines by
formylation and subsequent reduction with LiAlH4 according
to Ref. [21]. Methyl esters of (3-chloro-4-hydroxyphenyl)-
acetic acid (27), (4-hydroxyphenyl)acetic acid (28) and
(4-hydroxy-3-methoxyphenyl)acetic acid (29) were prepared
by the esterification of corresponding acids according to liter-
ature [22].
3. Results and discussion
2. Chemistry
3.1. Biological activities
The series of compounds 1e9 was synthesized using the N-
methyl-N-(arylethyl)amino group as lipophilic part of mole-
cule and the arylacetic acid moiety as a carrier of carboxyl
group. The structure of compounds was modified by the sub-
stitution on aromatic rings of the amine and acid and by the
length of a spacer between both structure fragments. For the
preparation of compounds 1e8 and 9, respectively, two syn-
thetic routes described in Schemes 1 and 2 were used. N-Ary-
lethylamides of 4-methoxyphenylacetic acid 16e20 were
prepared by the condensation of 4-methoxyphenylacetyl
chloride with corresponding arylethylamine, and their deme-
thylation afforded the key intermediates 21e25. Methyl [4-
(u-bromoalkyloxy)aryl]acetates 30 and 31 were prepared as
other synthons in the group of compounds 1e8. The alkylation
under the conditions of the Williamson reaction [20] gave es-
ters 32e39, which were hydrolysed to the corresponding acids
1e8. The reverse technique of alkylation, where N-methyl-N-
phenethylamide of [4-(4-bromoalkyloxy)phenyl] acetic acid
26 was used as an alkylating agent, was utilized for the
Compounds 1e9 were subjected to evaluation of antileuko-
trienic activity by testing in vitro the inhibition of LTB4 bio-
synthesis as a criterion of 5-LO inhibition, and affinity to
LTB4 receptors, which is a prerequisite for antagonistic activ-
ity toward this leukotriene. Both antileukotrienic activities
were expressed by the concentration IC50 causing 50% inhibi-
tion of LTB4 biosynthesis or LTB4 binding to receptors, re-
spectively. The phenethylamino derivatives 1b and 2b are
inactive in the inhibition of LTB4 biosynthesis; the presence
of tertiary nitrogen probably stimulates this antileukotrienic
activity of the compounds under study. The compounds
were also tested for their anti-inflammatory efficiency in
two in vivo models of inflammation, i.e. carrageenan induced
oedema in rats and arachidonic-acid-induced ear inflammation
in mice. The effects were expressed as percentage inhibition
in comparison to untreated control. Selected compounds
were subjected to evaluation of anti-inflammatory activity in
the in vivo model (mice) of ulcerative colitis (UC) induced
by sodium dextrane sulfate. Sulfasalazine was used as the
Table 1
Characterization of compounds 1be9b
Z
OH
N
[
]
n
O
O
O
O
X
Y
Acid
X
Y
H
Z
n
1b
2b
3a
3b
4a
4b
5b
6b
7b
8a
8b
9a
9b
H
H
4
4
3
4
3
4
4
4
4
3
4
3
4
H
OCH3
H
H
H
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
H
H
H
OCH3
OCH3
H
H
3-CH3
4-CH3
4-Br
4-Br
4-Br
H
H
H
OCH3
OCH3
Cl
H
Cl

1086
R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
Z
Z
a
+
NH
N
Cl
O
O
O
X
X
O
16-20
11-15
10
b
Z
c
O
O
N
+
n
O
O
[ ]
O
O
OH
HO
Br
X
Y
30,31
Y
28,29
21-25
d
Z
O
N
[ ]n
O
O
O
O
O
O
X
32-39
Y
Y
e
Z
OH
N
[ ]nO
O
X
1-8
Scheme 1. Synthesis of compounds 1be8b. a. (C2H5)3N, CH2Cl2, 20 ꢀC; b. BBr3, CH2Cl2, ꢁ72 to 20 ꢀC; c. K2CO3, butan-2-one, 1,3-dibromopropane (1,4-di-
bromobutane), reflux; d. K2CO3, KI, butan-2-one, reflux; e. tetrahydrofuranewater 4:1, LiOH, 20 ꢀC.
standard. UC was evaluated clinically (loss of weight, rectal
prolaps, blood in stool, stool consistency), pathologically (co-
lonic bleeding, length of colon), and histologically. The re-
sults of evaluation of antileukotrienic and anti-inflammatory
efficiencies are summarized in Table 2; the values document-
ing the effect in the model of ulcerative colitis are shown in
Table 3.
3.2. QSAR analysis
3.2.1. Parametrization of lipophilicity
To evaluate total lipophilicity of the compounds studied,
values of log P (calculated in program KOWWIN, Version
1.63) were used. Lipophilicity was also evaluated using exper-
imental values determined by reverse phase HPLC and
a
O
N
N
+
O
[ ]
O
O
n
HO
OH
Br
O
b
Cl
26
27
22
c
O
N
OH
N
[ ]
[ ]
O
n
O
O
n
O
O
O
O
O
Cl
Cl
9
40
Scheme 2. Synthesis of compounds 9: a. 18-crown-6, K2CO3, butan-2-one, 1,3-dibromopropane (1,4-dibromobutane), reflux; b. K2CO3, butan-2-one, reflux; c.
tetrahydrofuranewater 4:1, LiOH, 20 ꢀC.

R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1087
Table 2
Antileukotrienic and anti-inflammatory activities of derivatives of phenethylcarbamoylmethylephenoxyalkyloxyphenylacetic acids 1e9
Compound
Log P
Log k
LTB4 biosynthesis
LTB4 receptor binding
Carrageenan oedema %
of inhibition
Ear lobe affection % of inhibition
IC50 (mM)
Log(1/IC50
)
IC50 (mM)
Log(1/IC50
)
Oedema
Hyperaemia
1b
2b
5.44
5.01
5.16
5.65
4.73
5.22
6.20
6.20
6.54
5.62
6.11
5.81
6.30
n.d.
0.089
>100a
>100a
40
e
n.d.
n.d.
18
e
n.s.
n.s.
39
30
n.s.
0
23
23
20
45
14
21
44
20
35
38
38
20
23
n.s.
0
ꢁ0.079
0.166
0.287
0.013
0.120
0.470
0.471
0.468
0.193
0.354
0.253
0.364
n.d.
e
e
7.7 (s)b
n.s.
n.s.
n.s.
n.s.
n.s.
24
3a
3b
4.398
4.699
e
4.745
5.328
4.174
5.065
5.959
6.180
5.770
e
20
4.7
4a
4b
>50a
32
67
4.495
5.000
4.959
4.825
e
8.6
1.1
5b
6b
10
11
14
n.s.
39
3!
0.66
1.7
7b
8a
15
0
n.d.
9.5
n.d.
1.9
n.s.
n.s.
n.s.
n.s.
13
8b
9a
5.022
4.796
4.959
e
5.721
5.620
5.921
e
27
12
32
46
16
11
0.01a
2.4
1.2
>100a
9b
Zileuton
n.d. ¼ not determined; n.s. ¼ not significant (the level of statistical significance p > 0.05).
a
Not included in correlation.
