New 1-aryl-3-substituted propanol derivatives as antimalarial agents

Article abstract of DOI:10.3390/molecules14104120

This paper describes the synthesis and in vitro antimalarial activity against a P. falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of the tested compounds showed an IC₅₀ lower than 1 μM. These compounds were

Full text of DOI:10.3390/molecules14104120

Molecules 2009, 14, 4120-4135; doi:10.3390/molecules14104120
OPEN ACCESS
molecules
ISSN 1420-3049
www.mdpi.com/journal/molecules
Article
New 1-Aryl-3-Substituted Propanol Derivatives as Antimalarial
Agents
Silvia Pérez-Silanes 1,*, Luis Berrade 1, Rory N. García–Sánchez 2, Adela Mendoza 1,
Silvia Galiano 1, Berta Martín Pérez-Solórzano 2, Juan J. Nogal-Ruiz 2,
Antonio R. Martínez-Fernández 2, Ignacio Aldana 1 and Antonio Monge 1
1
Unidad en Investigación y Desarrollo de Medicamentos, Centro de Investigación en
Farmacobiología Aplicada (CIFA), University of Navarra, c/Irunlarrea s/n, 31080 Pamplona, Spain;
E-Mail: luisberrade@msn.com (L.B.)
2
Departamento de Parasitología, Facultad de Farmacia, Complutense University of Madrid, Spain
* Author to whom correspondence should be addressed; E-Mail: sperez@unav.es.
Received: 11 August 2009; in revised form: 21 September 2009 / Accepted: 14 October 2009 /
Published: 14 October 2009
Abstract: This paper describes the synthesis and in vitro antimalarial activity against a P.
falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of
the tested compounds showed an IC50 lower than 1 µM. These compounds were also tested
for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated
for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited
more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was
performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data
indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic
option for the treatment of malaria.
Keywords: antimalarial agents; benzo[b]thiophene; 1-aryl-3-substituted propanol
derivatives; P. Falciparum; ferriprotoporphyrin
1. Introduction
Malaria is a major health disease with hundreds of millions of people being infected.
Approximately 50% of the world’s population, mostly those living in the world’s poorest countries,

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are at risk of malaria [1]. Every year, more than 500 million people become severely ill with malaria.
Most cases and deaths occur in tropical and subtropical countries. Early diagnosis and prompt
treatment are the basic elements needed for the control of this condition.
Chloroquine was the most effective and widely used drug in malaria therapy because of its rapid
onset of action, good tolerability and low cost. However, the increasing resistance of the malaria
parasite Plasmodium falciparum to currently available drugs, and especially to chloroquine, demands a
continuous effort to develop new effective therapeutic options [2].
The arylamine alcohols (Figure 1) are antimalarial drugs structurally derived from quinine.
Mefloquine is considered a standard therapeutic agent for chloroquine-resistant malaria; however, its
use is limited by high costs and the appearance of neuropsychiatric side effects [3]. The administration
of halofantrine is highly effective, but has been severely restricted due to its potential to induce fatal
adverse cardiac effects [4]. Lumefantrine, which is an analogue of halofantrine with no cardiac effects,
is available coformulated with arthemether in an oral preparation [5].
Strains of P. falciparum that are resistant to chloroquine and many other antimalarial drugs have
since emerged and this has created a near desperate situation, where the need for new, inexpensive
antimalarial agents has become vital. Identification of new molecular scaffolds structurally unrelated
to existing antimalarial agents represents a valuable strategy to bypass resistance phenomena.
Figure 1. Antimalarial drugs: Arylaminealcohol derivatives.
H
H
Quinine
Mefloquine
Quinidine
HO
N
H
N
N
HO
HO
O
O
N
CF3
N
N
CF3
N
N
Halofantrine
HO
HO
Lumefantrine
Cl
Cl
F3C
Cl
Cl
More recently aminopropanol derivatives have been described as antimalarial agents [6-8], so we
focused our attention on a series of 1-aryl-3-[4-arylpiperazin-1-yl]-1-propane derivatives synthesized
by our group and recently published as antidepressants [9-12] (Figure 2). Our efforts have been

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focused on identifying new antimalarial drug candidates. As a result, we thought that the structural
similarity of our compounds with the active arylamine alcohols in Figure 1 could also be interesting.
Therefore, after several months of coordinated work between the synthesis and experimental
chemotherapy, we report the synthesis and the antimalarial activity of 1-aryl-3-substituted propanol
derivatives. We carried out both in vitro and in vivo assays in order to determine whether our
compounds have potential for being considered as future antimalarial drugs. In addition, we performed
an easy in vitro test in order to measure the ability of the compounds to inhibit the biomineralization
process from ferriprotoporphyrin IX to hemozoin, as a possible mechanism of action.
2. Results and Discussion
The synthesis of some of the tested compounds has been published previously [9-12] (see reference
publications in Tables 1-3. Methods for the synthesis of compounds 6-10, 16, 28-35, 38, 40, 41, 44 and
45 are presented in Schemes 1-3, while derivatives 1-5, 11-15, 17-27, 36, 37, 39, 42 and 43 were
previously reported [9-11].
The benzo[b]thiophene derivatives 6-10 were prepared using the 1-(3-benzo[b]thio phenyl)-3-
chloropropan-1-one precursor IV previously synthesized by a Friedel-Craft acylation of
benzo[b]thiophene as described in [12]. Ketones were obtained by a SN2 nucleophilic attack of the
corresponding arylamine III to IV (Scheme 1).
The ketone intermediates VI were prepared by condensation of the corresponding commercially
available acetophenones V with the different aryl amines III via Mannich reactions[12] (Scheme 2).
Scheme 1. Synthesis of benzo[b]thiophenyl propanol derivatives 6-10, 16 and 28-35.
Cl
O
R
Amine
HO
Amine
Ar
R
Ar
O
H
S
R
(IV)
+
MeOH/NaBH4
0ºC/2 h.
THF/K2CO3
72 h.
S
S
Ar Amine
(III)
(6 - 10)
(16), (28 - 35)
Scheme 2. Synthesis of 1-aryl-3-substituted propanol derivatives 38, 40, 41, 44 and 45.
O
O
OH
H
Ar '
EtOH / [H+]
(CH2O)n
V
MeOH/NaBH4
0ºC/2 h.
Amine
Amine
Ar
Ar '
Ar '
Ar
+
Ar Amine
(VI)
(38), (40), (41), (44), (45)
(III)

