New N-(phenoxydecyl)phthalimide derivatives displaying potent inhibition activity towards α-glucosidase

Article abstract of DOI:10.1016/j.bmc.2010.06.088

Several members of a new family of non-sugar-type α-glucosidase inhibitors, bearing a phthalimide moiety connected to a variously substituted phenoxy ring by an alkyl chain, were synthesized and their activities were investigated. The efficacy of the inhibition activity appeared to be governed by the chain length of the substrate. Substrates possessing 10 carbons afforded the highest levels of activity, which were one to two orders of magnitude more potent than the known inhibitor 1-deoxynojirimycin (dNM). Furthermore, structure-activity relationship studies indicated a critical role of electron-withdrawing substituents at the phenoxy group for the activity. Derivatives bearing a chlorine atom along with a strong electron-withdrawing group, such as a nitro group, were the most potent of the series.

Full text of DOI:10.1016/j.bmc.2010.06.088

Bioorganic & Medicinal Chemistry 18 (2010) 5903–5914
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
New N-(phenoxydecyl)phthalimide derivatives displaying potent inhibition
activity towards
a
-glucosidase
a
a
a
Rossana Pascale a, Alessia Carocci a, , Alessia Catalano , Giovanni Lentini , Anna Spagnoletta ,
*
Maria Maddalena Cavalluzzi a, Francesco De Santis c, Annalisa De Palma b, Vito Scalera c, Carlo Franchini a
a Dipartimento Farmaco-Chimico, Università degli Studi di Bari, via E. Orabona 4, 70126 Bari, Italy
b Dipartimento Farmaco-Biologico, Università degli Studi di Bari, via E. Orabona 4, 70126 Bari, Italy
c Dipartimento di Fisiologia Generale e Ambientale, Università degli Studi di Bari, via Amendola 165/A, 70126 Bari, Italy
a r t i c l e i n f o
a b s t r a c t
Article history:
Several members of a new family of non-sugar-type
a-glucosidase inhibitors, bearing a phthalimide
Received 14 April 2010
Revised 26 May 2010
Accepted 28 June 2010
Available online 1 July 2010
moiety connected to a variously substituted phenoxy ring by an alkyl chain, were synthesized and their
activities were investigated. The efficacy of the inhibition activity appeared to be governed by the chain
length of the substrate. Substrates possessing 10 carbons afforded the highest levels of activity, which
were one to two orders of magnitude more potent than the known inhibitor 1-deoxynojirimycin
(dNM). Furthermore, structure–activity relationship studies indicated a critical role of electron-with-
drawing substituents at the phenoxy group for the activity. Derivatives bearing a chlorine atom along
with a strong electron-withdrawing group, such as a nitro group, were the most potent of the series.
Ó 2010 Elsevier Ltd. All rights reserved.
Keywords:
a-Glucosidase
Enzyme inhibitors
Phthalimide
Structure–activity relationships
Substituent effects
1. Introduction
OH
OH
HO
OH
OH
HO
HN
a
-Glucosidase (EC 3.2.1.20,
key enzyme which catalyzes the final step in the digestive process
of carbohydrates in mammalians. Hence, -glucosidase inhibitors
can retard the liberation of -glucose of oligosaccharides and disac-
a-D-glucoside glucohydrolase) is the
N
HO
a
D
HO
HO
OH
HO
charides from dietary complex carbohydrates and delay glucose
absorption, resulting in reduced post-prandial plasma glucose levels
and suppressed post-prandial hyperglycaemia.1 Consequently,
OH
O
miglitol
OH
OH
O
HO
HO
HO
-glucosidase inhibitors such as acarbose2 and miglitol3 (Fig. 1) have
H
N
a
O
been approved for clinical use in the management of type 2 diabetes,
as well as the treatment of obesity. Glucosidase inhibition may also
retard cancer growth since the spread of cancer as well as the
structural changes of cell surface glycoconjugates within neoplasmic
O
HO
O
OH
OH
OH
HO
cells is proliferated by glycosidases.4
a
-Glucosidase inhibitors have
also been observed to block viral infections5 and proliferation in
HIV-infections.6 In fact, the well established
-glucosidase inhibitor
acarbose
dNM
Figure 1. Structures of acarbose, miglitol and dNM.
a
1-deoxynojirimycin (dNM, Fig. 1) exhibits potential anti-human
HIV activity.7 As a consequence, many efforts have been made to
dase inhibitors are sugar mimics which require tedious multi-steps
chemical procedures.17–19 Amongst the various types of glucosidase
inhibitors, also non-sugar derivatives have drawn considerable atten-
tion. Indeed, there is great structural diversity amongst glucosidase
inhibitors, which are not based on a sugar scaffold. In particular, bas-
ing on pharmacological studies involving thalidomide, it was found
that phenylalkyltetrachlorophthalimidederivativesexhibitedpotent
develop new
a-glucosidase inhibitors, as recently reviewed in an
extensive fashion.8 These include transition state analogues,9 newly
identified synthetic compounds,10–13 and natural products isolated
from a variety of species.14–16 However, most of developed glycosi-
* Corresponding author. Tel.: +39 080 5442746; fax: +39 080 5442724.
E-mail address: carocci@farmchim.uniba.it (A. Carocci).
a
-glucosidase inhibition.20,21 The structure–activity relationship
0968-0896/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2010.06.088

5904
R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
studies revealed the importance of the distance between the phthal-
imide ring and the phenyl moiety and the positive influence of elec-
tron-withdrawing groups attached to the phthalimide moiety. The
authors suggested that the length of four methylene units was the
Tables 1–3 and was performed as described in Section 5; as a
positive control, dNM was adopted. At first, the effect of the dis-
tance between the phthalimide ring and a phenoxy moiety was
considered. The compounds listed in Table 1 have a methylene
spacer of different length inserted between the phthalimide moi-
ety and the phenoxy group. As expected, the length of the methy-
lene spacer seems to be critical for enzyme inhibition. Amongst
optimum for the fitting/binding of the compound to a-glucosidase
as exemplified by 4,5,6,7-tetrachloro-2-(4-phenylbutyl)-1H-isoin-
dole-1,3(2H)-dione (CP4P, Fig. 2) which possesses activity one order
of magnitude higher than that of dNM.20 Although the tetrachloroph-
thalimide skeletonisausefulnon-sugar-typesugarmimicpharmaco-
phore, the above mentioned compounds are characterized by high
lipophilicity which could influence their pharmacokinetic properties
and biological activity. In the present study, with the ultimate aim of
this series (n = 2–10), the potency of the
a-glucosidase inhibitory
activity increased as the length of the methylene spacer increased
to n = 10, being compound 20a the most potent of the series. Next,
we investigated the effects of substitution at the phenoxy ring
starting from compounds 8a (n = 2) and 9a (n = 3) as scaffolds
(Table 2). Introduction of a chlorine atom at the para-position
(R3), that is, compounds 8b and 9b, caused the enhancement of
the activity, which seemed to be further increased by the introduc-
tion of one or two additional methyl groups at the ortho-positions
(R1, R4) (8e,f and 9e,f). Dichlorination of compound 9a clearly en-
developing more potent and selective
a-glucosidase inhibitors, a
large series of phenoxyalkyl derivatives, bearing a non-substituted
phthalimide moiety, were prepared in order to investigate struc-
ture–activity relationships and improve druglikeness. In particular,
the effects of substitutions at the aryloxy moiety and the length of
the methylene spacer between the phthalimide group and the phen-
oxy moiety were investigated.
hanced a-glucosidase inhibitory activity (9c,d). Thus, the very po-
tent activity of 20a (Table 1) and the results shown in Table 2 led
us to develop new decamethylene derivatives, variously substi-
tuted at the phenoxy moiety (Table 3). Notably, all the compounds
2. Chemistry
of the 20 series showed IC50 values ranging from 0.5 to 3.5 lM
which are one to two orders of magnitude more potent than the
dNM. Interestingly, compounds 20b,d,f showed an activity higher
than 20a, with only slight differences between each others. The re-
sults obtained with these compounds revealed the importance of
the presence of an electron-withdrawing group at the 4-position
(R3); in fact, compounds 20b,j,p were more potent than the
corresponding 4-methyl derivative 20i [the order of potency is:
20p > 20j > 20b > 20i]. Introduction of a nitro group at the ortho-
position (R1) of 20b markedly enhanced the activity giving the
Compounds 8a,b,e,f, 9a–f, 10a and 11a were prepared via the
synthetic route shown in Scheme 1. It starts from the efficient
protection of aminoalcohols 1–3 with phthalic anhydride. The
phthalimido alcohols obtained (5–7) or commercial 4 were sub-
mitted to condensation with the appropriate phenol under Mitsun-
obu conditions22 to give the desired compounds. Compounds 18a,
19a, 20a,b,d,f,g (Scheme 2) were prepared by submitting commer-
cial bromo propanols 12–14 to Williamson reaction with the
appropriate phenol. The alcohols obtained underwent Mitsunobu
oxidoreductive condensation with phthalimide to give the final
compounds. Compounds 20h–o were obtained by submitting dec-
ane-1,10-diol (21) to two successive Mitsunobu reactions with
phthalimide, the former, and the appropriate phenol, the latter,
via the intermediate 22 as shown in Scheme 3. For the synthesis
of compound 20p (Scheme 4) the replacement of hydroxy group
of 22 with iodine in the presence of triphenylphosphine was
needed before reaction of iodo derivative 23 with 4-(trifluoro-
methyl)phenol. Compounds 20j,q–x were obtained by nitration
of the appropriate phthalimidoalkyl aryl ether with sodium nitrite
(Scheme 5). For the preparation of compound 25a, (4-bromobut-
oxy)benzene (24) was reacted with potassium phthalimide accord-
ing to the Scheme 6.
most potent compound of the series (20q, IC50 = 0.475 lM). How-
ever, the same substitution run on compounds 20j,p, that is, com-
pounds 20t,u, respectively, did not increase the activity;
conceivably, this behaviour could be ascribed to the presence of
two strong electron-withdrawing group at the phenoxy ring simul-
taneously. An additional chlorine atom on 20q at meta-position
(20r) or at the other ortho-position (20s) did not substantially af-
fect the activity. Concerning the effect of o,o0-methyl substituents,
the activity decreased in the order of 20w > 20f > 20m > 20v. Final-
ly, it is noteworthy that compound 20x showed an activity compa-
rable to that of the best compounds of the series (20q,r,s), outlying
the importance of the simultaneous presence of at least a chlorine
atom and a strong electron-withdrawing group, such as a nitro
group, at the phenoxy moiety. Notably, these results are in agree-
ment with those recently reported in the literature by Rawlings
et al.23 which identified a dNM derivative, bearing a nitro substi-
3. Results and discussion
tuted phenyl moiety, as the best
to date. The most potent compounds of the series (20q,r,s,x) con-
cerned for b-glucosidase, -mannosidase, and -galactosidase
showed no inhibition activity at the maximal tested concentration
of 25 M (i.e., two orders of magnitude higher than IC50 values ob-
served for -glucosidase). The results obtained from the MTT assay
a-glucosidase inhibitor reported
On the basis of the studies of Takahashi et al.,20,21 starting from
CP4P as lead compound, a large series of new phthalimide deriva-
tives (Fig. 2) were prepared. All the developed compounds are
characterized by an unsubstituted phthalimide moiety connected
to a variously decorated phenoxy group by an alkyl chain. The
a
a
l
a
a-glucosidase inhibitory activity of the compounds is reported in
on SH-SY5Y human neuroblastoma cells indicate that these com-
pounds show no cytotoxicity.
O
Cl
Cl
O
R1
R2
4. Conclusions
Cl
Cl
N
( )
O
n
N
R3
Application of simple chemical transformations to easily avail-
able starting materials has generated several members of a new
family of non-sugar-type sugar mimic
O
O
R4
a-glucosidase inhibitors
bearing a phthalimide skeleton connected to a variously substi-
tuted phenoxy ring by an alkyl chain. All the compounds (Tables
CP4P
8-11, 18-20, 25
1–3) were screened for
a-glucosidase inhibitory activity, and struc-
Figure 2. Structures of CP4P and newly synthesized N-(phenoxyalkyl) phthalimide
ture–activity relationship studies were carried out. As a result, we
derivatives.