Stimulation.
b
expressed by values of log k, where k is capacity factor (cf.
log k ¼ 0:299ð ꢂ 0:109Þlog P þ 1:457ð ꢂ 0:625Þ
Section 4). Relations between the values of log P representing
calculated values of logarithm of the partition coefficient in
the system of n-octanolewater and experimental values of
log k are expressed by the regression Eq. (1), where n is the
number of compounds in correlation, r, s and F are the statis-
tical criteria (cf. Section 4). Regression Eq. (1) did not show
any systematic deviations from linearity. It can be stated that
the intramolecular hydrophobic interactions of aromatic rings
are not exerted in the chromatographic separation. The intro-
duction of polar constants s1 of substituents on the phenethyl
group and the indicator variable INH characterizing the pres-
ence of methyl on the N-atom of amide group to the Eq. (2)
improves the relationship between both lipophilic parameters
substantially. The reasons of frequent imperfect correlations
between log P values and logarithm of retention factor log k
have been extensively discussed [23e26].
n ¼ 13; r ¼ 0:925; s ¼ 0:068; F ¼ 72:0; p ¼ 0:01
ð1Þ
ð2Þ
logk ¼ 0:273ðꢂ0:075ÞlogPþ0:141ðꢂ0:099ÞINH
ꢁ0:230ðꢂ0:226Þs1 ꢁ1:422ðꢂ0:404Þ
n ¼ 13; r ¼ 0:973; s ¼ 0:041; F ¼ 73:2; p ¼ 0:01
3.2.2. Regression analysis of antileukotrienic activities
Eqs. (3) and (4) were derived for inhibition of biosynthesis of
LTB4. The optimum value of lipophilicity, log Popt ¼ 6.24 can
be calculated from the parabolic dependence of Eq. (4). Similar
dependences for lipophilicity, (Eqs. (5) and (6)), were obtained
for LTB4 receptor binding. The optimum value of lipophilicity
calculated from Eq. (6), log Popt ¼ 6.57, lies very close to the
previous optimum. The inactive phenethylamino derivatives
Table 3
Activities of derivatives of phenethylcarbamoylmethylephenoxyalkyloxyphenylacetic acids 2e9 in model ulcerative colitis induced by dextran sodium sulfate
(DSS)
Compound
Stool consistencea
Rectal prolapsa
Intestine bleedinga
Weight lossb,c (%)
Colon lengthc (cm)
Histologyc
Small
Large
2b
3b
2/5
3/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/10
0/15
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/10
6/15
4/5
2/5
80.0 ꢂ 5.7
86.8 ꢂ 6.5
91.8 ꢂ 14.7
78.1 ꢂ 6.2
96.1 ꢂ 5.7
91.4 ꢂ 10.8
91.8 ꢂ 4.6
74.2 ꢂ 5.3
87.2 ꢂ 7.9
89.6 ꢂ 11.0
6.6 ꢂ 0.3
8.1 ꢂ 0.8
8.6 ꢂ 0.4
7.4 ꢂ 0.9
9.6 ꢂ 1.1
8.4 ꢂ 0.5
9.1 ꢂ 0.5
6.8 ꢂ 1.0
7.9 ꢂ 0.3
8.4 ꢂ 0.8
1.6 ꢂ 0.6
1.0 ꢂ 0.2
1.2 ꢂ 0.6
1.1 ꢂ 0.5
0.8 ꢂ 0.4
0.9 ꢂ 0.2
0.6 ꢂ 0.2
1.9 ꢂ 0.4
1.0 ꢂ 0.4
0.9 ꢂ 0.2
5b
6b
4/5
2/5
3/5
3/5
7b
8a
1/5
2/5
1/5
3/5
8b
9b
0/5
5/5
0/5
5/5
Sulfasalazine
Controld
4/10
15/15
7/10
15/15
a
The ratio of diseased and total number of animals.
Percent indicates body weight change at day 6 compared with day 1.
b
c
d
The data are expressed as means ꢂ SD at the level of significance p < 0.05 (unpaired two-tailed Student’s t-test).
DSS in drinking water, 0.5% aqueous solution of (carboxymethyl)cellulose.

1088
R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1b and 2b were not included in the regression analysis. The
quantity IC50 represents concentration causing 50% inhibition
of biosynthesis of LTB4 in Eqs. (3) and (4) and concentration
causing 50% inhibition of LTB4 binding to receptors in Eqs.
(5) and (6), respectively.
3.3. Conclusions
The relationships between the individual activities, espe-
cially when they are evaluated in various models in vitro
and in vivo, can be remarkably affected by different transport
through the biological system. In spite of that, at least in the
case of the anti-inflammatory effect evaluated in vivo, it can
be stated that the compounds active in both models of
inflammatory oedema are also effective in the treatment of
ulcerative colitis. This statement is valid for compounds
7b, 8b and 3b. Unfortunately, compound 6b, belonging
also to the derivatives active in ulcerative colitis, does not
correspond with this conclusion. With respect to close values
of log P, the different transport of these compounds to the
site of action is obviously no reasonable explanation of the
observed discrepancy. Some compounds prepared are active
at 10ꢁ5 to 10ꢁ7 level of molar inhibitory concentration
(IC50) in both antileukotrienic activities. Three compounds,
6b, 7b and 8b, significantly active in the inhibition of UC,
are simultaneously distinguished by high antileukotrienic ac-
tivities in both tests. Also in this case, exceptions from this
rule exist, and two compounds, 5b and 9b, are not active in
UC inhibition in spite of high antileukotrienic activities. The
additional studies of relationships between the anti-inflam-
matory and antileukotrienic activities are in the preparation.
Nevertheless, in the present relatively small group of com-
pounds, five compounds manifest a higher (8b, 7b) or an
equal (3b, 6b, 8a) UC inhibitory activity in comparison
with the standard sulfasalazine.
logð1=IC50Þ¼0:411ðꢂ0:287ÞlogPþ2:369ðꢂ1:703Þ
n¼9; r¼0:869; s¼0:112; F¼25:1; p¼0:01
ð3Þ
À
Á
À
Á
À
Á
log 1=IC50 ¼5:936 ꢂ5:627 logPꢁ0:476 ꢂ0:471
2
ꢃðlog PÞ ꢁ13:549
n¼9; r¼0:954; s¼0:068; F¼41:1; p¼0:01 ð4Þ
logð1=IC50Þ¼0:993ðꢂ0:429Þlog Pꢁ0:301
n¼10; r¼0:932; s¼0:226; F¼60:4; p¼0:01 ð5Þ
À
Á
À
Á
À
Á
log 1=IC50 ¼7:044 ꢂ5:279 log Pꢁ0:536 ꢂ0:467
À
Á
2
ꢃðlog PÞ ꢁ17:199 ꢂ14:785
n¼10; r¼0:963; s¼0:169; F¼57:9; p¼0:05 ð6Þ
A comparison of quadratic relationships (4) and (6) indi-
cates different character in the ascending part of parabola.
We have evaluated the ascending linear parts of both the rela-
tionships for lipophilicity. Eq. (7) was obtained for the inhibi-
tion of biosynthesis of LTB4 and Eq. (8) for the binding to the
LTB4 receptor. The slopes of these straight lines indicate that
the different sites of action e as can be expected e operate in
both models. The Gibbs energy of intermolecular hydrophobic
interaction in both sites is obviously different.
4. Experimental
logð1=IC50Þ¼0:604ðꢂ0:064Þlog Pþ1:282ðꢂ1:012Þ
n¼5; r¼0:991; s¼0:025; F¼213:2; p¼0:01 ð7Þ
4.1. Chemistry
General: Melting points were determined on a Boeticus-
logð1=IC50Þ¼1:184ðꢂ0:370Þlog Pþ1:321ðꢂ2:093Þ
n¼8; r¼0:976; s¼0:145; F¼140:8; p¼0:01 ð8Þ
1
type Kofler block and are not corrected. The H NMR spectra
of 6% solutions of the compounds in CDCl3 (or in DMSO-d6)
containing TMS or 3-(trimethylsilyl)propanoic acid-d4 as the
internal standard and 13C NMR of the compounds in
DMSO-d6 were measured on a Bruker-250-DXP (250 MHz).
Chemical shifts are given in the d-scale (ppm), coupling con-
stants J in Hz. The following numbering was used for whole
molecule of:
The use of experimental values of log k afforded Eqs. (9)
and (10) with lower total statistical significance in compari-
son with corresponding Eqs. (4) and (6). The quadratic mem-
bers in Eqs. (9) and (10) have a markedly lower level of
statistical significance ( p ¼ 0.2). This discrepancy can be
probably explained by the fact that log k values do not fully
characterize lipophilicity of compounds under study (cf. Eqs.
(1) and (2)).
