Synthesis and pharmacological activity of O-aminoalkyl derivatives of 7-hydroxycoumarin

Article abstract of DOI:10.1016/j.ejmech.2011.03.006

A series of novel O-aminoalkyl substituted 7-hydroxycoumarins were synthesized and evaluated for antibacterial and anticancer toxicity. Two different synthetic procedures, conventional and microwave assisted were used, and the structures of the compounds

Full text of DOI:10.1016/j.ejmech.2011.03.006

European Journal of Medicinal Chemistry 46 (2011) 2252e2263
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and pharmacological activity of O-aminoalkyl derivatives of
7-hydroxycoumarin
a
a
b
c
_
Joanna Trykowska Konc , Elzbieta Hejchman , Hanna Kruszewska , Irena Wolska ,
,
Dorota Maciejewska a
*
a Department of Organic Chemistry, Faculty of Pharmacy, Medical University of Warsaw, 1 Banacha Strasse, 02 097 Warsaw, Poland
b National Medicines Institute, Department of Antibiotics and Microbiology, 30/34 Chełmska, 00 725 Warsaw, Poland
c
ꢀ
Department of Crystallography, Faculty of Chemistry, Adam Mickiewicz University, 6 Grunwaldzka Strasse, 60 780 Poznan, Poland
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of novel O-aminoalkyl substituted 7-hydroxycoumarins were synthesized and evaluated for
antibacterial and anticancer toxicity. Two different synthetic procedures, conventional and microwave
assisted were used, and the structures of the compounds were confirmed by IR, 1H, 13C NMR and MAS
spectroscopic data. The molecular and crystal structures of 8-acetyl-7-[2-(1-morpholino)ethoxy]
4-methylchromen-2-one in solid state were analyzed by single crystal X-ray diffraction. The compound
crystallizes in the monoclinic space group P21/c. The main driving forces for the supramolecular structure
Received 7 December 2010
Received in revised form
2 March 2011
Accepted 3 March 2011
Available online 10 March 2011
are the CeH/O hydrogen bonds and the p/p intermolecular interactions. The most active compounds
are those, where the O-aminoalkyl substituent has N,N-diethylamino part, and acetyl group is at C6 or at
C8 atoms.
Keywords:
Coumarin derivatives
Cytotoxicity
Antibacterial activity
Microwave-assisted synthesis
X-ray diffraction
Ó 2011 Elsevier Masson SAS. All rights reserved.
1. Introduction
anticancer agents for the breast and colon human cancer cell lines
has been described [4].
Coumarin and chromone derivatives are of great interest due to
their diverse bioactivity [1]. In particular, their antibacterial, anti-
fungal and anticancer activities make the compounds attractive for
further derivatization and screening as novel therapeutic agents [2].
The literature investigation revealed cytotoxic activity of coumarins
against several human tumor cell lines [3]. Auraptene: 7-[(E)-
3,7-dimethylocta-2,6-dienyloxy]-2H-chromen-2-one, is a bioactive
coumarin ether, isolated from members of the genus Citrus. Many
studies have reported the effect of auraptene as a chemopre-
ventative agent against cancers of skin, oral cavity, esophagus,
and large bowel in rodent models. Geiparvarin: 7-{[(2E)-
3-(5,5-dimethyl-4-oxo-4,5-dihydrofuran-2-yl)but-2-en-1-yl]oxy}-
2H-chromen-2-one, a naturally occurring coumarin compound
shows significant inhibitory activity against several cell lines
including sarcoma 180, Lewis lung carcinoma P-388, lymphocytic
leukemia. Moreover, the use of aminoalkyl ethers of phenols as
The antibacterial activity of coumarin per se and substituted
coumarins was evaluated and their structure against activity was
analyzed. It was shown [5] that coumarins with a methoxy function
at C-7 are effective against Gram-negative bacteria and the Gram-
positive strains of Staphylococcus aureus. On the other hand,
coumarins having at least two methoxy and at least one additional
phenolic groups emerge as promising candidates with broad-
spectrum antibacterial activity. Moreover, the antifungal potential
of osthenol: 7-hydroxy-8-(3-methylbut-2-enyl)chromen-2-one,
can be related to the presence of the branched alkyl group at C-8
position [6].
Based on this these findings and as a continuation of our
previous research [7e9], we have planned synthesis and the eval-
uation of biological activity of coumarin derivatives bearing
O-aminoalkyl, methyl and acetyl substituents at positions 4, 6, 7
and 8 (see Scheme 1). In the present paper we report their
synthesis under conventional conditions and discuss advantages of
using microwave-assisted method as well as their anticancer and
antimicrobial activity. Additionally, the X-ray structure of 8-acetyl-
7-[2-(1-morpholino)ethoxy]4-methylchromen-2-one (5d) is pre-
sented together with the inter and intramolecular interactions in
solid state.
* Corresponding author. Tel./fax: þ48 22 5720 643.
E-mail address: dmaciejewska@wum.edu.pl (D. Maciejewska).
0223-5234/$ e see front matter Ó 2011 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2011.03.006

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2253
R1
O
R2
20
CH3I
x CH3I
(CH3CH2)O
RO
O
R-Cl
R1
O
R1
R3
acetone
reflux
5
4
R2
R2
(2am, 3am, 3bm,
6
4a
8a
3
4am, 4bm)
7
2
HO
O
RO
O
O
8
R1
1
R3
R3
R-Cl
MW
R2
21
C2H5OH/HCl
x HCl
O
(a, b, c, d)
(1a-d, 2a-d, 3a-d,
4a-d, 5a-d, 6c-d)
RO
O
R3
(1ah-dh, 2bh-dh, 3ah-dh,
4ah-dh, 5ah-bh, 6ch-dh)
15'
15
18'
15'
a: R1, R2, R3 = H
R:
1
4
2
5
3
14
19
17 '
14'
14
9
15'
N
N
N
b: R1 = CH3; R2, R3 = H
15
18
12
12
12
16
13
14'
14
13
15
13
17
10
11
9
15
17
c: R1 = CH3; R2 = COCH3, R3 = H
15'
15'
6
10
11
9
16
15
16
15
14'
14'
O
18
d: R1 = CH3; R2 = H; R3 = COCH3
N
N
N
15
12
12
12
14
13
14
19
14
13
13
Scheme 1. Syntheses of O-aminoalkyl derivatives of 7-hydroxycoumarin.
2. Results and discussion
twisted with respect to the plane of the coumarin fragment as
indicate the C7eC8eC10eC11 and C7eC8eC10eO11 torsion angles
(the values of the appropriate torsion angles are given in Table S2 in
Supplementary data). In consequence the C11 and O11 atoms are
found above and below of the best plane of the coumarin moiety.
This orientation is quite different compared with 8-acetyl-7-
hydroxy-4-methylcoumarin [7]. The orientation of the substituent
at C7 with respect to the two-ring framework can be described by
the torsion angle C8eC7eO7eC12 of ꢁ174.7(1)ꢀ. The chain
between C7 and N13 atoms is in an extended trans conformation
and the morpholine ring adopts the conformation of a chair. The
best plane of the coumarin fragment and the C14/C15/C140/C150
plane make an angle of 44.29(6)ꢀ.
In the crystal of 5d, the packing of molecules is stabilized by
intermolecular CeH/O hydrogen bonds and stacking forces. The
geometric parameters of all intermolecular interactions are given in
Table 1. The molecules are linked by C6eH6A/O15(x, 1.5 ꢁ y,
0.5 þ z), C12eH12B/O15 (x, 1.5 ꢁ y, 0.5 þ z) and C11eH11A/O2
2.1. Chemistry
The planned compounds were obtained from 7-hydroxy and 4-, 6-
or 8-substituted coumarin. In the first step the corresponding O-alky-
lamino derivatives 1aed, 2aed, 3aed, 4aed, 5aed and 6ced were
prepared by alkylation of the phenolic group with appropriate chlor-
oethylamines (Scheme 1). Two methods were employed, conventional
and with microwave irradiation (see Supplementary data). Microwave
irradiation was used in order to shorten time of reaction as well as
increase yield, and sometimes it was the only method that could be
used [9]. In the second step, the majority of O-alkylamino derivatives
were converted into the hydrochlorides 1ahedh, 2bhedh, 3ahedh,
4ahedh, 5ahebh, 6chedh or the methiodides 2am, 3am, 3bm, 4am,
4bm to increase solubility in polar solvents.
2.2. Crystal structure of 8-acetyl-7-[2-(1-morpholino)ethoxy]4-
methylchromen-2-one (5d)
The molecular and crystal structures of 8-acetyl-7-[2-(1-mor-
pholino)ethoxy]4-methylchromen-2-one (5d) in solid state were
analyzed by single crystal X-ray diffraction. A view of the molecular
structure together with the atomic numbering scheme is shown in
Fig. 1 (the drawings were performed with Mercury program [10]).
The results indicate that the compound 5d crystallizes in the
monoclinic space group P21/c with one ordered molecule in the
asymmetric unit. The bond lengths and angles in the coumarin ring
system compare well with those observed in other coumarin
derivatives [7,8,11e15]. The coumarin moiety is almost planar with
ꢁ
a maximum deviation of 0.046(1) A for O2. The dihedral angle
between the least-squares planes of the pyrone and benzene rings
is 1.97(4)ꢀ. The C9 and O7 atoms are nearly coplanar with the
coumarin ring system. The acetyl group at C8 is considerably
Fig. 1. A view of the molecule of 5d.

2254
J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
Table 1
Table 2
Hydrogen bonding geometry [A and ꢀ] for 5d.
Antibacterial activity of synthesized novel series of 7-hydroxycoumarins.
ꢁ
DeH/A
C9eH9B/O11i
d (DeH)
d(H/A)
d(D/A)
<(DHA)
Compound
MIC
M.l.a
ei
ei
m
mol/mL
M.l.b
ei
ei
B.s.c
B.c.d
S.a.e
S.a.f
E.c.g
E.c.h
0.96
0.93
0.97
0.96
0.97
0.97
0.97
2.71
2.54
2.67
2.72
2.79
2.78
2.80
3.600(2)
3.463(2)
3.289(2)
3.402(2)
3.589(2)
3.595(2)
3.465(2)
154
175
122
128
140
142
126
C6eH6A/O15ii
C12eH12B/O15ii
C11eH11A/O2iii
C140eH14D/O2iv
C150eH15C/O1iv
C15eH15B/O2v
a
b
c
d
ei
ei
ei
ei
ei
ei
ei
85.1
4.6
22.9
30.7
2.9
ei
ei
ei
ei
45.8
68.7
46.0
7.4
37.5
25.0
40.7
1.5
6.0
8.4
2.0
31.5
1.8
45.8
68.7
61.4
44.1
37.5
ei
22.9
45.8
46.0
2.9
45.8
68.7
ei
ei
ei
ei
ei
ei
ei
1ah
1bh
1ch
1dh
2bh
2ch
2dh
3ah
3bh
3c
61.4
44.1
ei
ei
ei
61.4
44.1
ei
ei
ei
46.0
14.7
ei
ei
ei
44.1
ei
ei
ei
Symmetry codes: (i) ꢁx, 1 ꢁ y, 1 ꢁ z; (ii) x, 1.5 ꢁ y, 0.5 þ z; (iii) x,
0.5 ꢁ y, ꢁ0.5 þ z;(iv) ꢁx, 0.5 þ y, 0.5 ꢁ z; (v) 1 ꢁ x, 0.5 þ y, 0.5 ꢁ z.
12.5
12.5
ei
ei
40.7
1.5
6.0
16.8
8.0
31.5
1.8
ei
ei
(x, 0.5 ꢁ y, ꢁ0.5 þ z) hydrogen bonds forming layers parallel to the
(100) plane (Fig. 2). C9eH9B/O11 (ꢁx, 1 ꢁ y, 1 ꢁ z),
C140eH14D/O2 (ꢁx, 0.5 þ y, 0.5 ꢁ z), C150eH15C/O1 (ꢁx, 0.5 þ y,
24.3
2.4
8.4
2.0
31.5
0.4
24.3
2.4
8.4
2.0
63.0
0.4
24.3
35.7
ei
24.3
23.8
67.2
32.1
ei
24.3
ei
24.3
35.7
16.8
8.0
ei
33.6
8.0
ei
32.1
ei
0.5 ꢁ z) contacts and
p/p stacking forces connect adjacent layers
into bilayers. In the stacks, cohesion between molecules results in
interactions by partly overlapping coumarin units from
3ch
3d
7.1
3.9
ei
7.1
14.1
ei
ei
7.1
ei
ei
p/p
2.0
2.0
3.9
3.9
3.9
neighboring layers (details are given in Supplementary data).