R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
5905
O
O
R1
R2
i
ii
( )n
O
N
( )n
H2N
( )n
N
R3
OH
OH
O
O
R4
1-3
4-7
8a,b,e,f, 9a-f, 10a, 11a
1
2
3
4
a:
b:
c:
d:
e:
f:
R = R = R = R = H
4, 8:
n = 2
1
2
4
3
R = R = R = H, R = Cl
1, 5, 9:
n = 3
1
2
3
4
2, 6, 10:
3, 7, 11:
n = 5
n = 6
R = R = Cl, R = R = H
1
4
2
3
R = R = H, R = R = Cl
1
2
4
3
R = CH3, R = R = H, R = Cl
1
4
2
3
R = R = CH3, R = H, R = Cl
Scheme 1. Reagents and conditions: (i) phthalic anhydride, Et3N, toluene, reflux; (ii) substituted phenol, TPP, DEAD or DIAD, anhyd THF, rt.
O
R1
R4
R2
R1
R2
i
ii
( )n
O
HO
( )n
O
N
( )n
Br
R3
R3
OH
O
R4
12-14
15a, 16a, 17a,b,d,f,g
18a, 19a, 20a,b,d,f,g
1
2
3
4
a:
b:
d:
f:
R = R = R = R = H
12, 15, 18:
13, 16, 19:
14, 17, 20:
n = 8
n = 9
n = 10
1
2
4
3
R = R = R = H, R = Cl
1
4
2
3
R = R = H, R = R = Cl
1
4
2
3
R = R = CH3, R = H, R = Cl
1
3
2
4
g:
R = R = Cl, R = R = H
Scheme 2. Reagents and conditions: (i) substituted phenol, K2CO3, anhyd DMF, 130 °C; (ii) phthalimide, TPP, DEAD or DIAD, anhyd THF, rt.
O
O
R1
R4
R2
i
ii
( )10
O
N
( )10
OH
HO
( )10
OH
N
R3
O
O
20h-o
21
22
1
4
2
3
h:
i:
R = R = H, R = CF3, R = NO2
1
2
4
3
R = R = R = H, R = CH3
1
2
4
3
j:
R = R = R = H, R = NO2
1
2
3
4
k:
l:
R = NO2, R = R = R = H
1
3
4
2
R = R = R = H, R = NO2
1
4
2
3
m:
n:
R = R = CH3, R = R = H
1
3
4
2
R = R = R = H, R = Cl
1
3
2
4
o:
R = R = H, R = Cl, R = CH3
Scheme 3. Reagents and conditions: (i) phthalimide, TPP, DBAD, anhyd THF, rt; (ii) substituted phenol, TPP, DIAD, anhyd THF, rt.

5906
R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
O
O
O
i
ii
( )10
OH
( )10
I
N
N
N
( )10
O
CF3
O
O
O
22
23
20p
Scheme 4. Reagents and conditions: (i) TPP, I2, anhyd toluene, reflux; (ii) 4-(trifluoromethyl)phenol, NaH, anhyd DMF, 0 °C then 75 °C.
O
O
R1
R4
R2
R1
R2
( )10
O
N
( )10
O
i
N
R3
R3
O
O
R4
20a,b,d,f,g,m,o,p
20j,q-x
1
2
3
4
1
2
4
3
a:
b:
d:
f:
j:
R = R = R = R = H
R = R = R = H, R = NO2
1
2
4
3
1
2
4
3
q:
r:
s:
R = R = R = H, R = Cl
R = NO2, R = R = H, R = Cl
1
4
2
3
1
2
3
4
R = R = H, R = R = Cl
R = H, R = R = Cl, R = NO2
1
4
2
3
1
3
2
4
R = R = CH3, R = H, R = Cl
R = R = Cl, R = H, R = NO2
1
3
2
4
1
3
2
4
g:
m:
t:
R = R = Cl, R = R = H
R = R = NO2, R = R = H,
1
4
2
3
1
2
4
3
u:
v:
w:
x:
R = R = CH3, R = R = H
R = NO2, R = R = H, R = CF3
, R2
= NO2, R3 = Cl
1
3
2
4
1
4
o:
p:
R = R = H, R = Cl, R = CH3
R = R = CH3
1
2
4
3
1
4
2
3
R = R = R = H, R = CF3
R = R = CH3, R = H, R = NO2
1
2
3
4
R = H, R = Cl, R = NO2, R = CH3
Scheme 5. Reagents and conditions: (i) NaNO2, trifluoroacetic acid, rt.
Table 2
O
a-Glucosidase inhibitory activity of substituted N-(phenoxyalkyl)phthalimide deriv-
( )
O
Br
atives
i
4
( )4
O
N
O
R2
R1
R4
O
( )n
O
N
24
25a
R3
O
Scheme 6. Reagents and conditions: (i) potassium phthalimide, anhyd DMF, 80 °C.
Compd
n
R1
R2
R3
R4
IC50
(lM)
dNM
8a
8b
8e
8f
9a
9b
9c
—
2
2
2
2
3
3
3
3
3
3
52 2a
Table 1
H
H
CH3
CH3
H
H
Cl
H
CH3
CH3
H
H
H
H
H
H
Cl
Cl
H
H
H
H
H
H
CH3
H
H
H
H
H
296
94
4
4
a
-Glucosidase inhibitory activity of N-(phenoxyalkyl)phthal-
Cl
Cl
Cl
H
Cl
H
Cl
Cl
Cl
imide derivatives
14.8 0.8
13.0 0.1
240 40
59.0 0.5
15.0 0.8
7.55 0.25
8.9 0.4
O
N
( )n
O
9d
9e
9f
O
CH3
9.5 0.3
Compd
n
IC50
(lM)
a
34 4 (Ref. 20).
dNM
8a
—
52 2a
296
2
4
9a
3
4
5
6
8
240 40
identified potent
possess activity one to two orders of magnitude higher than dNM,
with IC50 values of 0.5–3.6 M in our assay system. These biological
results clearly demonstrated that the length of 10 methylene units
and the simultaneous presence of a chlorine atom and a strong elec-
tron-withdrawing group, such as a nitro group, at the phenoxy moi-
a-glucosidase inhibitors (20 series, Table 3) which
25a
10a
11a
18a
19a
20a
33
3
20.2 0.2
10.3 0.1
6.5 0.2
3.04 0.01
2.5 0.2
l
9
10
a
34 4 (Ref. 20).
ety, are the optimum for the binding to a-glucosidase (see 20q,r,s).

R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
5907
Table 3
-Glucosidase inhibitory activity of N-(phenoxydecyl)phthalimide derivatives
5.2. General procedure for the preparation of phthalimido
alcohols (5–7)
a
O
R2
R1
The method adopted for the synthesis of 2-(3-hydroxypropyl)-
1H-isoindole-1,3(2H)-dione (5) is described. A mixture of 3-amino-
propan-1-ol (1) (2.0 g, 26.6 mmol), phthalic anhydride (3.9 g,
26.6 mmol), Et3N (0.27 g, 2.66 mmol) and toluene (40 mL) was
heated under reflux in a flask fitted with a Dean–Stark tube for
3 h. During this period, the temperature of the oil bath was main-
tained at about 130 °C and water separates. All volatile matter was
then evaporated under vacuum and the solid residue was taken up
with EtOAc and washed with 2 N HCl, NaHCO3 saturated solution,
and H2O. The organic phase was dried (Na2SO4) and concentrated
under vacuum. The crude solid was recrystallized (EtOAc/hexane)
to give 5.2 g (95%) of 5 as white crystals: mp 79–80 °C, lit. mp
74–75 °C (MeOH);25 IR (KBr): 3450 (OH), 1775, 1715 (C@O)
cmꢀ1; MS (70 eV) m/z (%) 205 (M+, 22), 160 (100). Anal. Calcd for
( )10
O
N
R3
O
R4
Compd
R1
R2
R3
R4
IC50 (lM)
52 2a
2.5 0.2
dNM
20a
20b
20d
20f
20g
20h
20i
H
H
H
CH3
Cl
H
H
H
NO2
H
CH3
H
H
H
NO2
H
H
H
Cl
H
H
CF3
H
H
H
NO2
H
Cl
Cl
H
H
Cl
H
H
H
NO2
H
Cl
H
Cl
Cl
Cl
H
H
H
1.2 0.2
1.00 0.01
1.34 0.04
1.19 0.11
0.83 0.05
2.10 0.01
0.86 0.03
1.78 0.01
1.075 0.005
3.25 0.02
1.09 0.08
0.91 0.05
0.83 0.12
0.475 0.05
0.52 0.02
0.75 0.01
0.97 0.04
1.31 0.01
3.6 1.5
CH3
H
Cl
NO2
CH3
NO2
H
H
H
H
H
CF3
Cl
Cl
H
H
H
H
20j
20k
20l
C
11H11NO3 (205.21): C, 64.38; H, 5.40; N, 6.83. Found: C, 64.66;
H
H, 5.44; N, 6.90. 1H NMR and 13C NMR are in agreement with those
reported in the literature.25
20m
20n
20o
20p
20q
20r
20s
20t
20u
20v
20w
20x
CH3
H
CH3
H
5.2.1. 2-(5-Hydroxypentyl)-1H-isoindole-1,3(2H)-dione (6)
Prepared as reported above for 5 starting from 2. Yield: 48%;
slightly yellowish oil. Spectroscopic data were in agreement with
those reported in the literature.26
H
NO2
NO2
H
Cl
Cl
NO2
NO2
CH3
CH3
H
NO2
CF3
Cl
NO2
NO2
H
CH3
CH3
CH3
5.2.2. 2-(6-Hydroxyhexyl)-1H-isoindole-1,3(2H)-dione (7)
Prepared as reported above for 5 starting from 3. Yield: 65%;
white solid: mp 55–57 °C (CHCl3/hexane), lit. mp 49–50 °C;27 IR
1.32 0.12
0.65 0.01
a
(KBr): 3461 (OH), 1771, 1708 (C@O) cmꢀ1
.
Anal. Calcd for
34 4 (Ref. 20).
C
14H17NO3 (247.29): C, 68.00; H, 6.93; N, 5.66. Found: C, 67.99; H,
The results obtained strongly suggest that the phenoxy moiety,
appropriately substituted, is an important core for -glucosidase
inhibitory activity. It is interesting to note that all of the most
6.96; N, 5.69. Other spectroscopic data were in agreement with
those reported in the literature.27
a
potent compounds of the series (20q,r,s,x) did not inhibit other
glycosidases, such as b-glucosidase, a-mannosidase, and a-galacto-
sidase, neither did they show cytotoxicity on SH-SY5Y human neu-
5.3. General procedure for the preparation of phthalimidoalkyl
aryl ethers (8a,b,e,f)
roblastoma cells.
The method adopted for the synthesis of 2-[2-(4-chloro-2,6-dim-
ethylphenoxy)ethyl]-1H-isoindole-1,3(2H)-dione (8f) is described. A
solution of diethyl azodicarboxylate (DEAD, 0.96 g, 5.50 mmol) in dry
THF (30 mL) was added dropwise to a solution of commercial 2-(2-
hydroxyethyl)-1H-isoindole-1,3(2H)-dione (4) (0.70 g, 3.66 mmol),
4-chloro-2,6-dimethylphenol (0.86 g, 5.50 mmol), and triphenyl-
phosphine (1.44 g, 5.50 mmol) in dry THF (60 mL) under N2 atmo-
sphere at room temperature. The reaction mixture was stirred
overnight and then concentrated in vacuo. Et2O was added to the
residue and the solid filtered off. The filtrate was evaporated and
the residue was purified by flash chromatography (EtOAc/petro-
leum ether 0.5:9.5) to give 0.39 g of a white solid (32%): IR (KBr):
5. Experimental section
5.1. General methods and materials
All chemicals were purchased from Sigma–Aldrich or Lancaster.
Yields refer to purified products and were not optimized. The struc-
tures of the compounds were confirmed by routine spectrometric
analyses. Only spectra for compounds not previously described
are given. Melting points were determined on a Gallenkamp
melting point apparatus in open glass capillary tubes and are uncor-
rected. Infrared spectra were recorded on a Perkin–Elmer (Norwalk,
CT) Spectrum One FT spectrophotometer and band positions are
given in reciprocal centimetres (cmꢀ1). 1H NMR and 13C NMR spec-
tra were recorded on a Varian VX Mercury spectrometer operating
at 300 and 75 MHz for 1H and 13C, respectively, using CDCl3 as sol-
vent. Chemical shifts are reported in parts per million (ppm) rela-
1773, 1713 (C@O) cmꢀ1 1H NMR d 2.14 (s, 6H, 2CH3), 3.95–4.02
;
(m, 2H, CH2), 4.07–4.15 (m, 2H, CH2), 6.92 (s, 2H, ArO), 7.70–7.78
(m, 2H, Ar), 7.84–7.92 ppm (m, 2H, Ar); 13C NMR d 16.3 (2C), 38.2
(1C), 68.6 (1C), 123.6 (2C), 128.7 (2C), 128.9 (1C), 132.2 (2C), 132.7
(2C), 134.4 (2C), 154.1 (1C), 168.5 ppm (2C); MS (70 eV) m/z (%)
329 (M+, 6), 174 (100). A small amount of 8f was recrystallized from
i-Pr2O/petroleum ether to give white crystals: mp 94–95 °C. Anal.
Calcd for C18H16ClNO3 (329.78): C, 65.56; H, 4.89; N, 4.25. Found:
C, 65.29; H, 4.88; N, 4.27.
tive to solvent resonance: CDCl3, d 7.26 (1H NMR) and d 77.3 (13
C
NMR). J values are given in Hz. EIMS spectra were recorded on a
Hewlett–Packard 6890-5973 MSD gas chromatograph/mass spec-
trometer at low resolution. GC was performed on a Varian 3800
gas chromatograph equipped with a flame ionization detector and
5.3.1. 2-(2-Phenoxyethyl)-1H-isoindole-1,3(2H)-dione (8a)
Prepared as reported above for 8f starting from 4 and phenol.
Yield: 59%; white solid: mp 130–132 °C; IR (KBr): 1771, 1716
a
Jew Scientific DB-5 capillary column (30 m, 0.25 mm i.d.,
0.25 m film thickness). Chromatographic separations were per-
l
formed on silica gel columns by flash chromatography (Kieselgel
60, 0.040–0.063 mm, Merck, Darmstadt, Germany) as described
by Still et al.24 TLC analyses were performed on precoated silica
gel on aluminium sheets (Kieselgel 60 F254, Merck).
(C@O) cmꢀ1 1H NMR d 4.11 (t, J = 5.8 Hz, 2H, CH2N), 4.22 (t,
;
J = 5.6 Hz, 2H, CH2O), 6.85–6.97 (m, 3H, ArO), 7.18–7.30 (m, 2H,
ArO), 7.67–7.78 (m, 2H, Ar), 7.82–7.90 (m, 2H, Ar); 13C NMR d 37.6
(1C), 64.8 (1C), 114.8 (2C), 121.3 (1C), 123.6 (2C), 129.7 (2C), 132.3