Bromoalkoxy derivatives 26, 30, 31:
À
Á
À
Á
À
Á
log 1=IC50 ¼ 4:491 ꢂ 4:490 log k ꢁ 4:912 ꢂ 4:411
À
Á
2
1
2
ꢃ ðlog kÞ þ3:930 ꢂ 0:960
6
9
13
1
4
6
5
12
H3CO
2
3
N
9
7
n ¼ 9; r ¼ 0:865; s ¼ 0:113; F ¼ 12:8
ð9Þ
14 16
7
O
5
3
O
O
Br
10
O
Br
4
8
15
11
13
8
1
Y
2
6
9
À
Á
À
Á
À
Á
1
6
H3CO
5
12
9
2
N
log 1=IC50 ¼ 6:467 ꢂ 6:398 log k ꢁ 5:336 ꢂ 4:931
7
14 16
15
O
Br
3
7
À
Á
3
5
Br
O
O
2
10
Y 4
8
O
ꢃ ðlog kÞ ꢁ4:129 ꢂ 0:760
10
17
4
11
Y: H, OCH3
n ¼ 10; r ¼ 0:936; s ¼ 0:220; F ¼ 32:7
ð10Þ

R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1089
Substituted phenylacetic acids 1e9 and their methyl esters
32e40:
J ¼ 7.3 Hz, 1H), 3.59 (s, 1H), 3.75 (s, 3 H, OCH3), 6.81e
6.83 (m, 2H), 7.00e7.34 (m, 7H).
8
8
9
13
11
1
6
9
13
11
1
6
19
21
12
N
2
3
X
OCH3(H)
12
N
20
2
3
X
14
21
19
16
14
7
16
20
O
O
7
5
O
O
O
O
10
18
5
O
10
O
17 Y
4
15
4
15
OCH3(H)
Y
22
X: H, 3-Me; 4-Me; 4-Br
Y: H, OCH3 Cl
,
The purity of compounds 1e9, 16e26, and 30e40 was
evaluated by HPLC on an Alliance Waters 2695 liquid chro-
matograph (Waters Assoc., Milford, MA, USA) with UV de-
tection (Waters 2487 dual detector) at 225 nm range.
Cromasil C18 100A (300 mm ꢃ 4.6 mm) was obtained from
Chromservis (Czech Republic). Gradient chromatography
was performed with water (Q plus, Millipore, Germany) and
acetonitrile (Merck, Darmstadt) with 0.1% of phosphoric
acid (Merck, Darmstadt) as a mobile phase. The eluent flow-
rate was 1 ml/min. Purity of compounds 1e9 was higher
than 98.0%, purity of compounds 16e26 and 30e40 was
higher than 95.0%.
4.1.4. 2-(4-Methoxyphenyl)-N-methyl-N-(3-methylphenethyl)
acetamide 18
Yellowish oil (29.0 g, 66%). Anal Calcd. for C19H23NO2
(297.4): C, 76.73; H, 7.80; N, 4.71; Found: C, 76.59; H,
7.83; N, 4.68%. 1H NMR (CDCl3) d: 2.30 (s, 3H, CH3),
2.68 (t, J ¼ 7.8 Hz, 1H), 2.78 (t, J ¼ 7.6 Hz, 1H), 2.85 (s,
1.5H, NCH3), 2.96 (s, 1.5H, NCH3), 3.42 (s, 1H), 3.48 (t,
J ¼ 7.6 Hz, 1H), 3.58 (t, J ¼ 7.6 Hz, 1H), 3.61 (s, 1H), 3.77
(s, 3H, OCH3), 6.78e6.92 (m, 3H), 6.93e7.25 (m, 5H).
4.1.5. 2-(4-Methoxyphenyl)-N-methyl-N-(4-methylphenethyl)
acetamide 19
Yellowish oil (33.4 g, 76%). Anal Calcd. for C19H23NO2
(297.4): C, 76.73; H, 7.80; N, 4.71; Found: C, 76.49; H,
7.91; N, 4.70%. 1H NMR (CDCl3) d: 2.32 (s, 3H, CH3),
2.68 (t, J ¼ 7.4 Hz, 1H), 2.76 (t, J ¼ 7.3 Hz, 1H), 2.81 (s,
1.5H, NCH3), 2.93 (s, 1.5H, NCH3), 3.39 (s, 1H), 3.42 (t,
J ¼ 7.3 Hz, 1H), 3.51 (t, J ¼ 7.3 Hz, 1H), 3.59 (s, 1H), 3.73
(s, 3H, OCH3), 6.70e6.72 (m, 2H), 6.92e7.08 (m, 6H).
4.1.1. Synthesis of N-arylethylamides of (4-methoxyphenyl)-
acetic acid 16e20
To a mixture of appropriate arylethylamine (11e15)
(0.164 mol) and triethylamine (24 ml) in dichloromethane
(120 ml) was added 4-methoxyphenylacetyl chloride (10)
(0.182 mol) in dichloromethane (110 ml) in 25 min. Mixture
was stirred at ambient temperature in water bath and con-
trolled by TLC, using n-hexaneeethyl acetate (3:2) as the el-
uent. 600 ml of dichloromethane was added when the absence
of the starting compound was observed and the solution was
washed with water (300 ml), 10% HCl (20 ml) and brine
(300 ml). The organic layer was then dried with sodium sulfate
and evaporated. These intermediates were used for subsequent
O-demethylation without further purification. For microanaly-
sis purpose, the solid form was recrystallized from EtOH or
was purified by column chromatography.
4.1.6. N-(4-Bromophenethyl)-2-(4-methoxyphenyl)-N-
methylacetamide 20
Yellowish oil (41.8 g, 95%). Anal Calcd. for C18H20BrNO2
(362.3): C, 59.68; H, 5.56; Br, 22.06; N, 3.87; Found: C,
1
59.41; H, 5.50; Br, 21.89; N, 3.86%. H NMR (CDCl3) d:
2.68 (t, J ¼ 7.3 Hz, 1H), 2.79 (t, J ¼ 7.4 Hz, 1H), 2.86 (s,
1.5H, NCH3), 2.94 (s, 1.5H, NCH3), 3.40 (s, 1H), 3.53 (t,
J ¼ 7.5 Hz, 1H), 3.59 (t, J ¼ 7.4 Hz, 1H), 3.62 (s, 1H), 3.71
(s, 3H, OCH3), 6.80e6.82 (m, 2H), 6.86e6.94 (m, 4H), 7.38
(m, 2H).
4.1.2. 2-(4-Methoxyphenyl)-N-phenethylacetamide 16
Yellowish crystals (23.3 g, 53%); m.p. 92e95 ꢀC (EtOH).
Anal Calcd. for C17H19NO2 (269.3): C, 75.81; H, 7.11; N,
4.1.7. Preparation of N-phenethylamides of (4-hydroxyphenyl)
acetic acid 21e25
1
5.20; Found: C, 75.71; H, 7.13; N, 5.17%. H NMR (CDCl3)
d: 2.72 (t, J ¼ 6.9 Hz, 2H), 3.46 (m, 4H), 3.80 (s, 3H, OCH3),
The solution of appropriate amide (16e20) (0.052 mol) in
dichloromethane (150 ml) was cooled to ꢁ72 ꢀC and under
N2 atmosphere boron tribromide (0.097 mol) in dichlorome-
thane (140 ml) was added drop wise. The mixture was then
spontaneously heated to the ambient temperature and poured
in ice (200 g). Water layer was washed by dichloromethane
(50 ml) and combined organic layers were washed with 5%
potassium carbonate (30 ml) and water (3ꢃ 20 ml), dried
with magnesium sulfate and evaporated. The crude arylamides
formed were recrystallized from appropriate solvents or were
purified by column chromatography on silica gel.
5.38 (bs, 1H, NH), 6.83 (m, 2H), 7.05 (m, 4H), 7.22 (m, 3H).
