A novel series of 2,6,7-substituted 2,3-dihydro-1,4-benzodioxin and 2,6,7-substituted 1,4-benzodioxin derivatives as lipid peroxidation inhibitors. Structure-activity relationships for high inhibition of human low-density lipoprotein peroxidation

Article abstract of DOI:10.1021/jm0108045

A series of 6- or 7-substituted 2-carboxamido- or 2-(aminomethyl)-1,4-benzodioxin and -2,3- dihydro-1,4-benzodioxin derivatives were synthesized and evaluated to determine the necessary structural requirements for a high inhibition of human low-density li

Full text of DOI:10.1021/jm0108045

3904
J . Med. Chem. 2001, 44, 3904-3914
A Novel Ser ies of 2,6,7-Su bstitu ted 2,3-Dih yd r o-1,4-Ben zod ioxin a n d
2,6,7-Su bstitu ted 1,4-Ben zod ioxin Der iva tives a s Lip id P er oxid a tion In h ibitor s.
Str u ctu r e-Activity Rela tion sh ip s for High In h ibition of Hu m a n Low -Den sity
Lip op r otein P er oxid a tion
Vale´rie Thie´ry,†,‡ Ge´rard Coudert,† J ean-Guy Bizot-Espiard,§ Bruno Pfeiffer,| Pierre Renard,|
Albert Lindenbaum, and Ge´rald Guillaumet*,†
Institut de Chimie Organique et Analytique, UMR CNRS 6005, Universite´ d’Orle´ans, B.P. 6759,
F-45067 Orle´ans Cedex 2, France, Laboratoire de Ge´nie Prote´ique et Cellulaire, Universite´ de La Rochelle,
Avenue Michel Cre´peau, F-17042 La Rochelle Cedex 1, France, Service de Biochimie, Hopital Antoine Be´clere,
92141 Clamart, France, IRI Servier, 6 Place des Ple´iades, F-92415 Courbevoie Cedex, France, and ADIR,
1 rue Carle He´bert, F-92415 Courbevoie Cedex, France
Received J anuary 3, 2001
A series of 6- or 7-substituted 2-carboxamido- or 2-(aminomethyl)-1,4-benzodioxin and -2,3-
dihydro-1,4-benzodioxin derivatives were synthesized and evaluated to determine the necessary
structural requirements for a high inhibition of human low-density lipoprotein copper-induced
peroxidation. The most active compounds (21, 25, 28, 36, and 37) were found between 5 and
>45 times more active than probucol itself. Due to both their potency and their structural
features, compounds 25 and 36 were selected with others for complementary in vitro and in
vivo investigations. Both of them exhibit calcium antagonist properties in the same range of
potency as flunarizine itself. Compound 36 was also found to have significant hypolipaemic
activity in mice at 100 and 300 mg/kg po, while compound 25 proved to be clearly active in a
normobar hypoxia test.
In tr od u ction
Too many people still suffer and die worldwide from
coronary heart diseases such as atherosclerosis mainly
due to hypercholesterolemia. In recent years, the patho-
genesis of atherosclerosis lesions through oxidative
modification of native low-density lipoproteins (LDLs)
has been discussed.1-5 In many cases heart disease and
atherogenesis can be correlated with low levels of high-
density lipoproteins (HDLs) and inversely elevated
levels of LDLs. Oxidative modifications of the lipopro-
teins, and more particularly of LDLs (oxidized LDLs,
ox-LDLs), appear to be one of the earliest phenomena
F igu r e 1. Natural and synthetic antioxidants.
in the development of atherosclerosis pathology. ox-
LDLs are key components in endothelial injury.6-10
or the treatment of atherosclerosis by attenuating foam-
cell formation.11-14 A number of natural or synthetic
antioxidants (vitamin E, probucol; Figure 1) can lower
coronary heart disease risk. Like vitamin E and probu-
col a lot of potent antioxidants have a structure based
on hindered phenols or hydroxybenzopyrans.15-17 This
is the case, among others, for Trolox18 and some of its
analogues such as U-78517F19,20 as well as some hy-
droxybenzylamine antioxidants21 (Figure 2). Some of us
have shown that 5-hydroxyindole-2-carboxamide deriva-
tives22 are potent inhibitors of human LDL peroxidation
(Figure 3). 2,3-Dihydro-1,4-benzodioxin and 1,4-benzo-
dioxin ring systems are present in a large number of
structures of therapeutic agents possessing important
biological activities.23 Some of them are antagonists of
R- or â-adrenergic receptors, giving them antihyperten-
sive properties.24-30 Others have affinities for serotonin
receptors, which are involved in nervous breakdown and
schizophrenia,31-33 or represent an attractive thera-
Under pathological conditions (oxidative stress, free
radicals) ox-LDLs are no longer recognized by the LDL
receptor and are taken up in an unregulated manner
by the subendothelial macrophages with a consequent
accumulation of cholesterol esters and formation of foam
cells. Not removed from the circulation, ox-LDL en-
hances the formation of damaged lesions on membrane
lipids. Numerous available epidemiological, biochemical,
and experimental data have led to the conclusion that
antioxidant compounds able to protect lipids from
peroxidation could be of value for the prevention and/
* To whom correspondence should be addressed. Phone: 33 2 38
41 70 73. Fax: 33 2 38 41 72 81. E-mail: gerald.guillaumet@univ-
orleans.fr.
† Universite´ d’Orle´ans.
‡ Universite´ de la Rochelle.
§ IRI Servier.
| ADIR.
Hopital Antoine Be´clere.
10.1021/jm0108045 CCC: $20.00 © 2001 American Chemical Society
Published on Web 10/13/2001

Benzodioxins as Lipid Peroxidation Inhibitors
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23 3905
Sch em e 1a
a
Reagents and conditions: (a) m-CPBA, CH2Cl2, 40 °C; (b) NBS, AIBN, CCl4 reflux; (c) NaI, acetone, 20 °C.
Sch em e 2a
a
Reagents and conditions: (a) C2H5ONa, C2H5OH, room tem-
perature, 86%; (b) t-BuOH, TFA, room temperature, 84%.
substitution under typical Friedel-Crafts conditions.43,44
On the other hand, experimental and clinical studies
suggest that structurally disparate calcium channel
blockers retard the progression of atherosclerosis. Cal-
cium antagonists such as nifedipine, verapamil, and
diltiazem exert antiperoxidative activity.45-49 To coun-
teract oxidative cardiovascular disease such as the
development of atherosclerosis, our therapeutic ap-
proach suggests the use of mixed drugs.50 The required
amides were readily available via the condensation of
6- or 7-hydroxylated acids with amines possessing
features that could potentially introduce calcium an-
tagonist properties into the molecules.
F igu r e 2. Antioxidants with a structure based on hydroxy-
benzopyran moieties or hindered phenol.
F igu r e 3. 5-Hydroxyindole-2-carboxamide derivatives.
Ch em istr y
F igu r e 4. General formulas of new potent antioxidants.
The synthetic pathway to the carboxylic acids 11-17
is described by three schemes. Pathway 1 (Scheme 1)
was used to prepare the derivatives 3-6 bearing an
acetoxy group at the 6 or 7 position. The benzodioxans
3 and 4, obtained by Baeyer-Villiger oxidation51 of
suitably acylated starting materials43 1 and 2, are
converted to benzodioxins 5 and 6 in high yields via
bromination-elimination.52 Pathway 2 (Scheme 2) was
used to convert unsaturated ester 5 into hydroxylated
analogue 7 by treatment with sodium ethoxide in
ethanol. The tert-butylation of compound 7 under acid-
catalyzed conditions in trifluoroacetic acid (TFA) using
tert-butyl alcohol53 afforded the corresponding product
8 in good yield (84%). Pathway 3 (Scheme 3) leads to
the carboxylic acids 11-17. Alkaline hydrolysis of
compounds 3-6 and 8-10 at room temperature, fol-
lowed by acid workup, provided the corresponding acids
in high yields. Protected aminated carboxylic acid 16
was obtained under the same conditions from the
analogous ester previously described.44
peutic target for the treatment of glaucoma.34 Recently,
2,3-dihydro-1,4-benzodioxins have been developed as
inhibitors of 5-lipoxygenase, an enzyme involved in the
oxygenation of arachidonic acid to the leukotrienes:
they are also useful for the treatment of inflammatory
diseases such as asthma and arthritis.35 The occur-
rence of the 2,3-dihydro-1,4-benzodioxin structure in
various naturally abundant compounds has also been
reported.36-41 As the hydroxybenzodioxin or hydroxy-
dihydrobenzodioxin skeletons could be considered as
bioisosters of hydroxychromane or hydroxyindole, we
have described in this paper the synthesis and the
pharmacological evaluation of new antioxidants having
the general formulas given in Figure 4. A new series of
6- and 7-substituted 2-carboxamido- or 2-(aminomethyl)-
1,4-benzodioxin and -2,3-dihydro-1,4-benzodioxin de-
rivatives bearing at least a hydroxyl functionality have
been developed.42 The key synthetic precursors for the
carboxamides are 2,3-dihydro-1,4-benzodioxin-2-carbox-
ylic acid and 1,4-benzodioxin-2-carboxylic acid deriva-
tives bearing a hydroxyl group on C6 or C7. We
previously reported the regioselective functionalization
on the aromatic ring at C6 and C7 by electrophilic
The carboxamides listed in Table 1 were synthesized
by condensation of carboxylic acids 11-17 in N,N-
dimethylformamide (DMF) with the appropriate amines
a -e (Figure 5) in the presence of 1-[3-(dimethylamino)-
propyl]-3-ethylcarbodiimide hydrochloride (EDCI) and

3906 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23
Thie´ry et al.
Ta ble 1. 6- or 7-Substituted 2-Carboxamido- or 2-(Aminomethyl)-1,4-benzodioxins or -2,3-Dihydro-1,4-benzodioxins
compd
YsZ
R1
R2
X
NRR′
yield, %
mp, °C
empirical formula
Anal.
18
19
20
21
22
23
24
25
26
27
28
29
30a
31
32
33
34
35
36
37
CHsCH2
CHsCH2
CHsCH2
CHsCH2
CHsCH2
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
CdCH
HO
H
HO
H
H
HO
H
HO
H
H
HO
H
HO
HO
H
HO
H
HO
H
(CH3)3C
H
H
HO
H
HO
O
a
a
b
b
c
a
a
b
b
b
b
b
b
c
d
d
d
e
b
e
75
75
80
73
75
72
63
85
85
80
84
78
95
73
80
83
77
80
86
86
147
158
201
136
93
210
206
163
221
156
244
220
>240
88
124
156
226
166
190
185
C15H13NO4
C15H13NO4
C26H24N2O4F2
C26H24N2O4F2
C23H28N2O7
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
C, H, N
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
H2
H2
C
C
C
C
C
15H11NO4
15H11NO4
26H22N2O4F2
26H22N2O4F2
26H22N2O3F2
H
HO
NHBoc
NH2
H
HO
H
HO
HO
HO
HO
C30H30N2O4F2
31H31N3O5F2
C26H23N3O3F2
C
C
C
C
23H26N2O7
19H19NO4
19H19NO4
(CH3)3C
C23H27NO4
27H21NO4
H
H
H
C
CdCH
CdCH
C26H24N2O3F2
C27H23NO3F2
a
Compound 30 was obtained by acidic hydrolysis of carbamate 29.