3dh
4ah
4bh
4ch
4dh
6ch
6dh
5a
5b
5c
5d
2am
4bm
3.5
14.1
30.9
14.4
13.2
24.6
1.7
13.0
18.2
8.6
ei
ei
ei
15.4
14.4
6.6
12.3
1.7
6.5
18.2
8.6
30.9
14.4
1.6
24.6
1.7
39.1
72.6
69.1
30.2
ei
30.9
28.8
1.6
24.6
1.7
26.1
72.6
69.1
30.2
ei
46.3
43.2
26.3
24.6
13.3
39.1
72.6
ei
61.8
28.8
26.3
24.6
6.7
39.1
36.3
69.1
30.2
ei
15.4
7.2
ei
30.9
14.4
26.3
49.2
13.3
13.0
36.3
51.8
30.2
ei
2.3. Pharmacological screening
2.3.1. Anticancer screening
36.9
26.7
26.1
36.3
51.8
30.2
ei
Three
compounds,
7-[2-(N,N-diisopropylamino)ethoxy]
4-methylchromen-2-one (1b), 8-acetyl-7-[2-(2-methylpiperidinyl)
ethoxy]4-methylchromen-2-one (4d) and 6-acetyl-7-[2-(1-mor-
pholino)ethoxy]4-methylchromen-2-one (5c) were selected by the
Division of Cancer Treatment and Diagnosis, National Cancer
Institute Bethesda, USA to be evaluated in the full panel of 60
different cell lines, representing human leukemia, non-small cell
lung cancer, colon cancer, central nervous system (CNS) cancer,
melanoma, ovarian cancer, renal cancer, prostate cancer and breast
cancer cell lines (the details are available at the web site http://dtp.
nci.nih.gov).
30.2
30.2
1.4
30.2
30.2
5.5
30.2
ei
21.9
22.6
21.2
45.1
21.2
ei
21.2
ei
21.2
ei
21.2
ei
22.6
22.6
a
M.l.: Micrococcus luteus ATCC 9341 (Gram-positive bacterial strain).
M.l.: Micrococcus luteus ATCC 10240 (Gram-positive bacterial strain).
B.s.: Bacillus subtilis ATCC 6633 (Gram-positive bacterial strain).
B.c.: Bacillus cereus ATCC 11778 (Gram-positive bacterial strain).
S.a.: Staphylococcus aureus ATCC 6538 (Gram-positive bacterial strain).
S.a: Staphylococcus aureus ATCC 6538P (Gram-positive bacterial strain).
E.c.: Escherichia coli ATCC 8739 (Gram-negative bacterial strain).
E.c.: Escherichia coli ATCC 10536 (Gram-negative bacterial strain).
Not active in the concentration 20 mg/mL.
b
c
d
e
f
g
h
i
The growth inhibition (GI) was measured at the concentration of
10ꢁ5 M, which is further explained at the web site http://dtp.nci.
nih.gov/branches/btb/onedose_interp.html.
Compound 1b was found to be inactive. Compound 4d inhibited
the growth of renal cancer 786-0, GI ¼ 45.94, and slightly inhibited
the growth of leukemia cell line HL-60 (TB), GI ¼ 31.95. Compound
5c appears to be somewhat more active. It inhibited the growth of
leukemia CCRF-CEM (GI ¼ 62.71), non-small cell lung cancer HOP-
92 (GI ¼ 23.78) and colon cancer HCC-2998 (GI ¼ 34.14).
were soluble in polar solvent enough to perform the measure-
ments. The activity of novel derivatives was compared with the
activity of 7-hydroxycoumarin (a), 7-hydroxy-4-methylcoumarin
(b), 6-acetyl-7-hydroxy-4-coumarin (c) and 8-acetyl-7-hydroxy-4-
coumarin (d), which were used as the model compounds.
Compound a was not active against all tested strains, while
compound b was slightly active against Bacillus cereus. Compounds
c and d showed some activity against Bacillus strains, and lower
2.3.2. Antimicrobial screening
The majority of 7-hydroxycoumarin derivatives were evaluated
as salts with the exception of compounds 2ced and 5aed which
Fig. 2. The interconnections within a layer.

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2255
activity against Micrococcus and Staphylococcus strains. The
4.2. General procedures for O-alkylation compounds a, b, c and d
compounds that are more active in antimicrobial screening than
the model compounds are shown in Table 2.
The most active derivatives are 3ch and 3d, in which the
O-aminoalkyl substituent has N,N-diethylamino part, and acetyl
group is present at C6 (in 3ch) or at C8 (in 3d) atoms. Compound
3ch does not only inhibit growth of Bacillus subtilis and B. cereus
4.2.1. Conventional syntheses to obtain compounds 1aed, 2aed,
3aed, 4aed, 5aed, 6ced
7-Hydroxycoumarin (a) or 7-hydroxy-4-methylcoumarin (b),
6-acetyl-7-hydroxy-4-methylcoumarin (c), 8-acetyl-7-hydroxy-4-
methylcoumarin (d) (3 mmol) and appropriate alkylating agent
R1e6Cl (3.3e4.5 mmol) dissolved in dry acetone as well as anhy-
drous potassium carbonate (15.6 mmol) were added into the flask.
The mixture was refluxed and monitored by TLC on silica gel
plates, (eluents and Rf values are shown together with structural
data). After completion of each reaction as indicated by TLC, the
inorganic salts were filtered out and the volume of the mixture
was reduced by half due to evaporation. The final solution was
poured out to the flask with water and ice, stirred for 30 min and
then the mixtures were treated according to the method described
as follows.
strains in the lowest concentration (MIC ¼ 0.4e1.8
mmol/mL), but is
also active against all bacterial strains used in the test. Compounds
3ah and 3bh are also active, but because they lack the acetyl group,
their activity against Staphylococcus is decreased. Compounds 2ch
and 2dh with benzyl and 6ch with piperidine groups, and also with
acetyl group showed some activity against Micrococcus luteus and
Bacillus strains. All five methyliodies, 2am, 3am, 3bm, 4am and
4bm were tested, but only 2am bearing benzyl ring was active
against M. luteus.
Antimicrobial activity of the tested compounds against Gram-
negative and Gram-positive bacterial strains suggests that other
effects than those related only to the composition of bacterial wall
may be implicated in bacteria growth inhibition. The mechanism of
their action is probably related in different enzymatic routes in
particular bacterial strains.
Procedure I: the precipitate was filtered out, washed with water,
dried and crystallized.
Procedure II: the mixture was extracted with chloroform. The
organic layer was dried over anh. Na2SO4. The solvent was evapo-
rated and the solid residue was crystallized.
The yields of products and synthetic details are also presented in
Table S1 in Supplementary data.
3. Conclusion
The presented synthetic procedures allowed to obtain
7-hydroxycoumarin derivatives with good yields. Application of
microwave irradiation considerably increased rate and yield of the
reactions as well as the purity of the products. 8-Acetyl-7-[2-(1-
morpholino)ethoxy]4-methylchromen-2-one crystallizes in the
monoclinic space group P21/c. The molecules are linked by CeH/O
contacts type of the hydrogen bonds, length of 2.54e2.80 A. Three-
dimensional supramolecular structure results from combination of
intermolecular CeH/O hydrogen bonds and p/p stacking forces.
Alkylamination of OH group at C7 atom of coumarin resulted in
compounds with better antibacterial activity than the model
molecules. The compounds found to be most active are those, in
which the O-aminoalkyl substituent has N,N-diethylamino part, and
acetyl group was present at C6 or at C8 atoms. 6-Acetyl-7-[2-(1-
morpholino)ethoxy]4-methylchromen-2-one inhibited the growth
of leukemia CCRF-CEM (GI ¼ 62.71) at the concentration of 10ꢁ5 M.
4.2.2. Microwave-assisted syntheses to obtain compounds 1aed,
2aed, 3aed, 4aeb, 4d, 5aeb, 5d, 6ced
7-Hydroxycoumarin (a) or 7-hydroxy-4-methylcoumarin (b), 6-
acetyl-7-hydroxy-4-methylcoumarin (c), 8-acetyl-7-hydroxy-4-
methylcoumarin (d) (1 mmol) and appropriate alkylating agent
R1e6Cl (1.1e1.5 mmol), dry acetone (5 mL) or 1-methyl-2-pyrroli-
done (0.5e2 mL) as well as anhydrous potassium carbonate
(5.2 mmol) were added into the flask. The mixture was heated
under reflux in the monomode microwave oven under the condi-
tions described in Table 1 (see Supplementary data). The reaction
was monitored by TLC in the same way as described in the tradi-
tional method. Procedures I and II (see the general procedure in
Section 4.2.1) were used to isolate products. Some compounds were
pure enough for the structural characterization. The yields of
products and synthetic details are also presented in Table S1 in
Supplementary data.
ꢁ
Syntheses and analytical data of compounds 1a and 1b have
been described in our previous work [8].
4. Experimental protocols
4.1. General methods
4.2.3. 6-Acetyl-7-[2-(N,N-diisopropylamino)ethoxy]4-
methylchromen-2-one (1c)
Melting points were determined with ElectroThermal 9001
Digital Melting Point apparatus and are uncorrected. Microwave
oven Plazmatronika 1000 W equipped with a single mode cavity
suitable for the microscale synthesis and microwave choked outlet
connected to external condenser set to 30% power, was used
(http://www.plazmatronika.com.pl). Microanalysis was carried in
the Department of Analytical Chemistry, Warsaw Technical
University using Vario EL III, Elementar GmbH. High resolution
mass spectra were recorded on Quattro LCT (TOF). 1H NMR, 13C
NMR, HSQC and HMBC spectra in solution were recorded at 25 ꢀC
with a Varian NMRS-300 or Varian Unity plus-500 spectrometers
(as indicated in the text) and standard Varian software was
employed. The calculated shielding constants were used as an aid
in an assignment of resonances of 13C atoms. Chemical shifts
M.p.: 117e117.5 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEt 10:3:1), Rf (1c) ¼ 0.22; IR (KBr) cmꢁ1
:
3074 (nCeHarom), 2962 (nCeHasym), 2863 (nCeHsym), 1735, 1677 (nC]O),
1621, 1604, 1496 (nC]C), 1465 (dCeHasym), 1388 (dCeHsym), 1283
(
nCeOeCasym), 1056 (nCeOeCsym), 849 (gCeH); 1H NMR (500 MHz,
(CD3)2CO)
d
ppm: 1.06 (d, J ¼ 6.5 Hz, 12H, H-15, 150), 2.45 (d,
J ¼ 1.5 Hz, 3H, H-9), 2.63 (s, 3H, H-11), 3.03 (t, J ¼ 6.8 Hz, 2H, H-13),
3.14 (heptet, J ¼ 6.5 Hz, 2H, H-14, 140), 4.22 (t, J ¼ 6.8 Hz, 2H, H-12),
6.17 (bq, J ¼ 1.5 Hz, 1H, H-3), 7.02 (s, 1H, H-8), 7.97 (s, 1H, H-5); 13C
NMR (125 MHz, (CD3)2CO)
d
ppm: 18.43 (C-9), 21.26 (C-15, 150),
32.23 (C-11), 44.45 (C-13), 49.59 (C-14, 140), 70.94 (C-12), 101.63 (C-
8), 113.16 (C-3), 113.90 (C-4a), 125.94 (C-6), 128.20 (C-5), 153.68 (C-
4), 158.38 (C-8a), 160.23 (C-7), 162.02 (C-2), 197.41 (C-10). TOF MS
ESþ: [M þ H]þ calcd for C20H28NO4: 346.2018 found 346.1993.
d
[ppm] were referenced to TMS. The notation used in detailed
description of NMR resonances is given in Scheme 1. IR spectra
were recorded on an FT IR PerkineElmer instrument. TLC was
carried out using Kieselgel 60 F254 sheets and spots were visualized
by UV e 254 and 365 nm.
4.2.4. 8-Acetyl-7-[2-(N,N-diisopropylamino)ethoxy]4-
methylchromen-2-one (1d)
M.p.: 96.5e97 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEt 10:3:1), Rf (1d) ¼ 0.27.;IR (KBr)cmꢁ1
:

2256
J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
3074 (nCeHarom), 2959 (nCeHasym), 2867 (nCeHsym), 1726, 1713 (nC]O),
1604, 1566, 1496, 1450 (nC]C), 1462 (dCeHasym), 1385 (dCeHsym), 1296
TOF MS ESþ: [M þ H]þ calcd for C22H24NO4: 366.1705 found
366.1719.