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The 4-chloro-, 2-methoxy- and 3-methoxyphenyl piperazines were commercially available. The rest
of the aryl amines were synthesized using the corresponding BOC-arylamines and p-nitrophenyl, p-
nitro-o-trifluoromethylphenyl and 2-quinoxalinyl aryl fluorides by an SNAr reaction [13] and
subsequent removal of the BOC-group with HCl and acetic acid (Scheme 3).
Scheme 3. Synthesis of the non-commercially available arylamines.
Acetic Acid /HCl
2 h.
F-Ar / K2CO3/ CH3CN
reflux 48 h.
Ar Amine
BOC Amine
Ar Amine BOC
(II)
(I)
(III)
Finally, all the hydroxyl derivatives 11-46 were obtained by reduction of the corresponding
carbonyl group with NaBH4 in methanol. All of the compounds were chemically characterized by thin
layer chromatography (TLC), melting point (m.p.), infrared (IR) and nuclear magnetic resonance (1H-
NMR) spectra, as well as by elemental microanalysis.
Forty-six compounds were evaluated for in vitro antimalarial activity against P. falciparum, and
twelve of them showed good activity, with IC50 values lower than 1 µM. We paid special attention to
compounds 12, 15, 22, 23 and 31 since they were the most active, only two to fourfold less active than
chloroquine. On the other hand, twenty-nine compounds showed moderate or low activity with IC50
values between 1 and 14.63 µM. All other compounds were considered to be inactive because they
either showed no activity or their activity was quite insignificant (see Tables 1 and 2). Chloroquine,
the positive control, showed an IC50 of 0.08 µM, which coincides with the value reported by other
authors.
Table 1. In vitro antimalarial activity of Benzo[b]thiophenyl derivatives versus
Chloroquine Sensitive ·3D7 Strain of Plasmodium falciparum.
AMINE
Ar
Z
R
S
P. falciparum 3D7
Compd.
R
Z
Amine
Ar
IC50 M
N
1a
2 c
3 b
4a
5a
6
F
F
C=O
C=O
C=O
C=O
C=O
C=O
C=O
C=O
C=O
1-naphthyl
2-methoxyphenyl
2-methoxyphenyl
8-quinolyl
IN
N
N
N
IN
N
N
H
F
IN
N
N
IN
N
N
H
H
H
H
H
8-quinaldinyl
IN
N
N
4-nitro-2-trifluromethyl phenyl
4-nitro-2-trifluromethyl phenyl
4-nitrophenyl
IN
N
7
IN
N
H
N
8
IN
N
N
9
4-nitrophenyl
IN

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Table 1. Cont.
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
10
11a
12a
13b
14b
15c
16
17a
18a
19b
20a
21a
22a
23a
24a
25a
26a
27a
28
H
H
F
C=O
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
2-quinoxaline
1-naphthyl
IN
6.13
0.16
1.07
13.73
0.33
1.67
6.99
3.81
5.65
2.15
0.79
0,66
0.38
1.30
2.22
3.56
0.90
0.68
2.99
0.97
0.19
IN
1-naphthyl
H
H
F
2-methoxyphenyl
2-hydroxyphenyl
2-methoxyphenyl
3-methoxyphenyl
4-indolyl
F
H
F
4-indolyl
H
H
F
4-chlorophenyl
8-quinolyl
8-quinolyl
H
F
8-quinaldinyl
8-quinaldinyl
H
H
H
F
5-quinolyl
2-quinolyl
2,3-dihydro-1,4-benzodioxin-5-yl
2,3-dihydro-1,4-benzodioxin-5-yl
4-nitro-2-trifluromethyl phenyl
4-nitro-2-trifluromethyl phenyl
4-nitro-2-trifluromethyl phenyl
4-nitro-2-trifluromethyl phenyl
4-nitrophenyl
N
N
H
H
H
H
F
29
N
H
N
30
N
H
N
31
N
N
32
N
H
N
33
H
H
H
4-nitrophenyl
1.00
3.43
0.62
0.08
N
N
34
4-nitrophenyl
N
N
35
2-quinoxalinyl
Chloroq.
a
b
c
Drugs from [11]; Drugs from [9]; Drugs from [10]. IC50 is the 50% inhibitory concentration of the in
vitro parasite growth. Each value is the mean of two experiments in triplicate. All the compounds with IC50
value higher than 20 µM was considered inactive (IN).
From the point of view of the SAR and in order to assess the importance of the OH group present in
the arylamine moiety, the in vitro antimalarial activity of some ketone intermediates (compounds 1-10)
against P. falciparum was evaluated. It is important to point out that none of them were active. This
fact suggests that the OH group present in the arylamine moiety is essential for the activity. In
addition, an increase in the activity was observed in the benzothiophene derivatives, when substituted
in position 5 with an electron withdrawing group (R=F; compounds 12, 15, 18, 21, 23, 27) in
comparison with the corresponding unsubstituted derivatives (R=H; compounds 11, 13, 17, 20, 22,
26). Regarding the different amines employed, the activity data suggest that the most interesting
compounds are those containing the 4-aminopiperidine moiety (see compounds 28-31 and 32-34).
Finally, it is evident that the presence of a benzocondensed group in Ar' (benzothiophenyl or naftyl)
contributes to a notable improvement in the activity compared to other aromatic substituents.

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Before testing the in vivo antimalarial activity, we evaluated the cytoxicity of every active
compound on a murine macrophages J774 cell line. Although the majority of them were toxic at 100
µg/mL, only compound 31 showed toxicity at 10 µg/mL. From our point of view, if a compound
shows a toxicity percentage higher than 30% at this concentration, it will be toxic in vivo. However,
we decided to include it in an in vivo test with mice (Table 3). Only compound 12 inhibited more than
50% of parasite growth and the appearance of the mice was good at the end of the experiment. The
mice in groups treated with compounds 23 and 15 looked unhealthy and showed clear evidence of
weight loss. Unfortunately, the cytotoxicity of compound 31 was confirmed in the in vivo test.
Ferriporotoporphyrin IX (FPIX) biocrystallization is a Plasmodium-specific process in which the
toxic FPIX derived from the digestion of ingested haemoglobin is converted into an insoluble nontoxic
crystalline species called haemozoin. This is the mechanism through which chloroquine exerts its
antimalarial effect. Due to the structural similarity of our compounds with other antimalarial arylamine
alcohol derivatives, we felt that it could be important to examine this. The results showed that no
compound was active in the FBIT test. This fact supports the hypothesis that 1-aryl-3-substituted
propanol derivatives, such as quinine, have a weaker binding coefficient to FP [14]. This was
demonstrated by Deharo [15], who reported an IC50 = 324µM for quinine in the FBIT test. This fact is
of great importance because the parasite has developed resistance to the majority of the antimalarials
of the 4-aminoquinoline group, all of which inhibit the formation of haemozoin.
Table 2. In vitro antimalarial activity of 1-aryl-3-substituted propanol derivatives versus
Chloroquine Sensitive ·3D7 Strain of Plasmodium falciparum.
OH
H
Ar '
AMINE
Ar
P. falciparum 3D7
Compd.
Ar’
Amine
Ar
IC50 M
N
36b
37b
38
3-thiophenyl
phenyl
IN
N
4-chlorophenyl
4-chlorophenyl
N
N
13.04
IN
N
N
4-chlorophenyl
biphenyl
N
39b
phenyl
IN
N
2-methoxyphenyl
2-methoxyphenyl
2-methoxyphenyl
2-methoxyphenyl
2-methoxyphenyl
2-methoxyphenyl
N
N
40
biphenyl
14.63
IN
N
N
41
3-indolyl
2-naphthyl
2,4-
N
42b
43a
0.83
16.91
9.64
9.10
18.16
0.08
N
N
N
N
N
6-methylnapht-2-
44
N
N
H
4-nitro-2-trifluromethyl phenyl
2-hydroxyphenyl
45
46a
2-naphthyl
2,4-
N
N
Chloroq.
a Drugs from [11]; b Drugs from [9]. IC50 is the 50% inhibitory concentration of the in vitro parasite growth.
Each value is the mean of two experiments in triplicate. All the compounds with IC50 value higher than 20
µM was considered inactive (IN).