Sch em e 3a
Sch em e 4a
a
Reagents and conditions: (a) HNRR′, EDCl, HOBt, DMF, 0
°C and then 20 °C; (b) LiAlH4, THF reflux.
aluminum hydride (LiAlH4) provided high yields of the
aminomethyl analogues 36 and 37, respectively (Scheme
4). Compound 25 was structurally modified to enhance
its antioxidant properties (Scheme 5). Compound 25 was
exhaustively methylated to compound 38 in 83% yield
by treatment with sodium hydride in DMF in the
presence of methyl iodide. The thionation of carboxa-
mide 25 using Lawesson’s reagent55 in boiling toluene
gave a low yield (12%) of the thiocarboxamide 39.
Product 25 with nicotinoyl chloride hydrochloride in
dichloroethane in the presence of pyridine gave the
corresponding nicotine derivative 40 in high yield.
a
Reagents and conditions: (a) KOH, C2H5OH, 20 °C; (b) 2 N
HCl.
Resu lts a n d Discu ssion
Twenty-two 2,3-dihydro-1,4-benzodioxin- and 1,4-ben-
zodioxin-2-carboxamide derivatives were synthesized
and evaluated. All were prescreened in vitro for their
ability to protect human LDLs against copper-induced
peroxidation.
Two tests were used for this preliminary evaluation.
The first is based on an electrophoretic method
(FPLC, fast protein liquid chromatography) that allows
the separation of five different oxidized forms of LDLs.56
Forms A and B correspond to the native forms of LDLs,
and forms C, D, and E correspond to the different states
of LDL oxidation (form E being the most oxidized). All
the compounds were tested at a 10 µM concentration
and evaluated for their ability to protect native human
LDLs from copper (Cu2+)-induced oxidation. The results
are expressed as the percentages of the LDLs corre-
sponding to the different degrees of LDL oxidation, and
F igu r e 5. Amines to be condensed.
1-hydroxybenzotriazole54 (HOBt) as shown in Scheme
4. Hydrolysis of the protected amino derivative 29
followed by a basic workup generated quantitatively the
6-aminocarboxamide 30. Subsequent reduction of the
amido group of compounds 25 and 35 with lithium

Benzodioxins as Lipid Peroxidation Inhibitors
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23 3907
Sch em e 5a
a
NRR′ ) b. Reagents and conditions: (a) NaH, CH3I, DMF, room temperature, 83%; (b) Lawesson’s reagent, toluene reflux, 12%; (c)
pyridinylacyl chloride, DCE, pyridine, reflux, 93%.
Ta ble 2. Inhibition of Copper-Induced Lipid Peroxidation by 2,3-Dihydro-1,4-benzodioxin Derivatives. Evaluation by FPLC
Methodology or MDA Dosage
FPLCa
C
MDA
IC50 (M)
compd
R1
R2
NRR′
A
B
D
E
rb
18
19
20
21
22
HO
H
HO
H
H
HO
H
HO
HO
a
a
b
b
c
-
-
-
-
-
-
-
-
-
-
-
26
-
76
68
88
59
73
24
6
12
12
21
NTc
-
NTc
-
3 × 10-6
2 × 10-7
1.7
10
3
29
6
H
1.7 × 10-6
Control without Cu2+, 100% B; control with Cu2+, 75% D, 25% E. Compounds were tested on 10 µM. Activity ratio versus probucol.
a
b
c NT ) not tested.
a protective effect is demonstrated by a displacement
of the E form toward the D form, or even toward the C
and B forms for the most powerful compounds.
The second test is based on a malondialdehyde (MDA)
dosage, and the results are expressed as IC50 (concen-
tration inhibiting 50% of the copper-induced lipid per-
oxidation) determined using the thiobarbituric acid
reactive substance (TBARS) and expressed as an MDA
equivalent.57 To correct slight variations in response
between the same evaluation procedures not performed
with the same batch of human LDLs, results were also
expressed as an activity ratio versus probucol (r).
Results of these preliminary evaluations are reported
in Tables 2 and 3.
In the first step we prepared anilide derivatives and
investigated the influence of the hydroxyl group position
with regard to the amide bond. Evaluation of compounds
18, 19, 23, and 24 with the electrophoretic (FPLC)
method showed that, in both benzodioxan and benzo-
dioxin series, the best results were obtained for the
7-hydroxy-substituted compounds with a significant
proportion of LDLs in the C form, especially for com-
pounds 24 and 19 with around 20% of the LDLs in the
C form.
In the second step we substituted the heterocycles
with a “flunarizine-like” (fluorobenzhydryl)piperazine
moiety to provide them with some calcium antagonist
activity and consequently with additional cytoprotective
potentialities.21 These compounds were evaluated ac-
cording to both FPLC and MDA methodologies.56,57
Surprisingly, the structure-activity relationships con-
cerning the 6- or 7-hydroxy-substituted compounds
differ between the two series, 6-hydroxy-2-substituted
benzodioxin 25 (r > 45) being more active in both tests
than its 7-hydroxy-substituted counterpart 26 (r ) 2.9),
while in the benzodioxan series the best results are
obtained in both tests with the 7-hydroxy-substituted
21 (r ) 10). Compound 25 appeared to be a remarkably
potent antioxidant compound with 95% B form observed
in the FPLC test and a IC50 of 1 × 10-7 M in the MDA
test (at least 45 times more potent than probucol itself).
It is worth noting that carboxamide 25 is clearly more
active than its benzodioxan analogue 20 (r ) 1.7), which
is only as active as probucol in the MDA test (the
7-hydroxy-substituted benzodioxane 21 being 10 times
more active than probucol in the same test). The
unsubstituted benzodioxane 27 appeared clearly less
active in the FPLC test with 55% D form. As it appeared
difficult to discriminate between the compounds with
the FPLC method, all further compounds were exclu-
sively evaluated with the MDA procedure. To determine
structure-activity relationships, some chemical modu-
lations were then performed with the very active
compound 25 as the starting point by (1) introduction
of a tert-butyl group on the aromatic ring, (2) modifica-
tion of the hydroxyl group by substitution with func-
tionalities exerting temporary interruption of cholesterol
biosynthesis activities, (3) replacement of the hydroxyl
group by an isostere amino group, (4) replacement of
the NsCdO bond by a theoretically more metabolically
labile NsCH2, and (5) conversion of the NsCdO group
to a NsCdS group.
Replacement of the hydroxyl function by a methoxy
group, 38 (r < 0.005), or an amine group, 30 (r ) 0.1),
proved to be deleterious for the activity. Introduction
of a tert-butyl group in the C-7 position, 28 (r ) 5), or
reduction of the amide to the aminomethylene group,
36 (r ) 5), decreased, but did not suppress, the anti-

3908 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23
Thie´ry et al.
Ta ble 3. Inhibition of Copper-Induced Lipid Peroxidation by 1,4-Benzodioxin Derivatives. Evaluation by FPLC Methodology or MDA
Dosage
a
b
Control without Cu2+, 100% B; control with Cu2+, 75% D, 25% E. Compounds were tested on 10 µM. Activity ratio versus probucol.
c NT ) not tested.
Ta ble 4. Inhibition of KCl-Induced Rat Thoracic Aorta
Contractions
oxidant properties of these compounds, which were still
5 times more active than probucol. In contrast, replace-
ment of the amide by a thioamide group resulted in a
drastic (100-fold) decrease in activity (compound 39, r
) 0.5). Replacement of the benzhydrylpiperazine moiety
by [bis(fluorophenyl)methylene]piperidine resulted in
the moderately active compound 35 (r ) 2), while
additional reduction of the amide function surprisingly
strongly enhanced the activity, the resulting compound
37 being at least 45 times more active than probucol (r
> 45).
Amide formation with (2,3,4-trimethoxybenzyl)pip-
erazine (compounds 22 (r ) 3) and 31 (r ) 1.7)) or
N-butylaniline (32 (r ) 2), 33 (r ) 2), and 34 (r ) 5))
did not clearly modify the activity compared to that of
the anilide derivative 24 (activity ratio between 1.7 and
5 compared to probucol). To provide our antioxidant
compounds with additional hypolipaemic activity, we
prepared analogue 40, which can be considered as a
prodrug of 25 and nicotinic acid. Unfortunately com-
pound 40 was found prooxidant.
compd IC50 (µM) compd IC50 (µM)
compd
36
flunarizine
IC50 (µM)
20
21
25
3.0
2.2
0.56
26
27
28
5.0
1.8
3.1
0.57
0.27
In conclusion to this preliminary evaluation, our
chemical modifications led to the discovery of new
compounds much more potent than probucol in their
ability to prevent human LDLs from copper-induced
peroxidation.
Complementary pharmacological evaluations were
performed on some of them. Compounds 20, 21, 25, 26,
27, 28, and 36, which are all substituted with a
flunarizine-like (fluorobenzhydryl)piperazine moiety,
were therefore evaluated for interactions with the
calcium channel (Table 4).58 All these compounds proved
to inhibit the KCl-induced rat thoracic aorta contrac-
tions. Compounds 25 and 36 proved to be only 2 times
less active than flunarizine (0.27 µM), with IC50 values

Benzodioxins as Lipid Peroxidation Inhibitors
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23 3909
Ta ble 5. Normobar Hypoxia Testa
obtained with a Perkin-Elmer 196 infrared spectrometer, and
the data are reported in inverse centimeters. Mass spectra
were recorded on an R 10-10 C Nermag (70 eV) apparatus.
Organic solvents were purified when necessary by methods
described by D. D. Perrin, W. L. F. Armarengo, and D. R.
Perrin (Purification of Laboratory Chemicals; Pergamon: Ox-
ford, 1986) or purchased from Aldrich Chimie. All solutions
were dried over anhydrous magnesium sulfate and evaporated
on a Bu¨chi rotatory evaporator. Analytical thin-layer chroma-
tography (TLC) was carried out on precoated plates (silica gel,
60 F254), and the spots were visualized with UV light or an
alcohol solution of ammonium cerium(IV) nitrate. Column
chromatography was performed with Kieselgel 60 (70-230
mesh) silica gel for gravity columns. Where analyses in the
tables are indicated by the symbols of the elements, analytical
results obtained for those elements were (0.3% of the theo-
retical values. All anhydrous reactions were performed in oven-
dried glassware under an atmosphere of argon. The column
chromatography solvents employed were distilled, and solvent
mixtures were reported as volume-to-volume ratios. Com-
pounds 1, 2, 9, 10, and 17 were prepared according to
dose
time (s) before
the first gasps
compd
(mg/kg ip)
untreated control
36 + 4
inactive
vincamine
vincamine
2.5
20
1
2.5
20
1
147 ( 14b
55 ( 12 (NS)
108 ( 29b
67 ( 19a
25
25
25
36
36
36
78 ( 11 (NS)
60 ( 10 (NS)
65 ( 11 (NS)
20
2.5
a
b
NS ) nonsignificant. p < 0.05.