4.1.3. 2-(4-Methoxyphenyl)-N-methyl-N-phenethylacetamide
17
Yellowish oil (36.5 g, 83%). Anal Calcd. for C18H21NO2
(283.4): C, 76.29; H, 7.47; N, 4.94; Found: C, 76.14; H,
7.50; N, 4.91%. 1H NMR (CDCl3) d: 2.69 (t, J ¼ 7.3 Hz,
1H), 2.82 (s, 1.5H, NCH3), 2.83 (t, J ¼ 7.3 Hz, 1H), 2.95 (s,
1.5H, NCH3), 3.37 (s, 1H), 3.46 (t, J ¼ 7.3 Hz, 1H), 3.51 (t,

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R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
4.1.8. 2-(4-Hydroxyphenyl)-N-phenethylacetamide 21
White crystals from 80% EtOH (6.5 g, 49%). Anal Calcd.
for C16H17NO2 (255.3): C, 75.27; H, 6.71; N, 5.49; Found:
The solution was filtered and evaporated. The crude 30ae
31b were purified by crystallization from n-hexane.
1
C, 75.13; H, 6.75; N, 5.47%. H NMR (CDCl3) d: 2.72 (t,
4.1.14. Methyl 4-(3-bromopropoxy)phenyl acetate 30a
White crystals (20.7 g, 72%); m.p. 34e36 ꢀC (n-hexane).
Anal Calcd. for C12H15BrO3 (287.2): C, 50.19; H, 5.27; Br,
27.83; Found: C, 49.98; H, 5.21; Br, 27.71%. 1H NMR
(CDCl3) d: 2.23 (m, 2H), 3.47 (t, J ¼ 6.3 Hz, 2H), 3.52 (s,
2H), 3.63 (s, 3H, OCH3), 4.02 (t, J ¼ 5.9 Hz, 2H), 6.83 (m,
2H), 7.15 (m, 2H).
J ¼ 6.7 Hz, 2H), 3.46 (m, 4H), 5.56 (bs, 1H), 6.77e6.79 (m,
2H), 6.97e6.99 (m, 2H), 7.00e7.02 (m, 2H), 7.15e7.29 (m,
3H).
4.1.9. 2-(-4-Hydroxyphenyl)-N-methyl-N-phenethylacetamide
22
White crystals (9.2 g, 66%); m.p. 138e141 ꢀC (toluene).
Anal Calcd. for C17H19NO2 (269.3): C, 75.81; H, 7.11; N,
5.20; Found: C, 75.74; H, 7.13; N, 5.18%. 1H NMR
(CDCl3) d: 2.73 (t, J ¼ 7.4 Hz, 1H), 2.81 (t, J ¼ 7.2 Hz, 1H),
2.88 (s, 1.5H, NCH3), 3.00 (s, 1.5H, NCH3), 3.34 (s, 1H),
3.51 (t, J ¼ 7.3 Hz, 1H), 3.57 (s, 1H), 3.59 (t, J ¼ 7.3 Hz,
1H), 6.68 (m, 2H), 6.90 (d, J ¼ 10.5, 10.5 Hz, 1H), 6.99 (dd,
J ¼ 10.5, 10.5, 1H), 7.10e7.32 (m, 5H).
4.1.15. Methyl [4-(4-bromobutoxy)phenyl]acetate 30b
White crystals (21.7 g, 72%); m.p. 28e31 ꢀC (n-hexane).
Anal Calcd. for C13H17BrO3 (301.2): C, 51.84; H, 5.69; Br,
26.53; Found: C, 51.67; H, 5.61; Br, 26.25%. 1H NMR
(CDCl3) d: 1.80e2.05 (m, 4H), 3.41 (t, J ¼ 6.4 Hz, 2H),
3.51 (s, 2H), 3.62 (s, 3H, OCH3), 3.90 (t, J ¼ 6.0 Hz, 2H),
6.80 (m, 2H), 7.14 (m, 2H).
4.1.10. 2-(4-Hydroxyphenyl)-N-methyl-N-(3-methylphenethyl)-
acetamide 23
4.1.16. Methyl [4-(3-bromopropoxy)-3-methoxyphenyl]acetate
31a
Yellowish oil (15.6 g, 95%). Anal Calcd. for C18H21NO2
(283.4): C, 76.29; H, 7.47; N, 4.94; Found: C, 76.11; H,
7.48; N, 4.92%. 1H NMR (CDCl3) d: 2.30 (s, 3H, CH3),
2.69 (t, J ¼ 7.6 Hz, 1H), 2.80 (t, J ¼ 7.5 Hz, 1H), 2.85 (s,
1.5H, NCH3), 2.93 (s, 1.5H, NCH3), 3.42 (s, 1H), 3.49 (t,
J ¼ 7.5 Hz, 1H), 3.60 (t, J ¼ 7.4 Hz, 1H), 3.61 (s, 1H), 6.69
(m, 2H), 6.90 (m, 3H), 7.09e7.24 (m, 3H).
White crystals (22.8 g, 72%), m.p. 35e38 ꢀC (n-hexane).
Anal Calcd. for C13H17BrO4 (317.2): C, 49.23; H, 5.40; Br,
25.19; Found: C, 49.05; H, 5.36; Br, 24.93%. 1H NMR
(CDCl3) d: 2.19 (m, 2H), 3.46 (t, J ¼ 6.2 Hz, 2H), 3.51 (s,
2H), 3.59 (s, 3H, OCH3), 3.80 (s, 3H, OCH3), 3.97 (t,
J ¼ 6.2 Hz, 2H), 6.75e6.92 (m, 3H).
4.1.17. Methyl [4-(4-bromobutoxy)-3-methoxyphenyl]acetate
31b
4.1.11. 2-(4-Hydroxyphenyl)-N-methyl-N-(4-methylphenethyl)-
acetamide 24
White crystals (23.5 g, 71%); m.p. 28e31 ꢀC (n-hexane).
Anal Calcd. for C14H19BrO4 (331.2): C, 50.77; H, 5.78; Br,
24.13; Found: C, 50.59; H, 5.71; N, 23.97%. 1H NMR
(CDCl3) d: 1.87e2.13 (m, 4H), 3.48 (t, J ¼ 6.5, 2H), 3.55 (s,
2H), 3.68 (s, 3H, OCH3), 3.84 (s, 3H, OCH3), 4.01 (t,
J ¼ 6.2 Hz, 2H), 6.74e6.85 (m, 3H).
Yellowish oil (11.8 g, 72%). Anal Calcd. for C18H21NO2
(283.4): C, 76.29; H, 7.47; N, 4.94; Found: C, 76.10; H,
7.50; N, 4.91%. 1H NMR (CDCl3) d: 2.30 (s, 3H, CH3),
2.70 (t, J ¼ 7.3 Hz, 1H), 2.79 (t, J ¼ 7.4 Hz, 1H), 2.82 (s,
1.5H, NCH3), 2.93 (s, 1.5H, NCH3), 3.38 (s, 1H), 3.43 (t,
J ¼ 7.4 Hz, 1H), 3.51 (t, J ¼ 7.3 Hz, 1H), 3.61 (s, 1H), 6.73
(m, 2H), 6.82 (m, 2H), 6.95e7.14 (m, 4H).
4.1.18. Synthesis of arylacetic acids 1be8b
To a mixture of 21e25 (0.010 mol), potassium carbonate
(3.5 g), and potassium iodide (0.12 g) in butan-2-one
(40 ml), 30e31 (0.011 mol) were added. The mixture was
refluxed for 18 h and then filtered and evaporated. The crude
esters 32e39 were purified either by crystallization or by col-
umn chromatography on silica gel. Their purity was evaluated
4.1.12. N-(4-Bromophenethyl)-2-(4-hydroxyphenyl)-N-
methylacetamide 25
Colourless glassy oil (15.6 g, 77%). Anal Calcd. for
C17H18BrNO2 (348.2): C, 58.63; H, 5.21; Br, 22.95; N, 4.02;
Found: C, 58.42; H, 5.17; Br, 22.78; N, 4.00%. 1H NMR
(CDCl3) d: 2.68 (t, J ¼ 7.1 Hz, 1H), 2.78 (t, J ¼ 7.3 Hz, 1H),
2.88 (s, 1.5H, NCH3), 2.97 (s, 1.5H, NCH3), 3.40 (s, 1H),
3.41 (t, J ¼ 7.3 Hz, 1H), 3.49 (t, J ¼ 7.4 Hz, 1H), 3.61 (s,
1H), 6.71 (m, 2H), 6.84e7.04 (m, 4H), 7.38 (m, 2H).