(
nCeOeCasym), 1080 (nCeOeCsym), 847 (gCeH); 1H NMR (500 MHz,
(CD3)2CO)
d
ppm: 1.03 (d, J ¼ 6.5 Hz, 12H, H-15, 150), 2.45 (d,
4.2.8. 8-Acetyl-7-[2-(N-benzyl-N-methylamino)ethoxy]4-
methylchromen-2-one (2d)
J ¼ 1.0 Hz, 3H, H-9), 2.53 (s, 3H, H-11), 2.88 (t, J ¼ 6.5 Hz, 2H, H-13),
3.09 (heptet, J ¼ 6.5 Hz, 2H, H-14, 140), 4.11 (t, J ¼ 6.5 Hz, 2H, H-12),
6.15 (bq, J ¼ 1.0, 1H, H-3), 7.13 (d, J ¼ 8.8 Hz, 1H, H-6), 7.77 (d,
M.p.: 104e104.5 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEt 10:3:1:), Rf (2d) ¼ 0.11; IR (KBr) cmꢁ1
:
J ¼ 8.8 Hz, 1H, H-5); 13C NMR (125 MHz, (CD3)2CO)
d
ppm: 18.63 (C-
3065 (nCeHarom), 2977, 2960 (nCeHasym), 2882, 2853 (nCeHsym), 1741,
1704 (nC]O), 1600, 1565, 1494, 1453 (nC]C), 1460 (dCeHasym), 1383
9), 21.27 (C-15, 150), 32.53 (C-11), 44.56 (C-13), 49.67 (C-14, 140),
71.09 (C-12), 109.60 (C-6), 112.79 (C-3), 114.63 (C-4a), 120.37 (C-8),
127.64 (C-5), 151.33 (C-8a), 153.59 (C-4), 158.86 (C-7), 160.00 (C-2),
199.04 (C-10). TOF MS ESþ: [M þ H]þ calcd for C20H28NO4:
346.2018 found 346.2022.
(
dCeHsym), 1293 (nCeOeCasym), 1094 (nCeOeCsym), 873 (gCeH); 1H NMR
(300 MHz, (CD3)2CO)
d
ppm: 2.29 (s, 3H, H-14), 2.45 (d, J ¼ 1.2 Hz,
3H, H-9), 2.53 (s, 3H, H-11), 2.84 (t, J ¼ 5.7 Hz, 2H, H-13), 3.60 (s, 2H,
H-15), 4.32 (t, J ¼ 5.7 Hz, 2H, H-12), 6.16 (bq, J ¼ 1.2 Hz, 1H, H-3),
7.12 (d, J ¼ 15.0 Hz, 1H, H-6), 7.20e7.38 (m, 5 H, H-17, 170, 18, 180, 19),
4.2.5. 7-[2-(N-Benzyl-N-methylamino)ethoxy]chromen-2-one (2a)
Oil (column: CHCl3eAcOEt; 9:1); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (2a) ¼ 0.68; IR (KBr)
cmꢁ1: 3062 (nCeHarom), 2962 (nCeHasym), 2863 (nCeHsym), 1725 (nC]
O), 1614, 1505, 1491, 1449 (nC]C), 1461 (dCeHasym), 1373 (dCeHsym),
1261 (nCeOeCasym), 1021 (nCeOeCsym), 799 (gCeH); 1H NMR (300 MHz,
7.75 (d, J ¼ 15.0 Hz, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d ppm:
18.71 (C-9), 32.55 (C-11), 42.95 (C-14), 56.49 (C-13), 63.25 (C-15),
68.48 (C-12), 109.61 (C-6), 112.94 (C-3), 114.82 (C-4a), 120.45 (C-8),
127.73 (C-19), 127.81 (C-5), 129.09 (C-17, 170), 129.68 (C-18, 180),
140.40 (C-16), 151.30 (C-8a), 153.67 (C-4), 158.77 (C-7), 160.07 (C-2),
199.17 (C-10). TOF MS ESþ: [M þ H]þ calcd for C22H24NO4: 366.1705
found 366.1715.
CDCl3)
d
ppm: 2.37 (s, 3H, H-14), 2.87 (t, J ¼ 5.7 Hz, 2H, H-13), 3.64
(s, 2H, H-15), 4.16 (t, J ¼ 5.7 Hz, 2H, H-12), 6.24 (d, J ¼ 9.6 Hz, 1H, H-
3), 6.80 (d, J ¼ 2.4 Hz, 1H, H-8), 6.83 (dd, J1 ¼2.4 Hz, J2 ¼ 8.4 Hz, 1H,
H-6), 7.23e7.34 (m, 5H, H-17, 170, 18, 180, 19), 7.35 (d, J ¼ 8.4 Hz, 1H,
4.2.9. 7-[2-(N,N-Diethylamino)ethoxy]chromen-2-one (3a) [16,17]
M.p.: 47.7e48.2 ꢀC (without crystallization after microwave-
assisted synthesis) (lit. m.p.: 46 ꢀC [16]); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (3a) ¼ 0.14; IR (KBr)
cmꢁ1: 3082 (nCeHarom), 2964 (nCeHasym), 2870 (nCeHsym), 1724 (nC]
O), 1622, 1508, 1448 (nC]C), 1469 (dCeHasym), 1388 (dCeHsym), 1281
H-5), 7.62 (d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR (75 MHz, CDCl3)
d ppm:
43.17 (C-14), 55.55 (C-13), 62.90 (C-15), 67.09 (C-12), 101.70 (C-8),
112.77 (C-4a), 113.13 (C-6), 113.30 (C-3), 127.45 (C-19), 128.53 (C-17,
170), 128.90 (C-5), 129.26 (C-18, 180), 138.55 (C-16), 143.61 (C-4),
156.04 (C-8a), 161.37 (C-2), 162.21 (C-7). TOF MS ESþ: [M þ H]þ
calcd for C19H20NO3: 310.1443 found 310.1411.
(
nCeOeCasym), 1025 (nCeOeCsym), 832 (gCeH); 1H NMR (300 MHz,
CDCl3)
d
ppm: 1.09 (t, J ¼ 7.2 Hz, 6H, H-15, 150), 2.67 (q, J ¼ 7.2 Hz,
4H, H-14, 140), 2.92 (t, J ¼ 6.0 Hz, 2H, H-13), 4.12 (t, J ¼ 6.0 Hz, 2H, H-
12), 6.24 (d, J ¼ 9.6 Hz, 1H, H-3), 6.82 (d, J ¼ 2.4 Hz, 1H, H-8), 6.85
(dd, J1 ¼2.4 Hz, J2 ¼ 8.4 Hz, 1H, H-6), 7.36 (d, J ¼ 8.4 Hz, 1H, H-5),
4.2.6. 7-[2-(N-Benzyl-N-methylamino)ethoxy]4-methylchromen-2-
one (2b)
M.p.: 57e58 ꢀC (petroleum ether); eluent used in TLC:
7.62 (d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR (75 MHz, CDCl3)
d ppm: 11.89
(CHCl3e(CH3)2COeAcOEt 10:3:1:), Rf (2b) ¼ 0.32; IR (KBr) cmꢁ1
:
(C-15, 150), 48.08 (C-14, 140), 51.68 (C-13), 67.37 (C-12), 101.76 (C-8),
112.79 (C-4a), 113.13 (C-6), 113.33 (C-3), 128.99 (C-5), 143.58 (C-4),
156.07 (C-8a), 161.40 (C-2), 162.26 (C-7). TOF MS ESþ: [M þ H]þ
calcd for C15H20NO3 262.1443 found 262.1480.
3061 (nCeHarom), 2936 (nCeHasym), 2837 (nCeHsym), 1711 (nC]O), 1616,
1509, 1492
(
(
nC]C), 1451
(dCeHasym), 1392 (dCeHsym), 1280
nCeOeCasym), 1021 (nCeOeCsym), 831 (gCeH); 1H NMR (300 MHz,
(CD3)2CO)
d ppm: 2.32 (s, 3H, H-14), 2.43 (s, 3H, H-9), 2.86 (t,
J ¼ 6.0 Hz, 2H, H-13), 3.63 (s, 2H, H-15), 4.26 (t, J ¼ 6.0 Hz, 2H, H-12),
6.12 (s, 1H, H-3), 6.88 (d, J ¼ 2.1 Hz, 1H, H-8), 6.94 (dd, J1 ¼ 2.1 Hz,
J2 ¼ 8.7 Hz, 1H, H-6), 7.20e7.38 (m, 5H, H-17, 170, 18, 180, 19), 7.66 (d,
4.2.10. 7-[2-(N,N-Diethylamino)ethoxy]4-methylchromen-2-one
(3b)
M.p.: 50.1e50.7 ꢀC (without crystallization after microwave-
assisted synthesis); eluent used in TLC: (CHCl3e(CH3)2CO-
eAcOEteMeOH 10:3:1:1), Rf (3b) ¼ 0.17; IR (KBr) cmꢁ1: 3077
J ¼ 8.7 Hz, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d ppm: 18.61 (C-
9), 43.17 (C-14), 56.46 (C-13), 63.22 (C-15), 68.05 (C-12), 102.19 (C-
8), 112.46 (C-3), 113.33 (C-6), 114.40 (C-4a), 127.09 (C-5), 127.82 (C-
19), 129.07 (C-17, 170), 129.73 (C-18, 180), 140.47 (C-16), 153.76 (C-4),
156.40 (C-8a), 160.97 (C-7), 163.09 (C-2). TOF MS ESþ: [M þ H]þ
calcd for C20H22NO3: 324.1600 found 324.1588.
(
(
(
nCeHarom), 2972 (nCeHasym), 2870 (nCeHsym), 1717 (nC]O), 1617, 1509
nC]C), 1472 (dCeHasym), 1392 (dCeHsym), 1281 (nCeOeCasym), 1021
nCeOeCsym), 842 (gCeH); 1H NMR (300 MHz, CDCl3)
d ppm: 1.11 (t,
J ¼ 7.2 Hz, 6H, H-15, 150), 2.40 (d, J ¼ 1.0 Hz, 3H, H-9), 2.70 (q,
J ¼ 7.2 Hz, 4H, H-14, 140), 2.94 (t, J ¼ 6.0 Hz, 2H, H-13), 4.14 (t,
J ¼ 6.0 Hz, 2H, H-12), 6.13 (bq, J ¼ 1.0 Hz, 1H, H-3), 6.82 (d,
J ¼ 2.4 Hz, 1H, H-8), 6.87 (dd, J1 ¼ 2.4 Hz, J2 ¼ 9.0 Hz, 1H, H-6), 7.49
4.2.7. 6-Acetyl-7-[2-(N-benzyl-N-methylamino)ethoxy]4-
methylchromen-2-one (2c)
M.p.: 126.5e127 ꢀC (cyclohexane:acetone, 4:1); eluent used in
TLC: (CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (2c) ¼ 0.60; IR
(KBr) cmꢁ1: 3075 (nCeHarom), 2979, 2947 (nCeHasym), 2884, 2842
(d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, CDCl3)
d ppm: 11.81 (C-
15, 150), 18.86 (C-9), 48.06 (C-14, 140), 51.67 (C-13), 67.21 (C-12),
101.81 (C-8), 112.20 (C-3), 112.78 (C-6), 113.87 (C-4a), 125.71 (C-5),
152.71 (C-4), 155.45 (C-8a), 161.49 (C-2), 162.03 (C-7). TOF MS ESþ:
[M þ H]þ calcd for C16H22NO3: 276.1600 found 276.1581.
(
(
(
nCeHsym), 1728, 1670 (nC]O), 1599, 1493, 141447 (nC]C), 1459
dCeHasym), 1385 (dCeHsym), 1283 (nCeOeCasym), 1055 (nCeOeCsym), 731
gCeH); 1H NMR (300 MHz, CDCl3)
d ppm: 2.36 (s, 3H, H-14), 2.43 (d,
J ¼ 1.2 Hz, 3H, H-9), 2.63 (s, 3H, H-11), 2.93 (t, J ¼ 5.4 Hz, 2H, H-13),
3.62 (s, 2H, H-15), 4.23 (t, J ¼ 5.4 Hz, 2H, H-12), 6.17 (bq, J ¼ 1.2 Hz,
1H, H-3), 6.82 (s, 1H, H-8), 7.26e7.32 (m, 5 H, H-17, 170 18, 180 19),
4.2.11. 6-Acetyl-7-[2-(N,N-diethylamino)ethoxy]4-methylchromen-
2-one (3c)
M.p.: 104.8e105.1 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (3c) ¼ 0.15; IR (KBr)
cmꢁ1: 3077 (nCeHarom), 2966 (nCeHasym), 2870 (nCeHsym), 1733, 1712
8.05 (s, 1H, H-5); 13C NMR (75 MHz, CDCl3)
d ppm: 18.91 (C-9),
32.34 (C-11), 42.99 (C-14), 55.78 (C-13), 63.19 (C-15), 67.57 (C-12),
100.75 (C-8), 113.06 (C-3), 113.68 (C-4a), 125.22 (C-6), 127.58 (C-19),
128.16 (C-17, 170), 128.63 (C-18, 180), 129.22 (C-5), 139.47 (C-16),
152.97 (C-4), 157.75 (C-8a), 160.56 (C-7), 161.16 (C-2), 197.99 (C-10).