Ta ble 6. Evaluation of Hypolipaemic Activity in Mice
change in
the total
change in
the LDL-VLDL
fraction (%)
dose
compd
(mg/kg po)
cholesterol (%)
25
36
36
300
300
100
100
-7
-48
-33
-25
0
-52
-35
-20
44
procedures described by V. Thie´ry et al.43,
Typ ica l P r oced u r e for th e P r ep a r a tion of Acetoxy-2,3-
d ih yd r o-1,4-ben zod ioxin -2-ca r boxylic Acid Eth yl Ester s
3 a n d 4 (Sch em e 1). To a solution of 7.5 mmol of acetyl-2,3-
dihydro-1,4-benzodioxin-2-carboxylic acid ethyl ester 1 or 2 (2
g) in anhydrous dichloromethane (30 mL) was added 16.5
mmol of m-chloroperbenzoic acid (3.05 g). The stirred mixture
was heated at 40 °C for 18 h. The mixture was allowed to cool,
and the chlorobenzoic acid was filtered off. The extract was
washed with brine and saturated aqueous NaHCO3. The
organic phases were dried over MgSO4. The solvent was
removed under vacuum. The residue was purified by column
chromatography with AcOEt/petroleum ether (PE) as eluent.
bezafibrate
of, respectively, 0.56 and 0.57 µM. This could be of great
interest since calcium channel blockers such as nife-
dipine, diltiazem, and verapamil have already been
shown to protect cultured lymphoid cells against the
toxicity of oxidized LDLs.
Due to their in vitro activity profile, compounds 25
and 36 were evaluated in vivo for their antihypoxic
activity in mice in a “normobar hypoxia test”.59 Briefly
summarized, the mice received the compound to be
tested 30 min before being placed in an atmosphere poor
in oxygen. The results are expressed as the time until
the first signs of suffocation (or “gasps”) occurred, and
vincamine is used as the reference drug (Table 5).
While compound 36 proved to be inactive at all the
tested doses, compound 25 proved to be significantly
active at 2.5 and 20 mg/kg ip (vincamine active at 20
mg/kg ip, inactive at 2.5 mg/kg ip).
These two compounds were also investigated in mice
for their potential hypolipaemic activity at 300 and 100
mg/kg po (Table 6).60 Compound 36 proved to be more
active than bezabifrate at 100 mg/kg po with a decrease
of 33% in total cholesterol and 35% in the LDL-VLDL
fraction compared to 25% and 20% for bezafibrate.
Compound 25 was found inactive.
6-Acetoxy-2,3-dih ydr o-1,4-ben zodioxin -2-car boxylic acid
eth yl ester (3) was obtained with AcOEt/petroleum ether (PE)
(30/70) as eluent in 79% yield. Mp: 87-88 °C. IR (KBr): 1755
1
(CdO), 1745 (CdO). H NMR (CDCl3): δ 6.97 (1H, d, H8, J )
8.3 Hz.), 6.60-6.00 (2H, m, H8, H5), 4.79 (1H, t, H2,J ) 3.5
Hz) 4.37 (2H, d, H3, J ) 3.5 Hz), 4.26 (2H, d, CH2CH3, J ) 7.1
Hz), 2.22 (3H, s, CH3COO), 1.27 (3H, t, CH3CH2, J ) 7.2 Hz).
MS: m/z 267 (M + 1). Anal. (C13H14O6) C, H.
7-Acetoxy-2,3-dih ydr o-1,4-ben zodioxin -2-car boxylic acid
eth yl ester (4) was obtained with AcOEt/petroleum ether (PE)
(30/70) as eluent in 78% yield (oil). IR (film): 1745 (CdO), 1715
1
(CdO). H NMR (CDCl3): δ 6.84 (1H, d, H5, J ) 8.2 Hz), 6.78
(1H, d, H8, J ) 3.1 Hz), 6.60 (1H, dd, H6, J ) 8.2 Hz, J ) 3.1
Hz), 4.83 (1H, t, H2, J ) 3.5 Hz), 4.0.40-4.37 (2H, m, H3), 4.27
(2H, q, CH2CH3, J ) 7.1 Hz), 2.28 (3H, s, CH3COO), 1.30 (3H,
t, CH2CH3, J ) 7.1 Hz). MS: m/z 267 (M + 1). Anal. (C13H14O6)
C, H.
Typ ica l P r oced u r e for th e P r ep a r a tion of Acetoxy-1,4-
ben zod ioxin -2-ca r boxylic Acid Eth yl Ester s 5 a n d
6
Con clu sion
(Sch em e 1). To a solution of 11.2 mmol of acetoxy-2,3-dihydro-
1,4-benzodioxin-2-carboxylic acid ethyl ester 3 or 4 (3 g) in
anhydrous carbon tetrachloride (60 mL) were added 22.5 mmol
of N-bromosuccinimide (4.4 g) and a catalytic amount of AIBN.
The resulting mixture was stirred and heated with a bulb
lamp (75 W) at reflux for 3 h. The mixture was allowed to
cool and the succinimide filtered off. The filtrate was evapo-
rated to yield a solid sufficiently pure to be used directly in
the next step of the reaction. A solution of 11.8 mmol of
dibromo compound (5 g) in 60 mL of dry acetone was stirred
at room temperature for 4 h with 41.3 mmol of sodium iodide
(7.2 g). The acetone was removed from the green slurry under
reduced pressure, and then water (50 mL), diethyl ether (90
mL), and a 1 N solution of sodium hyposulfite (40 mL) were
added to the resulting brown residue. After extraction the
dried organic layers were removed. The residue was purified
by column chromatography with AcOEt/petroleum ether (PE)
as eluent.
The chemical modifications performed on the benzo-
dioxan and benzodioxin series led us to new compounds
25 and 36 which were very efficient in preventing
human LDLs from copper-induced peroxidation. Among
the numerous compounds more active than probucol,
compounds were selected for complementary in vitro
and in vivo investigations that showed additional prop-
erties of great interest for the treatment and for the
prevention of atherosclerosis and oxidative injuries.
Exp er im en ta l Section
Ch em ica l Syn th esis. Gen er a l P r oced u r e. Melting points
were determined on a Ko¨fler hot-stage apparatus and are
uncorrected. Proton NMR spectra were recorded on a Bruker
AM 300WB spectrometer. The coupling constants are recorded
in hertz (Hz), and the chemical shifts are reported in parts
per million (δ, ppm) downfield from tetramethylsilane (TMS),
which was used as an internal standard. Infrared spectra were
6-Acetoxy-1,4-ben zod ioxin -2-ca r boxylic a cid eth yl es-
ter (5) was obtained with AcOEt/petroleum ether (PE) (30/
70) as eluent in 97% yield. Mp: 97-98 °C. IR (KBr): 1765

3910 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23
Thie´ry et al.
(CdO), 1730 (CdO). 1H NMR (CDCl3): δ 6.93 (1H, s, H3), 6.82
(1H, d, H8, J ) 7.7 Hz), 6.62 (1H, dd, H7, J ) 7.7 Hz, J ) 2.5
Hz), 6.51 (1H, d, H5, J ) 2.5 Hz), 4.29 (2H, q, CH2CH3, J )
7.2 Hz), 2.26 (3H, s, CH3COO), 1.34 (3H, t, CH3CH2, J ) 7.2
Hz). MS: m/z 265 (M + 1). Anal. (C13H12O6) C, H.
7-Hyd r oxy-1,4-ben zod ioxin -2-ca r boxylic a cid (14) was
obtained in 88% yield. Mp: 279-280 °C. IR (KBr): 3640-3010
(OH), 1670 (CdO). 1H NMR (DMSO): δ 9.50 (1H, s, OH), 7.14
(1H, s, H3), 6.65 (1H, d, H5, J ) 8.3 Hz), 6.27 (1H, dd, H6, J )
2.9 Hz, J ) 8.3 Hz), 6.21 (1H, d, H8, J ) 2,95 Hz). MS: m/z
195 (M + 1), 212 (M + 18). Anal. (C9H6O5) C, H.
6-H yd r oxy-7-ter t-b u t yl-1,4-b en zod ioxin -2-ca r b oxylic
a cid (15) was obtained in 86% yield. Mp: 129-130 °C. IR
(KBr): 3600-2500 (OH), 1745(CdO). 1H NMR (DMSO): δ
13.00 (1H, br s, COOH), 9.40 (1H, s, OH), 7.09 (1H, s, H3),
6.55 (1H, s, H8), 6.26 (1H, s, H5), 1.28 (9H, s, (CH3)3C). MS:
m/z 251 (M + 1). Anal. (C13H14O5) C, H.
6-[N-(ter t-Bu toxyca r bon yl)a m in o]-1,4-ben zod ioxin -2-
ca r boxylic a cid (16) was obtained in 95% yield. Mp: 228-
230 °C. IR (KBr): 3345-2980, 2842-2095 (COOH, NH),
1676 (CdO). 1H NMR (DMSO + D2O): δ 7.17 (1H, s, H3),
6.94 (1H, d, H5, J ) 2.3 Hz), 6.91 (1H, dd, H7, J ) 2.3 Hz, J )
8.7 Hz), 6.67 (1H, d, H8, J ) 8.7 Hz), 1.46 (9H, s, (CH3)3C).
MS (IE, negative ions): m/z 292 (M - 1). Anal. (C14H15NO6)
C, H, N.
Typ ica l P r oced u r e for th e P r ep a r a tion of Am id es 18-
35 (Sch em e 4). To a stirred solution of 5.0 mmol of carboxylic
acids 11-17 (1 g) in anhydrous DMF (7 mL) were added at 0
°C 5.5 mmol (1.05 g) of 1-[3-(dimethylamino)propyl]-3-ethyl-
carbodiimide hydrochloride, 5.0 mmol (0.67 g) of hydroxyben-
zotriazole, and 5.5 mmol of amines a -f. The solution was
stirred at room temperature for 18 h. After evaporation of the
solvent, the residue was poured into water (50 mL) and
extracted with ethyl acetate (2 × 50 mL). The extracts were
dried over MgSO4, and the solvent was removed under
vacuum. The residue was purified by column chromatography
with AcOEt/petroleum ether (PE) (30/70) as eluent.