Molecules 2009, 14
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Table 3. In vivo antimalarial activity of selected 1-aryl-3-arylamino propanol derivatives
against Plasmodium berghei ANKA strain.
OH
H
AMINE
Ar '
Ar
GIP of
P. bergei
at 50 mg/kg/day
65,79
Compd.
Ar’
Amine
Ar
N
N
12
23
15
31
5-F-Benzo[b]thiophenyl
5-F-Benzo[b]thiophenyl
5-F-Benzo[b]thiophenyl
Benzo[b]thiophenyl
1-naphthyl
N
N
8-quinaldinyl
2-methoxyphenyl
4-NO2-2-CF3-phenyl
37,69
24,73
N
N
N
H
N
Toxic
100% at 10
mg/kg
Chloroq.
GIP = Growth inhibition percentage of the rodent malaria parasite after a four-day treatment. 10 mg/kg/day
of chloroquine, positive control, inhibited 100% the growth parasite. a Toxic = death of more than half of the
animals in the tested group.
3. Experimental
3.1. Biological evaluation
3.1.1. In vitro antimalarial activity screening against Plasmodium falciparum
The SYBR©GreenI-based micromethod [16] was followed for testing the antimalarial activity of the
compounds. Erythrocytic stages of P. falciparum 3D7 strain, chloroquine sensitive, were maintained in
RPMI 1640 culture medium supplemented with 0.5% Albumax II at 37 ºC in an atmosphere with 5%
CO2. An erythrocyte suspension, with initial 1% parasitemia and 4% hematocrit, was prepared using
the aforementioned culture and then distributed into a 96-well plate, 50 µL per well. Next, stock
solutions of each compound were prepared in DMSO and diluted in RPMI medium in order to obtain
concentrations from 10 to 0.01 µg/mL. The final DMSO concentration was never higher than 0.1%.
50 µL of each prepared concentration were added per well. DMSO and chloroquine were included as a
negative and positive control, respectively. All compounds and controls were placed in triplicate. The
plate was incubated under the same conditions. After 48 h, the plate was removed from the incubator
and frozen for at least 1 h at -70 °C and then thawed. Finally, 100 µL of SYBR©GreenI in lysis buffer
(0.2 µL/mL) was added per well and shaken for 5 minutes or until no precipitated erythrocytes were
observed. The plate was left to stand in the dark for 1 h at room temperature. Fluorescence intensity
(FI) for each well was measured. The background of the nonparasitized erythrocytes was subtracted
from each well tested. Percentage inhibition of the parasite growth for each concentration was
calculated by using the following formula:
% inhibition = 100 × [(F.I.control – F.I.comp)/(F.I.control)]
IC50 values were estimated by plotting drug concentration versus percentage inhibition.

Molecules 2009, 14
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3.1.2. Nonspecific cytotoxicity tests [17]
Murine J774 macrophages were maintained in RPMI 1640 medium supplemented with 10% FBS at
37 °C in a 5% CO2 atmosphere. First, in a flat bottom 96-well microplate, 100 µL of macrophage
suspension in RPMI medium, containing 5 × 104 cells, were distributed per well. The cells were
allowed to attach for 24 h at 37 °C. Next, the medium was replaced by different concentrations of the
compounds in 200 µL of medium, or DMSO at the same concentration as growth control, and the cells
were exposed to the compounds solutions for another 24 h. Each concentration was assayed three
times. Afterwards, the medium was eliminated and 100 µL/well of 3-(4,5-dimethythiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) solution, 0.4 mg/mL in PBS, was added and the plates were
returned to incubator for 1 h. The suspension was removed and the toxic effect of the compounds was
assessed by the reduction of MTT to formazan crystals (as a cell viability indicator); said crystals were
solubilized by adding 100 µL of DMSO. Finally, the optical density (OD) was measured at 595 nm
and the toxicity percentage was calculated as follows:
% toxicity = [(O.D.control - O.D.comp)/(O.D.control)] × 100
3.1.3. In vivo antimalarial activity
The in vivo antimalarial activity of the compounds was measured by the classical 4-day suppressive
test [18]. Briefly, on day 0, groups of five NMRI male mice, weighing 20 ± 2 g each , were inoculated
with 2 × 107 red blood cells RBCs infected by erythrocytic stages of rodent malaria parasite P. berghei
ANKA strain. Two hours later, each group of mice was treated intraperitoneally with a dose of
50 mg/kg of the selected compound, previously prepared in DMSO. Treatment was continued from
day 1 to day 3, always at similar times. On day 4, Giemsa-stained thin blood smears from the tail of
the mice were prepared and microscopically examined with 1,000× magnification. The mean of the
parasitemia of each group was calculated in a total of 1,000 RBCs, and the growth inhibition
percentage of parasite was estimated in relation to the control group, which received only the solvent
of the products.
% inhibition = [(Par control – Par comp)/(Par control)] × 100
3.1.4. Ferriprotoporphyrin IX biomineralization inhibition test (FBIT)
The procedure for testing FP biomineralization was carried out according to the method described
by Deharo [15]. A mixture containing 50 µL of a 10 mg/mL drug solution or 50 µL of solvent (for
control), 50 µL of 0.5 mg/mL of haemin chloride (Sigma H 5533) freshly dissolved in
dimethylsulphoxide (DMSO) and 100 µL of 0.5 M sodium acetate buffer pH 4.4 was incubated in a
non-sterile flat bottom 96-well plate at 37 °C for 18-24 hrs. After incubation, the plate was centrifuged
at 1,600 g for 5 min and the supernatant was discarded. The remaining pellet was resuspended with
200 µL of DMSO in order to remove unreacted FP. The plate was then centrifuged once again and the
supernatant discarded. The pellet (precipitate of ß-haematin), was dissolved in 150 µL of 0.1 M NaOH