5908
R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
(2C), 134.3 (2C), 158.5 (1C), 168.4 (2C); MS (70 eV) m/z (%) 267 (M+,
17), 174 (100). Anal. Calcd for C16H13NO3ꢁ0.33H2O (273.28):C, 70.32,
H, 5.04, N, 5.13. Found: C, 70.18, H, 4.85, N, 5.22.
2H, Ar), 7.78–7.86 ppm (m, 2H, Ar); 13C NMR d 28.6 (1C), 35.7 (1C),
67.6 (1C), 111.4 (1C), 122.2 (1C), 122.6 (1C), 123.4 (2C), 127.4 (1C),
132.4 (2C), 134.0 (1C), 134.2 (2C), 155.9 (1C), 168.6 ppm (2C); MS
(70 eV) m/z (%) 349 (M+, 3), 188 (100). Anal. Calcd for C17H13Cl2NO3
(350.20): C, 58.31; H, 3.74; N, 4.00. Found: C, 58.16; H, 3.74; N, 4.05.
5.3.2. 2-[2-(4-Chlorophenoxy)ethyl]-1H-isoindole-1,3(2H)-dione
(8b)
Prepared as reported above for 8f starting from 4 and 4-chloro-
phenol. Yield: 88%; white solid: mp 146–147 °C; IR (KBr): 1770,
5.3.7. 2-[3-(3,4-Dichlorophenoxy)propyl]-1H-isoindole-1,3(2H)-
dione (9d)
1714 (C@O) cmꢀ1
;
1H NMR d 4.04–4.14 (m, 2H, CH2), 4.16–4.24
Prepared as reported above for 8f starting from 5 and 3,4-
dichlorophenol. Yield: 51% (after recrystallization); white solid:
mp 143–144 °C (THF/petroleum ether); IR (KBr): 1771, 1706
(m, 2H, CH2), 6.75–6.84 (m, 2H, ArO), 7.14–7.24 (m, 2H, ArO),
7.68–7.78 (m, 2H, Ar), 7.82–7.90 ppm (m, 2H, Ar); 13C NMR d
34.4 (1C), 65.3 (1C), 116.2 (2C), 123.6 (2C), 126.3 (1C), 129.5
(2C), 132.2 (2C), 134.3 (2C), 157.1 (1C), 168.3 ppm (2C); MS
(70 eV) m/z (%) 301 (M+, 10), 174 (100). Anal. Calcd for C16H12ClNO3
(301.72): C, 63.69; H, 4.01; N, 4.64. Found: C, 63.70; H, 4.02; N,
4.68.
(C@O) cmꢀ1 1H NMR d 2.17 (quintet, J = 6.3 Hz, 2H, CH2), 3.89 (t,
;
J = 6.6 Hz, 2H, CH2), 3.98 (t, J = 5.8 Hz, 2H, CH2), 6.63 (dd, J = 8.8,
2.8 Hz, 1H, ArO), 6.85 (d, J = 3.0 Hz, 1H, ArO), 7.26 (d, J = 9.1 Hz,
1H, ArO), 7.68–7.76 (m, 2H Ar), 7.80–7.88 ppm (m, 2H, Ar); 13C
NMR d 28.3 (1C), 35.5 (1C), 66.5 (1C), 114.6 (1C), 116.5 (1C),
123.5 (2C), 124.2 (1C), 130.8 (1C), 132.3 (1C), 133.0 (2C), 134.3
(2C), 157.9 (1C), 168.6 ppm (2C); MS (70 eV) m/z (%) 349 (M+, 4),
188 (100). Anal. Calcd for C17H13Cl2NO3 (350.20): C, 58.31; H,
3.74; N, 4.00. Found: C, 58.35; H, 3.77; N, 3.99.
5.3.3. 2-[2-(4-Chloro-2-methylphenoxy)ethyl]-1H-isoindole-
1,3(2H)-dione (8e)
Prepared as reported above for 8f starting from 4 and 4-chloro-
2-methylphenol. Yield: 54% (after recrystallization); white solid:
mp 127–128 °C (THF/petroleum ether); IR (KBr): 1779, 1721
5.3.8. 2-[3-(4-Chloro-2-methylphenoxy)propyl]-1H-isoindole-
1,3(2H)-dione (9e)
(C@O) cmꢀ1 1H NMR d 2.08 (s, 3H, CH3), 4.08–4.22 (m, 4H,
;
2CH2), 6.64–6.72 (m, 1H, ArO), 7.00–7.08 (m, 2H, ArO), 7.68–7.76
(m, 2H, Ar), 7.82–7.90 ppm (m, 2H, Ar); 13C NMR d 16.2 (1C),
37.5 (1C), 65.2 (1C), 111.9 (1C), 123.6 (2C), 125.6 (1C), 126.5
(1C), 129.0 (1C), 130.7 (1C), 132.2 (2C), 134.3 (2C), 155.3 (1C),
168.4 ppm (2C); MS (70 eV) m/z (%) 315 (M+, 7), 174 (100). Anal.
Calcd for C17H14ClNO3 (315.75): C, 64.67; H, 4.47; N, 4.44. Found:
C, 64.68; H, 4.75; N, 4.54.
Prepared as reported above for 8f starting from 5 and 4-chloro-
2-methylphenol, using diisopropyl azodicarboxylate (DIAD) in-
stead of DEAD. Yield: 30% (after recrystallization); white solid:
mp 122–123 °C (THF/petroleum ether); IR (KBr): 1766, 1716
(C@O) cmꢀ1 1H NMR d 2.12 (s, 3H, CH3), 2.20 (quintet, J = 6.5 Hz,
;
2H, CH2), 3.92 (t, J = 6.9 Hz, 2H, CH2), 3.99 (t, J = 6.1 Hz, 2H, CH2),
6.65–6.72 (m, 1H, ArO), 7.02–7.10 (m, 2H, ArO), 7.68–7.76 (m, 2H
Ar), 7.78–7.88 ppm (m, 2H, Ar); 13C NMR d 16.2 (1C), 28.7 (1C),
35.6 (1C), 66.0 (1C), 112.1 (1C), 123.5 (2C), 125.3 (1C), 126.5
(1C), 129.0 (1C), 130.6 (1C), 132.3 (2C), 134.2 (2C), 155.7 (1C),
168.6 ppm (2C); MS (70 eV) m/z (%) 329 (M+, 7), 188 (100). Anal.
Calcd for C18H16ClNO3ꢁ0.33H2O (335.78): C, 64.38; H, 5.00; N,
4.17. Found: C, 64.21; H, 4.83; N, 4.20.
5.3.4. 2-(3-Phenoxypropyl)-1H-isoindole-1,3(2H)-dione (9a)
Prepared as reported above for 8f starting from 5 and phenol.
Yield: 61% (after recrystallization); white solid: mp 94–95 °C
(EtOAc/petroleum ether); IR (KBr): 1770, 1718 (C@O) cmꢀ1 1H
;
NMR d 2.10–2.30 (m, 2H, CH2), 3.91 (t, J = 6.9 Hz, 2H, CH2), 4.03
(t, J = 6.1 Hz, 2H, CH2), 6.76–6.96 (m, 3H, ArO), 7.12–7.35 (m, 2H,
ArO), 7.68–7.94 ppm (m, 4H, Ar); 13C NMR d 28.6 (1C), 35.7 (1C),
65.8 (1C), 114.7 (2C), 121.0 (1C), 123.4 (1C), 123.6 (1C), 129.5
(1C), 129.7 (1C), 132.4 (2C), 134.0 (1C), 134.3 (1C), 158.9 (1C),
168.6 (2C); MS (70 eV) m/z (%) 281 (M+, 6), 188 (100). Anal. Calcd
for C17H15NO3 (281.31): C, 72.58; H, 5.37; N, 4.98. Found: C,
72.36; H, 5.39; N, 5.04.
5.3.9. 2-[3-(4-Chloro-2,6-dimethylphenoxy)propyl]-1H-isoindole-
1,3(2H)-dione (9f)
Prepared as reported above for 8f starting from 5 and 4-
chloro-2,6-dimethylphenol, using DIAD instead of DEAD. Yield:
56% (after recrystallization); white solid: mp 136–137 °C (THF/
petroleum ether); IR (KBr): 1773, 1716 (C@O) cmꢀ1 1H NMR d
;
2.12–2.27 (m overlapping s at 2.22, 2H, CH2), 2.22 (s overlapping
m at 2.12–2.27, 6H, 2CH3), 3.81 (t, J = 6.2 Hz, 2H, CH2), 3.94 (t,
J = 7.3 Hz, 2H, CH2), 6.95 (s, 2H, ArO), 7.66–7.76 (m, 2H, Ar),
7.80–7.90 ppm (m, 2H, Ar); 13C NMR d 16.5 (2C), 29.7 (1C),
35.7 (1C), 70.1 (1C), 123.5 (2C), 128.6 (3C), 132.3 (2C), 132.8
(2C), 134.2 (2C), 154.7 (1C), 168.6 ppm (2C); MS (70 eV) m/z
(%) 343 (M+, 1), 188 (100). Anal. Calcd for C19H18ClNO3
(343.80): C, 66.38; H, 5.28; N, 4.07. Found: C, 66.75; H, 5.30;
N, 4.11.
5.3.5. 2-[3-(4-Chlorophenoxy)propyl]-1H-isoindole-1,3(2H)-
dione (9b)
Prepared as reported above for 8f starting from 5 and 4-chloro-
phenol. Yield: 64% (after recrystallization); white solid: mp
114–115 °C (EtOAc/petroleum ether); IR (KBr): 1772, 1705 (C@O)
;
cmꢀ1 1H NMR d 2.17 (apparent quintet, 2H, CH2), 3.90 (t,
J = 6.9 Hz, 2H, CH2), 3.99 (t, J = 6.1 Hz, 2H, CH2), 6.68–6.76 (m, 2H,
ArO), 7.14–7.22 (m, 2H, ArO), 7.68–7.76 (m, 2H, Ar), 7.80–
7.88 ppm (m, 2H, Ar); 13C NMR d 28.5 (1C), 35.6 (1C), 66.2 (1C),
115.9 (2C), 123.5 (2C), 125.9 (1C), 129.5 (2C), 132.4 (2C), 134.2
(2C), 157.5 (1C), 168.6 ppm (2C); MS (70 eV) m/z (%) 315 (M+, 7),
188 (100). Anal. Calcd for C17H14ClNO3 (315.75): C, 64.67; H, 4.47;
N, 4.44. Found: C, 64.33; H, 4.44; N, 4.45.
5.3.10. 2-(5-Phenoxypentyl)-1H-isoindole-1,3(2H)-dione (10a)
Prepared as reported above for 8f starting from 6 and phenol.
Yield: 61% (after recrystallization); white solid: mp 76–77 °C
(EtOAc/hexane); IR (KBr): 1771, 1704 (C@O) cmꢀ1 1H NMR d
;
1.45–1.60 (m, 2H, CH2), 1.68–1.90 (m, 4H, 2CH2), 3.72 (t,
J = 7.1 Hz, 2H, CH2), 3.95 (t, J = 6.5 Hz, 2H, CH2), 6.80–6.96 (m, 3H,
ArO), 7.18–7.32 (m, 2H, ArO), 7.65–7.75 (m, 2H, Ar), 7.76–
7.88 ppm (m, 2H, Ar); 13C NMR d 23.7 (1C), 28.6 (1C), 29.1 (1C),
38.1 (1C), 67.7 (1C), 114.7 (2C), 120.7 (1C), 123.4 (2C), 129.6
(2C), 132.4 (2C), 134.1 (2C), 159.2 (1C), 168.7 ppm (2C); MS
(70 eV) m/z (%) 309 (M+, 13), 160 (100). Anal. Calcd for
5.3.6. 2-[3-(2,3-Dichlorophenoxy)propyl]-1H-isoindole-1,3(2H)-
dione (9c)
Prepared as reported above for 8f starting from 5 and 2,3-dichlo-
rophenol. Yield: 72% (after recrystallization); white solid: mp 169–
170 °C (EtOAc/hexane); IR (KBr): 1770, 1715 (C@O) cmꢀ1; 1H NMR
d 2.25 (apparent quintet, 2H, CH2), 3.94 (t, J = 6.6 Hz, 2H, CH2), 4.09
(t, J = 6.1 Hz, 2H, CH2), 6.79 (dd, J = 8.0, 1.7 Hz, 1H, ArO), 7.03 (dd,
J = 8.1, 1.5 Hz, 1H, ArO), 7.10 (apparent t, 1H, ArO), 7.66–7.74 (m,
C19H19NO3ꢁ0.25H2O (313.86): C, 72.71; H, 6.26; N, 4.46. Found: C,
72.85; H, 6.10; N, 4.51.