1
by HPLC and structure confirmed by H NMR spectra.
To a mixture of esters 32e39 (0.005 mol) in 20 ml of tetra-
hydrofuranewater 4:1, 1.80 g of lithium hydroxide was added.
The mixture was stirred at ambient temperature overnight.
After evaporation of tetrahydrofuran, the crude product was
dissolved in water (50 ml) and acidified with acetic acid
and filtered. The crude acids were purified by crystallization
from appropriate solvents.
4.1.13. Synthesis of methyl [4-(u-bromoalkoxy)phenyl]
acetates 30ae31b
To a solution of appropriate methyl 4-hydroxyaryl acetate
28, 29 (0.1 mol; prepared by esterification [23]) in butan-2-
one (300 ml), potassium carbonate (55.0 g) and u,u0-dibro-
moalkane (0.4 mol) were added. The mixture was refluxed
and the reaction was stopped after the starting compound dis-
appeared (TLC, chloroformebenzeneeacetic acid 60:40:5).
4.1.19. 2-[4-(4-{4-[Phenethylcarbamoyl)-
methyl]phenoxy}butoxy)phenyl]acetic acid 1b
Hydrolysis of 32b [yellowish crystals (3.3 g, 63%); m.p.
124e125 ꢀC (EtOH)] afforded acid 1b as white precipitate

R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1091
(2.3 g, 92%); m.p. 159e161 ꢀC (CHCl3). Anal Calcd. for
C28H31NO5 (461.6): C, 72.86; H, 6.77; N, 3.03; Found: C,
4.1.23. 3-Methoxy-2-[4-(3-{4-[(N-methyl-N-phenethylcarba-
moyl)methyl]phenoxy}propoxy) phenyl]acetic acid 4a
1
73.05; H, 6.92; N, 3.29%. H NMR (DMSO-d6) d: 1.87 (m,
Hydrolysis of 35a [yellowish oil (3.0 g, 59%)] afforded
pure acid 4a as white crystals (1.7 g, 69%); m.p. 122e
123 ꢀC (i-PrOH). Anal Calcd. for C29H33NO6 (491.6): C,
70.86; H, 6.77; N, 2.85; Found: C, 70.58; H, 6.90; N,
2.81%. 1H NMR (CDCl3) d: 2.21 (m, 2H), 2.72 (t,
J ¼ 7.4 Hz, 1H), 2.78 (t, J ¼ 7.4 Hz, 1H), 2.81 (s, 1.5H,
NCH3), 2.94 (s, 1.5H, NCH3), 3.40 (s, 1H), 3.50 (t,
J ¼ 7.3 Hz, 1H), 3.56 (t, J ¼ 7.4 Hz, 1H), 3.56 (s, 2H), 3.58
(s, 1H), 3.78 (s, 3H, OCH3), 4.15e4.16 (m, 4H), 6.78e6.79
(m, 5H), 6.91e7.34 (m, 7H). 13C NMR (CDCl3) d: 29.54,
33.84, 34.97, 39.82, 41.04, 50.47, 56.20, 64.76, 66.05,
113.87, 115.02, 121.88, 126.56, 127.02, 127.32, 128.72,
129.01, 129.05, 129.11, 129.96, 139.23, 147.79, 149.75,
158.00, 172.02, 172.15, 176.32.
4H), 2.75 (t, J ¼ 7.1 Hz, 2H), 3.17 (t, J ¼ 7.0 Hz, 2H), 3.27
(m, 2H), 3.34 (s, 2H), 4.03 (m, 4H), 6.80e6.81 (m, 4H),
7.11e7.26 (m, 9H), 7.46 (s, 1H). 13C NMR (CDCl3) d: 26.0,
29.12, 33.23, 35.52, 38.41, 48.01, 50.78, 68.15, 114.78,
114.86, 115.07, 126.16, 126.41, 127.33, 127.81, 127.84,
128.44, 128.77, 130.22, 130.38, 139.89, 156.32, 157.87,
160.84, 170.66.
4.1.20. 3-Methoxy-2-[4-(4-{4-[(phenethylcarbamoyl)methyl]-
phenoxy}butoxy)phenyl]acetic acid 2b
Hydrolysis of 33b [yellowish crystals (3.3 g, 66%); m.p. 98e
102 ꢀC (4-methylpentan-2-one)] afforded pure acid 2b as white
crystals (2.1 g, 85%); m.p. 148e150 ꢀC (EtOH). Anal Calcd. for
C29H33NO6 (491.6): C, 70.86; H, 6.77; N, 2.85; Found:C, 71.05;
H, 6.62; N, 2.99%. 1H NMR (DMSO-d6) d: 1.86 (m, 4H), 2.72 (t,
J ¼ 7.2 Hz, 2H), 3.22 (t, J ¼ 7.3 Hz, 2H), 3.27 (s, 2H), 3.47 (s,
2H), 3.75 (s, 3H, OCH3), 4.02e4.03 (m, 4H), 6.80e6.81 (m,
5H), 7.11e7.29 (m, 7H), 7.60 (s, 1H). 13C NMR (CDCl3) d:
26.13, 26.33, 29.97, 35.66, 41.00, 41.23, 43.05, 56.23, 67.88,
68.96, 113.42, 113.51, 115.30, 121.89, 126.71, 127.00,
128.85, 128.98, 130.81, 138.87, 147.88, 149.73, 158.61,
172.30, 176.75.
4.1.24. 3-Methoxy-2-[4-(4-{4-[(N-methyl-N-phenethylcarba-
moyl)methyl]phenoxy}butoxy)phenyl] acetic acid 4b
Hydrolysis of 35b [yellowish oil (3.7 g, 71%)] afforded
pure acid 4b as white crystals (2.2 g, 86%); m.p. 143e
144 ꢀC (i-PrOH). Anal Calcd. for C30H35NO6 (505.6): C,
71.27; H, 6.98; N, 2.74; Found: C, 70.99; H, 7.06; N,
2.76%. 1H NMR (CDCl3) d: 1.98 (m, 4H), 2.73 (t,
J ¼ 7.3 Hz, 1H), 2.84 (t, J ¼ 7.3 Hz, 1H), 2.84 (s, 1.5H,
NCH3), 2.98 (s, 1.5H, NCH3), 3.40 (s, 1H), 3.50 (t,
J ¼ 7.4 Hz, 1H), 3.56 (t, J ¼ 7.3 Hz, 1H), 3.56 (s, 2H), 3.62
(s, 1H), 3.81 (s, 3H, OCH3), 4.05e4.06 (m, 4H), 6.77e6.78
(m, 5H), 6.92e7.26 (m, 7H). 13C NMR (CDCl3) d: 28.27,
28.44, 31.25, 34.29, 35.43, 44.89, 46.71, 50.62, 62.22,
63.62, 107.74, 107.89, 109.40, 116.26, 121.13, 121.64,
123.13, 123.43, 123.46, 123.53, 124.37, 132.80, 133.68,
144.12, 152.52, 156.30, 166.52, 176.58.
4.1.21. 2-[4-(3-{4-[(N-Methyl-N-phenethylcarbamoyl)]methyl]-
phenoxy}propoxy)phenyl]acetic acid 3a
Hydrolysis of 34a [yellowish oil (2.4 g, 51%)] afforded pure
acid 3a as white crystals (2.1 g, 92%); m.p. 78e83 ꢀC (aqueous
EtOH). Anal Calcd. for C28H31NO5 (461.6): C, 72.86; H, 6.76;
N, 3.03; Found: C, 72.60; H, 6.89; N, 2.88%. 1H NMR (CDCl3)
d: 2.21 (m, 2H), 2.72 (t, J ¼ 7.2 Hz, 1H), 2.82 (t, J ¼ 7.3 Hz,
1H), 2.83 (s, 1.5H, NCH3), 2.96 (s, 1.5H, NCH3), 3.39 (s, 1H),
3.49 (t, J ¼ 7.4 Hz, 1H), 3.56 (t, J ¼ 7.4 Hz, 1H), 3.58 (s, 2H),
3.61 (s, 1H), 4.12e4.13 (m, 4H), 6.83e6.84 (m, 4H), 6.98e
7.36 (m, 9H). 13C NMR (DMSO-d6) d: 29.14, 33.38, 34.39,
36.08, 49.20, 51.54, 64.65, 114.71, 126.51, 126.76, 127.49,
128.11, 128.39, 128.73, 128.86, 129.12, 129.38, 130.40,
130.45, 130.81, 139.18, 139.63, 157.49, 157.72, 170.71, 173.39.