Molecules 2009, 14
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and the absorbance quantified at 405 nm with a microplate reader. The data was expressed as the
percentage of inhibition of FP biomineralization, calculated using the following equation:
% inhibition = 100 × [(O.D.control - O.D.drug)/(O.D.control)]
3.2. Chemistry
The 1H-NMR spectra were recorded on a Bruker 400 Ultrashield (400 MHz) (Bruker, Rheinstetten,
Germany), using TMS as internal standard and chloroform (CDCl3) or dimethyl sulfoxide- d6 (DMSO-
d6) as solvents; the chemical shifts are reported in ppm (δ), and coupling constant (J) values are given
in Hertz (Hz). Signal multiplicities are represented by: s (singlet), bs (broad singlet), d (doublet), t
(triplet), q (quadruplet), dd (double doublet) and m (multiplet). The IR spectra were registered on a
Thermo Nicolet FT-IR Nexus Euro (Thermo, Madison, WI, USA) using KBr pellets; the frequencies
are expressed in cm-1. Elemental microanalyses were obtained on an Elemental Analyzer (LECO
CHN-900, Leco, Tres Cantos Spain) from vacuum-dried samples. The analytical results for C, H, and
N were within ± 0.4 of the theoretical values. Alugram SIL G/UV254 (Layer: 0.2 mm) (Macherey-
Nagel GmbH & Co. KG. Germany) was used for thin layer chromatography and silica gel 60
(0.040–0.063 mm) for column flash chromatography (Merck). Chemicals were purchased from E.
Merck (Darmstadt, Germany), Scharlau (F.E.R.O.S.A., Barcelona, Spain), Panreac Química S.A.
(Montcada i Reixac, Barcelona, Spain), Sigma-Aldrich Química, S.A., (Alcobendas, Madrid, Spain, ),
Acros Organics (Janssen Pharmaceuticalaan, Geel, Belgium) and Lancaster (Bischheim-Strasbourg,
France).
3.2.1. General method for the synthesis of protected aryl amines II
A mixture of the aryl fluoride (1 eq), the protected amine I (1.2 eq), K2CO3 (1.2 eq) and CH3CN
(50 mL) was heated at reflux for 48 hours. The solvent was removed under reduced pressure, the
residue was dissolved in CH2Cl2 (50 mL) and washed with water (3 × 30 mL). The organic phase was
dried with anhydrous Na2SO4 and filtered. After evaporating to dryness under reduced pressure, the
residue was precipitated and washed by adding diethyl ether or petroleum ether, affording the desired
protected aryl amine II.
3.2.2. General method for the preparation of deprotected amines III
The protected amine II was dissolved in 40 mL of a solution of HCl/AcOH (1:1) with stirring for
2 hours at room temperature. The solvent was removed under reduced pressure and the compound was
dissolved in water. The aqueous solution was basified with NaOH 2M to basic pH and stirred for
1 hour. Then the product was extracted with CH2Cl2. The organic phase was dried with anhydrous
Na2SO4 and filtered. After evaporating to dryness under reduced pressure the residue was precipitated
and washed by adding diethyl ether or petroleum ether, affording the desired deprotected amine III.
3.2.3. General method for the synthesis of ketones 6-10
A mixture of 1-(benzo[b]thiophen-3-yl)-3-chloropropan-1-one IV (1 eq), the arylamine III (1.2 eq)
and K2CO3 (1.2 eq) was stirred in THF (50 mL) for 72 hours at room temperature. The solvent was

Molecules 2009, 14
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removed under reduced pressure and the residue was dissolved in CH2Cl2 (40 mL) and washed with
water (3 × 30 mL). After evaporating to dryness under reduced pressure the residue was purified by
column chromatography (SP: silica gel), eluting with CH2Cl2/methanol 99:1 (v/v). In some cases the
compound has been purified by preparative chromatography (SP: silica gel), eluting with
CH2Cl2/methanol 95:5 (v/v). In the cases in which the hydrochloride salt was prepared, the process
consisted in adding an ethereal hydrogen chloride solution to a dichloromethane solution of the
compound.
3.2.4. General method for the synthesis of ketones VI
A mixture of the appropriated substituted acetophenone V (1 eq), arylamine III or a commercially
available one (1 eq) in absolute EtOH (40 mL) and concentrated HCl (pH = 2-3) was heated at reflux.
Paraformaldehyde (3 eq) was added in four equal portions over a period of 40 min. The reaction
mixture was refluxed for another 24 h, cooled and poured onto crushed ice. The separated solid was
filtered, dried and recrystallized from 1-propanol.
3.2.5. General method for preparation of hydroxyl derivatives 16, 28-35, 38, 40, 41, 44 and 45
Sodium borohydride (3 eq) was added little by little to a precooled suspension (0 ºC, 5 min) of the
corresponding ketone (1 eq) in methanol (40 mL) over a period of 30-60 minutes. The solvent was
removed under reduced pressure and the residue dissolved in dichloromethane (40 mL) was washed
with water (3 x 30 mL). The organic phase was dried with anhydrous Na2SO4 and filtered. After
evaporating the solvent to dryness under reduced pressure, the compound was purified by column
chromatography (SP: silica gel), eluting with CH2Cl2/methanol 99:1 (v/v) or by preparative
chromatography (SP: silica gel), eluting with CH2Cl2/methanol 95:5 (v/v).
1-(Benzo[b]thiophen-3-yl)-3-[4-(4-nitro-2-trifluoromethylphenyl)piperazin-1-yl]propan-1-ona
(6).
1
Yield 3%; Mp 140-141 ºC; H-NMR (CDCl3): δ 2.76-2.77 (m, 4H, H2 + H6 piperazine); 3.02 (c, 2H,
CO-CH2-CH2); 3.19-3.21 (t, 4H, H3 + H5 piperazine); 3.27-3.30 (c, 1H, CO-CH2-CH2); 7.29 (dd, 1H,
H6’ phenyl, J6’,5’ = 9.4 Hz, J6’,3’ = 2.5 Hz ); 7.46 (t, 1H, H6 benzothiophenyl, J6,5 = 8.0 Hz); 7.52 (t, 1H,
H5 benzothiophenyl, J5,4 = 8.1 Hz); 7.90 (d, 1H, H4 benzothiophenyl, J4,5 = 8.0 Hz); 8.33-8.36 (m, 2H,
H5’ phenyl + H7 benzothiophenyl); 8.53 (s, 1H, H2 benzothiophenyl); 8.78 (d, 1H, H3’ phenyl) ppm;
Anal. Calcd. for (C22H20N3F3O3S) C, 57.02; H, 4.32; N, 9.07. Found: C, 56.80; H, 4.53; N, 9.06.
1-(Benzo[b]thiophen-3-yl)-3-[3-(4-nitro-2-trifluoromethylphenylamino)-(R)-pyrrolidin-1-yl] propan-
1
1-one (7). Yield 5%; Mp 98-100 ºC; H-NMR (CDCl3): δ 1.76-1.83 (m, 1H, H4ec pyrrolidine); 2.40-
2.48 (m, 1H, H4ax pyrrolidine); 2.60 (dd, 1H, H5ax pyrrolidine); 2.80 (dd, 1H, H2ec pyrrolidine); 2.93
(dd, 1H, H2ax pyrrolidine); 3.00-3.10 (m, 3H, H5ec pyrrolidine + CO-CH2-CH2); 3.27 (t, 2H, CO-CH2,
JCH2-CH2 = 6.8 Hz); 4.16 (s.a, 1H, H3 pyrrolidine); 5.37 (d, 1H, NH); 6.68 (d, 1H, H6’ phenyl, J6’,5’ = 9.3
Hz); 7.45 (dd, 1H, H5 benzothiophenyl, J5,6 = 7.1 Hz, J5,4 = 8.0 Hz, J57 = 1.1 Hz); 7.51 (dd, 1H, H6
benzothiophenyl, J6,5 = 7.2 Hz, J6,7 = 8.2 Hz, J6,4 = 1.1 Hz); 7.88 (dd, 1H, H4 benzothiophenyl, J4,5
8.0 Hz, J46 = 1.0 Hz); 8.22 (dd, 1H, H5’ phenyl, J5’,6’ = 9.3 Hz, J5’,3’ = 2.3 Hz); 8.36 (s, 1H, H2
benzothiophenyl); 8.39 (d, 1H, H3’ phenyl, J3’,5’ = 2.5 Hz); 8.77 (dd, 1H, H7 benzothiophenyl, J7,6
=
=