7-Acetoxy-1,4-ben zod ioxin -2-ca r boxylic a cid eth yl es-
ter (6) was obtained with AcOEt/petroleum ether (PE) (30/
70) as eluent in 97% yield (oil). IR (film): 1760 (CdO), 1730
1
(CdO). H NMR (CDCl3): δ 6.94 (1H, s, H3), 7.00 (1H, d, H8,
J ) 3.1 Hz), 6.69 (1H, d, H5, J ) 8.2 Hz), 6.60-6.56 (2H, m,
H6, H8), 4.27 (2H, m, CH2CH3), 2.25 (3H, s, CH3COO), 1.31
(3H, t, CH2CH3, J ) 6.9 Hz). MS: m/z 265 (M + 1). Anal.
(C13H12O6) C, H.
6-Hyd r oxy-1,4-ben zod ioxin -2-ca r boxylic Acid Eth yl
Ester (7). To a solution of 1 g of ester 5 (3.78 mmol) in 15 mL
of ethanol was added 0.5 mL of sodium ethoxide, prepared by
addition of sodium (0.46 g, 20 mmol) to 200 mL of anhydrous
EtOH. The resulting solution was stirred at room temperature
for 6 h, then acidified at pH 6 with resin Dowex 50X8-400,
and filtered off. The filtrate was evaporated to dryness. The
resulting material was purified by column chromatography
with AcOEt/petroleum ether (PE) (30/70) as eluent.
7 was obtained in 86% yield. Mp: 187-188 °C. IR (KBr):
3560-3165 (OH), 1705 (CdO), 1670 (CdC). 1H NMR (CDCl3):
δ 6.91 (1H, s, H3), 6.69 (1H, d, H8, J ) 8.8 Hz), 6.33 (1H, dd,
H7, J ) 8.8 Hz, J ) 2.9 Hz), 6.26 (1H, d, H5, J ) 2.9 Hz), 4.50
(1H, s, OH), 4.27 (2H, q, CH2CH3, J ) 7.3 Hz), 1.31 (3H, t,
CH2CH3, J ) 7.3 Hz). MS: m/z 223 (M + 1). Anal. (C11H10O5)
C, H.
6-H yd r oxy-7-ter t-b u t yl-1,4-b en zod ioxin -2-ca r b oxylic
Acid Eth yl Ester (8). To a solution of 2.2 mmol of ester 7 (1
g) in 5 mL of trifluoroacetic acid was slowly added 4.5 mmol
of anhydrous tert-butyl alcohol (0.950 mL). The stirred solution
was allowed to stand at room temperature for 24 h. The
solvents were removed under vacuum, and ester 8 was isolated
by column chromatography with AcOEt/petroleum ether (PE)
(20/80) as eluent in 84% yield. Mp: 125-126 °C. IR (KBr):
3440-3215 (OH), 1705 (CdO). 1H NMR (DMSO): δ 9.44 (1H,
s, OH), 7.16 (1H, s, H3), 6.55 (1H, s, H8), 6.26 (1H, s, H5), 4.18
(2H, q, CH2CH3, J ) 7.3 Hz), 1.26 (9H, s, (CH3)3C), 1.22 (3H,
t, CH2CH3, J ) 7.3 Hz). MS: m/z 279 (M + 1). Anal. (C15H18O5)
C, H.
Typ ica l P r oced u r e for th e Syn th esis of Ca r boxylic
Acid s 11-16 (Sch em e 3). A stirred solution of 4.5 mmol of
esters 3-6 and 8-10 (2 g) in 20 mL of ethanol was treated
with 9.0 mmol of 10% aqueous sodium hydroxyde. After 4 h
at room temperature and evaporation under reduced pressure
of ethanol, the aqueous phases were acidified with HCl (2 N).
The combined extracts were dried over MgSO4. Evaporation
of the solvent yielded the crude acids, which were washed with
dry dichloromethane.
6-H yd r oxy-2,3-d ih yd r o-1,4-b en zod ioxin -2-ca r b oxylic
a cid (11) was obtained in 89% yield. Mp: 165-166 °C. IR
(KBr): 3650-2700 (OH), 1720 (CdO). 1H NMR (DMSO): δ
13.00 (1H, br s, COOH), 9.50 (1H, s, OH), 6.69 (1H, d, H8, J )
7.6 Hz), 6.27 (1H, dd, H7, J ) 7.6 Hz, J ) 2.84 Hz), 6.23 (1H,
d, H5, J ) 2.84 Hz), 4.88 (1H, t, H2, J ) 3.8 Hz), 4.27 (2H, d,
H3, J ) 3.8 Hz). MS: m/z 197 (M + 1), 214 (M + 18). Anal.
(C9H8O5) C, H.
6-H yd r oxy-N-p h en yl-2,3-d ih yd r o-1,4-b en zod ioxin -2-
ca r boxa m id e (18). With a similar procedure, 18 was prepared
from acid 11 and amine a in 75% yield. Mp: 146-147 °C. IR
(KBr): 3610-3100 (OH), 3370 (NH), 1665 (CdO). 1H NMR
(DMSO): δ 10.00 (1H, s, NH), 9.02 (1H, s, OH), 7.62 (2H, d,
H
arom, Harom, J ) 7.6 Hz), 7.30 (2H, t, H3, Harom, J ) 7.6 Hz),
7.07 (1H, t, Harom, J ) 7.1 Hz), 6.81 (1H, d, H8, J ) 8.3 Hz),
6.29-6.27 (2H, m, H7, H5) 4.81 (1H, dd, H2, J ) 2.7 Hz, J )
6.3 Hz), 4.78 (1H, dd, H3, J ) 2.7 Hz, J ) 11.4 Hz), 4.50 (1H,
dd, H3, J ) 11.4 Hz, J ) 6.3 Hz). MS: m/z 272 (M + 1). Anal.
(C15H13NO4) C, H, N.
7-H yd r oxy-N-p h en yl-2,3-d ih yd r o-1,4-b en zod ioxin -2-
ca r boxa m id e (19). With a similar procedure, 19 was prepared
from acid 12 and amine a in 75% yield. Mp: 157-158 °C. IR
1
(KBr): 3500-3000 (OH, NH), 1635 (CdO). H NMR (CDCl3):
δ 8.33 (1H, s, NH), 7.56 (2H, d, Harom, J ) 7.6 Hz), 7.35 (2H,
t, Harom, J ) 7.6 Hz), 7.16 (1H, t, Harom, J ) 7.6 Hz), 6.79 (1H,
d, H5, J ) 8.8 Hz), 6.57 (1H, d, H8, J ) 3.1 Hz), 6.41 (1H, dd,
H6, J ) 8.8 Hz, J ) 3.1 Hz), 5.10 (1H, s, OH), 4.79 (1H, d, H2,
J ) 7.1 Hz, J ) 3.1 Hz), 4.54 (1H, d, H3, J ) 11.9 Hz, J ) 3.1
Hz), 4.24 (1H, dd, H3, J ) 11.9 Hz, J ) 7.1 Hz). MS: m/z 272
(M + 1). Anal. (C15H13NO4) C, H, N.
6-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}oxo}-2,3-d ih yd r o-1,4-ben zod ioxin (20). With a similar
procedure, 20 was prepared from acid 11 and amine b in 80%
yield. Mp: 200-201 °C. IR (KBr): 3680-3000 (OH), 1630 (Cd
1
O). H NMR (CDCl3): δ 7.40-7.30 (4H, m, 2 × Harom, Harom),
7-H yd r oxy-2,3-d ih yd r o-1,4-b en zod ioxin -2-ca r b oxylic
a cid (12) was obtained in 88% yield. Mp: 205-206 °C. IR
(KBr): 3650-2700 (OH), 1720 (CdO). 1H NMR (DMSO): δ
13.20 (1H, br s, COOH), 9.00 (1H, s, OH), 6.61 (1H, d, H5, J )
8.3 Hz), 6.30 (1H, d, H8, J ) 2.7 Hz), 6.21 (1H, dd, H6, J ) 8.3
Hz, J ) 2.7 Hz), 4.94 (1H, t, H2, J ) 2.9 Hz), 4.3 (1H, dd, H3,
J ) 11.4 Hz, J ) 2.9 Hz), 4.13 (1H, dd, H3, J ) 2.9 Hz, J ) 11.4
Hz). MS: m/z 197 (M + 1), 214 (M + 18). Anal. (C9H8O5) C, H.
6-Hyd r oxy-1,4-ben zod ioxin -2-ca r boxylic a cid (13) was
obtained in 87% yield. Mp: 259-260 °C. IR (KBr): 3640-3010
(OH), 1670 (CdO). 1H NMR (DMSO): δ 13.00 (1H, br s,
COOH), 9.44 (1H, s, OH), 7.11 (1H, s, H3), 6.66 (1H, d, H8, J
) 8.3 Hz), 6.33 (1H, dd, H7, J ) 8.3 Hz, J ) 1.9 Hz), 6.24 (1H,
d, H5, J ) 1.9 Hz). MS: m/z 195 (M + 1), 212 (M + 18). Anal.
(C9H6O5) C, H.
7.00 (4H, t d, Harom, J ) 8.7 Hz), 6.71 (1H, d, H8, J ) 8.7 Hz),
6.40 (1H, d, H5, J ) 3.1 Hz), 6.32 (1H, dd, H7, J ) 3.7 Hz, J )
8.7 Hz), 4.92 (1H, s, OH), 4.72 (1H, dd, H2, J ) 2.3 Hz, J ) 7.9
Hz), 4.43 (1H, dd, H3, J ) 2.3 Hz, J ) 11.8 Hz), 4.29 (1H, dd,
H3, J ) 5.9 Hz, J ) 11.8 Hz), 4.27 (1H, s, NCHAr), 3.82-3.50
(4H, m, Hpiperaz), 2.50-2.32 (4H, m, Hpiperaz). MS: m/z 467 (M
+ 1). Anal. (C26H24N2O4F2) C, H, N.
7-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}oxo}-2,3-d ih yd r o-1,4-ben zod ioxin (21). With a similar
procedure, 21 was prepared from acid 12 and amine b in 73%
yield. Mp: 135-136 °C. IR (KBr): 3480-3300 (OH), 1640 (Cd
1
O). H NMR (CDCl3): δ 7.43-7.31 (4H, m, Harom), 7.04-6.98
(4H, m, Harom), 6.73 (1H, d, H5, J ) 8.2 Hz), 6.43 (1H, d, H8, J
) 2.7 Hz), 6.34 (1H, dd, H6, J ) 2.7 Hz, J ) 8.2 Hz), 5.2 (1H,
br s, OH), 4.81 (1H, dd, H2, J b ) 2.5 Hz, J ) 3.05 Hz), 4.37

Benzodioxins as Lipid Peroxidation Inhibitors
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23 3911
(1H, d, H3, J ) 3.05 Hz, J b ) 11.3 Hz), 4.30-4.12 (2H, m,
CHAr, H3), 3.80-3.50 (4H, m, Hpiperaz), 2.53-2.29 (4H, m,
Hpiperaz). MS: m/z 467 (M + 1). Anal. (C26H24N2O4F2) C, H, N.