(
(
nC]O), 1605, 1497 (nC]C), 1471 (dCeHasym), 1388 (dCeHsym), 1283
nCeOeCasym), 1058 (nCeOeCsym), 836 (gCeH); 1H NMR (300 MHz,
(CD3)2CO)
d
ppm: 1.03 (t, J ¼ 7.0 Hz, 6H, H-15,150), 2.47 (d, J ¼ 1.5 Hz,

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2257
3H, H-9), 2.63 (q, J ¼ 7.0 Hz, 4H, H-14, 140), 2.64 (s, 3H, H-11), 2.97 (t,
J ¼ 6.0 Hz, 2H, H-13), 4.34 (t, J ¼ 6.0 Hz, 2H, H-12), 6.20 (bq,
J ¼ 1.5 Hz, 1H, H-3), 7.07 (s, 1H, H-8), 8.01 (s, 1H, H-5); 13C NMR
(C-14), 67.96 (C-12), 102.15 (C-3), 112.40 (C-8), 113.31 (C-6), 114.31
(C-4a), 127.03 (C-5), 153.74 (C-4), 156.37 (C-8a), 160.95 (C-7),
163.15 (C-2). TOF MS ESþ: [M þ H]þ calcd for C18H24NO3:
302.1756 found 302.1719.
(75 MHz, (CD3)2CO)
d
ppm: 12.61 (C-15, 150), 18.54 (C-9), 32.30 (C-
11), 48.20 (C-14, 140), 52.85 (C-13), 69.04 (C-12), 101.76 (C-8), 113.28
(C-3), 114.10 (C-4a), 126.15 (C-6), 128.35 (C-5), 153.87 (C-4), 158.53
(C-8a), 160.37 (C-7), 162.18 (C-2), 197.64 (C-10). TOF MS ESþ:
[M þ Na]þ calcd for C18H23NO4Na: 340.1525 found 340.1489.
4.2.15. 6-Acetyl-7-[2-(2-methylpiperidinyl)ethoxy]4-
methylchromen-2-one (4c)
M.p.: 113e113.2 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (4c) ¼ 0.29; IR (KBr)
cmꢁ1: 3064 (nCeHarom), 2925 (nCeHasym), 2830 (nCeHsym), 1735 (nC]
O), 1605, 1555, 1496, 1449 (nC]C), 1461 (dCeHasym), 1387 (dCeHsym),
1280 (nCeOeCasym), 1058 (nCeOeCsym), 834 (gCeH); 1H NMR (500 MHz,
4.2.12. 8-acetyl-7-[2-(N,N-diethylamino)ethoxy]4-methylchromen-
2-one (3d)
M.p.: 88.3e88.7 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (3d) ¼ 0.10; IR (KBr)
cmꢁ1: 3092 (nCeHarom), 2966 (nCeHasym), 2870 (nCeHsym), 1725, 1708
(CD3)2CO)
d
ppm: 1.09 (d, J ¼ 6.0 Hz, 3H, H-19), 1.20e1.38 (m, 2H,
Hax-15, H-16), 1.44e1.67 (m, 4H, H-17, Heq-15, 16), 2.27 (td,
J1 ¼4.0 Hz, J2 ¼ 11.5 Hz, 1H, Hax-18), 2.41 (m, 1H, H-14), 2.47 (d,
J ¼ 1.2 Hz, 3H, H-9), 2.65 (s, 3H, H-11), 2.71 (dt, J1 ¼13.8 Hz,
J2 ¼ 6.0 Hz, 1H, Hax-13), 2.98 (dt, J1 ¼4.0 Hz, J2 ¼11.5 Hz, 1H, Heq-
18), 3.25 (dt, J1 ¼13.8 Hz, J2 ¼ 6.0 Hz, 1H, Heq-13), 4.35 (m, 2H, H-
12), 6.20 (bq, J ¼ 1.2 Hz, 1H, H-3), 7.08 (s, 1H, H-8), 8.00 (s, 1H, H-5);
(
nC]O), 1601, 1496 (nC]C), 1439 broad (dCeHasym), 1384 (dCeHsym),
1296 (nCeOeCasym), 1074 (nCeOeCsym), 811 (gCeH); 1H NMR (300 MHz,
(CD3)2CO)
d
ppm: 1.00 (t, J ¼ 7.2 Hz, 6H, H-15, 150), 2.45 (d,
J ¼ 1.5 Hz, 3H, H-9), 2.54 (s, 3H, H-11), 2.58 (q, J ¼ 7.2 Hz, 4H, H-14,
140), 2.85 (t, J ¼ 6.0 Hz, 2H, H-13), 4.23 (t, J ¼ 6.0 Hz, 2H, H-12), 6.16
(bq, J ¼ 1.5 Hz, 1H, H-3), 7.14 (d, J ¼ 9.0 Hz, 1H, H-6), 7.77 (d,
13C NMR (125 MHz, (CD3)2CO)
d ppm: 18.53 (C-9), 19.27 (C-19),
J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d ppm: 12.73 (C-
24.49 (C-16), 27.11 (C-17), 32.34 (C-11), 35.53 (C-15), 53.46 (C-
13,18), 57.25 (C-14), 68.67 (C-12), 101.80 (C-8), 113.27 (C-3), 114.09
(C-4a), 126.15 (C-6), 128.32 (C-5), 153.86 (C-4), 158.53 (C-8a), 160.37
(C-2), 162.18 (C-7), 197.63 (C-10). TOF MS ESþ: [M þ H]þ calcd for
C20H26NO4: 344.1862 found 344.1876.
15, 150), 18.72 (C-9), 32.56 (C-11), 48.43 (C-14, 140), 52.66 (C-13),
69.20 (C-12), 109.63 (C-6), 112.92 (C-3), 114.78 (C-4a), 120.52 (C-8),
127.74 (C-5), 151.41 (C-8a), 153.68 (C-4), 158.90 (C-7), 160.09 (C-2),
199.17 (C-10). TOF MS ESþ: [M þ Na]þ calcd for C18H23NO4Na:
340.1525 found 340.1510.
4.2.16. 8-Acetyl-7-[2-(2-methylpiperidinyl)ethoxy]4-
methylchromen-2-one (4d)
4.2.13. 7-[2-(2-Methylpiperidinyl)ethoxy]chromen-2-one (4a)
M.p.: 70e71 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (4a) ¼ 0.10; IR (KBr)
M.p.: 110e110.5 ꢀC (petroleum ether); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (4d) ¼ 0.12; IR (KBr)
cmꢁ1: 3084 (nCeHarom), 2927 (nCeHasym), 2851 (nCeHsym),1706 (nC]O),
1598, 1561, 1496 (nC]C), 1455 (dCeHasym), 1373 (dCeHsym), 1301
cmꢁ1
: 3085 (nCeHarom), 2964, 2930 (nCeHasym), 2853, 2820
(
nCeHsym), 1724 (nC]O), 1622, 1507, 1444 (nC]C), 1474 (dCeHasym),
1376 (dCeHsym), 1283 (nCeOeCasym) 1022 (nCeOeCsym), 830 (gCeH); 1H
NMR (500 MHz, (CD3)2CO)
ppm: 1.08 (d, J ¼ 6.0 Hz, 3H, H-19),
(
nCeOeCasym), 1076 (nCeOeCsym), 837 (gCeH); 1H NMR (500 MHz,
d
(CD3)2CO)
d
ppm: 1.06 (d, J ¼ 6.0 Hz, 3H, H-19), 1.21e1.31 (m, 2H,
1.26 (m, 2H, Hax-15, 16), 1.51 (m, 2H, H-17), 1.58 (m, 2H, Heq-15,
16) 2.31 (dt, J1 ¼11.5 Hz, J2 ¼ 4.0 Hz, Hax-18), 2.39 (m, 1H, H-14),
2.72 (dt, J1 ¼14.0 Hz, J2 ¼ 6.0 Hz, Hax-13), 2.95 (dt, J1 ¼11.5 Hz,
J2 ¼ 4.0 Hz, Heq-18), 3.09 (dt, J1 ¼14.0 Hz, J2 ¼ 6.0 Hz, Heq-13),
4.19 (t, J ¼ 6.0 Hz, 2H, H-12), 6.21 (d, J ¼ 9.5 Hz, 1H, H-3), 6.89 (d,
J ¼ 2.4 Hz, 1H, H-8), 6.92 (dd, J1 ¼2.4 Hz, J2 ¼ 8.5 Hz, 1H, H-6), 7.56
(d, J ¼ 8.5 Hz, 1H, H-5), 7.88 (d, J ¼ 9.5 Hz, 1H, H-4); 13C NMR
Hax-15, 16), 1.46e1.55 (m, 2H, H-17), 1.56e1.65 (m, 2H, Heq-15, 16),
2.26 (td, J1 ¼3.0 Hz, J2 ¼ 11.5 Hz, 1H, Hax-18), 2.38 (m, 1H, H-14),
2.45 (d, J ¼ 1.5 Hz, 3H, H-9), 2.55 (s, 3H, H-11), 2.70 (dt, J1 ¼14.5 Hz,
J2 ¼ 6.0 Hz, 1H, Hax-13), 2.92 (dt, J1 ¼11.5 Hz, J2 ¼ 3.0 Hz, 1H, Heq-
18), 3.10 (dt, J1 ¼14.5 Hz, J2 ¼ 6.0 Hz, 1H, Heq-13), 4.24 (t, J ¼ 6.0 Hz,
2H, H-12), 6.15 (bq, J ¼ 1.5 Hz, 1H, H-3), 7.14 (d, J ¼ 9.0 Hz, 1H, H-6),
7.77 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (125 MHz, (CD3)2CO)
d ppm:
(125 MHz, (CD3)2CO)
d ppm: 19.64 (C-19), 24.65 (C-16), 27.06 (C-
18.63 (C-9), 19.50 (C-19), 24.54 (C-16), 27.00 (C-17), 32.52 (C-11),
35.49 (C-15), 53.26 (C-13), 53.77 (C-18), 56.96 (C-14), 68.54 (C-12),
109.57 (C-6), 112.81 (C-3), 114.67 (C-4a), 120.40 (C-8), 127.64 (C-5),
151.29 (C-8a), 153.59 (C-4), 158.79 (C-7), 159.99 (C-2), 199.09 (C-10).
TOF MS ESþ: [M þ H]þ calcd for C20H26NO4: 344.1862 found
344.1858.
17), 35.55 (C-15), 53.34 (C-13), 53.97 (C-18), 56.90 (C-14), 67.96
(C-12), 102.10 (C-8), 113.44 (C-4a), 113.55 (C-6), 113.56 (C-3),
130.09 (C-5), 144.51 (C-4), 156.94 (C-8a), 160.93 (C-2), 163.23 (C-
7). TOF MS ESþ: [M þ H]þ calcd for C17H22NO3: 288.1600 found
288.1559.