Molecules 2009, 14
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8.2 Hz, J7,5 = 1.0 Hz) ppm; Anal. Calcd. for (C22H20N3F3O3S) C, 57.02; H, 4.32; N, 9.07. Found: C,
56.72; H, 4.32; N, 9.22.
1-(Benzo[b]thiophen-3-yl)-3-[1-(4-nitrophenyl)piperidin-4-ylamino]propan-1-one (8). Yield 57%; Mp
1
144-145 ºC; H-NMR (DMSO-d6): δ 1.22-1.31 (m, 2H, H3ax + H5ax piperidine); 1.79 (bs, 1H, NH);
1.78 (dd, 2H, H3ec + H5ec piperidine); 2.71-2.78 (m, 1H, H4 piperidine); 2.95 (t, 2H, CO-CH2, JCH2-CH2
= 6.6 Hz); 3.05-3.11 (m, 2H, H2ax + H6ax piperidine); 3.18 (t, 2H, CH2-NH, JCH2-CH2 = 6.6 Hz); 3.92 (d,
2H, H2ec + H6ec piperidine); 7.00 (d, 2H, H2’ + H6’ phenyl, J2’,3’ = J6’,5’ = 9.6 Hz); 7.43-7.52 (m, 2H, H5
+ H6 benzothiophenyl); 8.02 (d, 2H, H3’ + H5’ phenyl, J3’,2’ = J5’,6’ = 9.5 Hz); 8.08 (d, 1H, H4
benzothiophenyl); 8.61 (d, 1H, H7 benzothiophenyl); 8.97 (s, 1H, H2) ppm; Anal. Calcd. for
(C22H23N3O3S) C, 64.53; H, 5.66; N, 10.26. Found: C, 64.88; H, 5.67; N, 10.28.
Hydrochloride of 1-(benzo[b]thiophen-3-yl)-3-[4-(4-nitrophenyl)-1,4-diazepan-1-yl]propan-1-one (9).
1
Yield 57%; Mp 121-123 ºC; H-NMR (DMSO-d6): δ 2.22-2.28 (m, 1H, H6 diazepane); 2.43-246 (m,
1H, H6 diazepane); 3.20-3.25 (m, 2H, H7 diazepane); 3.35 (m, 2H, CO-CH2-CH2); 3.53-3.56 (m, 2H,
H2 diazepane); 3.63-3.67 (m, 2H, H5 diazepane); 3.70-3.72 (m, 2H, CO-CH2); 3.87-3.95 (m, 1H, H3
diazepane); 4.03-4.09 (m, 1H, H3 diazepane); 6.92(d, 2H, H2’ + H6’ phenyl, J2’,3’ = J6’,5’ = 9.4 Hz);
7.46-7.55 (m, 2H, H6 + H5 benzothiophenyl); 8.08-8.12 (m, 3H, H4 benzothiophenyl+ H3’+ H5’
phenyl); 8.60 (d, 1H, H7 benzothiophenyl, J7,6 = 8.1 Hz); 9.06 (s,1H, H2 benzothiophenyl); 10.95 (s.a.,
1H, HCl) ppm; Anal. Calcd. for (C22H23N3O3S·HCl) C, 59.25; H, 5.42; N, 9.42. Found: C, 58.86; H,
5.69; N, 9.08.
1-(Benzo[b]thiophen-3-yl)-3-[4-(quinoxalin-2-yl)piperazin-1-yl]propan-1-one (10). Yield 13%; Mp
145-146 ºC; 1H-NMR (CDCl3): δ 2.74 (t, 4H, H2 + H6 piperazine); 3.00 (t, 2H, CO-CH2-CH2); 3.08 (t,
2H, CO-CH2); 3.85 (t, 4H, H3 + H5 piperazine); 7.40-7.47 (m, 2H, H5 benzothiophenyl + H7’
quinoxalinyl); 7.53 (dd, 1H, H6 benzothiophenyl, J6,5 = 8.3 Hz, J6,7 = 7.1 Hz, J6,4 = 1.2 Hz); 7.60 (m,
1H, H6’ quinoxalinyl); 7.71 (dd, 1H, H5’ quinoxalinyl, J5’,6’ = 8.4 Hz, J5’,7’ = 1.3 Hz); 7.91 (m, 2H, H8’
quinoxalinyl + H4 benzothiophenyl); 8.38 (s, 1H, H2 benzothiophenyl); 8.60 (s, 1H, H3’quinoxalinyl);
8.79 (dd, 1H, H7 benzothiophenyl, J7,6 = 8.2 Hz, J7,5 = 0.7 Hz ) ppm; Anal. Calcd. for (C23H22N4OS) C,
68.63; H, 5.51; N, 13.92. Found: C, 68.58; H, 5.42; N, 13.77.
Dihydrochloride of 1-(5-fluorobenzo[b]thiophen-3-yl)-3-[4-(3-methoxyphenyl)piperazin-1-yl]propan-
1-ol (16). Yield 42%; Mp 135-137 ºC; 1H-NMR (DMSO-d6): δ 2.22-2.24 (m, 2H, CHOH-CH2); 3.12-
3.16 (m, 4H, 2H2 + 2H6 piperazine); 3.28-3.33 (m, 2H, CHCH2CH2); 3.56-3.58 (m, 2H, 1H3ec+1H5ec
piperazine); 3.73 (s, 3H, OCH3); 3.79-3.82 (m, 2H, H3ax+H5ax piperazine); 4.52 (bs, 1H, OH); 5.03 (t,
1H, CHOH, JCH-CH2 = 7.6 Hz); 6.44 (d, 1H, H4’ phenyl, J4’,5’ = 8.0 Hz, J4’,6’ = 2.0 Hz); 6.46 (s, 1H, H2’
phenyl); 6.52 (d, 1H, H6’ phenyl, J6’,5’ = 8.0 Hz, J6’,4’ = 2.0 Hz); 7.13 (t, 1H, H5’ phenyl, J5’,6’ = J5’,4’
=
8.4 Hz); 7.27 (t, 1H, H6 benzothiophenyl, J6,7 = 8.8 Hz, J6,4 = 2.4 Hz); 7.77 (s, 1H, H2
benzothiophenyl); 7.81 (d, 1H, H7 benzothiophenyl, J7,6 = 8.8 Hz); 8.03 (dd, 1H, H4 benzothiophenyl,
J = 8.8 Hz)); 10.91 (s, 1H, OH); ppm; Anal. Calcd. for (C22H25FN2O2S. 2HCl) C, 55.81; H, 5.70; N,
5.91. Found: C, 55.41; H, 5.82; N, 5.43.