4.1.25. 2-{4-[4-(4-{[N-Methyl-N-(3-methylphenethyl)carba-
moyl]methyl}phenoxy)butoxy]phenyl} acetic acid 5b
Hydrolysis of 36b [yellowish oil (4.6 g, 92%)] afforded
pure acid 5b as white crystals (1.7 g, 68%); m.p. 87e90 ꢀC
(tolueneen-hexane, 1:1). Anal Calcd. for C30H35NO6
(489.6): C, 72.26; H, 7.27; N, 2.80; Found: C, 72.09; H,
1
7.40; N, 2.56%. H NMR (CDCl3): 1.95 (m, 4H), 2.29 (s,
1.5H, CH3), 2.33 (s, 1.5H, CH3), 2.68 (t, J ¼ 7.3 Hz, 1H),
2.78 (t, J ¼ 7.4 Hz, 1H), 2.85 (s, 1.5H, NCH3), 2.97 (s,
1.5H, NCH3), 3.41 (s, 1H), 3.50 (t, J ¼ 7.4 Hz, 1H), 3.55 (t,
J ¼ 7.4 Hz, 1H), 3.55 (s, 2H), 3.62 (s, 1H), 4.01e4.02 (m,
4H), 6.82e6.84 (m, 5H), 6.86e7.23 (m, 7H). 13C NMR
(CDCl3) d: 21.08, 25.75, 33.29, 33.33, 34.41, 36.21, 49.84,
51.70, 67.25, 114.22, 114.41, 125.57, 126.75, 127.07,
127.17, 128.09, 128.38, 129.34, 129.56, 130.11, 137.65,
137.93, 138.75, 157.53, 157.62, 170.91, 171.06, 183.56.
4.1.22. 2-[4-(4-{4-[(N-Methyl-N-phenethylcarbamoyl)methyl]-
phenoxy}butoxy)phenyl]acetic acid 3b
Hydrolysis of 34b [yellowish oil 2.6 g, 54%)] afforded pure
3b as white crystals (1.3 g, 53%); m.p. 92e95 ꢀC (aqueous
EtOH). Anal Calcd. for C29H33NO5 (475.6): C, 73.24; H,
1
7.00; N, 2.94; Found: C, 73.56; H, 7.25; N, 2.72%. H NMR
(CDCl3) d: 1.95 (m, 4H), 2.73 (t, J ¼ 7.1 Hz, 1H), 2.83 (t,
J ¼ 7.3 Hz, 1H), 2.86 (s, 1.5H, NCH3), 2.97 (s, 1.5H,
NCH3), 3.40 (s, 1H), 3.50 (t, J ¼ 7.3 Hz, 1H), 3.53 (t,
J ¼ 7.4 Hz, 1H), 3.56 (s, 2H), 3.62 (s, 1H), 4.01e4.02 (m,
4H), 6.81e6.82 (m, 4H), 6.99e7.35 (m, 9H). 13C NMR
(CDCl3) d: 26.27, 33.87, 34.05, 35.00, 36.85, 39.87, 40.58,
50.50, 52.31, 67.77, 114.90, 115.01, 126.13, 126.57, 127.06,
127.33, 128.74, 129.06, 129.14, 130.03, 130.67, 138.42,
139.29, 158.13, 158.43, 172.13, 176.78.
4.1.26. 2-{4-[4-(4-{[N-Methyl-N-(4-methylphenethyl)carba-
moyl]methyl}phenoxy)butoxy]phenyl} acetic acid 6b
Hydrolysis of 37b [yellowish oil (2.4 g, 48%)] afforded pure
acid 6b as white crystals (1.31 g, 54%); m.p. 98e102 ꢀC (aque-
ous acetic acid). Anal Calcd. for C30H35NO6.2H2O (539.7): C,
68.99; H, 7.66; N, 2.60; Found: C, 69.07; H, 7.78; N, 2.67%. 1H

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R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
NMR (CDCl3) d: 1.95 (m, 4H), 2.29e2.30 (m, 3H, CH3), 2.65
(t, J ¼ 7.6 Hz, 1H), 2.74 (t, J ¼ 7.4 Hz, 1H), 2.84 (s, 1.5H,
NCH3), 2.95 (s, 1.5H, NCH3), 3.43 (s, 1H), 3.43 (t,
J ¼ 7.4 Hz, 1H), 3.48 (t, J ¼ 7.4 Hz, 1H), 3.56 (s, 2H), 3.60
(s, 1H), 4.02e4.03 (m, 4H), 6.83e6.84 (m, 4H), 6.95e7.42
(m, 8H). 13C NMR (CDCl3) d: 21.30, 26.32, 33.34, 33.96,
34.56, 36.77, 50.49, 52.37, 67.72, 114.75, 114.96, 127.13,
127.44, 128.92, 129.01, 129.42, 129.73, 130.04, 130.60,
135.32, 135.99, 136.19, 136.61, 158.11, 158.17, 171.94,
177.79.
(s, 1H), 3.81 (s, 3H, OCH3), 4.05e4.06 (m, 4H), 6.78e6.79
(m, 5H), 6.89e7.08 (m, 4H), 7.36e7.37 (m, 2H). 13C NMR
(CDCl3) d: 26.02, 26.09, 33.18, 34.44, 34.93, 36.84, 49.47,
51.72, 67.93, 108.61, 108.98, 109.85, 116.37, 121.33,
121.75, 123.32, 123.74, 123.85, 123.89, 124.52, 132.32,
133.59, 144.42, 152.74, 156.41, 166.77, 176.37.
4.1.30. Synthesis of 2-[4-(u-bromoalkoxy)phenyl]-N-methyl-
N-phenethyl acetamides 26a, 26b
A mixture of 22 (56.0 g, 0.208 mol), potassium carbonate
(145.9 g), 18-crown-6 (2.7 g) and appropriate dibromoalkane
(1.04 mol) in butan-2-one (1000 ml) was refluxed. The reac-
tion was stopped when the starting compound disappeared
(TLC, chloroformebenzeneeacetic acid 60:40:5), and was
then cooled and filtered. The solution was evaporated and
the crude product was purified by chromatography on silica
gel using dichloromethaneeethyl acetate as eluent.
4.1.27. 2-{4-[4-(4-{[N-(4-Bromophenethyl)-N-methylcarba-
moyl]methyl}phenoxy)butoxy]phenyl acetic acid 7b
Hydrolysis of 38b [yellowish oil (3.6 g, 64%)] afforded
pure acid 7b as white crystals (2.0 g, 73%); m.p. 98e102 ꢀC
(EtOH). Anal Calcd. for C29H32BrNO5 (554.5): C, 62.82; H,
5.82; Br, 14.41; N, 2.53; Found: C, 62.58; H, 5.70; Br,
1
14.14; N, 2.49%. H NMR (CDCl3) d: 1.95 (m, 4H), 2.66 (t,
J ¼ 7.7 Hz, 1H), 2.78 (t, J ¼ 7.5 Hz, 1H), 2.84 (s, 1.5H,
NCH3), 2.95 (s, 1.5H, NCH3), 3.43 (s, 1H), 3.44 (t,
J ¼ 7.5 Hz, 1H), 3.48 (t, J ¼ 7.5 Hz, 1H), 3.56 (s, 2H), 3.60
(s, 1H), 4.02e4.03 (m, 4H), 6.83e6.84 (m, 4H), 6.91e7.18
(m, 6H), 7.37e7.38 (m, 2H). 13C NMR (CDCl3) d: 26.29,
33.25, 34.04, 34.43, 36.82, 50.01, 51.99, 67.81, 114.92,
115.03, 126.09, 126.88, 127.18, 128.75, 129.06, 129.15,
130.02, 130.67, 130.77, 130.92, 131.80, 132.16, 137.36,
138.20, 158.15, 158.45, 172.05, 176.74.