R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
5909
5.3.11. 2-(6-Phenoxyhexyl)-1H-isoindole-1,3(2H)-dione (11a)
Prepared as reported above for 8f starting from 7 and phenol.
Yield: 53% (after recrystallization); white solid: mp 66–68 °C
116.0 (2C), 125.5 (1C), 129.5 (2C), 158.0 ppm (1C); MS (70 eV) m/
z (%) 284 (M+, 19), 128 (100).
(EtOAc/petroleum ether); IR (KBr): 1773, 1704 (C@O) cmꢀ1
;
1H
5.4.4. 10-(3,4-Dichlorophenoxy)decan-1-ol (17d)
NMR d 1.35–1.60 (m, 4H, 2CH2), 1.60–1.85 (m, 4H, 2CH2), 3.69 (t,
J = 7.1 Hz, 2H, CH2), 3.94 (t, J = 6.5 Hz, 2H, CH2), 6.82–6.97 (m, 3H,
ArO), 7.20–7.32 (m, 2H, ArO), 7.65–7.75 (m, 2H, Ar), 7.78–
7.88 ppm (m, 2H, Ar); 13C NMR d 25.9 (1C), 26.8 (1C), 28.7 (1C),
29.4 (1C), 38.1 (1C), 67.9 (1C), 114.8 (2C), 120.7 (1C), 123.3 (2C),
129.6 (2C), 132.5 (2C), 134.0 (2C), 159.3 (1C), 168.6 ppm (2C);
MS (70 eV) m/z (%) 323 (M+, 17), 160 (100). Anal. Calcd for
Prepared as reported above for 17a starting from 14 and
3,4-dichlorophenol. Yield: 47%; slightly yellowish oil: IR (neat):
3340 (OH) cmꢀ1 1H NMR d 1.20–1.62 (m, 15H, 7CH2 + OH), 1.76
;
(apparent quintet, 2H, CH2), 3.64 (t, J = 6.6 Hz, 2H, CH2), 3.90 (t,
J = 6.5 Hz, 2H, CH2), 6.74 (dd, J = 8.9, 2.9 Hz, 1H, Ar), 6.97 (d,
J = 2.8 Hz, 1H, Ar), 7.30 ppm (d, J = 8.8 Hz, 1H, Ar); 13C NMR d
25.9 (1C), 26.1 (1C), 29.3 (1C), 29.5 (1C), 29.6 (2C), 29.7 (1C),
33.0 (1C), 63.3 (1C), 68.9 (1C), 114.8 (1C), 116.6 (1C), 123.9 (1C),
130.8 (1C), 133.0 (1C), 158.5 ppm (1C); MS (70 eV) m/z (%) 318
(M+, 20), 162 (100).
C20H21NO3 (323.39): C, 74.28; H, 6.55; N, 4.33. Found: C, 74.61;
H, 6.59; N, 4.43.
5.4. General procedure for the preparation of phenoxy alcohols
(15a, 16a, 17a,b,d,f,g)
5.4.5. 10-(4-Chloro-2,6-dimethylphenoxy)decan-1-ol (17f)
Prepared as reported above for 17a starting from 14 and
4-chloro-2,6-dimethylphenol. Yield: 29%; slightly yellowish oil:
The method adopted for the synthesis of 10-phenoxydecan-1-ol
(17a) is described. K2CO3 (0.32 g, 2.32 mmol) was added to a solu-
tion of 10-bromodecan-1-ol (14) (0.50 g, 2.11 mmol) in dry DMF
(30 mL) under N2 atmosphere. The reaction mixture was heated
at 130 °C and then a solution of phenol (0.22 g, 2.32 mmol) in
20 mL of dry DMF was added dropwise during a period of 3 h.
The mixture was stirred at this temperature for 24 h. After evapo-
ration of the solvent, the residue was taken up with EtOAc, washed
with 2 N NaOH, and then with brine. The organic phase was dried
(Na2SO4) and concentrated under vacuum. The residue was puri-
fied by column chromatography on silica gel (EtOAc/petroleum
ether 1.5:8.5) to give 0.12 g (23%) of 17a as a white solid: mp
IR (neat): 3343 (OH) cmꢀ1 1H NMR d 1.26–1.42 (m, 10H, 5CH2),
;
1.42–1.62 (m overlapping br s at 1.50, 4H, 2CH2), 1.50 (br s over-
lapping m at 1.42–1.62, 1H, OH), 1.78 (apparent quintet, 2H,
CH2), 2.23 (s, 6H, 2CH3), 3.64 (t, J = 6.6 Hz, 2H, CH2), 3.71 (t,
J = 6.6 Hz, 2H, CH2), 6.97 ppm (s, 2H, Ar); 13C NMR d 16.4 (2C),
25.9 (1C), 26.3 (1C), 29.6 (1C), 29.7 (2C), 29.8 (1C), 30.6 (1C),
33.0 (1C), 63.3 (1C), 72.7 (1C), 128.4 (1C), 128.6 (2C), 132.9 (2C),
154.9 ppm (1C); MS (70 eV) m/z (%) 312 (M+, 9), 156 (100).
5.4.6. 10-(2,4-Dichlorophenoxy)decan-1-ol (17g)
Prepared as reported above for 17a starting from 14 and
2,4-dichlorophenol. Yield: 65%; slightly yellowish oil: IR (neat):
52–54 °C; IR (KBr): 3304 (OH) cmꢀ1 1H NMR d 1.20–1.50 (m,
;
12H, 6CH2), 1.50–1.62 (m, 2H, CH2), 1.67 (br s, 1H, OH), 1.78
(apparent quintet, 2H, CH2), 3.63 (t, J = 6.6 Hz, 2H, CH2), 3.95 (t,
J = 6.6 Hz, 2H, CH2), 6.85–6.98 (m, 3H, Ar), 7.22–7.32 ppm (m, 2H,
Ar); 13C NMR d 25.9 (1C), 26.3 (1C), 29.5 (1C), 29.6 (2C), 29.7
(2C), 33.0 (1C), 63.3 (1C), 68.1 (1C), 114.8 (2C), 120.7 (1C), 129.6
(2C), 159.4 ppm (1C); MS (70 eV) m/z (%) 250 (M+, 15), 94 (100).
3369 (OH) cmꢀ1 1H NMR d 1.20–1.40 (m, 11H, 5CH2 + OH), 1.40–
;
1.70 (m, 4H, 2CH2), 1.82 (apparent quintet, 2H, CH2), 3.64 (t,
J = 6.6 Hz, 2H, CH2), 3.98 (t, J = 6.5 Hz, 2H, CH2), 6.82 (d, J = 8.8 Hz,
1H, Ar), 7.15 (dd, J = 8.8, 2.5 Hz, 1H, Ar), 7.35 ppm (d, J = 2.8 Hz,
1H, Ar); 13C NMR d 25.9 (1C), 26.1 (1C), 29.2 (1C), 29.5 (1C), 29.6
(2C), 29.7 (1C), 33.0 (1C), 63.3 (1C), 69.8 (1C), 114.3 (1C), 124.0
(1C), 125.7 (1C), 127.7 (1C), 130.1 (1C), 153.8 ppm (1C); MS
(70 eV) m/z (%) 318 (M+, 15), 162 (100).
5.4.1. 8-Phenoxyoctan-1-ol (15a)
Prepared as reported above for 17a starting from 12 and phenol.
Yield: 20%; white solid: mp 37–39 °C; IR (KBr): 3305 (OH) cmꢀ1; 1H
NMR d 1.25–1.63 (m, 11H, 5CH2 + OH), 1.78 (apparent quintet, 2H,
CH2), 3.63 (t, J = 6.6 Hz, 2H, CH2), 3.95 (t, J = 6.6 Hz, 2H, CH2), 6.86–
6.97 (m, 3H, Ar), 7.23–7.32 ppm (m, 2H, Ar); 13C NMR d 25.9 (1C),
26.3 (1C), 29.5 (2C), 29.7 (1C), 33.0 (1C), 63.3 (1C), 68.1 (1C), 114.7
(2C), 120.7 (1C), 129.6 (2C), 159.3 ppm (1C); MS (70 eV) m/z (%)
222 (M+, 15), 94 (100).
5.4.7. 2-(8-Phenoxyoctyl)-1H-isoindole-1,3(2H)-dione (18a)
Prepared as reported above for 8f starting from 15a and phthal-
imide. Yield: 20% (after recrystallization); white crystals: mp
76–77 °C (THF/petroleum ether + hexane); IR (KBr): 1765, 1714
(C@O) cmꢀ1 1H NMR d 1.28–1.51 (m, 8H, 4CH2), 1.67 (apparent
;
br t overlapping apparent quintet at 1.76, 2H, CH2), 1.76 (apparent
quintet overlapping apparent br t at 1.67, 2H, CH2), 3.68 (t,
J = 7.3 Hz, 2H, CH2), 3.93 (t, J = 6.6 Hz, 2H, CH2), 6.82–6.96 (m, 3H,
ArO), 7.22–7.32 (m, 2H, ArO), 7.66–7.74 (m, 2H, Ar), 7.80–
7.88 ppm (m, 2H, Ar); 13C NMR d 26.2 (1C), 27.0 (1C), 28.8 (1C),
29.3 (1C), 29.5 (2C), 38.3 (1C), 68.0 (1C), 114.7 (2C), 120.7
(1C), 123.4 (2C), 129.6 (2C), 132.4 (2C), 134.1 (2C), 159.3 (1C),
168.7 ppm (2C); MS (70 eV) m/z (%) 351 (M+, 24), 160 (100). Anal.
Calcd for C22H25NO3 (351.44): C, 75.19; H, 7.17; N, 3.99. Found: C,
75.19; H, 7.18; N, 4.13.
5.4.2. 9-Phenoxynonan-1-ol (16a)
Prepared as reported above for 17a starting from 13 and phenol.
Yield: 28% (after recrystallization); white crystals: mp 49–51 °C
(EtOAc/petroleum ether); IR (KBr): 3307 (OH) cmꢀ1 1H NMR d
;
1.18–1.50 (m, 10H, 5CH2), 1.50–1.64 (m, 3H, CH2 + OH), 1.78
(apparent quintet, 2H, CH2), 3.64 (t, J = 6.5 Hz, 2H, CH2), 3.95 (t,
J = 6.6 Hz, 2H, CH2), 6.86–6.97 (m, 3H, Ar), 7.23–7.32 ppm (m, 2H,
Ar); 13C NMR d 25.9 (1C), 26.2 (1C), 29.5 (2C), 29.6 (1C), 29.7
(1C), 33.0 (1C), 63.3 (1C), 68.1 (1C), 114.8 (2C), 120.7 (1C), 129.6
(2C), 159.3 ppm (1C); MS (70 eV) m/z (%) 236 (M+, 25), 94 (100).
5.4.8. 2-(9-Phenoxynonyl)-1H-isoindole-1,3(2H)-dione (19a)
Prepared as reported above for 8f starting from 16a and phthal-
imide, using DIAD instead of DEAD. Yield: 60% (after recrystalliza-
tion); white crystals: mp 69–71 °C (EtOAc/hexane); IR (KBr): 1773,
5.4.3. 10-(4-Chlorophenoxy)decan-1-ol (17b)
Prepared as reported above for 17a starting from 14 and 4-chlo-
rophenol. Yield: 36%; slightly yellow solid: mp 44–45 °C; IR (KBr):
1705 (C@O) cmꢀ1 1H NMR d 1.25–1.52 (m, 10H, 5CH2), 1.67
;
(apparent br t overlapping apparent quintet at 1.76, 2H, CH2),
1.76 (apparent quintet overlapping apparent br t at 1.67, 2H,
CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 3.93 (t, J = 6.5 Hz, 2H, CH2),
6.84–6.96 (m, 3H, ArO), 7.22–7.32 (m, 2H, ArO), 7.66–7.74 (m,
2H, Ar), 7.80–7.88 ppm (m, 2H, Ar); 13C NMR d 26.2 (1C), 27.0
(1C), 28.8 (1C), 29.3 (1C), 29.5 (2C), 29.6 (1C), 38.3 (1C), 68.1
3370 (OH) cmꢀ1 1H NMR d 1.20–1.50 (m, 12H, 6CH2), 1.50–1.64
;
(m, 3H, CH2 + OH), 1.76 (apparent quintet, 2H, CH2), 3.64 (t,
J = 6.6 Hz, 2H, CH2), 3.91 (t, J = 6.6 Hz, 2H, CH2), 6.75–6.86 (m, 2H,
Ar), 7.14–7.26 ppm (m, 2H, Ar); 13C NMR d 25.9 (1C), 26.2 (1C),
29.4 (1C), 29.6 (2C), 29.7 (2C), 33.0 (1C), 63.3 (1C), 68.5 (1C),