7-Hyd r oxy-2-{[4-(2,3,4-tr im eth oxyben zyl)p ip er a zin -1-
yl]oxo}-2,3-d ih yd r o-1,4-ben zod ioxin (22). With a similar
amine b in 78% yield. Mp: 219-220 °C. IR (KBr): 3574-
3302-2715 (NH), 1718 (CdO), 1642 (CdO). 1H NMR (CDCl3):
δ 7.36 (4H, dd, Harom, J ) 8.70 Hz, J ) 5.3 Hz), 6.98 (4H, t,
H
arom, J ) 8.7 Hz), 6.86 (1H, d, H5, J ) 2.4 Hz), 6.76 (1H, dd,
H7, J ) 8.7 Hz, J ) 2.4 Hz), 6.56 (1H, s, H3), 6.55 (1H, d, H8,
J ) 8.7 Hz), 6.29 (1H, s, NH), 4.26 (1H, s, CHAr), 3.57-3.53
(4H, m, Hpiperaz), 2.42-2.38 (4H, m, Hpiperaz), 1.50 (9H, s,
(CH3)3C). MS: m/z 564 (M + 1). Anal. for (C31H31N3O5F2) C,
H, N.
procedure, 22 was prepared from acid 12 and amine c in 75%
1
yield. Mp: 92-93 °C. H NMR (CDCl3): δ 6.97 (1H, d, Harom
,
J ) 8.5 Hz), 6.74 (1H, d, Harom, J ) 8.5 Hz), 6.64 (1H, d, H5, J
) 8,1 Hz), 6.44 (1H, d, H8, J ) 2.5 Hz), 6.33 (1H, dd, J ) 2.5
Hz, J ) 8,2 Hz), 4.82 (1H, dd, H2, J ) 2.1 Hz, J ) 8.3 Hz),
4.40 (1H, dd, H3, J ) 2.1 Hz, J ) 11.4 Hz), 4.21 (1H, dd, H3,
J ) 8.3 Hz, J ) 11.4 Hz), 3.69-3.89 (9H, 3s, 3 × CH3O), 3.78-
3.52 (4H, m, Hpiperaz), 3.54 (s, 2H, NCH2Ar), 2.52-2.49 (4H,
m, Hpiperaz). MS: m/z 445 (M + 1). Anal. (C23H28N2O7) C, H, N.
6-H yd r oxy-N-p h en yl-1,4-b en zod ioxin -2-ca r b oxa m id e
(23). With a similar procedure, 23 was prepared from acid 13
and amine a in 72% yield. Mp: 209-210 °C. IR (KBr): 3610-
3000 (OH), 3380 (NH), 1675 (CdO). 1H NMR (DMSO): δ 9.50
6-Am in o-2-{{4-[bis(4-flu or op h en yl)m eth yl]p ip er a zin -
1-yl}oxo}-1,4-ben zod ioxin (30). Compound 30 was prepared
by acidic hydrolysis of 1 mmol of amide 29 in the presence of
2.5 mL of HCl (3 N). After 6 h at room temperature, the
aqueous phase was basified with NaHCO3. The product was
extracted with ethyl acetate. The organic layers were dried
over magnesium sulfate and evaporated in vacuo. Compound
30 was obtained in 95% yield. IR (KBr): 3600-3420-3310-
3100 (NH2), 1635 (CdO). 1H NMR (CDCl3 + D2O): δ 7.33 (4H,
dd, Harom, J ) 8.8 Hz, J ) 5.1 Hz), 6.97 (4H, t, Harom, J ) 8.8
Hz), 6.54 (1H, s, H3), 6.43 (1H, d, H8, J ) 8.4 Hz), 6.12 (1H,
dd, H7, J ) 2.9 Hz, J ) 8.4 Hz), 6.05 (1H, d, H5, J ) 2.9 Hz),
3.67-3.58 (4H, m, Hpiperaz), 2.46-2.38 (4H, m, Hpiperaz). MS: m/z
464 (M + 1), 481 (M + 18). Anal. (C26H23N3O3F2) C, H, N.
7-Hyd r oxy-2-{[4-(2,3,4-tr im eth oxyben zyl)p ip er a zin -1-
yl]oxo}-1,4-ben zod ioxin (31). With a similar procedure, 31
was prepared from acid 14 and amine c in 73% yield. Mp: 87-
88 °C. IR (KBr): 3610-3300 (OH), 1600 (CdO), 1590 (CdC).
(1H, s, OH), 7.68 (d, 2H, Harom, J ) 7.9 Hz), 7.32 (t, 2H, Harom
,
J ) 7.9 Hz), 7.09 (t, 1H, Harom, J ) 7.9 Hz), 7.07 (1H, s, H3),
6.78 (1H, d, H8, J ) 8.7 Hz), 6.37 (1H, dd, H7, J ) 8.7 Hz, J )
3.1 Hz), 6.27 (1H, d, H5, J ) 3.1 Hz), 4.64 (1H, s, NH). MS:
m/z 270 (M + 1). Anal. (C15H11NO4) C, H, N.
7-H yd r oxy-N-p h en yl-1,4-b en zod ioxin -2-ca r b oxa m id e
(24). With a similar procedure, 24 was prepared from acid 14
and amine a in 63% yield. Mp: 205-206 °C. IR (KBr): 3500-
1
2980 (OH), 3310 (NH), 1640 (CdO), 1220. H NMR (CDCl3):
1H NMR (CDCl3): δ 6.97 (1H, d, J ) 8.3 Hz), 6.63 (1H, d, Harom
,
δ 7.83 (1H, s, NH), 7.59 (2H, d, Harom, J ) 7.9 Hz), 7.36 (2H,
t, Harom, J ) 7.9 Hz), 7.16 (1H, t, Harom, J ) 7.9 Hz), 7.08 (1H,
s, H3) 6.64 (1H, d, H5, J ) 8.3 Hz), 6.38 (1H, d, H8, J ) 2.8
Hz), 6.36 (1H, dd, H6, J ) 2.8 Hz, J ) 2.3 Hz), 4.95 (1H, s,
OH). MS: m/z 270 (M + 1). Anal. (C15H11N O4) C, H, N.
6-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}oxo}-1,4-ben zod ioxin (25). With a similar procedure,
25 was prepared from acid 13 and amine b in 85% yield. Mp:
162-163 °C. IR (KBr): 3610-2980 (OH), 1665 (CdO). 1H NMR
(CDCl3): δ 7.34 (4H, dd, Harom, J ) 8.7 Hz, J ) 5.5 Hz), 6.98
(4H, t, Harom, J ) 8.7 Hz), 6.57 (1H, s, H3), 6.48 (1H, d, H8, J
) 8.7 Hz), 6.29 (1H, dd, H7, J ) 8.7 Hz, J ) 3.1 Hz), 6.23 (1H,
d, H5, J ) 3.1 Hz), 5.60 (1H, s, OH), 4.25 (1H, s, NCHAr), 3.65-
3.40 (4H, m, Hpiperaz), 2.39-2.29 (4H, m, Hpiperaz). MS: m/z 465
(M + 1). Anal. (C26H22N2O4F2) C, H, N.
7-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}oxo}-1,4-ben zod ioxin (26). With a similar procedure,
26 was prepared from acid 14 and amine b in 85% yield. Mp:
220-221 °C. IR (KBr): 3300 (OH), 1650 (CdO). 1H NMR
(CDCl3): δ 7.36 (4H, dd, 2 × Harom, Harom, J ) 8.7 Hz, J ) 5.6
Hz), 7.00 (4H, t, Harom, J ) 8.7 Hz, J ) 8.7 Hz), 6.58-6.52
(2H, m, H3, H5), 6.29 (1H, dd, H6, J ) 8.1 Hz, J ) 2.5 Hz),
6.23 (1H, d, H8, J ) 2.5 Hz), 5.40 (1H, br s, OH), 4.27 (1H, s,
CHAr), 3.69-3.63 (4H, m, Hpiperaz), 2.45-2.39 (4H, m, Hpiperaz).
MS: m/z 465 (M + 1). Anal. (C26H22N2O4F2) C, H, N.
J ) 8.3 Hz), 6.54 (1H, s, H3), 6.53 (1H, d, H5, J ) 8.3 Hz), 6.31
(1H, dd, H6, J ) 2.1 Hz, J ) 8.3 Hz), 6.25 (1H, d, H8, J ) 2.1
Hz), 3.87-3.89 (9H, 3s, 3 · CH3O), 3.61 (4H, m, Hpiperaz), 3.51
(s, 2H, NCH2Ar), 2.53 (4H, m, Hpiperaz). MS: m/z 443 (M + 1).
Anal. (C23H26N2O7) C, H, N.
N-Bu t yl-6-h yd r oxy-N-p h en yl-1,4-b en zod ioxin -2-ca r -
boxa m id e (32). With a similar procedure, 32 was prepared
from acid 13 and amine d in 80% yield. Mp: 123-124 °C. IR
1
(KBr): 3610-2980 (OH, NH), 1660 (CdO). H NMR (CDCl3):
δ 7.40-7.18 (5H, m, 5Harom), 6.62 (1H, s, H3), 6.14 (1H, d, H5,
J ) 2.9 Hz), 6.1 (1H, dd, H7, J ) 8.3 Hz, J ) 2.9 Hz), 5.71
(1H, d, H8, J ) 8.3 Hz), 5.14 (1H, s, OH), 3.90-3.70 (2H, m,
NCH2), 1.56-1.47 (2H, m, CH2), 1.50-1.20 (2H, m, CH2), 0.61
(3H, t, CH3, J ) 7.3 Hz). MS: m/z 326 (M + 1). Anal. (C19H19
NO4) C, H, N.
-
N-Bu t yl-7-h yd r oxy-N-p h en yl-1,4-b en zod ioxin -2-ca r -
boxa m id e (33). With a similar procedure, 33 was prepared
from acid 14 and amine d in 83% yield. Mp: 155-156 °C. IR
1
(KBr): 3610-2980 (OH, NH), 1660 (CdO). H NMR (CDCl3):
δ 7.43-7.17 (m, 5Harom), 6.60 (1H, d, H8, J ) 2.9 Hz), 6.44 (1H,
d, H5, J ) 8.7 Hz), 6.42 (1H, s, H3), 6.2 (1H, dd, H6, J ) 2.9
Hz, J ) 8.7 Hz), 5.56 (1H, s, OH), 3.76 (2H, t, NCH2, J ) 7.8
Hz), 1.70-1.48 (2H, m, CH2), 1.43-1.26 (2H, m, CH2), 0.89
(3H, t, CH3, J ) 7.31 Hz). MS: m/z 326 (M + 1). Anal. for
(C19H19NO4) C, H, N.