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1-(Benzo[b]thiophen-3-yl)-3-[4-(4-nitro-2-trifluoromethylphenyl)piperazin-1-yl]propan-1-ol
(28).
1
Yield 3%; Mp 154-155 ºC; H-NMR (CDCl3): 2.14-2.16 (m, 2H, CHOH-CH2); 2.77-2.87 (m, 6H,
CHOH-CH2-CH2 + H2+H6 piperazine); 3.20-3.29 (m, 4H, H3+ H5 piperazine); 5.38 (t, 1H, CHOH,
JCH-CH2 = 7.5 Hz); 7.33-7.42 (m, 3H, H6’ phenyl + H6 + H5 benzothiophenyl); 7.45 (s, 1H, H2
benzothiophenyl); 7.82 (d, 1H, H4 benzothiophenyl, J4,5 = 8.4 Hz); 7.88 (d, 1H, H7 benzothiophenyl,
J7,6 = 8.0 Hz); 8.37 (dd, 1H, H5’ phenyl J5’,6’ = 9.2 Hz, J5’,3’ = 2.8 Hz); 8.55 (d, 1H, H3’ phenyl) ppm;
Anal. Calcd. for (C22H22N3F3O3S) C, 57.77; H, 4.73; N, 9.03. Found: C, 57.01; H, 4.85; N, 8.54.
1-(Benzo[b]thiophen-3-yl)-3-[3-(4-nitro-2-trifluoromethylphenylamino)-(R)-pyrrolidin-1-yl]propan-1-
1
ol (29). Yield 47%; Mp 48-50 ºC; H-NMR (DMSO-d6): δ 1.82-1.89 (m, 1H, H4ec pyrrolidine); 2.06-
2.21 (m, 2H, CHOH-CH2); 2.47-2.56 (m, 1H, H4ax pyrrolidine); 2.76-2.85 (m, 3H, CHOH-CH2-CH2 +
H2ec + H5ax pyrrolidine); 3.00-3.15 (m, 2H, CHOH-CH2-CH2 + H5ec pyrrolidine); 3.07-3.11 (m, 1H,
H2ax pyrrolidine); 4.18-4.26 (m, 1H, H3 pyrrolidine); 5.27 (bs, 1H, NH); 5.36-5.38 (m, 1H, CHOH);
6.72 (dd, 1H, H6’ phenyl, J6’,5’ = 9.3 Hz, J6’,3’ = 2.3 Hz); 7.34-7.40 (m, 2H, H5, H6 benzothiophenyl);
7.44 (d, 1H, H2 benzothiophenyl, J = 7.3 Hz); 7.80-7.83 (m, 1H, H4 benzothiophenyl); 7.87-7.90 (m,
1H, H7 benzothiophenyl); 8.29 (dd, 1H, H5’ phenyl, J5’,6’ = 9.4 Hz, J5’,3’ = 2.2 Hz); 8.44 (t, 1H, H3’
phenyl, J3’,F = J3’,5’ = 2.9 Hz) ppm; Anal. Calcd. for (C22H22N3F3O3S) C, 56.77; H, 4.76; N, 9.07.
Found: C56.50; H, 4.88; N, 9.02.
1-(Benzo[b]thiophen-3-yl)-3-[1-(4-nitro-2-trifluoromethylphenyl)-(S)-pyrrolidin-3-ylamino]propan-1-
1
ol (30). Yield 18%; Mp 109-110 ºC;. H-NMR (CDCl3): δ 1.94-2.07 (m, 2H, CHOH-CH2); 2.15-2.20
(m, 1H, H4ec pyrrolidine); 2.24-2.31 (m, 1H, H4ax pyrrolidine); 2.91-3.00 (m, 1H, CHOH-CH2-CH2);
3.04-3.10 (m, 1H, CHOH-CH2-CH2) 3.20 (bs, 1H, OH); 3.41 (td, 1H, H2ec pyrrolidine); 3.49-3.54 (m,
1H, H5ec pyrrolidine); 3.58-3.65 (m, 1H, H2ax pyrrolidine); 3.72-3.80 (m, 2H, H5ax + H3 pyrrolidine);
5.35 (bs, 1H, CHOH); 6.84 (dd, 1H, H6’, J6’,5’ = 9.5 Hz, H6’ phenyl, J6’,3’ = 2.5 Hz); 7.33-7.43 (m, 3H,
H5 + H6 + H2 benzothiophenyl); 7.77-7.80 (m, 1H, H4 benzothiophenyl); 7.87-7.89 (m, 1H, H7
benzothiophenyl); 8.18-8.22 (m, 1H, H5’ phenyl); 8.58 (dd, 1H, H3’ phenyl, J3’,5’ = 5.1 Hz, J3’,6’ = 2.6
Hz) ppm; Anal. Calcd. for (C22H22N3F3O3S) C, 56.77; H, 4.76; N, 9.07. Found: C, 56.33; H, 4.94; N,
9.06.
1-(Benzo[b]thiophen-3-yl)-3-[1-(4-nitro-2-trifluoromethylphenyl)piperidin-4-ylamino]propan-1-ol
1
(31). Yield 33%; Mp 145-146 ºC; H-NMR (CDCl3): δ 1.57-1.68 (m, 2H, H3ax + H5ax piperidine);
1.94-2.03 (m, 1H, CHOH-CH2); 2.08 (d, 2H, H3ec + H5ec piperidine); 2.15-2.20 (m, 1H, CHOH-CH2);
2.71-2.77 (m, 1H, H4 piperidine); 2.91-3.01 (m, 3H, H2ax + H6ax piperidine + CH2-NH); 3.07-3.12 (m,
1H, CH2-NH); 3.41 (d, 2H, H2ec + H6ec piperidine); 5.38 (m, 1H, CHOH); 7.27 (d, 1H, H6’ phenyl,
J6’,5’ = 8.9 Hz); 7.34-7.40 (m, 2H, H5 + H6 benzothiophenyl); 7.46 (s, 1H, H2 benzothiophenyl); 7.81
(d, 1H, H4, benzothiophenyl J4,5 = 7.9 Hz); 7.88 (d, 1H, H7 benzothiophenyl, J7,6 = 7.8 Hz); 8.32 (dd,
1H, H5’ phenyl, J5’,6’ = 9.0 Hz, J5’,3’ = 2.3 Hz); 8.53 (d, 1H, H3’ phenyl, J3’,5’ = 2.4 Hz) ppm; Anal.
Calcd. for (C23H24N3F3O3S) C, 57.61; H, 5.04; N, 8.76. Found: C, 57.39; H, 5.06; N, 8.80.
1-(5-Fluorobenzo[b]thiophen-3-yl)-3-[4-(4-nitrophenyl)piperazin-1-yl]propan-1-ol (32). Yield 14%;
1
Mp 189-190 ºC; H-NMR (CDCl3): δ 1.60 (bs, 1H, OH); 2.10-2.15 (m, 2H, CHOH-CH2); 2.79-2.90