4.2.14. 7-[2-(2-Methylpiperidinyl)ethoxy]4-methylchromen-2-one
(4b)
4.2.17. 7-[2-(1-Morpholino)ethoxy]chromen-2-one (5a)
M.p.: 87e87.5 ꢀC (cyclohexane:acetone, 5:1); eluent used in
TLC: (CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (5a) ¼ 0.27; IR
(KBr) cmꢁ1: 3077 (nCeHarom), 2955, 2932 (nCeHasym), 2856, 2823
M.p.: 75e75.5 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (4b) ¼ 0.18; IR (KBr)
cmꢁ1: 3079 (nCeHarom), 2929 (nCeHasym), 2852 (nCeHsym), 1711 (nC]
O), 1618, 1508, 1442 (nC]C), 1461 (dCeHasym), 1392 (dCeHsym), 1353,
(
nCeHsym), 1725, 1705 (nC]O), 1615, 1555, 1508, (nC]C), 1462 (dCeHa-
sym), 1372 (dCeHsym), 1283 (nCeOeCasym), 1043 (nCeOeCsym), 837
gCeH); 1H NMR (500 MHz, (CD3)2CO)
1282
(nCeOeCasym), 1072
(nCeOeCsym), 843 (
gCeH); 1H NMR
(
d
ppm: 2.54 (t, J ¼ 4.6 Hz, 4H,
(300 MHz, (CD3)2CO)
d
ppm: 1.10 (d, J ¼ 6.0 Hz, 3H, H-19), 1.29 (m,
H-14,140), 2.79 (t, J ¼ 5.8 Hz, 2H, H-13), 3.62 (bt, J ¼ 4.6 Hz, 4H, H-15,
150), 4.26 (t, J ¼ 5.8 Hz, 2H, H-12), 6.21 (d, J ¼ 9.5 Hz, 1H, H-3), 6.90
(d, J ¼ 2.4 Hz, 1H, H-8), 6.93 (dd, J1 ¼2.4 Hz, J2 ¼ 8.6 Hz, 1H, H-6),
7.57 (d, J ¼ 8.6 Hz, 1H, H-5), 7.88 (d, J ¼ 9.5 Hz, 1H, H-4); 13C NMR
2H, Hax-15, 16), 1.55 (m, 2H, H-17), 1.63 (m, 2H, Heq-15, 16), 2.32
(dt broad, J1 ¼11.0 Hz, J2 ¼ 3.5 Hz, 1H, Hax-18), 2.40 (m, 1H, H-14),
2.45 (d, J ¼ 1.0 Hz, 3H, H-9), 2.73 (dt, J1 ¼14.0 Hz, J2 ¼ 6.0 Hz, 1H,
Hax-13), 2.94 (dt, J1 ¼12.0 Hz, J2 ¼ 3.5 Hz, 1H, Heq-18), 3.11 (dt,
J1 ¼14.0 Hz, J2 ¼ 6.0 Hz, 1H, Heq-13), 4.21 (t, J ¼ 6.0 Hz, 2H, H-12),
6.13 (bq, J ¼ 1.0 Hz, 1H, H-3), 6.89 (d, J ¼ 2.5 Hz, 1H, H-8), 6.95 (dd,
J1 ¼8.7 Hz, J2 ¼ 2.5 Hz, 1H, H-6), 7.68 (d, J ¼ 8.7 Hz, 1H, H-5); 13C
(125 MHz, (CD3)2CO)
d
ppm: 54.93 (C-14, 140), 58.08 (C-13), 67.47
(C-15, 150), 67.51 (C-12), 102.09 (C-8), 113.52 (C-4a), 113.55 (C-6),
113.65 (C-3), 130.12 (C-5), 144.51 (C-4), 156.91 (C-8a), 160.91 (C-7),
163.07 (C-2). TOF MS ESþ: [M þ H]þ calcd for C15H18NO4: 276.1236
found 276.1249.
NMR (75 MHz, (CD3)2CO)
d ppm: 18.61 (C-9), 19.76 (C-19), 24.76
(C-16), 27.15 (C-15), 35.64 (C-17), 53.42 (C-13), 54.07 (C-18), 57.00

2258
J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
4.2.18. 7-[2-(1-Morpholino)ethoxy]4-methylchromen-2-one (5b)
M.p.: 100-101 ꢀC (hexane) (Lit. m.p: 102 ꢀC (ethyl acetate) [18]);
eluent used in TLC: (CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1),
(C-4), 157.75 (C-8a), 160.51 (C-2), 161.15 (C-7), 197.96 (C-10). TOF MS
ESþ: [M þ H]þ calcd for C19H24NO4: 330.1705 found 330.1713.
Rf (5b) ¼ 0.27; IR (KBr) cmꢁ1
:
3075
(nCeHarom), 2920, 2956
4.2.22. 8-Acetyl-7-[2-piperidylethoxy]4-methylchromen-2-one
(6d)
(
(
(
nCeHasym), 2891, 2859 (nCeHsym), 1726 broad (nC]O), 1610, 1514
nC]C), 1476 (dCeHasym), 1392 (dCeHsym), 1267 (nCeOeCasym), 1071
M.p.: 93e93.5 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (6d) ¼ 0.14; IR (KBr)
cmꢁ1: 3092 (nCeHarom), 2933 (nCeHasym), 2847 (nCeHsym), 1727, 1704
nCeOeCsym), 871 (gCeH); 1H NMR (300 MHz, (CD3)2CO)
d
ppm: 2.43
(d, J ¼ 1.2 Hz, 3H, H-9), 2.54 (bt, J ¼ 4.8 Hz, 4H, H-14, 140), 2.79
(t, J ¼ 5.7 Hz, 2H, H-13), 3.61 (t, J ¼ 4.8 Hz, 4H, H-15, 150), 4.25
(t, J ¼ 5.7 Hz, 2H, H-12), 6.11 (q, J ¼ 1.2 Hz, 1H, H-3), 6.88
(d, J ¼ 2.7 Hz, 1H, H-8), 6.94 (dd, J1 ¼9.0 Hz, J2 ¼ 2.7 Hz, 1H, H-6),
(
nC]O), 1599, 1565, 1496 (nC]C), 1474 (dCeHasym), 1386 (dCeHsym),
1295 (nCeOeCasym),1098 (nCeOeCsym), 848 (gCeH); 1H NMR (500 MHz,
(CD3)2CO) ppm: 1.41 (br. quintet 2H, H-16), 1.53 (quintet,
d
7.66 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d
ppm:
J ¼ 5.5 Hz, 4H, H-15, 150), 2.45 (s, J ¼ 1.5 Hz, 3H, H-9), 2.46 (m, 4H,
H-14, 140), 2.55 (s, 3H, H-11), 2.71 (t, J ¼ 5.5 Hz, 2H, H-13), 4.27 (t,
J ¼ 5.5 Hz, 2H, H-12), 6.15 (bq, J ¼ 1.5 Hz, 1H, H-3), 7.14 (d, J ¼ 9.0 Hz
1H, H-6), 7.76 (s, J ¼ 9.0 Hz 1H, H-5); 13C NMR (125 MHz, (CD3)2CO)
18.61 (C-9), 55.03 (C-14, 140), 58.18 (C-13), 67.56 (C-12, 15, 150),
102.17 (C-8), 112.48 (C-3), 113.31 (C-6), 114.42 (C-4a), 127.08 (C-5),
153.74 (C-4), 156.36 (C-8a), 160.94 (C-7), 163.01 (C-2). TOF MS ESþ:
[M þ Na]þ calcd for C16H19NO4Na: 312.1212 found 312.1227.
d
ppm: 18.63 (C-9), 25.02 (C-16), 26.89 (C-15, 150), 32.43 (C-11),
55.59 (C-14, 140), 58.29 (C-13), 68.24 (C-12), 109.62 (C-6), 112.84 (C-
3), 114.72 (C-4a), 120.45 (C-8), 127.66 (C-5), 151.29 (C-8a), 153.57 (C-
4), 158.77 (C-7), 159.99 (C-2), 199.11 (C-10). TOF MS ESþ: [M þ H]þ
calcd for C19H24NO4: 330.1705 found 330.1737.
4.2.19. 6-Acetyl-7-[2-(1-morpholino)ethoxy]4-methylchromen-2-
one (5c)
M.p.: 175.5e176.5 ꢀC; eluent used in TLC: (CHCl3e(CH3)2CO-
eAcOEteMeOH 10:3:1:1), Rf (5c) ¼ 0.38; IR (KBr) cmꢁ1: 3072
(nCeHarom), 2952 (nCeHasym), 2859 (nCeHsym), 1737, 1672 (nC]O), 1604,
4.3. General procedure for the preparation hydrochlorides of
coumarin derivatives 1ahedh, 2bhedh, 3ahedh, 4ahedh,
5ahebh, 6chedh
1499 (nC]C), 1470 (dCeHasym), 1381 (dCeHsym), 1284 (nCeOeCasym),
1057 (nCeOeCsym), 847 (gCeH); 1H NMR (300 MHz, CDCl3)
d ppm:
2.47 (s, 3H, H-9), 2.55 (broad t, J ¼ 4.4 Hz, 4H, H-14, 140), 2.66 (s, 3H,
H-11), 2.90 (t, J ¼ 5.5 Hz, 2H, H-13), 3.62 (broad t, J ¼ 4.4 Hz, 4H,
H-15, 150), 4.41 (t, J ¼ 5.5 Hz, 2H, H-12), 6.20 (broad s, 1H, H-3), 7.07
Compounds 1aed, 2bed, 3aed, 4aed, 5aeb, 6ced (1.0 mmol)
was dissolved in anhydrous ethanol (4e10 mL) and 2e3 mL of
anhydrous ethanol saturated with gaseous hydrochloride was
added dropwise. The mixture was heated to boiling and then stir-
red at room temperature for 15e30 min. The mixture was then
poured out into a flask with diethyl ether (100 mL) and the
precipitate was filtered out and dried.
(s, 1H, H-8), 8.01 (s, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d ppm:
18.53 (C-9), 32.30 (C-11), 54.77 (C-14,140), 58.00 (C-13), 67.61 (C-15,
150), 67.76 (C-12), 101.75 (C-8), 113.31 (C-3), 114.17 (C-4a), 126.15 (C-
6), 128.37 (C-5), 153.87 (C-4), 158.52 (C-8a), 160.39 (C-2), 162.07 (C-
7), 197.62 (C-10). TOF MS ESþ: [M þ Na]þ calcd for C18H21NO5Na:
354.1317 found 354.1282.
4.3.1. 7-[2-(N,N-Diisopropylamino)ethoxy]chromen-2-one
hydrochloride (1ah)
4.2.20. 8-Acetyl-7-[2-(1-morpholino)ethoxy]4-methylchromen-2-
one (5d)
Yield 96%; m.p.: 183e183.3 ꢀC; C17H23NO3$HCl (325.84 g/mol):
calcd. C 62.67%; H 7.42%; N 4.30%; Cl 10.88%; found C 62.75%;
H 7.34%; N 4.28%; Cl 10.79%; IR (KBr) cmꢁ1: 3077 (nCeHarom), 2981
þ
M.p.: 100.5e101 ꢀC (diethyl ether); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (5d) ¼ 0.20; IR (KBr)
cmꢁ1: 3086 (nCeHarom), 2977, 2917 (nCeHasym), 2865, 2826 (nCeHsym),
1741, 1708 (nC]O), 1602, 1567, 1499, 1454 (nC]C), 1469 (dCeHasym),
1382 (dCeHsym), 1293 (nCeOeCasym), 1095 (nCeOeCsym), 858 (gCeH);
(
nCeHasym), 2876 (nCeHsym), 2700e2300 ðnN eHÞ, 1718 (nC]O), 1612,
1506, 1457
(nC]C), 1478
(
dCeHasym), 1397
(dCeHsym), 1274
(
nCeOeCasym), 1056 (nCeOeCsym), 848 (gCeH); 1H NMR (300 MHz,
1H NMR (300 MHz, (CD3)2CO)
d
ppm: 2.45 (d, J ¼ 1.5 Hz, 3H, H-9),
(CD3)2CO)
d
ppm: 1.45, 1.47 (2d, J ¼ 6.6 Hz, 12H, H-15, 150), 3.68 (t,
2.51 (m, 4H, H-14, 140), 2.55 (s, 3H, H-11), 2.77 (t, J ¼ 5.4 Hz, 2H,
H-13), 3.60 (bt, J ¼ 4.5 Hz, 4H, H-15, 150), 4.32 (t, J ¼ 5.4 Hz, 2H,
H-12), 6.16 (bq, J ¼ 1.5 Hz, 1H, H-3), 7.15 (d, J ¼ 9.0 Hz, 1H, H-6), 7.77
J ¼ 4.8 Hz, 2H, H-13), 3.85 (heptet, J ¼ 6.6 Hz, 2H, H-14, 140), 4.43
(t, J ¼ 4.8 Hz, 2H, H-12), 6.29 (d, J ¼ 9.6 Hz, 1H, H-3), 7.01 (d,
J ¼ 2.4 Hz, 1H, H-8), 7.02 (dd, J1 ¼2.4 Hz, J2 ¼ 9.0 Hz, 1H, H-6), 7.60
(d, J ¼ 9.0 Hz, 1H, H-5), 7.91 (d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR
(d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, (CD3)2CO)
d ppm: 18.71
(C-9), 32.54 (C-11), 54.89 (C-14, 140), 58.05 (C-13), 67.57 (C-15, 150),
68.02 (C-12), 109.70 (C-6), 112.99 (C-3), 114.89 (C-4a), 120.58 (C-8),
127.76 (C-5), 151.40 (C-8a), 153.65 (C-4), 158.75 (C-7), 160.06 (C-2),
199.19 (C-10). TOF MS ESþ: [M þ H]þ calcd for C18H22NO5: 332.1498
found 332.1534.
(75 MHz, (CD3)2CO)
d
ppm: 17.38, 19.24 (C-15, 150), 48.21 (C-13),
57.77 (C-14, 140), 66.26 (C-12), 102.82 (C-8), 114.07 (C-6), 114.40
(C-3), 115.08 (C-4a), 130.93 (C-5), 145.66 (C-4), 157.18 (C-8a),
162.42 (C-7), 163.12 (C-2).