5910
R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
(1C), 114.7 (2C), 120.6 (1C), 123.4 (2C), 129.6 (2C), 132.4 (2C),
134.1 (2C), 159.3 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 365
(M+, 25), 160 (100). Anal. Calcd for C23H27NO3ꢁ0.20H2O (369.06):
C, 74.85; H, 7.48; N, 3.80. Found: C, 75.13; H, 7.39; N, 3.86.
3.70, J = 7.4 Hz, 2H, CH2), 3.70 (t overlapping t at 3.67, J = 6.6 Hz,
2H, CH2), 6.97 (d, J = 0.6 Hz, 2H, ArO), 7.66–7.74 (m, 2H, Ar),
7.78–7.88 ppm (m, 2H, Ar); 13C NMR d 16.4 (2C), 26.3 (1C), 27.1
(1C), 28.8 (1C), 29.4 (1C), 29.6 (1C), 29.7 (2C), 30.6 (1C), 38.3
(1C), 72.7 (1C), 123.4 (2C), 128.4 (1C), 128.6 (2C), 132.4 (2C),
132.9 (2C), 134.1 (2C), 154.9 (1C), 168.7 ppm (2C); MS (70 eV) m/
z (%) 441 (M+, 5), 156 (100). Anal. Calcd for C26H32ClNO3ꢁ0.25H2O
(441.99): C, 69.94; H, 7.34; N, 3.14. Found: C, 70.24; H, 7.75; N,
3.17.
5.4.9. 2-(10-Phenoxydecyl)-1H-isoindole-1,3(2H)-dione (20a)
Prepared as reported above for 8f starting from 17a and phthal-
imide. Yield: 50% (after recrystallization); white crystals: mp
73–74 °C (EtOAc); IR (KBr): 1771, 1715 (C@O) cmꢀ1 1H NMR d
;
1.22–1.50 (m, 12H, 6CH2), 1.66 (apparent br t overlapping apparent
quintet at 1.76, 2H, CH2), 1.76 (apparent quintet overlapping
apparent br t at 1.66, 2H, CH2), 3.67 (t, J = 7.4 Hz, 2H, CH2), 3.94
(t, J = 6.6 Hz, 2H, CH2), 6.84–6.96 (m, 3H, ArO), 7.22–7.32 (m, 2H,
ArO), 7.66–7.74 (m, 2H, Ar), 7.78–7.88 ppm (m, 2H, Ar); 13C NMR
d 26.3 (1C), 27.1 (1C), 28.8 (1C), 29.4 (1C), 29.5 (1C), 29.6 (2C),
29.7 (1C), 38.3 (1C), 68.1 (1C), 114.7 (2C), 120.6 (1C), 123.4
(2C), 129.6 (2C), 132.4 (2C), 134.1 (2C), 159.3 (1C), 168.7 ppm
(2C); MS (70 eV) m/z (%) 379 (M+, 18), 160 (100). Anal. Calcd for
C24H29NO3 (379.49): C, 75.96; H, 7.70; N, 3.69. Found: C, 76.30;
H, 7.75; N, 3.71.
5.4.13. 2-[10-(2,4-Dichlorophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20g)
Prepared as reported above for 8f starting from 17g and phthali-
mide, using DIAD instead of DEAD. Yield: 40% (after recrystalliza-
tion); white crystals: mp 82–83 °C (EtOAc/petroleum ether); IR
(KBr): 1766, 1711 (C@O) cmꢀ1; 1H NMR d 1.20–1.40 (m overlapping
m at 1.38–1.52, 10H, 5CH2), 1.38–1.52 (m overlapping m at 1.20–
1.40, 2H, CH2), 1.58–1.73 (m, 2H, CH2), 1.81 (apparent quintet, 2H,
CH2), 3.67 (t, J = 7.4 Hz, 2H, CH2), 3.98 (t, J = 6.5 Hz, 2H, CH2), 6.81
(d, J = 8.8 Hz, 1H, ArO), 7.15 (dd, J = 8.8, 2.8 Hz, 1H, ArO), 7.34 (d,
J = 2.5 Hz, 1H, ArO), 7.66–7.74 (m, 2H, Ar), 7.78–7.88 ppm (m, 2H,
Ar); 13C NMR d 26.1 (1C), 27.1 (1C), 28.8 (1C), 29.2 (1C), 29.4 (2C),
29.6 (2C), 38.3 (1C), 69.7 (1C), 114.2 (1C), 123.4 (2C), 123.9 (1C),
125.6 (1C), 127.7 (1C), 130.1 (1C), 132.4 (2C), 134.1 (2C), 153.7
(1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 447 (M+, 2), 160 (100). Anal.
Calcd for C24H27Cl2NO3ꢁ0.33H2O (454.38): C, 63.44; H, 6.14; N, 3.08.
Found: C, 63.63; H, 6.00; N, 3.27.
5.4.10. 2-[10-(4-Chlorophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20b)
Prepared as reported above for 8f starting from 17b and phthal-
imide, using DIAD instead of DEAD. Yield: 75% (after recrystalliza-
tion); white crystals: mp 72–73 °C (THF/petroleum ether); IR
(KBr): 1768, 1695 (C@O) cmꢀ1 1H NMR d 1.20–1.48 (m, 12H,
;
6CH2), 1.66 (apparent br t overlapping apparent quintet at 1.75,
2H, CH2), 1.75 (apparent quintet overlapping apparent br t at
1.66, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 3.90 (t, J = 6.6 Hz, 2H,
CH2), 6.76–6.84 (m, 2H, ArO), 7.16–7.24 (m, 2H, ArO), 7.66–7.74
(m, 2H, Ar), 7.80–7.88 ppm (m, 2H, Ar); 13C NMR d 26.2 (1C),
27.1 (1C), 28.8 (1C), 29.4 (2C), 29.5 (1C), 29.6 (2C), 38.3 (1C),
68.5 (1C), 116.0 (2C), 123.4 (2C), 125.5 (1C), 129.4 (2C), 132.4
(2C), 134.1 (2C), 158.0 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%)
413 (M+, 13), 160 (100). Anal. Calcd for C24H28ClNO3ꢁ033H2O
(419.94): C, 68.64; H, 6.88; N, 3.34. Found: C, 68.68; H, 6.73; N,
3.44.
5.4.14. 2-{10-[4-Nitro-3-(trifluoromethyl)phenoxy]decyl}-1H-
isoindole-1,3(2H)-dione (20h)
Prepared as reported above for 8f starting from 22 and 4-nitro-
3-(trifluoromethyl)phenol, using DIAD instead of DEAD. Yield: 61%
(after recrystallization); white crystals: mp 89–91 °C (EtOAc/hex-
ane); IR (KBr): 1774, 1712 (C@O), 1532, 1355 (NO2) cmꢀ1 1H
;
NMR d 1.20–1.52 (m, 12H, 6CH2), 1.54–1.74 (m, 2H, CH2), 1.82
(apparent quintet, 2H, CH2), 3.67 (t, J = 7.4 Hz, 2H, CH2), 4.06 (t,
J = 6.5 Hz, 2H, CH2), 7.08 (dd, J = 8.9, 2.6 Hz, 1H, ArO), 7.28 (d,
J = 2.5 Hz, 1H, ArO), 7.66–7.75 (m, 2H, Ar), 7.78–7.88 (m, 2H, Ar),
8.00 ppm (d, J = 9.1 Hz, 1H, ArO); 13C NMR d 26.0 (1C), 27.0 (1C),
28.8 (1C), 29.0 (1C), 29.3 (1C), 29.4 (1C), 29.5 (1C), 29.6 (1C),
38.2 (1C), 69.5 (1C), 115.0 (q, JCF = 5.9 Hz, 1C), 116.7 (1C), 122.1
(br q, JCF = 273.5 Hz, 1C), 123.4 (2C), 126.3 (q, JCF = 34.0 Hz, 1C),
128.4 (1C), 132.4 (2C), 134.1 (2C), 140.8 (1C), 162.5 (1C),
168.7 ppm (2C). Anal. Calcd for C25H27F3N2O5 (492.49): C, 60.97;
H, 5.53; N, 5.69. Found: C, 61.21; H, 5.58; N, 5.79.
5.4.11. 2-[10-(3,4-Dichlorophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20d)
Prepared as reported above for 8f starting from 17d and phthal-
imide, using DIAD instead of DEAD. Yield: 57% (after recrystalliza-
tion); white crystals: mp 82–83 °C (THF/petroleum ether); IR
(KBr): 1771, 1720 (C@O) cmꢀ1 1H NMR d 1.20–1.48 (m, 12H,
;
6CH2), 1.66 (apparent br t overlapping apparent quintet at 1.74,
2H, CH2), 1.74 (apparent quintet overlapping apparent br t at
1.66, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 3.89 (t, J = 6.5 Hz, 2H,
CH2), 6.73 (dd, J = 8.8, 3.0 Hz, 1H, ArO), 6.97 (d, J = 2.8 Hz, 1H,
ArO), 7.29 (d, J = 9.1 Hz, 1H, ArO), 7.66–7.76 (m, 2H, Ar), 7.78–
7.88 ppm (m, 2H, Ar); 13C NMR d 26.1 (1C), 27.0 (1C), 28.8 (1C),
29.3 (2C), 29.5 (1C), 29.6 (2C), 38.3 (1C), 68.8 (1C), 114.8 (1C),
116.5 (1C), 123.4 (2C), 123.8 (1C), 130.8 (1C), 132.4 (1C), 133.0
(2C), 134.1 (2C), 158.4 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%)
447 (M+, 8), 160 (100). Anal. Calcd for C24H27Cl2NO3ꢁ0.25H2O
(452.88): C, 63.65; H, 6.12; N, 3.09. Found: C, 63.74; H, 6.06; N,
3.20.
5.4.15. 2-[10-(4-Methylphenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20i)
Prepared as reported above for 8f starting from 22 and 4-methyl-
phenol, using DIAD instead of DEAD. Yield: 90% (after recrystalliza-
tion); white crystals: mp 77–79 °C (THF/petroleum ether); IR
(KBr): 1770, 1703 (C@O), cmꢀ1 1H NMR d 1.20–1.50 (m, 12H,
;
6CH2), 1.55–1.82 (m, 4H, 2CH2), 2.27 (s, 3H, CH3), 3.67 (t, J = 7.3 Hz,
2H, CH2), 3.91 (t, J = 6.6 Hz, 2H, CH2), 6.72–6.82 (m, 2H, ArO), 7.02–
7.10 (m, 2H, ArO), 7.65–7.74 (m, 2H, Ar), 7.78–7.88 ppm (m, 2H,
Ar); 13C NMR d 20.7 (1C), 26.2 (1C), 27.1 (1C), 28.8 (1C), 29.4 (1C),
29.5 (2C), 29.6 (1C), 29.7 (1C), 38.3 (1C), 68.3 (1C), 114.6 (2C),
123.4 (2C), 129.8 (1C), 130.0 (2C), 132.4 (2C), 134.0 (2C), 157.2
(1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 393 (M+, 15), 108 (100).
Anal. Calcd for C25H31NO3ꢁ0.25H2O (398.02): C, 75.44; H, 7.98; N,
3.52. Found: C, 75.70; H, 7.87; N, 3.61.
5.4.12. 2-[10-(4-Chloro-2,6-dimethylphenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20f)
Prepared as reported above for 8f starting from 17f and phthal-
imide, using DIAD instead of DEAD. Yield: 87% (after recrystalliza-
tion); white crystals: mp 56–58 °C (EtOAc/petroleum ether); IR
5.4.16. 2-[10-(4-Nitrophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20j)
(KBr): 1770, 1706 (C@O) cmꢀ1 1H NMR d 1.22–1.40 (m, 10H,
;
5CH2), 1.40–1.54 (m, 2H, CH2), 1.62–1.70 (m, 2H, CH2), 1.77 (appar-
ent quintet, 2H, CH2), 2.22 (s, 6H, 2CH3), 3.67 (t overlapping t at
Prepared as reported above for 8f starting from 22 and 4-nitro-
phenol and DIAD. Yield: 52%; white solid: mp 100–102 °C; IR