2-{{4-[Bis(4-flu or op h en yl)m eth yl]p ip er a zin -1-yl}oxo}-
1,4-ben zod ioxin (27). With a similar procedure, 27 was
prepared from acid 17 and amine b in 90% yield. Mp: 156-
158 °C. IR (KBr): 1670 (CdO). 1H NMR (DMSO): δ 7.43
(4H, dd, 2 × Harom, Harom, J ) 8.8 Hz, J ) 5.2 Hz), 7.12 (4H, t,
N-Bu t yl-6-h yd r oxy-7-ter t-b u t yl-N-p h en yl-1,4-b en zo-
d ioxin -2-ca r boxa m id e (34). With a similar procedure, 34
was prepared from acid 15 and amine d in 77% yield. Mp:
225-226 °C. IR (KBr): 3610-3010 (OH), 1640 (CdO). 1H NMR
(CDCl3): δ 7.39-7.190 (5H, m, Harom aniline), 6.63 (1H, s, H3),
6.04 (1H, s, H8), 5.73 (1H, s, H5), 5.04 (1H, s, OH), 3.75 (t, 2H,
NCH2, J ) 7.6 Hz), 1.60-1.25 (4H, m, CH2), 1.22 (9H, s,
(CH3)3C), 0.87 (3H, t, CH3, J ) 7.1 Hz). MS: m/z 382 (M + 1).
Anal. (C23H27NO4) C, H, N.
6-Hyd r oxy-2-{{4-[bis(4-flu or op h en yl)m eth ylen e]p ip e-
r id in -1-yl}oxo}-1,4-ben zod ioxin (35). With a similar pro-
cedure, 35 was prepared from acid 13 and amine e in 80%
yield. Mp: 165-166 °C. IR (KBr): 3610-3010 (OH), 1645 (Cd
O). 1H NMR (CDCl3): δ 7.11-6.95 (m, 8H, Harom), 6.57 (1H, s,
H3), 6.54 (1H, d, H8, J ) 8.6 Hz), 6.31 (1H, dd, H7, J ) 2.6 Hz,
J ) 8.6 Hz), 6.25 (1H, d, H5, J ) 2.6 Hz), 5.13 (1H, s, OH),
3.69-3.59 (4H, m, Hpiperid), 2.48-2.38 (4H, m, Hpiperid). MS: m/z
462 (M + 1). Anal. (C27H21NO4F2) C, H, N.
H
arom, J ) 8.8 Hz), 6.92-6.78 (4H, m, Harom), 6.74 (1H, s, H3),
4.43 (1H, s, NCHAr), 3.70-3.40 (4H, m, Hpiperaz), 2.30-2.15
(4H, m, Hpiperaz). MS: m/z 449 (M + 1). Anal. (C26H22N2O3F2)
C, H, N.
6-Hyd r oxy-7-ter t-bu tyl-2-{{4-[bis(4-flu or op h en yl)m eth -
yl]p ip er a zin -1-yl}oxo}-1,4-ben zod ioxin (28). With a simi-
lar procedure, 28 was prepared from acid 15 and amine b in
84% yield. Mp: 242-244 °C. IR (KBr): 3600-3000 (OH), 1640
(CdO). 1H NMR (DMSO): δ 9.36 (1H, s, OH), 7.43 (4H, dd,
H
arom, J ) 8.3 Hz, J ) 5.8 Hz), 6.98 (4H, t, Harom, J ) 8.3 Hz),
6.64 (1H, s, H3), 6.52 (1H, s, H8 or H5), 6.24 (1H, s, H5 or H8),
4.44 (1H, s, NCHAr), 3.60-3.46 (4H, m, Hpiperaz), 2.50-2.10
(4H, m, Hpiperaz), 1.25 (9H, s, (CH3)3C). MS: m/z 521 (M + 1).
Anal. for (C30H30N2O4F2) C, H, N.
6-[N-(ter t-Bu toxyca r bon yl)a m in o]-2-{{4-[bis(4-flu or o-
p h en yl)m eth yl]p ip er a zin -1-yl}oxo}-1,4-ben zod ioxin (29).
With a similar procedure, 29 was prepared from acid 16 and
Typ ica l P r oced u r e for th e Syn th esis of Am in om eth yl
Der iva tives 36 a n d 37 (Sch em e 4). To a stirred suspension
of 1.5 mmol (0.05 g) of lithium aluminum hydride in 30 mL

3912 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23
Thie´ry et al.
of anhydrous THF was added 2 mmol of compound 25 or 35.
The mixtures were stirred and refluxed for 1 h, cooled, and
decomposed by adding dropwise ice-water. The mixtures were
filtered through Celite and evaporated. Pure materials 36 and
37 were obtained by purification by column chromatography
with AcOEt/petroleum ether (PE) as eluent.
7.45 (1H, dd, Hpyrid, J ) 5.0 Hz, J ) 8.0 Hz), 7.35 (4H, dd,
H
arom, J ) 8.5 Hz, J ) 5.3 Hz), 6.99 (4H, t, Harom, J ) J ) 8.5
Hz), 6.73 (1H, dd, H7, J ) 2.4 Hz, J ) 8.9 Hz), 6.69 (1H, d, H8,
J ) 8.9 Hz), 6.63 (1H, d, H5, J ) 2.4 Hz), 6.58 (1H, s, H3),
4.26 (1H, s, NCHAr), 3.70-3.50 (4H, m, Hpiperaz); 2.60-2.30
(4H, m, Hpiperaz). MS: m/z 570 (M + 1). Anal. (C32H25N3O5F2)
C, H, N.
6-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}m eth yl}-1,4-ben zod ioxin (36) was prepared from amide
25 in 86% yield and obtained with AcOEt/petroleum ether (PE)
(20/80) as eluent. Mp: 189-190 °C. IR (KBr): 3610-2985
P h a r m a cology. An tioxid a n t P r op er ties: Electr op h or -
etic Meth od (F P LC). The capacity of the compounds to
decrease the proportions of oxidized LDLs was measured by
incubating a preparation comprising native human LDLs, Cu2+
free radical generator, and the compounds to be tested for 24
h. The oxidation products were determined by FPLC in
accordance with the method described by Vedie.56 By this
method it was possible to identify five peaks corresponding to
different degrees of LDL oxidation. Peaks A and B correspond
to the native forms of LDLs, and peaks C, D, and E correspond
to the different states of oxidation of LDLs (peak E corre-
sponding to the most oxidized form). The results are expressed
as a percentage of the LDLs corresponding to those different
states of oxidation. A protective effect of a compound with
respect to oxidation induced by copper was demonstrated by
a displacement of the E form toward the D form, or even
toward the C form or the B form for the most powerful
compounds.
An tioxid a n t P r op er ties (MDA Dosa ge). LDLs were
isolated by ultracentrifugation (1.019 < d < 1.063) from the
pooled plasma of healthy normolipidemic human subjects with
EDTA (0.04%). The LDL oxidation was promoted by copper (5
µmol-1, 3 h, T ) 37 °C). The compounds in DMSO were
incubated at 10 concentrations just before the beginning of the
oxidation. For each compound, protection against lipid per-
oxidation formation was estimated by dosing the inhibition of
thiobarbituric acid reactive substance at each concentration
according to the method of Yagi.57 For each compound 10
concentrations between 10-7 and 10-3 M were evaluated in
duplicate. The variability between the duplicates was less than
5% in all cases. IC50 values were calculated using linear
regression analysis.
1
(OH), 1695 (CdC). H NMR (CDCl3): δ 9.00 (1H, s, OH), 7.34
(4H, dd, Harom, J ) 8.6 Hz, J ) 5.5 Hz), 6.96 (4H, t, Harom, J )
8.6 Hz), 6.48 (1H, d, H8, J ) 8.5 Hz), 6.23 (1H, dd, H7, J ) 8.5
Hz, J ) 2.8 Hz), 6.14 (1H, d, J ) 2.8 Hz), 5.79 (1H, s, H3), 4.23
(1H, s, NCHAr), 2.89 (s, 2H, CH2N), 2.63-2.36 (8H, m,
8Hpiperaz). MS: m/z 451 (M + 1). Anal. (C26H24N2O3F2) C, H, N.
6-Hyd r oxy-2-{{4-[bis(4-flu or op h en yl)m eth ylen e]p ip e-
r id in -1-yl}m eth yl}-1,4-ben zod ioxin (37) was prepared from
amide 35 in 86% yield and obtained with AcOEt/petroleum
ether (PE) (20/80) as eluent in 80% yield. Mp: 185-186 °C.
IR (KBr): 3605-3010 (OH), 1695 (CdC). 1H NMR (CDCl3): δ
7.09-6.92 (m, 8H, Harom), 6.49 (1H, d, H8, J ) 8.8 Hz), 6.25
(1H, dd, H7, J ) 2.9 Hz, J ) 8.8 Hz), 6.16 (1H, d, H5, J ) 2.9
Hz), 2.90 (s, 2H, NCH2), 2.63-2.52 (4H, m, Hpiperid), 2.48-2.36
(4H, m, Hpiperid). MS: m/z 448 (M + 1). Anal. (C27H23NO3F2)
C, H, N.
6-Meth oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}oxo}-1,4-ben zod ioxin (38). To a stirred suspension of
0.82 mmol of compound 25 (0.38 g) and 0.98 mmol of sodium
hydride (60% dispersion in mineral oil, 0.04 g) in 10 mL of
DMF was added dropwise 0.98 mmol of iodomethane (0.14 g).
After 2 h at room temperature, the solvent was removed under
reduced pressure, and the residue was hydrolyzed with water
(15 mL) and extracted with ethyl acetate (2 × 15 mL). The
organic layers dried over magnesium sulfate were evaporated
in vacuo. The product 38 was obtained by purification by
column chromatography with AcOEt/petroleum ether (PE) (50/
50) as eluent in 83% yield. Mp: 144-145 °C. IR (KBr): 1660
1
(CdO), 1605 (CdC). H NMR (CDCl3): δ 7.34 (4H, dd, Harom
,
J ) 8.6 Hz, J ) 5.4 Hz), 6.98 (4H, t, Harom, J ) 8.6 Hz), 6.56
(1H, d, H8, J ) 8.8 Hz), 6.52 (1H, s, H3), 6.36 (1H, dd, H7, J )
8.8 Hz, J ) 2.9 Hz), 6.28 (1H, d, H5, J ) 2.9 Hz), 4.25 (1H, s,
NCHAr), 3.70 (s, 3H, CH3O), 3.72-3.66 (4H, m, Hpiperaz), 2.50-
2.30 (4H, m, Hpiperaz). MS: m/z 479 (M + 1). Anal. (C26H22N2O3F2)
C, H, N.