4.2.21. 6-Acetyl-7-[2-piperidylethoxy]4-methylchromen-2-one (6c)
M.p.: 120.5e121 ꢀC (cyclohexane); eluent used in TLC:
(CHCl3e(CH3)2COeAcOEteMeOH 10:3:1:1), Rf (6c) ¼ 0.18; IR (KBr)
cmꢁ1: 3059 (nCeHarom), 2932 (nCeHasym), 2851 (nCeHsym), 1730, 1667
4.3.2. 7-[2-(N,N-Diisopropylamino)ethoxy]4-methylchromen-2-
one hydrochloride (1bh)
Yield 94%; m.p.: 188.5e190 ꢀC; C18H25NO3$HCl (339.86 g/mol):
calcd. C 63.61,H 7.71, N 4.12, Cl 10.43%; found C 63.47, H 7.73, N 4.20,
Cl 10.32%; IR (KBr) cmꢁ1: 3023 (nCeHarom), 2974 (nCeHasym), 2875
þ
(
(
nC]O),1605,1496,1453 (nC]C),1466 (dCeHasym),1387 (dCeHsym),1281
nCeOeCasym), 1057 (nCeOeCsym), 834 (gCeH); 1H NMR (300 MHz,
(
(
(
nCeHsym), 2650e2300 ðnN eHÞ, 1706 (nC]O), 1610, 1510 (nC]C), 1465
(CD3)2CO)
d
ppm: 1.44 (m, 2H, H-16), 1.55 (m, 4H, H-15, 150), 2.47 (d,
dCeHasym), 1388 (dCeHsym), 1283 (nCeOeCasym), 1073 (nCeOeCsym), 844
J ¼ 1.0 Hz, 3H, H-9), 2.51 (bt, J ¼ 5.0 Hz, 4H, H-14, 140), 2.65 (s, 3H,
H-11), 2.83 (t, J ¼ 5.7 Hz, 2H, H-13), 4.37 (t, J ¼ 5.7 Hz, 2H, H-12), 6.19
(bq, J ¼ 1.0 Hz, 1H, H-3), 7.05 (s, 1H, H-8), 8.00 (s, 1H, H-5); 13C NMR
gCeH); 1H NMR (300 MHz, CD3OD)
d
ppm: 1.45, 1.48 (2d, J ¼ 6.6 Hz,
12H, H-15, 150), 2.46 (d, J ¼ 0.9 Hz, 3H, H-9), 3.69 (bt, J ¼ 4.8 Hz, 2H,
H-13), 3.85 (heptet, J ¼ 6.6 Hz, 2H, H-14,140), 4.44 (bt, J ¼ 4.8 Hz, 2H,
H-12), 6.20 (bq, J ¼ 0.9 Hz,1H, H-3), 7.00 (d, J ¼ 2.3 Hz,1H, H-8), 7.04
(75 MHz, (CD3)2CO)
d ppm: 18.89 (C-9), 24.09 (C-16), 25.90 (C-15,
150), 32.23 (C-11), 55.19 (C-14,140), 57.50 (C-13), 67.33 (C-12),100.87
(C-8), 113.11 (C-3), 113.72 (C-4a), 125.26 (C-6), 128.10 (C-5), 152.88
(dd, J1 ¼8.8 Hz, J2 ¼ 2.3 Hz,1H, H-6), 7.65 (d, J ¼ 8.8 Hz,1H, H-5); 13
C
NMR (75 MHz, CD3OD) d
ppm: 17.39, 19.24 (C-15, 150), 48.22 (C-13),

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2259
57.76 (C-14, 140), 66.23 (C-12), 102.86 (C-8), 112.97 (C-3), 113.87 (C-
6),115.86 (C-4a),127.80 (C-5),155.64 (C-4),156.52 (C-8a),162.32 (C-
7), 163.34 (C-2).
1283
(300 MHz, CD3OD)
(
nCeOeCasym), 1058
(
nCeOeCsym), 826
(
gCeH); 1H NMR
d
ppm: 2.49 (d, J ¼ 1.0 Hz, 3H, H-9), 2.57 (s,
3H, H-11), 3.01 (s, 3H, H-14), 3.64, 3.82 (2 ꢂ m, 2H, H-13), 4.47,
4.59 (2 ꢂ d, J ¼ 12.6 Hz, 2H, H-15), 4.61 (m, 2H, H-12), 6.29 (bq,
J ¼ 1.0 Hz, 1H, H-3), 7.14 (s, 1H, H-8), 7.50e7.59 (m, 5H, H-17, 170,
4.3.3. 6-Acetyl-7-[2-(N,N-diisopropylamino)ethoxy]4-
methylchromen-2-one hydrochloride (1ch)
18, 180, 19), 8.12 (s, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d ppm:
Yield 98%; m.p.: 202.7e203.5 ꢀC; C20H27NO4$HCl$H2O (399.92 g/
mol): calcd. C 60.07, H 7.56, N 3.50, Cl 8.87%; found C 59.18, H 7.18, N
3.52, Cl 8.54%; IR (KBr) cmꢁ1: 3035 (nCeHarom), 2977 (nCeHasym), 2874
þ
18.66 (C-9), 31.21 (C-11), 41.47 (C-14), 55.79 (C-13), 62.15 (C-15),
65.19 (C-12), 103.02 (C-8), 114.10 (C-3), 115.54 (C-4a), 126.74 (C-
6), 129.41 (C-5), 130.74 (C-16, 17, 170), 131.67 (C-19), 132.48 (C-18,
180), 155.16 (C-4), 158.69 (C-8a), 160.78 (C-7), 162.24 (C-2), 200.12
(C-10).
(
nCeHsym), 2650e2350 ðnN eHÞ, 1726 (nC]O), 1617, 1601, 1495 (nC]C),
1466 (dCeHasym),1386 (dCeHsym),1281 (nCeOeCasym),1061 (nCeOeCsym),
889 (gCeH); 1H NMR (300 MHz, CD3OD)
d ppm: 1.45, 1.46 (2d,
J ¼ 6.6 Hz, 12H, H-15, 150), 2.51 (d, J ¼ 1.2 Hz, 3H, H-9), 2.69 (s, 3H,
H-11), 3.74 (t, J ¼ 5.1 Hz, 2H, H-13), 3.94 (heptet, J ¼ 6.6 Hz, 2H, H-14,
140), 4.57 (t, J ¼ 5.1 Hz, 2H, H-12), 6.29 (bq, J ¼ 1.2 Hz,1H, H-3), 7.18 (s,
4.3.7. 8-Acetyl-7-[2-(N-benzyl-N-methylamino)ethoxy]4-
methylchromen-2-one hydrochloride (2dh)
Yield 54%; hygroscopic compound; C22H23NO4$HCl$H2O
(419.91 g/mol): calcd. C 62.93, H 6.24, N 3.34, Cl 8.44%; found C
63.03, H 6.35, N 3.38, Cl 8.39%; IR (KBr) cmꢁ1: 3033 (nCeHarom), 2954
þ
1H, H-8), 8.14 (s, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d ppm: 17.82
(C-15),18.67 (C-9),19.07 (C-150), 30.82 (C-11), 47.23 (C-13), 57.07 (C-
14, 140), 66.52 (C-12),103.36 (C-8),114.15 (C-3),115.55 (C-4a),126.61
(C-6), 129.51 (C-5), 155.12 (C-4), 158.69 (C-8a), 160.63 (C-7), 162.20
(C-2), 200.87 (C-10).
(
nCeHasym), 2880 (nCeHsym), 2700e2300 ðnN eHÞ, 1730, 1705 (nC]O),
1599, 1495
(nC]C), 1458
(dCeHasym), 1384 (dCeHsym), 1291
(
nCeOeCasym), 1105 (nCeOeCsym), 746 (gCeH); 1H NMR (300 MHz,
CD3OD)
d
ppm: 2.47 (d, J ¼ 0.9 Hz, 3H, H-9), 2.59 (s, 3H, H-11), 2.93
4.3.4. 8-Acetyl-7-[2-(N,N-diisopropylamino)ethoxy]4-
methylchromen-2-one hydrochloride (1dh)
(s, 3H, H-14), 3.64, 3,71 (2 ꢂ m, 2H, H-13), 4.40, 4.55 (2 ꢂ d,
J ¼ 12.3 Hz, 2H, H-15), 4.60 (m, 2H, H-12), 6.25 (bq, J ¼ 0.9 Hz,1H, H-
3), 7.19 (d, J ¼ 9.0 Hz, 1H, H-6), 7.50e7.59 (m, 5H, H-17, 170, 18, 180,
Yield 91%; m.p.: 221.3e222 (dec.) ꢀC; C20H27NO4$HCl$H2O
(399.92 g/mol): calcd. C 60.07, H 7.56, N 3.50, Cl 8.87%; found C
60.20, H 7.14, N 3.68, Cl 8.74%; IR (KBr) cmꢁ1: 3037 (nCeHarom), 2980
þ
19), 7.85 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d ppm:
18.90 (C-9), 32.90 (C-11), 41.45 (C-14), 55.87 (C-13), 61.98 (C-15),
65.35 (C-12), 110.78 (C-6), 113.62 (C-3), 116.32 (C-4a), 120.68 (C-8),
129.04 (C-5), 130.67 (C-17, 170), 130.83 (C-16), 131.53 (C-19), 132.41
(C-18, 180), 152.13 (C-4), 155.21 (C-8a), 157.83 (C-7), 161.79 (C-2),
201.83 (C-10).
(
nCeHasym), 2878 (nCeHsym), 2650e2350 ðnN eHÞ, 1731, 1699 (nC]O),
1601, 1566, 1441 (nC]C), 1466 (dCeHasym), 1377 (dCeHsym), 1292
(
nCeOeCasym), 1105 (nCeOeCsym), 891 (gCeH); 1H NMR (300 MHz,
CD3OD)
d
ppm: 1.43 (d, J ¼ 6.6 Hz, 12H, H-15, 150), 2.48 (d, J ¼ 1.2 Hz,
3H, H-9), 2.63 (s, 3H, H-11), 3.68 (t, J ¼ 4.8 Hz, 2H, H-13), 3.85
(heptet, J ¼ 6.6 Hz, 2H, H-14, 140), 4.50 (t, J ¼ 4.8 Hz, 2H, H-12), 6.26
(bq, J ¼ 1.2 Hz, 1H, H-3), 7.19 (d, J ¼ 9.0 Hz, 1H, H-6), 7.87 (d,
4.3.8. 7-[2-(N,N-Diethylamino)ethoxy]chromen-2-one
hydrochloride (3ah)
J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d
ppm: 17.51 (C-9),
Yield 96%; m.p.: 183e184 ꢀC (Lit. m.p.: 174e175 ꢀC [17]).
C15H19NO3$HCl (297.78 g/mol): calcd. C 60.50, H 6.77, N 4.70, Cl
11.91%; found C 60.77, H 6.76, N 4.72, Cl 12.06%; IR (KBr) cmꢁ1: 3037
þ
18.90 (C-15, 150), 33.04 (C-11), 47.89 (C-13), 57.41 (C-14, 140), 67.11
(C-12), 110.43 (C-6), 113.59 (C-3), 116.26 (C-4a), 120.42 (C-8), 129.06
(C-5), 152.20 (C-8a), 155.29 (C-4), 157.90 (C-7), 161.88 (C-2), 202.21
(C-10).
(
nCeHarom), 2945 (nCeHasym), 2885 (nCeHsym), 2700e2300 ðnN eHÞ,
1726, 1708 (nC]O), 1627, 1506, 1445 (nC]C), 1468 (dCeHasym), 1380
(
dCeHsym), 1295 (nCeOeCasym), 1032 (nCeOeCsym), 838 (gCeH); 1H NMR
4.3.5. 7-[2-(N-Benzyl-N-methylamino)ethoxy]4-methylchromen-2-
one hydrochloride (2bh)
(300 MHz, CD3OD)
d
ppm: 1.39 (t, J ¼ 7.2 Hz, 6H, H-15,150), 3.36 (dq,
J1 ¼7.2 Hz, J2 ¼ 3.3 Hz, 4H, H-14, 140), 3.67 (bt, J ¼ 4.8 Hz, 2H, H-13),
4.48 (bt, J ¼ 4.8 Hz, 2H, H-12), 6.30 (d, J ¼ 9.6 Hz, 1H, H-3), 7.03 (bs,
1H, H-8), 7.04 (dd, J1 ¼ 2.4 Hz, J2 ¼ 9.4 Hz, 1H, H-6), 7.61 (d,
J ¼ 9.6 Hz, 1H, H-5), 7.91 (d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR (75 MHz,
Yield 83%; m.p.: 168.2e169.2 ꢀC; C20H21NO3$HCl$1/2H2O
(368.86 g/mol): calcd. C 65.12, H 6.28, N 3.80, Cl 9.61%; found C
65.17, H 6.20, N 3.79, Cl 9.59%; IR (KBr) cmꢁ1: 3037 (nCeHarom),
2951 (nCeHasym), 2882 (nCeHsym), 2700e2300 ðnN eHÞ, 1733, 1700
CD3OD) d
ppm: 9.28 (C-15, 150), 49.64 (C-14, 140), 52.27 (C-13), 64.14
þ
(
nC]O), 1616, 1511, 1496 (nC]C), 1458 (dCeHasym), 1389 (dCeHsym),
(C-12), 103.01 (C-8), 114.08 (C-6), 114.42 (C-3), 115.13 (C-4a), 130.90
(C-5), 145.65 (C-4), 157.12 (C-8a), 162.37 (C-7), 163.10 (C-2).