R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
5911
(KBr): 1772, 1718 (C@O), 1501, 1345 (NO2) cmꢀ1; 1H NMR d 1.22–
5.4.20. 2-[10-(3-Chlorophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20n)
1.50 (m, 12H, 6CH2), 1.54–1.70 (m, 2H, CH2), 1.80 (apparent quintet,
2H, CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 4.03 (t, J = 6.5 Hz, 2H, CH2),
6.86–6.96 (m, 2H, ArO), 7.66–7.74 (m, 2H, Ar), 7.78–7.88 (m, 2H,
Ar), 8.14–8.22 ppm (m, 2H, ArO); 13C NMR d 26.1 (1C), 27.0 (1C),
28.8 (1C), 29.2 (1C), 29.3 (1C), 29.4 (1C), 29.5 (1C), 29.6 (1C), 38.3
(1C), 69.1 (1C), 114.6 (2C), 123.4 (2C), 126.1 (2C), 132.4 (2C), 134.1
(2C), 141.5 (1C), 164.5 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%)
407 (M+ ꢀ 17, <1), 160 (100). Anal. Calcd for C24H28N2O5 (424.49):
C, 67.91; H, 6.65; N, 6.60. Found: C, 68.14; H, 6.83; N, 6.43.
Prepared as reported above for 8f starting from 22 and 3-chlo-
rophenol, using DIAD instead of DEAD. Yield: 95% (after recrystal-
lization); white crystals: mp 70–71 °C (EtOAc/hexane); IR (KBr):
1768, 1715 (C@O) cmꢀ1 1H NMR d 1.22–1.50 (m, 12H, 6CH2),
;
1.55–1.72 (m, 2H, CH2), 1.75 (apparent quintet, 2H, CH2), 3.67 (t,
J = 7.4 Hz, 2H, CH2), 3.92 (t, J = 6.6 Hz, 2H, CH2), 6.77 (ddd, J = 8.3,
2.3, 1.0 Hz, 1H, ArO), 6.88 (d overlapping ddd at 6.89, J = 1.4 Hz,
1H, ArO), 6.89 (ddd overlapping d at 6.88, J = 10.2, 1.9, 0.8 Hz, 1H,
ArO), 7.17 (apparent t, 1H, ArO), 7.66–7.74 (m, 2H, Ar), 7.80–
7.88 ppm (m, 2H, Ar); 13C NMR d 26.2 (1C), 27.0 (1C), 28.8 (1C),
29.3 (2C), 29.5 (1C), 29.6 (2C), 38.3 (1C), 68.4 (1C), 113.3 (1C),
115.1 (1C), 120.8 (1C), 123.4 (2C), 130.3 (1C), 132.4 (2C), 134.1
(2C), 135.0 (1C), 160.1 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%)
413 (M+, 12), 160 (100). Anal. Calcd for C24H28ClNO3 (413.94): C,
69.64; H, 6.82; N, 3.38. Found: C, 69.46; H, 6.80; N, 3.41.
5.4.17. 2-[10-(2-Nitrophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20k)
Prepared as reported above for 8f starting from 22 and 2-nitro-
phenol, using DIAD instead of DEAD. Yield: 88% (after recrystalliza-
tion); white crystals: mp 101–103 °C (EtOAc/hexane); IR (KBr):
1766, 1714 (C@O), 1518, 1337 (NO2) cmꢀ1 1H NMR d 1.21–1.40
;
(m overlapping m at 1.38–1.52, 10H, 5CH2), 1.38–1.52 (m overlap-
pingm at1.21–1.40, 2H, CH2), 1.58–1.72(m, 2H, CH2), 1.81 (apparent
quintet, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 4.03 (t, J = 6.5 Hz, 2H,
CH2), 6.99 (t, J = 7.8 Hz, 1H, ArO), 7.05 (d, J = 8.5 Hz, 1H, ArO), 7.45–
7.54 (m, 1H, ArO), 7.66–7.74 (m, 2H, Ar), 7.78–7.88 (m overlapping
d at 7.79, 2H, Ar), 7.79 ppm (d overlapping m at 7.78–7.88,
J = 1.6 Hz, 1H, ArO); 13C NMR d 26.0 (1C), 27.0 (1C), 28.8 (1C), 29.1
(1C), 29.3 (1C), 29.4 (1C), 29.6 (2C), 38.3 (1C), 69.8 (1C), 114.7 (1C),
120.2 (1C), 123.4 (2C), 125.7 (1C), 132.4 (2C), 134.0 (2C), 134.1
(1C), 140.3 (1C), 152.7 (1C), 168.7 ppm (2C). Anal. Calcd for
5.4.21. 2-[10-(5-Chloro-2-methylphenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20o)
Prepared as reported above for 8f starting from 22 and 5-chloro-
2-methylphenol, using DIAD instead of DEAD. Yield: 94% (after
recrystallization); white crystals: mp 63–64 °C (THF + i-Pr2O/petro-
leum ether); IR (KBr): 1772, 1721 (C@O), cmꢀ1; 1H NMR d 1.24–1.40
(m overlapping m at 1.38–1.50, 10H, 5CH2), 1.38–1.50 (m overlap-
ping m at 1.24–1.40, 2H, CH2), 1.58–1.72 (m, 2H, CH2), 1.78 (appar-
ent quintet, 2H, CH2), 2.15 (s, 3H, CH3), 3.67 (t, J = 7.4 Hz, 2H, CH2),
3.91 (t, J = 6.5 Hz, 2H, CH2), 6.78 (dd, J = 6.1, 1.9 Hz, 1H, ArO), 6.81
(d, J = 1.9 Hz, 1H, ArO), 7.02 (dd, J = 7.8, 0.7 Hz, 1H, ArO), 7.66–7.74
(m, 2H, Ar), 7.79–7.87 ppm (m, 2H, Ar); 13C NMR d 16.0 (1C), 26.3
(1C), 27.1 (1C), 28.8 (1C), 29.4 (2C), 29.5 (1C), 29.6 (1C), 29.7 (1C),
38.3 (1C), 68.4 (1C), 111.7 (1C), 120.0 (1C), 123.4 (2C), 125.5 (1C),
131.2 (1C), 131.9 (1C), 132.4 (2C), 134.1 (2C), 160.0 (1C), 168.7
(2C); MS (70 eV) m/z (%) 427 (M+, 15), 160 ppm (100). Anal. Calcd
for C25H30ClNO3ꢁ0.50H2O (436.96): C, 68.72; H, 7.15; N, 3.21. Found:
C, 68.96; H, 6.99; N, 3.28.
C24H28N2O5 (424.49): C, 67.91; H, 6.65; N, 6.60. Found: C, 68.33; H,
6.65; N, 6.63.
5.4.18. 2-[10-(3-Nitrophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20l)
Prepared as reported above for 8f starting from 22 and 3-nitro-
phenol, using DIAD instead of DEAD. Yield: 78% (after recrystalliza-
tion); white crystals: mp 68–71 °C (EtOAc/hexane); IR (KBr): 1775,
1720 (C@O), 1517, 1353 (NO2) cmꢀ1; 1H NMR d 1.22–1.52 (m, 12H,
6CH2), 1.58–1.72 (m, 2H, CH2), 1.80 (apparent quintet, 2H, CH2),
3.67 (t, J = 7.4 Hz, 2H, CH2), 4.01 (t, J = 6.5 Hz, 2H, CH2), 7.20 (dd,
J = 8.5, 2.5 Hz, 1H, ArO), 7.40 (t, J = 8.3 Hz, 1H, ArO), 7.66–7.74
(m, 2H, Ar + 1H, ArO), 7.76–7.88 ppm (m, 2H, Ar + 1H, ArO); 13C
NMR d 26.1 (1C), 27.0 (1C), 28.7 (1C), 29.2 (1C), 29.3 (1C), 29.4
(1C), 29.5 (1C), 29.6 (1C), 38.3 (1C), 69.0 (1C), 109.0 (1C), 115.7
(1C), 121.8 (1C), 123.3 (2C), 130.0 (1C), 132.5 (2C), 134.0 (2C),
149.5 (1C), 160.0 (1C), 168.6 ppm (2C). Anal. Calcd for
5.4.22. 2-{10-[4-(Trifluoromethyl)phenoxy]decyl}-1H-isoindole-
1,3(2H)-dione (20p)
NaH (0.100 g, 0.24 mmol) was added to a solution of 4-(trifluo-
romethyl)phenol (0.044 g, 0.27 mmol) in dry DMF (10 mL) under
N2 atmosphere. The suspension was kept under stirring at 0 °C
for 1 h, and then a solution of 2-(10-iododecyl)-1H-isoindole-
1,3(2H)-dione (23) (0.100 g, 0.24 mmol) in dry DMF (10 mL) was
added dropwise. The reaction mixture was heated at 75 °C and stir-
red at this temperature for 1 h. After evaporation of the solvent, the
residue was taken up with EtOAc and washed with water. The or-
ganic phase was dried (Na2SO4) and concentrated under vacuum.
The crude solid was recrystallized (THF/petroleum ether) to give
0.095 g (89%) of 20p: mp 77–79 °C; IR (KBr): 1770, 1715 (C@O),
C
24H28N2O5ꢁ0.33H2O (424.49): C, 66.96; H, 6.71; N, 6.51. Found:
C, 67.08; H, 6.53; N, 6.37.
1333 (CF3) cmꢀ1 1H NMR d 1.20–1.42 (m overlapping m at 1.38–
;
5.4.19. 2-[10-(2,6-Dimethylphenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20m)
1.50, 10H, 5CH2), 1.38–1.50 (m overlapping m at 1.20–1.42, 2H,
CH2), 1.60–1.72 (m, 2H, CH2), 1.78 (apparent quintet, 2H, CH2),
3.67 (t, J = 7.3 Hz, 2H, CH2), 3.97 (t, J = 6.6 Hz, 2H, CH2), 6.93 (d,
J = 8.5 Hz, 2H, ArO), 7.51 (d, J = 8.5 Hz, 2H, ArO), 7.66–7.74 (m,
2H, Ar), 7.78–7.88 ppm (m, 2H, Ar); 13C NMR d 26.1 (1C), 27.0
(1C), 28.8 (1C), 29.4 (2C), 29.5 (1C), 29.6 (2C), 38.3 (1C), 68.4
(1C), 114.6 (2C), 122.7 (q, JCF 30.1 Hz, 1C), 123.4 (2C), 124.7 (br q,
JCF 271.5 Hz, 1C), 127.0 (q, JCF 3.9 Hz, 2C), 132.4 (2C), 134.0 (2C),
161.8 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 447 (M+, 6), 160
(100). Anal. Calcd for C25H28F3NO3 (447.49): C, 67.10; H, 6.31; N,
3.13. Found: C, 66.69; H, 6.35; N, 3.21.
Prepared as reported above for 8f starting from 22 and
2,6-dimethylphenol, using DIAD instead of DEAD. Yield: 56% (after
recrystallization); white crystals: mp 41–42 °C (i-Pr2O/petroleum
ether); IR (KBr): 1772, 1713 (C@O) cmꢀ1 1H NMR d 1.24–1.40 (m,
;
10H, 5CH2), 1.41–1.53 (m, 2H, CH2), 1.62–1.74 (m overlapping
apparent quintet at 1.78, 2H, CH2), 1.78 (apparent quintet overlap-
ping m at 1.62–1.74, 2H, CH2), 2.26 (s, 6H, 2CH3), 3.67 (t, J = 7.3 Hz,
2H, CH2), 3.73 (t, J = 6.6 Hz, 2H, CH2), 6.88 (dd, J = 8.3, 6.6 Hz, 1H,
ArO), 6.98 (d, J = 7.4 Hz, 2H, ArO), 7.66–7.74 (m, 2H, Ar), 7.78–
7.88 ppm (m, 2H, Ar); 13C NMR d 16.5 (2C), 26.3 (1C), 27.1 (1C),
28.8 (1C), 29.4 (1C), 29.6 (1C), 29.7 (1C), 30.6 (1C), 31.1 (1C), 38.3
(1C), 72.5 (1C), 123.3 (2C), 123.8 (1C), 128.9 (2C), 131.2 (2C), 132.4
(2C), 134.0 (2C), 156.3 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%)
407 (M+, 9), 122 (100). Anal. Calcd for C26H33NO3 (407.54): C,
76.62; H, 8.16; N, 3.44. Found: C, 77.05; H, 8.16; N, 3.55.
5.5. General procedure for the aromatic nitration (20j,q–x)
The method adopted for the synthesis of 2-[10-(4-chloro-2-nitro-
phenoxy)decyl]-1H-isoindole-1,3(2H)-dione (20q) is described. To