Molecules 2009, 14
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(m, 6H, CHOH-CH2-CH2 + H2+H6 piperazine); 3.53 (t, 4H, H3+ H5 piperazine); 5.30 (dd, 1H,
CHOH); 6.88 (d, 2H, H2’+ H6’ phenyl, J2’,3’ = J6’,5’ = 9.4 Hz); 7.14 (td, 1H, H6 benzothiophenyl, J6,7 =
J6,F = 8.7 Hz, J6,4 = 2.4 Hz); 7.50-7.53 (m, 2H, H2 + H4 benzothiophenyl); 7.81 (dd, 1H, H7
benzothiophenyl, J7,6 = 8.8 Hz, J7,F = 4.8 Hz); 8.17 (d, 2H, H3’+ H5’ phenyl, J3’,4’ = J5’,6’ = 9.4 Hz)
ppm; Anal. Calcd. for (C21H22N3FO3S) C, 60.71; H, 5.34; N, 10.11. Found: C, 60.44; H, 5.43; N, 9.79.
1-(Benzo[b]thiophen-3-yl)-3-(1-(4-nitrophenyl)piperidin-4-ylamino)propan-1-ol (33). Yield 57%; Mp
153-155 ºC; 1H-NMR (DMSO-d6): δ 1.23-1.31 (m, 2H, H3ax + H5ax piperidine); 1.86-1.96 (m, 4H, H3ec
+ H5ec piperidine + CHOH-CH2); 2.69-2.73 (m, 3H, H2ax + H6ax + H4 piperidine); 3.07 (t, 2H, CH2-
NH); 3.95 (d, 2H, H2ec + H6ec piperidine); 5.08 (s.a., 1H, CHOH); 7.27 (d, 1H, H2’+ H6’ phenyl, J2’,3’
=
J6’,5’ = 8.7 Hz); 7.33-7.39 (m, 2H, H5 + H6 benzothiophenyl); 7.53 (s, 1H, H2 benzothiophenyl); 7.93-
7.97 (m, 2H, H4 + H7 benzothiophenyl); 8.32 (dd, 1H, H3’+ H5’ phenyl, J3’,2’ = J5’,6’ = 8.8 Hz) ppm;
Anal. Calcd. for (C22H25N3O3S) C, 64.21; H, 6.12; N, 10.21. Found: C, 64.00; H, 5.97; N, 10.43.
1-(Benzo[b]thiophen-3-yl)-3-(4-(4-nitrophenyl)-1,4-diazepan-1-yl)propan-1-ol (34). Yield 61%; Mp
47-48 ºC; 1H-NMR (DMSO-d6): δ 2.00-2.16 (m, 4H, 2H6 diazepane + CHOH-CH2); 2.68-3.00 (m, 6H,
CH-CH2-CH2 + 2H2 + 2H7 diazepane); 3.64-3.68 (m, 2H, 2H5 diazepane); 3.74 (bs, 2H, 2H3
diazepane); 5.32-5.38 (m, 1H, CHOH); 6.67 (d, 2H, H2’+ H6’ phenyl, J2’,3’ = J 6’,5’ = 9.4 Hz); 7.36-7.39
(m, 2H, H6+H5 benzothiophenyl); 7.43 (s, 1H, H2 benzothiophenyl); 7.78 (d, 1H, H4, J4,5 = 7.42
benzothiophenyl); 7.88 (d, 1H, H7 benzothiophenyl, J7,6 = 7.03 Hz); 8.15 (d, 2H, H3’+H5’ phenyl, J3’,2’
= J5’,6’ = 9.0 Hz) ppm; Anal. Calcd. for (C22H25N3O3S) C, 65.23; H, 6.08; N, 10.22. Found: C, 65.44;
H, 6.45; N, 9.79.
1-(Benzo[b]thiophen-3-yl)-3-(4-(quinoxalin-2-yl)piperazin-1-yl)propan-1-ol (35). Yield 15%; Mp
1
155-156 ºC; H-NMR (DMSO-d6): δ 2.29-2.32 (m, 2H, CHOHCH2); 3.13-3.22 (m, 6H, CH-CH2-CH2
+ 2H2 + 2H6 piperazine); 3.46-3.54 (m, 2H, H3 piperazine); 3.56-3.64 (m, 2H, H5 piperazine); 5.05-
5.07 (m, 1H, CHOH); 5.76 (bs, 1H, OH); 7.37-7.44 (m, 2H, H5 + H6 benzothiophenyl); 7.45-7.49 (m,
1H, H7’ quinoxalinyl); 7.63-7.66 (m, 3H, H2 + H4 benzothiophenyl + H6’ quinoxalinyl); 8.88 (d, 1H,
H7 benzothiophenyl, J7,6 =8.4); 7.99 (dd, 2H, H5’ + H8’ quinoxalinyl, J5’,6’ = J8’,7’ = 8.9 Hz, J5’,7’=J8’,6’
=
1.2 Hz); 8.90 (s, 1H, H3’ quinoxalinyl) ppm; Anal. Calcd. for (C23H24N4OS) C, 68.31; H, 5.94; N,
13.86. Found: C, 68.70; H, 6.22; N, 13.65.
1-(4-Phenyl)phenyl -3-[4-(4-chlorophenyl)piperazin-1-yl]propan-1-ol (38). Yield 47%; Mp 169-170
ºC; 1H-NMR (DMSO-d6): δ 1.80-1.85 (m, 2H, CHOHCH2); 3.12-3.16 (m, 6H, CH-CH2-CH2 + 2H2 +
2H6 piperazine); 3.34 (bs, 4H, 2H3 + 2H5 piperazine); 4.68-4.70 (m, 1H, CHOH); 5.51 (s, 1H, OH);
6.93 (d, 2H, H2+H6 Cl-phenyl, J = 9.0 Hz); 7.22 (d, 2H, H3+H5 Cl-phenyl, J = 8.8 Hz); 7.35 (t, 1H, H4’
phenyl, J = 8.4 Hz); 7.31-7.38 (m, 4H, H2+H6 p-phenylphenyl + H3’+H5’ phenyl); 7.61-7.67 (m, 4H,
H3+H5 p-phenylphenyl + H2’+H6’ phenyl); ppm; Anal. Calcd. for (C25H27ClN2O) C, 73.80; H, 6.64; N,
6.88. Found: C, 73.48; H, 6.89; N, 6.78.
1-(4-Phenyl)phenyl-3-[4-(2-methoxyphenyl)piperazin-1-yl]propan-1-ol (40). Yield 77% yield; Mp
109-110 ºC; 1H-NMR (DMSO-d6): δ 1.79-1.83 (m, 2H, CHOHCH2); 2.38-2.54 (m, 6H, CHCH2CH2 +