1294
(nCeOeCasym), 1073
(
nCeOeCsym), 844
(
gCeH); 1H NMR
(300 MHz, CD3OD)
d
ppm: 2.47 (d, J ¼ 1.0 Hz, 3H, H-9), 2.96 (s,
3H, H-14), 3.66 (bs, 2H, H-13), 4.47 (bs, 2H, H-15), 4.50 (t,
J ¼ 5.1 Hz, 2H, H-12), 6.22 (bq, J ¼ 1.0 Hz, 1H, H-3), 7.00 (d,
J ¼ 2.4 Hz, 1H, H-8), 7.05 (dd, J1 ¼ 2.4 Hz, J2 ¼ 9.0 Hz, 1H, H-6),
7.49e7.57 (m, 5H, H-17, 170, 18, 180, 19), 7.75 (d, J ¼ 9.0 Hz, 1H, H-
4.3.9. 7-[2-(N,N-Diethylamino)ethoxy]4-methylchromen-2-one
hydrochloride (3bh)
Yield 92%; m.p.: 215e216 ꢀC (Lit. 213e215 ꢀC [19]);
C16H21NO3$HCl (311.81 g/mol): calcd. C 61.63, H 7.11, N 4.49, Cl
11.37%; found C 61.32, H 6.93, N 4.53, Cl 11.16%; IR (KBr) cmꢁ1: 3054
þ
5); 13C NMR (75 MHz, CD3OD)
d ppm: 18.77 (C-9), 41.41 (C-14),
55.70 (C-13), 61.77 (C-15), 63.93 (C-12), 103.05 (C-8), 113.03 (C-
6), 113.87 (C-3), 115.96 (C-4a), 127.77 (C-5), 130.65 (C-17, 170),
131.52 (C-16, 19), 132.43 (C-18, 180), 155.58 (C-4), 156.47 (C-8a),
162.20 (C-7), 163.30 (C-2).
(
nCeHarom), 2974 (nCeHasym), 2885 (nCeHsym), 2650e2300 ðnN eHÞ,
1720 broad (nC]O), 1609, 1510, 1443 (nC]C), 1463 (dCeHasym), 1389
(
dCeHsym), 1283 (nCeOeCasym), 1070 (nCeOeCsym), 834 (gCeH); 1H NMR
(300 MHz, CD3OD)
d
ppm: 1.39 (t, J ¼ 7.2 Hz, 6H, H-15, 150), 2.46 (d,
J ¼ 1.2 Hz, 3H, H-9), 3.37 (dq, J1 ¼7.2 Hz, J2 ¼ 2.4 Hz, 4H, H-14, 140),
3.67 (t, J ¼ 5.1 Hz, 2H, H-13), 4.48 (t, J ¼ 5.1 Hz, 2H, H-12), 6.22 (bq,
J ¼ 1.2 Hz, 1H, H-3), 7.03 (d, J ¼ 2.4 Hz, 1H, H-8), 7.07 (dd, J1 ¼2.4 Hz,
J2 ¼ 8.7 Hz, 1H, H-6), 7.75 (d, J ¼ 8.7 Hz, 1H, H-5); 13C NMR (75 MHz,
4.3.6. 6-Acetyl-7-[2-(N-benzyl-N-methylamino)ethoxy]4-
methylchromen-2-one hydrochloride (2ch)
Yield 92%; m.p.: 208e208.5 (dec.) ꢀC; C22H23NO4$HCl$H2O
(410.90 g/mol): calcd. C 64.31, H 6.13, N 3.41, Cl 8.63%; found C
64.59, H 6.13, N 3.55, Cl 8.54%; IR (KBr) cmꢁ1: 3043 (nCeHarom),
CD3OD) d
ppm: 9.27 (C-15, 150), 18.77 (C-9), 49.64 (C-14, 140), 52.29
(C-13), 64.09 (C-12), 103.02 (C-8), 113.03 (C-3), 113.85 (C-6), 115.94
(C-4a), 127.78 (C-5), 155.57 (C-4), 156.48 (C-8a), 162.26 (C-7), 163.29
(C-2).
þ
2933 (nCeHasym), 2870 (nCeHsym), 2700e2300 ðnN eHÞ, 1716, 1676
(nC]O), 1601, 1497, 1450 (nC]C), 1465 (dCeHasym), 1388 (dCeHsym),

2260
J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
4.3.10. 6-Acetyl-7-[2-(N,N-diethylamino)ethoxy]4-methylchromen-
2-one hydrochloride (3ch)
(bm, 1H, Heq-18), 3.86e3.95 (m, 1H, Heq-13), 4.45e4.58 (m, 2H, H-
12), 6.22 (bq, J ¼ 1.0 Hz, 1H, H-3), 7.03 (d, J ¼ 2,7 Hz, 1H, H-8), 7.08
Yield 73%; m.p.: 220.5e221 (dec.) ꢀC. C18H23NO4$HCl
(353.85 g/mol): calcd. C 61.10, H 6.84, N 3.96, Cl 10.02%; found C
60.97, H 6.80, N 3.99, Cl 10.05%; IR (KBr) cmꢁ1: 3071 (nCeHarom),
(dd, J1 ¼9.0 Hz, J2 ¼ 2.7 Hz,1H, H-6), 7.76 (d, J ¼ 9.0 Hz,1H, H-5); 13
C
NMR (75 MHz, CD3OD) d ppm: 18.78 (C-9),14.24,18.49, 20.11, 23.05,
21.76, 24.48, 28.84, 33.01 (C-19, C-16, C-17, C-15), 50.78, 53.79,
54.62, 59,34, 62.40, 63.87 64.30 (C-13, C-18, C-14, C-12), 103.00 (C-
8), 112.98 (C-3), 113.89 (C-6), 115.89 (C-4a), 127.76 (C-5), 155.60 (C-
4), 156.48 (C-8a), 162.32 (C-7), 163.32 (C-2).
þ
2966 (nCeHasym), 2885 (nCeHsym), 2650e2300 ðnN eHÞ, 1733 broad,
1679 (nC]O), 1600, 1497, (nC]C), 1459 (dCeHasym), 1386 (dCeHsym),
1285
(300 MHz, CD3OD)
(nCeOeCasym), 1062 (nCeOeCsym), 894 (
gCeH); 1H NMR
d
ppm: 1.39, 1.41 (2d, J ¼ 7.2 Hz, 6H, H-15, 150),
2.50 (d, J ¼ 0.9 Hz, 3H, H-9), 2.68 (s, 3H, H-11), 3.40, 3.44 (2q,
J ¼ 7.2 Hz, 4H, H-14, 140), 3.73 (t, J ¼ 4.8 Hz, 2H, H-13), 4.59 (t,
J ¼ 4.8 Hz, 2H, H-12), 6.29 (bq, J ¼ 0.9 Hz, 1H, H-3), 7.18 (s, 1H, H-
4.3.14. 6-Acetyl-7-[2-(2-methylpiperidinyl)ethoxy]4-
methylchromen-2-one hydrochloride (4ch)
Yield 95%; m.p.: 216e217 (dec.) ꢀC; C20H25NO4$HCl (379.88 g/
mol): calcd. C 63.24, H 6.90, N 3.69, Cl 9.33%; found C 63.06, H
6.86, N 3.71, Cl 8.96%; IR (KBr) cmꢁ1: 3066 (nCeHarom), 2941
þ
8), 8.13 (s, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d ppm: 9.41 (C-15,
150), 18.66 (C-9), 31.11 (C-11), 49.79 (C-14, 140), 52.52 (C-13), 65.41
(C-12), 103.06 (C-8), 114.09 (C-3), 115.50 (C-4a), 126.77 (C-6),
129.39 (C-5), 155.16 (C-4), 158.67 (C-8a), 160.80 (C-7), 162.26 (C-
2), 200.24 (C-10).
(
nCeHasym), 2852 (nCeHsym), 2650e2300 ðnN eHÞ, 1732, 1675 (nC]O),
1600, 1498,
nCeOeCasym), 1057 (nCeOeCsym), 889 (gCeH); Diasteroisomers. 1H
NMR (300 MHz, CD3OD)
(nC]C), 1461 (dCeHasym), 1384 (dCeHsym), 1282
(
d
ppm: 1.44, 1.49 (2d, J ¼ 6.0 Hz, 3H, H-
4.3.11. 8-Acetyl-7-[2-(N,N-diethylamino)ethoxy]4-methylchromen-
2-one hydrochloride (3dh)
19), 1.84e2.09 (m, 6H, H-15, 16, 17), 2.49 (bs, 3H, H-9), 2.68 (s,
3H, H-11), 3.21 (m, 1H, Hax-18), 3.45 (m, 1H, H-14), 3.62 (m, 1H,
Hax-13), 3.81 (m, 1H, Heq-18), 3.97 (m, 1H, Heq-13), 4.60 (m, 2H,
H-12), 6.27 (bs, 1H, H-3), 7.18 (s, 1H, H-8), 8.12 (s, 1H, H-5); 13C
Yield 92%; m.p.: 213e213.5 ꢀC; C18H23NO4$HCl (353.85 g/mol):
calcd. C 61.10, H 6.84, N 3.96, Cl 10.02%; found C 60.98, H 6.77, N
4.03, Cl 9.91%; IR (KBr) cmꢁ1: 3084 (nCeHarom), 2974 (nCeHasym), 2878
þ
NMR (75 MHz, CD3OD)
d ppm: 18.67 (C-9), 31.23 (C-11), 13.77,
(
(
(
nCeHsym), 2700e2300 ðnN eHÞ, 1711 (nC]O), 1603, 1564, 1494, 1445
18.56, 22.26, 23.03, 24.36, 24.52, 33.06 (C-19, C-16, C-17, C-15),
50.61, 51.89, 53.66, 55.16, 59.55, 62.19, 65.21 (C-13, C-18, C-14, C-
12), 102.98 (C-8), 114.03 (C-3), 115.39 (C-4a), 126.74 (C-6), 129.31
(C-5), 155.17 (C-4), 158.66 (C-8a), 160.85 (C-7), 162.28 (C-2),
200.15 (C-10).
nC]C), 1461 (dCeHasym), 1388 (dCeHsym), 1292 (nCeOeCasym), 1106
nCeOeCsym), 861 (gCeH); 1H NMR (300 MHz, CD3OD)
d ppm: 1.37 (t,
J ¼ 7.2 Hz, 6H, H-15, 150), 2.48 (d, J ¼ 1.2 Hz, 3H, H-9), 2.63 (s, 3H, H-
11), 3.35 (q, J ¼ 7.2 Hz, 4H, H-14, 140), 3.66 (t, J ¼ 4.8 Hz, 2H, H-12),
4.54 (t, J ¼ 4.8 Hz, 2H, H-13), 6.27 (d, J ¼ 1.2 Hz, 1H, H-3), 7.20 (d,
J ¼ 9.0 Hz, 1H, H-6), 7.87 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz,
4.3.15. 8-Acetyl-7-[2-(2-methylpiperidinyl)ethoxy]4-
methylchromen-2-one hydrochloride (4dh)
CD3OD)
d
ppm: 9.50 (C-15, 150), 18.89 (C-9), 32.92 (C-11), 50.07 (C-
14, 140), 52.23 (C-13), 65.57 (C-12), 110.56 (C-6), 113.64 (C-3), 116.33
(C-4a), 120.62 (C-8), 129.03 (C-5), 152.16 (C-8a), 155.21 (C-4), 157.87
(C-7), 161.79 (C-2), 201.78 (C-10).