5912
R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
a solution of 2-[10-(4-chlorophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20b) (0.032 g, 0.08 mmol) in TFA (2 mL), NaNO2 (0.016 g,
0.23 mmol) was added. The resulted dark brown mixture was
stirred for 8 h at room temperature, and, during this period, the
mixture turned to orange. Water (120 mL) was then added and the
solution was extracted with EtOAc. The combined organic phases
were washed with water and with saturated NaHCO3 aqueous solu-
tion, dried (Na2SO4) and then the solvent evaporated. The yellow
solid obtained was purified by column chromatography on silica
gel (EtOAc/petroleum ether 2:8) and then recrystallized from
EtOAc/hexane to give 0.026 g of 20q as yellow crystals (71%): mp
1.72 (m, 2H, CH2), 1.82–1.94 (m, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H,
CH2), 4.22 (t, J = 6.3 Hz, 2H, CH2), 7.18 (d, J = 9.1 Hz, 1H, ArO),
7.66–7.74 (m, 2H, Ar), 7.78–7.88 (m, 2H, Ar), 8.41 (dd, J = 9.4,
2.8 Hz, 1H, ArO), 8.73 ppm (d, J = 2.8 Hz, 1H, ArO); 13C NMR d
25.8 (1C), 27.0 (1C), 28.8 (2C), 29.2 (2C), 29.5 (2C), 38.3 (1C),
71.1 (1C), 114.4 (1C), 122.1 (1C), 123.4 (2C), 129.2 (1C), 132.4
(2C), 134.1 (2C), 139.2 (1C), 140.1 (1C), 157.1 (1C), 168.7 ppm
(2C). Anal. Calcd for C24H27N3O7 (469.49): C, 61.40; H, 5.80; N,
8.95. Found: C, 61.42; H, 5.88; N, 8.74.
5.5.4. 2-{10-[2-Nitro-4-(trifluoromethyl)phenoxy]decyl}-1H-
isoindole-1,3(2H)-dione (20u)
97–98 °C; IR (KBr): 1769, 1713 (C@O), 1519, 1340 (NO2) cmꢀ1 1H
;
NMR d 1.22–1.40 (m overlapping m at 1.38–1.52, 10H, 5CH2),
1.38–1.52 (m overlapping m at 1.22–1.40, 2H, CH2), 1.60–1.72 (m,
2H, CH2), 1.81 (apparent quintet, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H,
CH2), 4.07 (t, J = 6.5 Hz, 2H, CH2), 7.01 (d, J = 9.1 Hz, 1H, ArO), 7.46
(dd, J = 9.1, 2.5 Hz, 1H, ArO), 7.66–7.74 (m, 2H, Ar), 7.79–7.86 ppm
(m, 2H, Ar + 1H, ArO); 13C NMR d 25.9 (1C), 27.0 (1C), 28.8 (1C),
29.0 (1C), 29.3 (2C), 29.5 (2C), 38.3 (1C), 70.3 (1C), 115.9 (1C),
123.4 (2C), 125.2 (1C), 125.6 (1C), 132.4 (2C), 134.0 (2C), 134.1
(1C), 140.3 (1C), 151.4 (1C), 168.7 ppm (2C). Anal. Calcd for
Prepared as reported above for 20q starting from 20p.
Yield: 94% (after recrystallization); yellow crystals: mp 84–86 °C
(EtOAc/hexane); IR (KBr): 1770, 1713 (C@O), 1540, 1332 (NO2),
1332 (CF3) cmꢀ1 1H NMR d 1.20–1.40 (m, 10H, 5CH2), 1.40–1.54
;
(m, 2H, CH2), 1.54–1.72 (m, 2H, CH2), 1.84 (apparent quintet, 2H,
CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2), 4.15 (t, J = 6.5 Hz, 2H, CH2), 7.16
(d, J = 8.8 Hz, 1H, ArO), 7.66–7.79 (m, 2H, Ar + 1H, ArO), 7.80–
7.88 (m, 2H, Ar), 8.09 ppm (d, J = 2.2 Hz, 1H, ArO); 13C NMR d
25.9 (1C), 27.0 (1C), 28.8 (1C), 28.9 (1C), 29.3 (2C), 29.5 (2C),
38.3 (1C), 70.4 (1C), 114.8 (1C), 122.7 (q, JCF = 34.5 Hz, 1C), 123.3
(s overlapping q at 123.4, 2C), 123.3 (br q, JCF = 271.4 Hz, 1C),
C24H27N2O5 (458.93): C, 62.81; H, 5.93; N, 6.10. Found: C, 63.13; H,
6.00; N, 6.14.
123.4 (q overlapping
s at 123.3, JCF = 4.1 Hz, 1C), 130.9 (q,
5.5.1. 2-[10-(4,5-Dichloro-2-nitrophenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20r)
JCF = 3.3 Hz, 1C), 132.4 (2C), 134.0 (2C), 140.0 (1C), 155.0 (1C),
168.7 ppm (2C). Anal. Calcd for C25H27F3N2O5ꢁ0.50C6H14 (535.58):
C, 62.79; H, 6.40; N, 5.23. Found: C, 62.86; H, 6.08; N, 5.11.
Prepared as reported above for 20q starting from 20d. Yield: 46%
(after recrystallization); white crystals: mp 100–102 °C (THF/petro-
leum ether); IR (KBr): 1771, 1710 (C@O), 1512, 1337 (NO2) cmꢀ1; 1H
NMR d 1.20–1.42 (m overlapping m at 1.38–1.52, 10H, 5CH2), 1.38–
1.52 (m overlapping m at 1.20–1.42, 2H, CH2), 1.53–1.72 (m, 2H,
CH2), 1.82 (apparent quintet, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H, CH2),
4.07 (t, J = 6.5 Hz, 2H, CH2), 7.17 (s, 1H, ArO), 7.66–7.74 (m, 2H, Ar),
7.78–7.88 (m, 2H, Ar), 7.97 ppm (s, 1H, ArO); 13C NMR d 25.9 (1C),
27.0 (1C), 28.8 (1C), 28.9 (1C), 29.3 (2C), 29.5 (2C), 38.3 (1C), 70.7
(1C), 116.6 (1C), 123.4 (2C), 123.8 (1C), 127.2 (1C), 132.4 (2C),
134.1 (2C), 138.4 (1C), 138.6 (1C), 151.7 (1C), 168.7 ppm (2C). Anal.
Calcd for C24H26Cl2N2O5ꢁH2O (511.39): C, 56.37; H, 5.52; N, 5.48.
Found: C, 56.14; H, 5.20; N, 5.73.
5.5.5. 2-[10-(4-Chloro-2,6-dimethyl-3-nitrophenoxy)decyl]-1H-
isoindole-1,3(2H)-dione (20v)
Prepared as reported above for 20q starting from 20f. Yield: 67%
(after recrystallization); white crystals: mp 50–52 °C (EtOAc/petro-
leum ether); IR (KBr): 1766, 1717 (C@O), 1528, 1364 (NO2) cmꢀ1
;
1H NMR d 1.25–1.40 (m, 10H, 5CH2), 1.40–1.53 (m, 2H, CH2),
1.55–1.72 (m, 2H, CH2), 1.78 (apparent quintet, 2H, CH2), 2.21 (s,
3H, CH3), 2.28 (s, 3H, CH3), 3.67 (t, J = 7.3 Hz, 2H, CH2), 3.73 (t,
J = 6.6 Hz, 2H, CH2), 7.14 (s, 1H, ArO), 7.65–7.75 (m, 2H, Ar),
7.80–7.87 ppm (m, 2H, Ar); 13C NMR d 11.8 (1C), 16.6 (1C), 26.2
(1C), 27.0 (1C), 28.8 (1C), 29.3 (1C), 29.6 (2C), 29.9 (1C), 30.4
(1C), 38.3 (1C), 73.6 (1C), 119.2 (1C), 123.4 (2C), 125.5 (1C),
129.8 (1C), 132.4 (2C), 134.1 (2C), 135.3 (1C), 149.0 (1C), 155.4
(1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 586 (M+ ꢀ 200, 16), 160
(100). Anal. Calcd for C26H31ClN2O5ꢁ0.50H2O (495.99): C, 62.96;
H, 6.50; N, 5.65. Found: C, 63.02; H, 6.33; N, 5.77.
5.5.2. 2-[10-(4,6-Dichloro-2-nitrophenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20s)
Prepared as reported above for 20q starting from 20g. Yield: 90%
(after recrystallization); pale yellow crystals: mp 46–48 °C (i-Pr2O/
hexane); IR (KBr): 1772, 1714 (C@O), 1538, 1356 (NO2) cmꢀ1 1H
;
NMR d 1.22–1.40 (m overlapping m at 1.38–1.50, 10H, 5CH2),
1.38–1.50 (m overlapping m at 1.22–1.40, 2H, CH2), 1.52–1.74 (m,
2H, CH2), 1.81 (apparent quintet, 2H, CH2), 3.67 (t, J = 7.4 Hz, 2H,
CH2), 4.10 (t, J = 6.6 Hz, 2H, CH2), 7.60 (d, J = 2.8 Hz, 1H, ArO), 7.66–
7.74 (m, 2H, Ar + 1H, ArO), 7.80–7.88 ppm (m, 2H, Ar); 13C NMR d
25.7 (1C), 27.1 (1C), 28.8 (1C), 29.4 (1C), 29.5 (1C), 29.6 (2C), 30.0
(1C), 38.3 (1C), 76.2 (1C), 123.4 (2C), 123.8 (1C), 129.3 (1C), 129.3
(1C), 131.9 (1C), 132.4 (2C), 134.1 (1C), 134.5 (1C), 145.7 (1C),
148.3 (1C), 168.7 ppm (2C); MS (70 eV) m/z (%) 476 (M+ ꢀ 16, <1),
160 (100). Anal. Calcd for C24H26Cl2N2O5 (493.38): C, 58.42; H,
5.31; N, 5.68. Found: C, 58.22, H, 5.44; N, 5.57.
5.5.6. 2-[10-(2,6-Dimethyl-4-nitrophenoxy)decyl]-1H-isoindole-
1,3(2H)-dione (20w)
Prepared as reported above for 20q starting from 20m. Yield:
21% (after recrystallization); white solid: mp 68–70 °C (EtOAc/
hexane); IR (KBr): 1773, 1720 (C@O), 1513, 1343 (NO2) cmꢀ1
;
1H NMR d 1.20–1.42 (m, 10H, 5CH2), 1.42–1.52 (m, 2H, CH2),
1.60–1.74 (m, 2H, CH2), 1.81 (apparent quintet, 2H, CH2), 2.33
(s, 6H, 2CH3), 3.67 (t, J = 7.3 Hz, 2H, CH2), 3.80 (t, J = 6.5 Hz, 2H,
CH2), 7.67–7.75 (m, 2H, Ar), 7.80–7.88 (m, 2H, Ar), 7.91 ppm (s,
2H, ArO); 13C NMR
d 16.8 (2C), 26.2 (1C), 27.0 (1C), 28.8
(1C), 29.3 (1C), 29.6 (2C), 29.9 (1C), 30.5 (1C), 38.3 (1C), 73.0
(1C), 123.4 (2C), 124.4 (2C), 132.4 (2C), 132.6 (2C), 134.1 (2C),
143.6 (1C), 161.9 (1C), 168.7 ppm (2C). Anal. Calcd for
5.5.3. 2-[10-(2,4-Dinitrophenoxy)decyl]-1H-isoindole-1,3(2H)-
dione (20t)
C
26H32N2O5ꢁ0.5C6H14 (495.63): C, 70.28; H, 7.93; N, 5.65. Found:
Prepared as reported above for 20q starting from 20a. It was ob-
tained in 50% yield along with 20j. The mixture of 20t and 20j was
purified by flash chromatography (EtOAc/petroleum ether 2:8) to
give 20t as a yellow solid which was recrystallized from EtOAc/
petroleum ether. Yield: 18%; pale yellow crystals: mp 111–
C, 70.10; H, 7.61; N, 5.72.
5.5.7. 2-[10-(5-Chloro-2-methyl-4-nitrophenoxy)decyl]-1H-
isoindole-1,3(2H)-dione (20x)
Prepared as reported above for 20q starting from 20o. Yield: 14%
(after recrystallization); pale yellow crystals: mp 106–107 °C (THF/
113 °C; IR (KBr): 1766, 1712 (C@O), 1526, 1345 (NO2) cmꢀ1 1H
;
NMR d 1.20–1.40 (m, 10H, 5CH2), 1.40–1.50 (m, 2H, CH2), 1.50–