6-Hydr oxy-2-{{4-[bis(4-flu or oph en yl)m eth yl]piper azin -
1-yl}th ioxo}-1,4-ben zod ioxin (39). A stirred solution of 1.1
mmol of product 25 (0.5 g) in 8 mL of anhydrous toluene was
treated with 1.1 mmol of commercially avalaible Lawesson’s
reagent (0.4 g). The mixture was refluxed for 12 h. Then the
solvent was evaporated to dryness and the resulting material
purified by column chromatography with AcOEt/petroleum
ether (PE) (30/70) as eluent to afford 39 in 12% yield. IR
(KBr): 3600-2980-2600 (OH), 1280 (CdS). 1H NMR (CDCl3):
δ 7.36 (4H, dd, Harom, J ) 8.6 Hz, J ) 5.4 Hz), 7.00 (4H, t,
Ca lciu m Ch a n n el Block in g Activity. Isolated rat aorta
was contracted by hyperpotassic solution (KCl, 60 mM).58 The
inhibition of the contraction was evaluated in the presence of
increasing concentrations of compound (eight concentrations
between 10-8 and 3 × 10-5 M). Each concentration was
performed in duplicate. Two different preparations were used.
The concentration-related curve allowed us to calculate the
IC50 values using linear regression analysis. The flunarizine
was used as a reference compound and inhibits with an IC50
of 2.7 × 10-7 M.
An tih yp oxic Activity in Vivo. Male mice (Swiss CD1)
weighing from 25 to 30 g were, before experiment, housed for
1 week under conditions customary for animals (20-22 °C,
55% humidity, light/darkness cycle 12/12, commercial feed and
water as desired).59 The mice were placed in a box (7 × 5 × 5
cm) in which an atmosphere poor in oxygen was created by
passing through a stream of air (96% N2, 4% O2, 12 L/min).
The time taken until the first signs of suffocation (or gasps)
occurred was measured. The mice received a dose of the
compounds to be tested by the intraperitoneal route 30 min
before the hypoxia was induced. Vincamine was used as the
reference drug.
H
arom, J ) 8.6 Hz), 6.60 (1H, s, H3), 6.48 (1H, d, H8, J ) 8.6
Hz), 6.30 (1H, dd, H7, J ) 2.9 Hz), 4.28 (1H, s, NCHAr), 4.12-
3.92 (4H, m, Hpiperaz), 3.45 (1H, s, OH), 2.57-2.47 (4H, m,
H
piperaz). MS: m/z 481 (M + 1). Anal. (C26H22N2O3F2S) C, H,
N.
6-(Nicot in oyloxy)-2-{{4-[b is(4-flu or op h en yl)m et h yl]-
p ip er a zin -1-yl}oxo}-1,4-b en zod ioxin (40). To a solution
of 1.37 mmol of compound 25 (0.635 g) in 25 mL of dry
dichloroethane were added 4.5 mmol of nicotinoyl chloride
hydrochloride (0.805 g) and 3.0 mmol of anhydrous pyridine
(0.275 mL). The resulting mixture was refluxed for 8 h. After
cooling, the organic layer was washed with a saturated solution
of NaHCO3, then dried over magnesium sulfate, and evapo-
rated in vacuo. The residue was purified by column chroma-
tography with AcOEt/petroleum ether (PE) (30/70) as eluent
to give 40 in 93% yield. Mp: 141-142 °C. IR (KBr): 2950-
Hyp olip a em ic Activity. Groups each comprising six mice
were rendered hypercholesterolaemic by a diet that was high
in cholesterol and in cholic acid for 7 days.60 The compounds
were administered po (100 mg/kg) on the sixth and seventh
days (half the dose being administered on day 6 and the other
half on day 7). The animals were then left without
food and drink for one night. The reduction in the concen-
tration of cholesterol in the serum compared with that of
hypercholesterolaemic control mice was then evaluated, as
was the reduction in the concentration of lipoproteins (corre-
sponding to the LDL-VLDL fractions), after precipitation
by the addition of heparin to the serum, in the same hyper-
cholesterolaemic mice compared with the control animals.
1
2740 (CH3, CH2), 1740 (CdO), 1675 (CdO). H NMR (CDCl3):
δ 9.32 (1H, d, Hpyrid, J ) 1.9 Hz), 8.94 (1H, dd, Hpyrid, J ) 2.0
Hz, J ) 5.0 Hz), 8.39 (1H, ddd, Hpyrid, J ) 8.0 Hz, J ) 2.0 Hz),

Benzodioxins as Lipid Peroxidation Inhibitors
J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23 3913
(22) Kuehm-Caubere, C.; Caubere, P.; J amart-Gregoire, B.; Negre-
Salvayre, A.; Bonnefont-Rousselot, D.; Bizot-Espiard, J .-G.;
Pfeiffer, B.; Caignard, D.-H.; Guardiola-Lemaitre, B.; Renard,
P. Novel indole-2-carboxamide and cycloalkeno[1,2-b]indole
derivatives. Structure-activity relationships for high inhibition
of human LDL peroxidation. J . Med. Chem. 1997, 40, 1201-
1210.
(23) Guillaumet, G. In Comprehensive Heterocyclic Chemistry II, 1st
ed.; Katritzky, A. R., Rees, C. W., Scriven, E. F. V., Eds.;
Pergamon: Oxford, 1996; Vol. 6, pp 447-500.
(24) Lalloz, J .; Loppinet, V.; Coudert, G.; Guillaumet, G.; Loubinoux,
B.; Labrid, C.; Beaughard, M; Dureng, G.; Lamar, J . 2-Benzo-
dioxinylaminoethanols: a new class of â-adrenergic blocking and
antihypertensive agents. J . Med. Chem. 1981, 24, 994-998.
(25) Stillings, M. R.; Chapleao, C. B.; Butler, R. C.; Davis, J . A.;
England, C. D.; Myers, M.; Tweddle, N.; Welbourn, A. P.; Doxey,
J . C.; Smith, C. F. C. Alpha-adrenoreceptor reagents. 3. Syn-
thesis of some 2-substituted 1,4-benzodioxans as selective pre-
synaptic alpha 2-adrenoreceptor antagonists. J . Med. Chem.
1985, 28, 1054-1062.
(26) Campbell, S. F.; Davey, M. J .; Hardstone, J . D.; Lewis, B. N.;
Palmer, M. J . 2,4-Diamino-6,7-dimethoxyquinazolines. 1. 2-[4-
(1,4-Benzodioxan-2-ylcarbonyl)piperazin-1-yl] derivatives as al-
pha 1-adrenoceptor antagonists and antihypertensive agents. J .
Med. Chem. 1987, 30, 49-57.
(27) Ruffolo, R. R., J r.; Bondinell, W.; Hieble, J . P. Alpha- and beta-
adrenoceptors: from the gene to the clinic. 2. Structure-activity
relationships and therapeutic applications. J . Med. Chem. 1995,
38, 3681-3716.
(28) Khouili, M.; Guillaumet, G.; Coudert, G.; Pujol, M. D. Synthesis
and R,â-adrenergic blocking potency of 2,3-dihydro-1,4-benzo-
dioxin derivatives. Farmaco 1996, 51, 185-188.
(29) Quaglia, W.; Pigini, M.; Piergentili, A.; Giannella, M.; Marucci,
G.; Poggesi, E.; leonardi, A.; Melchiorre, C. Structure-activity
relationships in 1,4-benzodioxan-related compounds. 6. Role of
the dioxane unit on selectivity for alpha(1)-adrenoreceptor
subtypes. J . Med. Chem. 1999, 42, 2961-2968.
(30) Melchiorre, C.; Angeli, P.; Bolognesi, M. L.; Chiarini, A.; Giar-
dina`, D.; Gulini, U.; Leonardi, A.; Marucci, G.; Minarini, A.;
Pigini, M.; Quaglia, W.; Rosini, M.; Tumiatti, V. Alpha 1-adreno-
receptor antagonists bearing a quinazoline or a benzodioxane
moiety. Pharm. Acta Helv. 2000, 74, 181-190.
(31) Hibert, M. F.; Gittos, M. W.; Middlemiss, D. N.; Mir, A. K.;
Fozard, J . R. Graphics computer-aided receptor mapping as a
predictive tool for drug design: development of potent, selective,
and stereospecific ligands for the 5-HT1A receptor. J . Med.
Chem. 1988, 31, 1087-1093.
(32) Nikam, S.; Martin, A. R.; Nelson, D. L. Serotonergic properties
of spiroxatrine enantiomers. J . Med. Chem. 1988, 31, 1965-
1968.
(33) Birch, A. M.; Bradley, P. A.; Gill, J . C.; Kerrigan, F.; Needham,
P. L. N-substituted-(2,3-dihydro-1,4-benzodioxin-2yl)methyl-
amine derivatives as D-2 antagonists/5-HT1A partial agonists
with potential as atypical antipsychotic agents. J . Med. Chem.
1999, 42, 3342-3355.
(34) Munk, S. A.; Harcourt, D. A.; Arasasingham, P. N.; Burke, J .
A.; Kharlamb, A. B.; Manlapaz, C. A.; Padillo, E. U.; Roberts,
D.; Runde, E.; Williamns, L.; Wheeler, L. A.; Garst, M. E.
Synthesis and evaluation of 2-(arylimino)imidazoles as alpha
2-adrenergic agonists. J . Med. Chem. 1997, 40, 18-23.
(35) Satoh, Y.; Powers, C.; Toledo, L. M.; Kowalski, T. J .; Peters,
P. A.; Kimble, E. F. Derivatives of 2-[[N-(aminocarbonyl)-N-
hydroxyamino]methyl]-1,4-benzodioxan as orally active 5-lipoxy-
genase inhibitors. J . Med. Chem. 1995, 38, 68-75.
Ack n ow led gm en t. Antagonist calcium activity was
measured by CEREP (Le Bois l’Eveˆque, 86000 l’Evescaut,
France). Hypolipaemic activity was measured by Pan-
labs (WA 98011). Antihypoxic activity was measured by
Neurotech (1228, Geneva, Switzerland). The technical
support of Marie-Laure Baudin is greatly appreciated
and gratefully acknowledged. We are especially grateful
to Pr. C. W. Rees (Imperial College of Medicine and
Science, London) for a fruitful collaboration.
Refer en ces
(1) Witztum, J . L.; Steinberg, D. Role of oxidized low-density lipo-
protein in atherogenosis. J . Clin. Invest. 1991, 88, 1785-1792.
(2) Dieber-Rotheneder, M.; Puhl, H.; Waeg, G.; Striegl, G.; Ester-
bauer, H. Effect of oral supplementation with D-R-tocopherol on
the vitamin E content of human low-density lipoprotein and
resistance to oxidation. J . Lipid Res. 1991, 32, 1325-1332.
(3) Witztum, J . L. The oxidation hypothesis of atherosclerosis.
Lancet 1994, 344, 793-795.
(4) Steinberg, D. Low density lipoprotein oxidation and its patho-
biological significance. J . Biol. Chem. 1997, 272 (34), 20963-
20966.
(5) Holvoet, P.; Collen, D. Oxidation of low density lipoproteins in
the pathogenesis of atherosclerosis. Atherosclerosis 1998, 137
(Suppl.), S33-S38.