4.1.31. 2-[4-(3-Bromopropoxy)phenyl]-N-methyl-N-phenethyl
acetamide 26a
Yellowish oil (67.4 g, 83%). Anal Calcd. for C19H22BrNO2
(376.3): C, 60.65; H, 5.89; Br, 21.23; N, 3.72; Found: C,
1
60.48; H, 5.84; Br, 20.99; N, 3.71%. H NMR (CDCl3) d:
2.10 (m, 2H), 2.74 (t, J ¼ 7.4 Hz, 1H), 2.85 (t, J ¼ 7.4 Hz,
1H), 2.97 (s, 1.5H, NCH3), 3.39 (s, 1.5H, NCH3), 3.39 (s,
1H), 3.51 (t, J ¼ 7.3 Hz, 1H), 3.58 (t, J ¼ 7.4 Hz, 1H),
3.58e3.59 (m, 2H), 3.60 (s, 1H), 4.08 (m, 2H), 6.85e6.86
(m, 2H), 7.06e7.23 (m, 7H).
4.1.28. 3-Methoxy-2-{4-[3-(4-{[N-(4-bromophenethyl)-N-
methylcarbamoyl]methyl}phenoxy) propoxy]phenyl} acetic
acid 8a
4.1.32. 2-[4-(4-Bromobutoxy)phenyl]-N-methyl-N-phenethyl
acetamide 26b
Hydrolysis of 39a [yellowish oil (3.7 g, 63%) afforded pure
acid 8a as white crystals (2.9 g, 78%); m.p. 118e122 ꢀC (tol-
uene). Anal Calcd. for C29H32BrNO6 (570.5): C, 61.06; H,
5.65; Br, 14.01; N, 2.46; Found: C, 61.31; H, 5.69; Br,
Yellowish oil (69.0 g, 85%). Anal Calcd. for C20H24BrNO2
(390.3): C, 61.54; H, 6.20; Br, 20.47; N, 3.59; Found: C,
1
61.33; H, 6.17; Br, 20.19; N, 3.56%. H NMR (CDCl3) d:
1.90 (m, 2H), 2.00 (m, 2H), 2.69 (t, J ¼ 7.3 Hz, 1H), 2.78 (t,
J ¼ 7.4 Hz, 1H), 2.85 (s, 1.5H, NCH3), 2.97 (s, 1.5H,
NCH3), 3.38 (s, 1H), 3.47 (m, 2H), 3.49 (t, J ¼ 7.2, 1H),
3.59 (t, J ¼ 7.4 Hz, 1H), 3.60 (s, 1H), 3.98 (m, 2H), 6.82e
6.83 (m, 2H), 7.06e7.23 (m, 7H).
1
13.99; N, 2.46%. H NMR (CDCl3) d: 2.25 (m, 2H), 2.65 (t,
J ¼ 7.3 Hz, 1H), 2.77 (t, J ¼ 7.4 Hz, 1H), 2.83 (s, 1.5H,
NCH3), 2.96 (s, 1.5H, NCH3), 3.42 (s, 1H), 3.44 (t,
J ¼ 7.4 Hz, 1H), 3.49 (t, J ¼ 7.4 Hz, 1H), 3.56 (s, 2H), 3.60
(s, 1H), 3.82 (s, 3H, OCH3), 4.16e4.17 (m, 4H), 6.81e6.82
(m, 5H), 6.90e7.09 (m, 4H), 7.35e7.36 (m, 2H). 13C NMR
(CDCl3) d: 29.48, 33.75, 34.90, 39.36, 39.54, 49.82, 50.68,
52.24, 67.60, 114.19, 114.97, 121.36, 126.71, 127.35,
127.39, 128.63, 129.09, 130.05, 130.39, 131.67, 139.54,
145.90, 150.31, 156.47, 170.79, 176.33.
4.1.33. Synthesis of arylacetic acids 9a, 9b
To a mixture of 26 (0.0064 mol), potassium carbonate
(4.5 g), and potassium iodide (0.8 g) in butan-2-one (30 ml),
27 (1.2 g, 0.064 mol) was added. The mixture was refluxed
for 15 h and then filtered and evaporated. The crude esters
were purified by column chromatography on silica gel. The
purity of intermediate esters was evaluated by HPLC, and their
4.1.29. 3-Methoxy-2-{4-[4-(4-{[N-(4-bromophenethyl)-N-
methylcarbamoyl]methyl}phenoxy)butoxy]phenyl}acetic
acid 8b
1
structure confirmed by H NMR and 13C NMR spectra.
To a solution of ester 40 (0.005 mol) in 15 ml of MeOH,
20 ml of aqueous 0.5 M sodium hydroxide was added and
the mixture was stirred at ambient temperature for 13 h. After
evaporation of methanol, the crude product was dissolved in
water (50 ml) and acidified with 15 ml of 2 M acetic acid. Wa-
ter solution was washed with ethyl acetate (3 ꢃ 40 ml) and the
organic layer once with brine, dried with anhydrous sodium
sulfate and evaporated to dryness. The crude acids were puri-
fied by crystallization from appropriate solvents.
Hydrolysis of 39b [yellowish oil (4.4 g, 74%) afforded pure
acid 8b as white crystals (1.6 g, 54%); m.p. 143e144 ꢀC
(EtOH). Anal Calcd. for C30H34BrNO6 (584.5): C, 61.65; H,
5.86; Br, 13.67; N, 2.40; Found: C, 61.37; H, 5.54; Br,
1
13.76; N, 2.43%. H NMR (CDCl3) d: 1.98 (m, 4H), 2.65 (t,
J ¼ 7.3 Hz, 1H), 2.75 (t, J ¼ 7.4 Hz, 1H), 2.84 (s, 1.5H,
NCH3), 2.98 (s, 1.5H, NCH3), 3.40 (s, 1H), 3.41 (t,
J ¼ 7.4 Hz, 1H), 3.52 (t, J ¼ 7.3 Hz, 1H), 3.56 (s, 2H), 3.62

R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
1093
4.1.34. 3-Chloro-2-[4-(3-{4-
[(N-methyl-N-phenethylcarbamoyl)methyl]-
phenoxy}propoxy)phenyl] acetic acid 9a
The coefficients in the regression equations were calculated
from experimental results by multiple regression analysis and
their statistical significance was tested with the Student’s t-
test. Statistical significance of regression equations was tested
by standard deviations (s), coefficients of multiple correlations
(r) and the FishereSnedecor criterion (F ). The statistical sig-
nificance level p was better than 0.005 for both the whole
equations and individual variables with the exceptions men-
tioned in the text.
Hydrolysis of 40a [yellowish crystals (3.0 g, 92%); m.p.
68e71 ꢀC (ethyl acetate)] afforded pure acid 9a as white crys-
tals (2.0 g, 82%), m.p. 116e117 ꢀC (acetoneediethyl ether).
Anal Calcd. for C28H30ClNO5 (495.6): C, 67.80; H, 6.10; N,
2.82; Found: C, 67.78; H, 6.26; N, 2.73%. 1H NMR
(CDCl3) d: 2.24 (m, 2H), 2.73 (t, J ¼ 7.4 Hz, 1H), 2.83 (t,
J ¼ 7.2 Hz, 1H), 2.84 (s, 1.5H, NCH3), 2.98 (s, 1.5H,
NCH3), 3.39 (s, 1H), 3.50 (t, J ¼ 7.4 Hz, 1H), 3.51 (m, 2H),
3.60 (t, J ¼ 7.3 Hz, 1H), 3.61 (s, 1H), 4.21e4.23 (m, 4H),
6.79e6.80 (m, 3H), 6.96e7.09 (m, 4H), 7.14e7.30 (m, 5H).