R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
5913
petroleum ether); IR (KBr): 1772, 1717 (C@O), 1519, 1334 (NO2) cm
;
C18H17NO3 (295.33): C, 73.20; H, 5.80; N, 4.74. Found: C, 72.77;
H, 5.82; N, 4.75.
ꢀ1
1H NMR d 1.20–1.40 (m, 10H, 5CH2), 1.40–1.54 (m, 2H, CH2),
1.60–1.73 (m, 2H, CH2), 1.75–1.88 (m, 2H, CH2), 2.22 (s, 3H, CH3),
3.67 (t, J = 7.4 Hz, 2H, CH2), 4.01 (t, J = 6.5 Hz, 2H, CH2), 6.86 (s, 1H,
ArO), 7.26 (s, 1H, ArO), 7.68–7.74 (m, 2H, Ar), 7.80–7.88 ppm (m,
2H, Ar); 13C NMR d 16.0 (1C), 26.1 (1C), 27.0 (1C), 28.8 (1C), 29.1
(1C), 29.3 (1C), 29.5 (1C), 29.9 (1C), 31.1 (1C), 38.3 (1C), 69.4 (1C),
113.5 (1C), 123.4 (2C), 127.0 (1C), 127.2 (1C), 128.2 (1C), 132.4
(2C), 134.1 (2C), 139.9 (1C), 161.0 (1C), 168.7 ppm (2C). Anal. Calcd
for C25H29ClN2O5ꢁ0.33H2O (478.96): C, 62.69; H, 6.24; N, 5.85.
Found: C, 62.77; H, 6.58; N, 5.50.
5.6. Biology
5.6.1.
a
a
-Glucosidase inhibitory activity determination
-glucosidase inhibitory activity of the newly synthesized
The
compounds (Tables 1–3) was determined as described in the liter-
ature20 and was expressed as the inhibitor concentration required
for 50% inhibition of the
-glucosidase from Saccharomyces cerevisiae (Sigma, G-0660 Lot
015K0869) was dissolved in 445 L of 10 mM phosphate buffer
(pH 7.28) at a final concentration of 25 mU/mL and incubated in
the presence of 5 L of test compound in DMSO at 37 °C for
5 min. The reaction was started by the addition of 50 L of 4-nitro-
phenyl -glucopyranoside (p-NPG, final concentration 80 M)
and stopped after 10 min with 500 L of 0.5 M Na2CO3. The
a-glucosidase activity (IC50). Briefly,
a
l
5.5.8. 2-(10-Hydroxydecyl)-1H-isoindole-1,3(2H)-dione (22)
Prepared as reported above for 8f starting from 21, phthalimide
and di-tert-butyl azodicarboxylate (DBAD). Yield: 55% (after
recrystallization); white crystals: mp 76–78 °C (EtOAc/petroleum
l
l
a
-D
l
ether); IR (KBr): 3510 (OH), 1774, 1700 (C@O) cmꢀ1 1H NMR d
;
l
amount of released 4-nitrophenol from p-NPG was measured as
the absorbance at 400 nm. The assay was performed with eight dif-
ferent concentrations around the IC50 values, approximately esti-
mated in previous experiments. In each set of experiments the
assay was performed in triplicate and at least two times. The in-
creased absorbance was compared with that of the control con-
taining 5 lL of DMSO in the place of the test solution. The IC50
values were measured graphically by a plot of percent activity ver-
sus log of the test compound concentration.
1.15–1.40 (m, 12H, 6CH2), 1.42–1.62 (m overlapping m at 1.58–
1.72, 2H, CH2 + 1H, OH), 1.58–1.72 (m overlapping m at 1.42–
1.62, 2H, CH2), 3.63 (t overlapping t at 3.67, J = 6.6 Hz, 2H, CH2),
3.67 (t overlapping t at 3.63, J = 7.3 Hz, 2H, CH2), 7.65–7.73 (m,
2H, Ar), 7.75–7.88 ppm (m, 2H, Ar); 13C NMR d 25.9 (1C), 27.0
(1C), 28.8 (1C), 29.3 (1C), 29.5 (2C), 29.6 (1C), 33.0 (1C), 38.3
(1C), 63.3 (1C), 123.4 (2C), 132.4 (2C), 134.1 (2C), 168.7 ppm
(2C); MS (70 eV) m/z (%) 303 (M+, 14), 160 (100). Anal. Calcd for
C18H25NO3 (303.40): C, 71.26; H, 8.31; N, 4.62. Found: C, 71.20;
H, 8.31; N, 4.74.
5.6.2. b-Glucosidase,
inhibitory activity determination
The inhibitory activity of b-glucosidase from almonds (Sigma,
G-0395 Lot 109K4039), -mannosidase from Canavalia ensiformis
(Sigma, M-7257 Lot 039K7695), and -galactosidase from green
coffee beans (Sigma, G-8507 Lot 068K1400) was determined as
for -glucosidase. The enzymatic hydrolysis of substrates was
monitored by measuring the amount of p-nitrophenol released
from 4-nitrophenyl b- -glucopyranoside, 4-nitrophenyl -man-
nopyranoside, and 4-nitrophenyl -galactopyranoside, respec-
tively. The enzymes (12.5 mU per sample test) were dissolved in
445 L of buffer: b-glucosidase in 50 mM sodium citrate (pH 5.0),
-mannosidase in 10 mM sodium acetate (pH 4.5) and -galactosi-
dase in 50 mM potassium phosphate (pH 6.5). Five microlitres of
test compound in DMSO, at the concentration of 25 M, were incu-
bated at 37 °C for 5 min and the reaction was started by the addi-
tion of 50 L of the substrate (final concentration 80 M). The
reaction was stopped after 10 min of incubation with 500 L of
1 M Na2CO3. The absorbance in the presence of the test compound
a-mannosidase, and a-galactosidase
5.5.9. 2-(10-Iododecyl)-1H-isoindole-1,3(2H)-dione (23)
a
To a refluxing solution of 2-(10-hydroxydecyl)-1H-isoindole-
1,3(2H)-dione (22) (0.150 g, 0.49 mmol) and triphenylphosphine
(0.170 g, 0.65 mmol) in dry toluene (16 mL), iodine (0.165 g,
0.65 mmol) was added portionwise. The mixture was heated at re-
flux for 1 h, and then absolute ethanol (1 mL) was added in two
portions at ca. 30 min. intervals. After evaporation of the solvent,
the residue was taken up with EtOAc, washed twice with saturated
Na2S2O3 aqueous solution and then with water. The organic phase
was dried and the solvent evaporated. The white solid obtained
was purified by column chromatography on silica gel (EtOAc/
petroleum ether 1:9) giving 0.104 g (51%) of 23 as a white solid:
a
a
D
a-D
a-D
l
a
a
mp 68–70 °C; IR (KBr): 1764, 1700 (C@O) cmꢀ1 1H NMR d 1.22–
;
l
1.42 (m, 12H, 6CH2), 1.60–1.72 (m, 2H, CH2), 1.81 (apparent quin-
tet, 2H, CH2), 3.18 (t, J = 7.0 Hz, 2H, CH2), 3.67 (t, J = 7.3 Hz, 2H,
CH2), 7.66–7.74 (m, 2H, Ar), 7.80–7.88 ppm (m, 2H, Ar); 13C NMR
d 7.1 (1C), 26.8 (1C), 28.4 (1C), 28.5 (1C), 29.1 (1C), 29.3 (2C),
30.4 (1C), 33.6 (1C), 38.0 (1C), 123.1 (2C), 132.2 (2C), 133.8 (2C),
168.4 ppm (2C); MS (70 eV) m/z (%) 413 (M+, <1), 160 (100).
l
l
l
was compared to that of the control (5
iments were carried out in triplicate.
lL of DMSO). All the exper-
5.6.3. MTT assay
5.5.10. 2-(4-Phenoxybutyl)-1H-isoindole-1,3(2H)-dione (25a)
Potassium phthalimide (0.50 g, 2.69 mmol) was added to a
solution of (4-bromobutoxy)benzene (24) (0.550 g, 2.40 mmol)
in dry DMF (10 mL) under N2 atmosphere. The reaction mixture
was heated to 80 °C and stirred at this temperature for 5 h. The
solid residue was filtered off. After evaporation of the solvent,
the residue was taken up with EtOAc and washed with water.
The organic phase was dried (Na2SO4) and concentrated under
vacuum. The residue was purified by crystallization (EtOAc/hex-
ane) to give 0.50 g (71%) of 25a as white crystals: mp 103–
The cytotoxicity of compounds on SH-SY5Y human neuroblas-
toma cells was evaluated by slightly modifying the MTT cell prolifer-
ation assay.28 Briefly, the cell were seeded in a 96-well plate and the
test compounds were added at both the concentration of 5
the one corresponding to IC50 value, and after 2 h exposure, 12
of a solution of MTT (5 mg/mL) dissolved in DMEM + 10% FBS were
added to each well and each plate was incubated at 37 °C for 4 h.
The supernatants were then aspirated and 100 microlitres of DMSO
were added to each well. The absorbance at 540 nm was measured
using a Wallac Victor 3 1421 Multilabel Counter. All experiments
were carried out in sextuplicate and were repeated twice.
lM and
lL
104 °C; IR (KBr): 1775, 1712 (C@O) cmꢀ1 1H NMR d 1.75–1.96
;
(m, 4H, 2CH2), 3.77 (t, J = 6.7 Hz, 2H, CH2), 3.99 (t, J = 5.8 Hz, 2H,
CH2), 6.82–6.96 (m, 3H, ArO), 7.20–7.32 (m, 2H, ArO), 7.66–7.76
(m, 2H, Ar), 7.80–7.88 ppm (m, 2H, Ar); 13C NMR d 25.6 (1C),
26.9 (1C), 37.9 (1C), 67.2 (1C), 114.7 (2C), 120.8 (1C), 123.4
(2C), 129.6 (2C), 132.3 (2C), 134.1 (2C), 159.1 (1C), 168.7 ppm
(2C); MS (70 eV) m/z (%) 295 (M+, 9), 160 (100). Anal. Calcd for
Acknowledgement
This work was accomplished thanks to financial support of the
Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR).

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R. Pascale et al. / Bioorg. Med. Chem. 18 (2010) 5903–5914
13. Liu, H.; Sim, L.; Rose, D. R.; Pinto, B. M. J. Org. Chem. 2006, 71, 3007.
Supplementary data
14. Luo, J.-G.; Wang, X.-B.; Ma, L.; Kong, L.-Y. Bioorg. Med. Chem. Lett. 2007, 17,
4460.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.bmc.2010.06.088. These data
include MOL files and InChiKeys of the most important compounds
described in this article.
15. Saludes, J. P.; Lievens, S. C.; Molinski, T. F. J. Nat. Prod. 2007, 70, 436.
16. Du, Z.-Y.; Liu, R.-R.; Shao, W.-Y.; Mao, X.-P.; Ma, L.; Gu, L.-Q.; Huang, Z.-S.;
Chan, A. S. C. Eur. J. Med. Chem. 2006, 41, 213.
17. Atsushi, K.; Noriko, K.; Erika, K.; Isao, A.; Kyoko, I.; Liang, Y.; Tadashi, O.;
Yasunori, B.; Hidekazu, O.; Hiroki, T.; Naoki, A. J. Med. Chem. 2005, 48,
2036.
18. Schaller, C.; Demange, R.; Picasso, S.; Vogel, P. Bioorg. Med. Chem. Lett. 1999, 9,
277.
References and notes
19. Chen, X.; Fan, Y.; Zhen, Y.; Shen, Y. Chem. Rev. 2003, 103, 1955.
20. Takahashi, H.; Sou, S.; Yamasaki, R.; Sodeoka, M.; Hashimoto, Y. Chem. Pharm.
Bull. 2000, 48, 1494.
21. Sou, S.; Mayumi, S.; Takahashi, H.; Yamasaki, R.; Kadoya, S.; Sodeoka, M.;
Hashimoto, Y. Bioorg. Med. Chem. Lett. 2000, 10, 1081.
22. Mitsunobu, O. Synthesis 1981, 1.
23. Rawlings, A. J.; Lomas, H.; Illing, A. V.; Lee, M. J.-R.; Alonzi, D. S.; Rountree, J. S.
S.; Jenkinson, S. F.; Fleet, G. W. J.; Dwek, R. A.; Jones, J. H.; Butters, T. D.
ChemBioChem 2009, 10, 1101.
24. Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem. 1978, 43, 2923.
25. Pierwocha, A. W.; Walczak, K. Carbohydr. Res. 2008, 343, 2680.
26. Xiao, X.; Antony, S.; Kohlhagen, G.; Pommier, Y.; Cushman, M. Bioorg. Med.
Chem. 2004, 12, 5147.
1. Gao, H.; Huang, Y. N.; Gao, B.; Lee, P.; Inagaki, C.; Kawabata, J. Nees. Food Chem.
2008, 108, 965.
2. Balfour, J. A.; McTavish, D. Drugs 1993, 46, 1025.
3. Pogano, G.; Marena, S.; Corgiat-Mansin, L.; Cravero, F.; Giorda, C.; Bozza, M.
Diabetes Metab. 1995, 21, 162.
4. Bernaeki, R. J.; Niedbala, M. J.; Korytryk, W. Cancer Metastasis Rev. 1985, 4, 81.
5. Metha, A.; Zitzmann, N.; Rudd, P. M.; Block, T. M.; Dwek, R. A. FEBS Lett. 1998,
430, 17.
6. Gruters, R. A.; Neefjes, J. J.; Tersmetti, M.; De Goede, R. E. W.; Tulp, A.; Huisman,
H. G.; Miedeme, F.; Ploegh, H. C. Nature 1987, 330, 74.
7. Ratner, L.; Wander Heyden, N. AIDS Res. Hum. Retroviruses 1993, 9, 291.
8. de Melo, E. B.; Gomes, A. S.; Carvalho, I. Tetrahedron 2006, 62, 10277.
9. Lillelund, V. H.; Gensen, H. H.; Liang, X.; Bols, M. Chem. Rev. 2002, 102, 515.
10. Xu, H.-W.; Dai, G.-F.; Liu, G.-Z.; Wang, J.-F.; Liu, H.-M. Bioorg. Med. Chem. 2007,
15, 4247.
11. Seo, W. D.; Kim, J. H.; Kang, J. E.; Rwu, H. W.; Curtis-Long, M. J.; Lee, H. S.; Jang,
M. S.; Park, K. H. Bioorg. Med. Chem. Lett. 2005, 15, 5514.
12. Hakamata, W.; Nakanishi, I.; Masuda, Y.; Shimizu, T.; Higuchi, H.; Nakamura,
Y.; Saito, S.; Urano, S.; Oku, T.; Ozawa, T.; Ikota, N.; Miyata, N.; Okuda, H.;
Fukuhara, K. J. Am. Chem. Soc. 2006, 128, 6524.
27. Neelakantan, S.; Surjawan, I.; Karacelik, H.; Hicks, C. L.; Crooks, P. A. Bioorg.
Med. Chem. Lett. 2009, 19, 5722.
28. Polimeno, L.; Pesetti, B.; Lisowsky, T.; Iannone, F.; Resta, L.; Giorgio, F.;
Mallamaci, R.; Buttiglione, M.; Santovito, D.; Vitiello, F.; Mancini, M. E.;
Francavilla, A. Free Radical Res. 2009, 43, 865.