(6) Heinecke, J . W. Is lipid peroxidation relevant for atherogenesis?
J . Clin. Invest. 1999, 104 (2), 133-136
(7) Hodis, H. N.; Kramsch, D. M.; Avogaro, P.; Bittolo-Bon, G.;
Cazzoloto, G.; Hwang, J .; Peterson, H.; Sevanian, A. Biochemical
and cytotoxic characteristics of an in vivo circulating oxidized
low-density lipoprotein (LDL). J . Lipid Res. 1994, 35, 669-677.
(8) Steinberg, D. Role of oxidized LDL and antioxidants in athero-
sclerosis. Adv. Exp. Med. Biol. 1995, 369, 39-48.
(9) Steinbrecher, U. P. Receptors for oxidized low density lipo-
protein. Biochim. Biophys. Acta/Mol. Cell Biol. Lipids 1999,
1436, 279-298.
(10) Hevonoja, T.; Pentika¨inen, M. O.; Hyvo¨nene M. T.; Kovanen, P.
T.; Korpela, M. A. Structure of low density lipoprotein (LDL)
particles: basis for understanding molecular changes in modified
LDL. Biochim. Biophys. Acta/Mol. Cell Biol. Lipids 2000, 1488,
189-210.
(11) Parthasarathy, S.; Santanam, N.; Ramachandran, S.; Meilhac,
O. Oxidants and antioxidants in atherogenesis. An appraisal.
J . Lipid Res. 1999, 40 (12), 2143-2157.
(12) Steinberg, D. Clinical trials of antioxidants in atherosclerosis:
are we doing the right thing? Lancet 1995, 346, 36-38.
(13) Steinberg, D. Antioxidants in the prevention of human athero-
sclerosis. Summary of the proceedings of a national heart, lung
and blood institute workshop: September 5-6, 1991, Bethesda,
Maryland. Circulation 1992, 85, 2338-2344.
(14) Aviram M. Review of human studies on oxidative damage and
antioxidant protection related to cardiovascular diseases. Free
Radical Res. 2000, 33 (Suppl.), S85-97.
(15) Zimetbaumm, P.; Eder, H.; Frishman, W. Probucol: pharmacol-
ogy and clinical application. J . Clin. Pharmacol. 1990, 30, 3-9.
(16) Daugherty, A.; Zweifel, B. S.; Schonfeld, G. The effect of probucol
on the progression of atherosclerosis in mature Watanabe
heritable hyperlipidaemic rabbits. Br. J . Pharmacol. 1991, 103,
1013-1018.
(17) Mao, S. J . T.; Yates, M. T.; Rechtin, A. E.; J ackson, R. L.; Van
Sickle, W. A. Antioxidant activity of probucol and its analogues
in hypercholesterolemic Watanabe rabbits. J . Med. Chem. 1991,
34, 298-302.
(36) Antus, S.; Seligmann, O.; Wagner, H. The definite structure of
americanin-A and hydnocarpin. Liebigs Ann. Chem. 1986, 4647-
4654.
(37) Fukuyama, Y.; Hasegawa, T.; Toda, M.; Kodama, M.; Okazaki,
H. Structures of americanol A and isoamericanol A having a
neurotrophic property from the seeds of Phytolacca americana.
Chem. Pharm. Bull. (Tokyo) 1992, 40, 252-254.
(38) She, X.; Gu, W.; Wu, T.; Pan, X. A convenient synthesis of
(()-3-methoxybenzodioxane-4,9,9′-triol neolignan, and methyl
ethers of isoamericanol A and isoamericanin A. J . Chem. Res.
(S) 1999, 100-101.
(18) Scott, J . W.; Cort, W. M.; Harlery, H.; Parrish, D. R.; Saucy, G.
6-Hydroxychroman-2-carboxylic acids: novel antioxidants. J .
Am. Oil Chem. Soc. 1994, 51, 200-203.
(19) J on J acobsen, E.; Van Doornick, F. J .; Ayer, D. E.; Belonger, R.
L.; Braugler, J . M.; Hall, E. D.; Houser, D. J . 2-(Aminomethyl)-
chromans that inhibit iron-dependent lipid peroxidation and
protect against central nervous system trauma and ischemia.
J . Med. Chem. 1992, 35, 4464-4472.
(39) Matsumoto, K.; Takahashi, H.; Miyake, Y.; Fukuyama, Y.
Convenient syntheses of neurotrophic americanol A and isoamer-
icanol A by HRP catalyzed oxidative coupling of caffeic acid.
Tetrahedron Lett. 1999, 40, 3185-3186.
(40) She, X.; J ing, X.; Pan, X.; Chan A.; Yank, T. Total Synthesis of
(()-sinaiticin. Tetrahedron Lett. 1999, 40, 4567-4570.
(41) Gu, W.; J ing, X.; Pan, X.; Chan, A.; Yang T. First asymmetric
synthesis of chiral 1,4-benzodioxane lignans. Tetrahedron Lett.
2000, 41, 6079-6082.
(20) Linserman, D. A.; Wall, T. M.; Hartman. The Trolox analog,
U-78517 F attenuates hyposcic injury in isolated cardiac myo-
cyts. J . Mol. Cell Cardiol. 1994, 26, 1249-1257.
(21) Yu, M. J .; McCowan, J . R.; Phebus, L. A.; Towner, R. D.; Ho, P.
P. K.; Keith P. T.; Luttman, C. A.; Saunders, R. D.; Ruterbories,
K. J .; Lindstrom, T. D.; Wikel, J . H.; Morgan, E.; Hahn, R. A.
Benzylamine antioxidant: relationships between structure, per-
oxyl radical scavenging, lipid peroxidation inhibition, and cyto-
protection. J . Med. Chem. 1993, 36, 1262-1271.

3914 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 23
Thie´ry et al.
(42) Adam, G.; Bizot-Espiard, J . G.; Coudert, G.; Guillaumet, G.;
Pfeiffer, B.; Renard, P.; Thie´ry, V. New substituted benzodioxins-
2-substituted with amide or thioamide group. Antioxidant for
lipoproteins, antilipemic agents, anticholesterol agents. Eur. Pat.
Appl. EP 624,582; Chem. Abstr. 1995, 122, 105899r.
(43) Thie´ry, V.; Coudert, G.; Morin-Allory, L.; Guillaumet, G. Con-
venient synthesis of 2-substituted-6 or 7-acylated-1,4-benzo-
dioxin or 2,3-dihydro-1,4-benzodioxin derivatives. Tetrahedron
1995, 51, 2619-2628.
(52) Coudert, G.; Guillaumet, G.; Loubinoux, B. Synthese de benzo-
dioxines-1,4. Tetrahedron Lett. 1978, 12, 1059-1962.
(53) Stokker, G. E.; Deana, A. A.; deSolms, S. J .; Schultz, E. M.; Smith
R. L.; Cragoe, E. J ., J r.; Baer A. E.; Ludden, C. T.; Russo, H. F.;
Scriabine, A.; Sweet, C. S.; Watson, L. S. 2-(Aminomethyl)-
phenols, a new class of saluretic agents. Effect of nuclear
substitution. J . Med. Chem. 1980, 23, 1414-1427.
(54) Ko¨nig, W.; Geiger, R. A new method for synthesis peptides:
activation of the carboxyl group with dicyclohexylcarbodiimide
using 1-hydroxybenzotriazoles as additives. Chem. Ber. 1970,
103, 788-798.
(55) Scheibye, S.; Shabana, R.; Lawesson, S. O.; Romming, C. Studies
on organophosphorous compounds-XL. Reactions of ketones with
2,4-bis(4-methoxyphenyl)1,3,2,4-dithiadiphosphetane-2,4-disul-
fide. Tetrahedron 1982, 38, 993-1002.
(56) Vedie, B.; Pech, M. A.; Maziere, J . C.; Maziere, C.; Caprani, A.;
Moatti, N. Fractionation of charge-modified low density lipo-
proteins by fast protein liquid chromatography. J . Lipid Res.
1991, 32, 1359-1369.
(57) Yagi, K. Lipids peroxides and human diseases. Chem. Phys.
Lipids 1987, 45, 337-351 and references therein.
(44) Thie´ry, V.; Coudert, G.; Guillaumet, G. Convenient synthesis of
6-amino-1,4-benzodioxin-2-carboxylic acid ethyl ester. Synth.
Commun. 1997, 27, 431-440.
(45) J anero, D. R.; Burghardt, B.; Lopez, R.; Cardell, M. Influence of
cardioprotective cyclooxygenase and lipoxygenase inhibitors on
peroxidative injury to myocardial-membrane phospholipid. Bio-
chem. Pharmacol. 1989, 38, 4381-4387.
(46) J anero, D. R.; Burghardt, B. Antiperoxidant effects of dihydro-
pyridine calcium antagonists. Biochem. Pharmacol. 1989, 38,
4344-4348.
(47) Henry, P. D. Calcium channel blockers and atherosclerosis. J .
Cardiovasc. Pharmacol. 1990, 16 (Suppl.), S12-5.
(48) Henry, P. D. Antiperoxidative actions of calcium antagonists
and atherogenesis. J . Cardiovasc. Pharmacol. 1991, 18 (Suppl.),
S6-10.
(58) Okamiya, Y.; Kishimito, T.; Aoki, K.; Tanabe, H.; Takeshita, T.;
Naruchi, T. Effect of TC-81, a new dihydropyridine derivative,
on K+ induced contraction in rat aorta. Eur. J . Pharmacol. 1991,
205, 49-54.
(59) Gill, R.; Foster, A. C.; Woodruff, G. N. Systemic administra-
tion of MK-801 protects against ischemia-induced hippocampal
neurodegeneration in the gerbil. J . Neurosci. 1987, 7, 3343-
3349.
(49) Negre-Salvayre, A.; Salvayre, R. Protection by Ca2+ channel
blockers (nifedipine, diltiazem and verapamil) against the toxic-
ity of oxidized low density lipoproteins to cultured lymphoid cells.
Br. J . Pharmacol. 1992, 107, 738-744.
(50) Yu, M. J .; McCowan, J . R.; Trasher, K. J .; Keith, P. T.; Luttman,
C. A.; Towner, R. D.; Bertsch, B.; Horng, J . S.; Um, S. L.; Phebus,
L. A.; Saunders, R. D. Phenothiazines as lipid peroxidation
inhibitors and cytoprotective agents. J . Med. Chem. 1992, 35,
716-724.
(51) Canan Koch, S. S.; Chamberlin, A. R. Modified conditions for
efficient Baeyer-Villiger oxidation with m-CPBA. Synth. Com-
mun. 1989, 19, 829-853.
(60) Day, C. E.; Schurr, P. E.; Heyd, W. E.; Lednicer, D. In
Atherosclerosis Drug Discovery; Day, C., E., Ed.; Plenum Pub-
lishing Corp.: New York, 1976; pp 231-249.
J M0108045