Molecules 2009, 14
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2H2 + 2H6 piperazine); 2.96 (bs, 4H, 2H3 + 2H5 piperazine); 3.76 (bs, 3H, OCH3); 4.70 (t, 1H,
CHOH); 5.52 (bs, 1H, OH); 6.87-6.93 (m, 4H, H3+H4+H5+H6 OCH3-phenyl); 7.35 (t, 1H, H4’
phenyl); 7.42-7.48 (m, 4H, H2+H6 p-phenylphenyl + H3’+H5’ phenyl); 7.61-7.67 (m, 4H, H3+H5 p-
phenylphenyl + H2’+H6’ phenyl); ppm; Anal. Calcd. for (C26H30N2O2) C, 77.61; H, 7.46; N, 6.96.
Found: C, 77.58; H, 7.75; N, 6.84.
1-(3-Indolyl)-3-[4-(2-methoxyphenyl)piperazin-1-yl]propan-1-ol (41). Yield 30% yield; Mp 188-189
1
ºC; H-NMR (DMSO-d6): δ 1.91-2.03 (m, 2H, CHOHCH2); 2.38-2.51 (m, 6H, CHCH2CH2 + 2H2 +
2H6 piperazine); 2.96 (bs, 4H, 2H3 + 2H5 piperazine); 3.76 (s, 3H, OCH3); 4.92 (t, 1H, CHOH); 5.16
(bs, 1H, OH); 6.87-6.98 (m, 5H, H3’+H4’+H5’+H6’ phenyl + H6 indolyl); 7.04-7.06 (t, 1H, H5 indolyl,
J5,6 = 8.0 Hz, J5,4 = 7.4 Hz); 7.20 (s, 1H, H2 indolyl); 7.33 (d, 1H, H7 indolyl, J7,6 = 8.4 Hz); 7.63 (d,
1H, H4 indolyl, J4,5 = 7.4 Hz); 10.83 (s, 1H, NH) ppm; Anal. Calcd. for (C22H27N3O2) C, 72.33; H,
7.39; N, 11.51. Found: C, 72.23; H, 7.85; N, 11.19.
Dihydrochloride of 1-(6-methylnapth-2-yl)-3-[4-(2-methoxyphenyl) piperazin-1-yl]propan-1-ol (44).
Yield 35%; M.p.: 116-117 ºC; 1H-NMR (DMSO-d6): δ 2.10-2.19 (m, 2H, CHCH2); 2.47 (s, 3H, CH3);
2.95-3.02 (m, 2H, H2ax + H6ax piperazine); 3.16-3.29 (m, 4H, H2ec + H6ec piperazine + CHCH2CH2);
3.45-3.57 (m, 4H, H3 + H5 piperazine); 3.78 (s, 3H, OCH3); 4.80-4.83 (m, 1H, CH); 6.91-7.05 (m, 4H,
H3’+H4’+H5’+H6’ phenyl); 7.36 (d, 1H, H7 naphthyl, J7,8 = 8.4 Hz); 7.50 (d, 1H, H3 naphthyl, J3,4 = 8.8
Hz); 7.67 (s, 1H, H5 naphthyl); 7.81 (m, 3H, H1+H4+H8 naphthyl) ppm; Anal. Calcd. for (C25H30N2O2.
2HCl) C, 64.79; H, 6.91; N, 6.04. Found: C, 64.62; H, 7.05; N, 5.88.
Hydrochloride of 1-(2-naphthyl)-3-[3-(4-nitro-2-trifluoromethylphenyl)-(S)-pyrrolidin-3-yl amino]-
1
propan-1-ol (45). Yield 20%; Mp.: 181-183 ºC; H-NMR (DMSO-d6): δ 2.07-2.14 (m, 2H, CHOH-
CH2); 2.29-2.31 (m, 1H, H4ec pyrrolidine); 2.36-2.41 (m, 1H, H4ax pyrrolidine); 3.11 (bs, 2H, CHOH-
CH2-CH2); 3.57-3.64 (m, 1H, H2ec pyrrolidine); 3.75-3.79 (m, 2H, H5ec+ H2ax pyrrolidine); 3.85-3.89
(m, 1H, H5ax pyrrolidine); 3.97 (bs, 1H, H3 pyrrolidine); 5.90 (bs, 1H, CHOH); 5.76 (s, 1H, OH); 7.10
(d, 1H, H6’ phenyl, J6’,5’ = 9.6); 7.47-7.55 (m, 3H, H3 + H6 + H7 naphthyl); 7.86 (s, 1H, H1 naphthyl);
7.90-7.92 (m, 3H, H4 + H5 + H8 naphthyl); 8.24-8.9 (d, 1H, H5’ phenyl, J5’,6’ = 9.5); 8.40 (s, 1H, H3’
phenyl); 9.49 (bs, 1H, NH) ppm; Anal. Calcd. for (C24H24N3F3O3.HCl) C, 58.24; H, 5.04; N, 8.48.
Found: C, 57.87; H, 4.92; N, 8.21.
4. Conclusions
The biological evaluation showed a broad range of activities, thereby offering new structural hits
for future chemical pharmacomodulation of 1-aryl-3-substituted propanol derivatives as a new
therapeutic option for the treatment of malaria.
Acknowledgements
This work has been carried out with the financial support of the PIUNA Project from University of
Navarra. A. M. is indebted to the Navarra Government for a grant.

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