13C NMR (CDCl3) d: 29.52, 33.85, 34.98, 39.79, 40.27,
50.51, 52.33, 65.93, 113.87, 115.04, 123.20, 126.60, 127.09,
127.38, 127.43, 128.75, 129.04, 129.14, 130.03, 131.39,
138.37, 139.23, 153.80, 157.94, 172.15, 175.64.
4.4. Biological evaluation
The production of LTB4 was determined in rat polymorpho-
nuclear cells from the pleural exudate elicited by heat-inacti-
vated rat serum [27,28]. The cells were stimulated with
Ca2þ ionophore A23187 (Sigma) and incubated with various
concentrations of the tested compounds. LTB4 was determined
using a commercial RIA kit (Amersham). The in vitro activity
was expressed in concentration IC50 (mM) causing 50% inhibi-
tion of LTB4 biosynthesis and calculated by linear regression.
For the LTB4 receptor binding studies, a slightly modified
method of Cheng et al. [29] was used. The membrane fraction
was prepared from male guinea pig spleen; 2 mg of the mem-
4.1.35. 3-Chloro-2-[4-(4-{4-[(N-methyl-N-phenethylcarba-
moyl)methyl]phenoxy}butoxy)phenyl] acetic acid 9b
Hydrolysis of 40b [yellowish crystals (2.8 g, 84%), m.p.
50e52 ꢀC (acetone)] afforded pure acid 9b as white crystals
(1.3 g, 52%), m.p. 90e93 ꢀC (ethyl acetate). Anal Calcd. for
C29H32ClNO5 (510.0): C, 68.29; H, 6.32; N, 2.75; Found: C,
68.07; H, 6.24; N, 2.69%. 1H NMR (CDCl3) d: 1.99 (m,
4H), 2.75 (t, J ¼ 7.4 Hz, 1H), 2.82 (t, J ¼ 7.3 Hz, 1H), 2.83
(s, 1.5H, NCH3), 2.95 (s, 1.5H, NCH3), 3.38 (s, 1H), 3.52
(m, 2H), 3.52 (t, J ¼ 7.3 Hz, 1H), 3.59 (t, J ¼ 7.6 Hz, 1H),
3.60 (s, 1H), 4.05 (m, 4H); 6.78e6.79 (m, 3H), 6.98e7.08
(m, 4H), 7.11e7.30 (m, 5H). 13C NMR (CDCl3) d: 26.25,
26.37, 33.84, 34.86, 36.54, 40.70, 49.74, 51.92, 67.99,
114.49, 115.14, 121.83, 126.96, 127.23, 128.39, 129.18,
129.31, 129.83, 130.05, 130.81, 131.58, 139.64, 140.09,
153.43, 158.07, 171.21, 173.69.
3
branes was incubated with 0.3 nM H-LTB4 in 100 ml of the
incubating mixture at 25 ꢀC for 30 min. Non-specific binding
was determined in the presence of 0.1 mM of LTB4. The mem-
branes were filtered through Whatman GF/C paper and
washed with buffer three times. The radioactivity was mea-
sured by liquid scintillation spectrometry and the specific
binding of 3H-LTB4 to the receptor was determined. The bind-
ing activity was expressed in concentration IC50 (mM), calcu-
lated by linear regression, causing 50% inhibition of LTB4
binding to receptor. Six points at different concentrations
were used for the calculation of C in both in vitro activities.
All tests, including controls, were performed in duplicate
with internal difference not higher than 10% and experimental
data were analysed by program GraphPad Prism (U.S.A.).
Inhibition of carrageenan oedema was evaluated by the
method of Winter [30]; the experimental conditions are de-
scribed elsewhere [31]. The values of oedema were deter-
mined as mean ꢂ SD not higher than 10% and expressed as
a percentage inhibition after a dose of 100 mg/kg in compari-
son with untreated control. Arachidonic-acid-induced ear in-
flammation in mice was performed by the method of Opas
[32], the ear pinna inflammation was induced by application
of 20 ml of arachidonic acid solution in acetone (concentration
100 mg/ml). The compound was given orally (200 mg/kg) 1 h
before oedema induction. The degree of ear hyperaemia and
the weight of ear, evaluated 1 h after application of arachi-
donic acid, were determined as mean ꢂ SD not higher than
10% and expressed as a percentage inhibition relative to un-
treated control. Ulcerative colitis in mice [33] was induced 7
days after the last dose of compound by the repeating addition
of 3% dextran sodium sulfate (MW 40 000; ICN cat.
No.160110) into drinking water for 7 days (days 21e28) to
BALB/c mice of 250 g average weight. The compound was
given in three doses of 250 mg/1 kg in 0.5% aqueous solution
4.2. Evaluation of lipophilicity
The values of log P were calculated using the KOWWIN
program, version 1.63 (Syracuse Research Corp., U.S.A.).
Evaluation of lipophilicity by the HPLC method [16].
Experiments were carried out using a liquid chromatograph
with an LCP 4100 pump (Ecom, Prague, Czech Republic), au-
tosampler Waters 717 plus, UV detector Waters 486 (Waters
Assoc., Milford, MA, U.S.A.) and data module CSW
(DataApex, CR). Thermoquest Hypersil ODS 5 mm (Thermo
Hypersil-Keystone, Asmoor Runcorn, GB) in a 250 ꢃ 4.6 mm
I.D. column was used as a stationary phase and the mixture of
acetonitrile and pH 5.75 buffer (1:1) was used as a mobile phase.
Detection was performed by UV absorption at 233 nm. The
retention time of sodium nitrate (0.02% solution) was taken as
a t0 and the capacity factor k was evaluated from the retention
time of the solute, tR, by the relationship: k ¼ (tR ꢁ t0)/t0.
4.3. Quantitative structureeactivity analysis
The regression equations were calculated using Stat-
graphics Program, U.S. Version 4 (STSC Inc. U.S.A.).

1094
R. Junek et al. / European Journal of Medicinal Chemistry 42 (2007) 1084e1094
[12] F.C. Huang, W.-K. Chan, J.D. Warus, M.M. Morrissette, K.J. Moriarty,
M.N. Chang, J.J. Travis, L.S. Mitchell, G.W. Nuss, C.A. Sutherland,
J. Med. Chem. 35 (1992) 4253e4255.
of (carboxymethyl)cellulose in weekly intervals (days 0, 7 and
14). Colitis was evaluated clinically (loss of weight, rectal pro-
laps, blood in stool, stool consistency), pathologically (colonic
bleeding, length of colon) as the ratio of diseased and total
number of animals, and histologically.
[13] L.J. Askonas, J.F. Kachur, D. Villani-Price, C.D. Liang, M.A. Russell,
W.G. Smith, J. Pharmacol. Exp. Ther. 300 (2002) 577e582.
[14] W.-K. Chan, F.C. Huang, M.M. Morrissette, J.D. Warus, K.J. Moriarty,
R.A. Galemmo, W.P. Dankulich, G. Poli, C.A. Sutherland, J. Med.
Chem. 39 (1996) 3756e3768.
Acknowledgement
ꢀ
ˇ
´
´
´
´
[15] M. Kuchar, K. Culıkova, V. Panajotovova, B. Bru˚nova, A. Jandera,
´
ꢀ
V. Kmonıcek, Collect. Czech. Chem. Commun. 63 (1998) 103e114.
´ꢀ
The project was supported by a grant of the Ministry of
Education, Youth and Sports of the Czech Republic (No LN
00B125) and by a grant of the Czech Science Foundation
(No. 310/03/H147).
ˇ
´
[16] M. Kuchar, V. Kmonıcek, V. Panajotova, A. Jandera, B. Brunova,
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R. Junek, V. Bucharova, J. Cejka, D. Satınsky, Collect. Czech. Chem.
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Commun. 69 (2004) 2098e2120.
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Collect. Czech. Chem. Commun. 70 (2005) 1357e1371.
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