Yield 56%; m.p.: 199.8e200.8 (dec.) ꢀC; C20H25NO4$HCl$11/
2H2O (406.91 g/mol): calcd. C 59.04, H 7.18, N 3.44, Cl 8.71%;
found C 59.01, H 6.97, N 3.67, Cl 9.07%; IR (KBr) cmꢁ1: 3075
þ
(
nCeHarom), 2950 (nCeHasym), 2873 (nCeHsym), 2700e2300 ðnN eHÞ,
4.3.12. 7-[2-(2-Methylpiperidinyl)ethoxy]chromen-2-one
hydrochloride (4ah)
1743, 1702
dCeHsym), 1286 (nCeOeCasym), 1101 (nCeOeCsym), 868 (gCeH); 1H
NMR (300 MHz, CD3OD)
(nC]O), 1599, 1453 (nC]C), 1472 (dCeHasym), 1385
(
Yield 85%; m.p.: 171.5e172 ꢀC. C17H21NO3$HCl (323.82 g/mol):
calcd. C 63.06, H 6.85, N 4.33, Cl 10.95%; found C 63.06, H 6.86, N
4.32, Cl 11.11%; IR (KBr) cmꢁ1: 3034 (nCeHarom), 2939 (nCeHasym),
d
ppm: 1.44, 1.40 (2bd, J ¼ 6.3 Hz, 3H, H-
19), 1.58-2.12 (m, 6H, H-15, 16, 17), 2.48 (d, J ¼ 0.6 Hz, 3H, H-9),
2.63 (s, 3H, H-11), 3.07e3.22 (m, 1H, Hax-18), 3.38 (m, 1H, H-14),
3.55e3.70 (m, Hax-13, Heq-18), 3.74e3.83 (m, 1H, Heq-13), 4.55
(bs, 2H, H-12), 6,27 (bq, J ¼ 0.6 Hz, 1H, H-3), 7.20 (d, J ¼ 9.0 Hz, 1H,
H-6), 7.87 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, CD3OD)
þ
2864 (nCeHsym), 2700e2300 ðnN eHÞ, 1725, 1706 (nC]O), 1626, 1554,
1505, (nC]C), 1458 (dCeHasym), 1356 (dCeHsym), 1296 (nCeOeCasym),
1016 (nCeOeCsym), 838 (gCeH); 1H NMR (300 MHz, CD3OD)
d ppm:
1.48 (d, J ¼ 6.0 Hz, 3H, H-19), 1.60e2.10 (m, 6H, H-15, 16, 17), 3.16
(m, 1H, Hax-18), 3.38 (m, 1H, H-14), 3.59 (m, 1H, Hax-13), 3.70 (m,
1H, Heq-18), 3.88 (m, 1H, Heq-13), 4.47 (m, 1H, H-12), 6.30 (d,
J ¼ 9,6 Hz, 1H, H-3), 7.03 (bd, J ¼ 2.7 Hz, 1H, H-8), 7.04 (dd,
J1 ¼8.6 Hz, J2 ¼ 2.7 Hz, 1H, H-6), 7.61 (d, J ¼ 8.6 Hz, 1H, H-5), 7.91
d ppm: 18.54 (C-19), 18.88 (C-9), 23.02 (C-17), 24.58 (C-16), 32.91
(C-11), 33.12 (C-15), 53.56 (C-13), 55.34 (C-18), 61.96 (C-14), 65.09
(C-12), 110.50 (C-6), 113.63 (C-3), 115.21 (C-4a), 120.62 (C-8),
129.01 (C-5), 155.20 (C4), 157.88 (C-8a), 161.78 (C-7), 163.32 (C-2),
201.91 (C-10).
(d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR (75 MHz, CD3OD)
d ppm: 18.51
(C-9), 23.05 (C-16), 24.51 (C-17), 33.01 (C-15), 53.81 (C-13), 54.61
(C-18), 62.41 (C-14), 63.90 (C-12), 102.96 (C-8), 114.09 (C-6), 114.44
(C-3), 115.13 (C-4a), 130.90 (C-5), 145.64 (C-4), 157.16 (C-8a), 162.41
(C-2), 163.13 (C-7).
4.3.16. 7-[2-(1-Morpholino)ethoxy]chromen-2-one hydrochloride
(5ah)
Yield 91%; m.p.: 231e232 (dec.) ꢀC; C15H17NO4$HCl$2H2O
(347.8 g/mol): calcd. C 51.80, H 6.38, N 4.03, Cl 10.19%; found C 52.20,
H 5.92, N 4.15, Cl 9.90%; IR (KBr) cmꢁ1: 3056 (nCeHarom), 2935
þ
4.3.13. 7-[2-(2-Methylpiperidinyl)ethoxy]4-methylchromen-2-one
hydrochloride (4bh)
(
nCeHasym), 2868 (nCeHsym), 2700e2300 ðnN eHÞ, 1727, 1705 (nC]O),
1609, 1507, 1451 (nC]C), 1460 (dCeHasym), 1355 (dCeHsym), 1299
nCeOeCasym), 1038 (nCeOeCsym), 836 (gCeH); 1H NMR (300 MHz,
CD3OD)
ppm: 3.30 (bm, 2H, H-14), 3.58 (bm, 2H, H-140), 3.70 (bt,
Yield 99%; m.p.: 229e230 (dec.) ꢀC; C18H23NO3$HCl$1/2H2O
(346.86 g/mol): calcd. C 62.33, H 7.26, N 4.04, Cl 10.22%; found C
62.35, H 7.13, N 4.08, Cl 10.25%; IR (KBr) cmꢁ1: 3092, 3035
þ
(
d
J ¼ 4.8 Hz, 2H, H-13), 3.90 (bm, 2H, H-15), 4.06 (bm, 2H, H-150), 4.53
(bt, J ¼ 4.8 Hz, 2H, H-12), 6.29 (d, J ¼ 9.3 Hz, 1H, H-3), 7.03 (d,
J ¼ 2.4 Hz,1H, H-8), 7.05 (dd, J1 ¼8.5 Hz, J2 ¼ 2.4 Hz,1H, H-6), 7.60 (d,
J ¼ 8.5 Hz, 1H, H-5), 7.90 (d, J ¼ 9.3 Hz, 1H, H-4); 13C NMR (75 MHz,
(
nCeHarom), 2940 (nCeHasym), 2860 (nCeHsym), 2700e2300 ðnN eHÞ,
1710 (nC]O),1624,1616,1510 (nC]C),1450 (dCeHasym),1392 (dCeHsym),
1297 (nCeOeCasym), 1017 (nCeOeCsym), 838 (gCeH); Diastereoisomers:
1H NMR (300 MHz, CD3OD)
d
ppm: 1.46, 1.50 (2d, J ¼ 6.6 Hz, 3H, H-
CD3OD) d
ppm: 53.92 (C-14,140), 57.44 (C-13), 63.68 (C-12), 65.05 (C-
19), 1.61e2.08 (m, 6H, H-15, 16, 17), 2.47 (2, J ¼ 1.0 Hz, 3H, H-9), 3.16
15, 150), 103.06 (C-8), 114.10 (C-6), 114.42 (C-3), 115.14 (C-4a), 130.88
(C-5), 145.64 (C-4), 157.11 (C-8a), 162.34 (C-7), 163.11 (C-2).
(m,1H, Hax-18), 3.39 (m, 1H, H-14), 3.52e3.59 (m,1H, Hax-13), 3.71

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2261
4.3.17. 7-[2-(1-Morpholino)ethoxy]4-methylchromen-2-one
4.4.1. 7-[2-(N-benzyl-N,N-dimethylamino)ethoxy]chromen-2-one
hydrochloride (5bh)
iodide (2am)
Yield 77%; m.p.: 199e199.5 (dec.) ꢀC; C16H19NO4$HCl$21/2H2O
(370.83 g/mol): calcd. C 51.82, H 6.80, N 3.78, Cl 9.56%; found C
52.30, H 6.79, N 3.81, Cl 9.74%; IR (KBr) cmꢁ1: 3040 (nCeHarom), 2935
þ
Yield 68%; m.p.: 161e162 (dec.) ꢀC; IR (KBr) cmꢁ1: 3033
nCeHarom), 2963 (nCeHasym), 2885 (nCeHsym), 1718, 1701 (nC]O), 1631,
(
1610 1508, 1455 (nC]C), 1469 (dCeHasym), 1384 (dCeHsym), 1285
nCeOeCasym), 1054 (nCeOeCsym), 839 (gCeH); 1H NMR (300 MHz,
DMSO-d6)
(
nCeHasym), 2868 (nCeHsym), 2700e2300 ðnN eHÞ, 1707 (nC]O), 1622,
(
1510 (nC]C), 1442 (dCeHasym), 1392 (dCeHsym), 1296 (nCeOeCasym),
d
ppm: 3.09 (s, 6H, H-14, 20), 3.82 (t, J ¼ 4.5 Hz, 2H, H-
1067 (nCeOeCsym), 838 (gCeH); 1H NMR (300 MHz, CD3OD)
d
ppm:
13), 4.68 (s, 2H, H-15), 4.68 (t, J ¼ 4.5 Hz, 2H, H-12), 6.34 (d,
J ¼ 9.6 Hz, 1H, H-3), 7.03 (dd, J1 ¼8.7 Hz, J2 ¼ 2.4 Hz, 1H, H-6), 7.14
(d, J ¼ 2.4 Hz, 1H, H-8), 7.54e7.62 (m, 5 H, H-17, 170, 18, 180, 19), 7.70
(d, J ¼ 8.7 Hz, 1H, H-5), 8.03 (d, J ¼ 9.6 Hz, 1H, H-4); 13C NMR
2.46 (d, J ¼ 1.2 Hz, 3H, H-9), 3.31 (bm, 2H, H-14), 3.58e3.66 (bm, 2H,
H-140), 3.71 (bt, J ¼ 4.8 Hz, 2H, H-13), 3.82-3.90 (bm, 2H, H-15),
4.07e4.11 (bm, 2H, H-150), 4.53 (bt, J ¼ 4.8 Hz, 2H, H-12), 6.21 (d,
J ¼ 1.2 Hz, 1H, H-3), 7.03 (d, J ¼ 2.4 Hz, 1H, H-8), 7.08 (dd, J1 ¼8.7 Hz,
J2 ¼ 2.4 Hz, 1H, H-6), 7.74 (d, J ¼ 8.7 Hz, 1H, H-5); 13C NMR (75 MHz,
(75 MHz, DMSO-d6) d ppm: 49.77 (C-14, 20), 62.07 (C-15), 62.26 (C-
13), 67.30 (C-12), 101.68 (C-8), 112.87 (C-6), 112.92 (C-3), 112.98 (C-
4a), 127.87 (C-19), 128.95 (C-17, 170), 129.55 (C-16), 130.37 (C-5),
133.11 (C-18, 180), 144.23 (C-4), 155.22 (C-8a), 160.12 (C-2), 160.39
(C-7).
CD3OD) d
ppm: 18.76 (C-9), 53.91 (C-14, 140), 57.44 (C-13), 63.59 (C-
12), 65.03 (C-15, 150), 103.08 (C-8), 113.02 (C-3), 113.86 (C-6), 115.94
(C-4a), 127.75 (C-5), 155.57 (C-4), 156.45 (C-8a), 162.22 (C-7), 163.29
(C-2).
4.4.2. 7-[2-(N,N-Diethyl-N-methylamino)ethoxy]chromen-2-one
iodide (3am)
4.3.18. 6-Acetyl-7-[2-piperidylethoxy]4-methylchromen-2-one
hydrochloride (6ch)
Yield 73%; m.p.: 231.5e232 (dec.) ꢀC; IR (KBr) cmꢁ1: 3055, 3025
Yield 95%: m.p.: 227e229 (dec.) ꢀC; C19H23NO4$HCl$H2O
(374.86 g/mol): calcd. C 60.88, H 6.72, N 3.74, Cl 9.46%, found C
60.97, H 6.77, N 3.69, Cl 8.76%; IR (KBr) cmꢁ1: 3025 (nCeHarom), 2949
þ
(nCeHarom), 2979, 2952 (nCeHasym), 2848 (nCeHsym), 1724 (nC]O), 1612,
1507 (nC]C), 1450 broad (nC]C) (dCeHasym), 1380 (dCeHsym), 1279
(
nCeOeCasym), 1023 (nCeOeCsym), 837 (gCeH); 1H NMR (300 MHz,
(
nCeHasym), 2878 (nCeHsym), 2700e2300 ðnN eHÞ, 1731, 1672 (nC]O),
DMSO-d6)
d
ppm: 1.27 (t, J ¼ 5.7 Hz, 6H, H-15, 150), 3.06 (s, 3H, H-
1600, 1497, 1447 (nC]C), 1465 (dCeHasym), 1365 (dCeHsym), 1287
16), 3.43 (q, J ¼ 5.7 Hz, 4H, H-14, 140), 3.76 (t, 2H, H-13), 4.55 (t, 2H,
H-12), 6.33 (d, J ¼ 9.0 Hz, 1H, H-3), 7.01 (dd, J1 ¼7.5 Hz, 1H, H-6),
7.10 (d, 1H, H-8), 7.69 (d, J ¼ 7.5 Hz, 1H, H-5), 8.02 (d, J ¼ 9.0 Hz, 1H,
(
nCeOeCasym), 1062 (nCeOeCsym), 844 (gCeH); 1H NMR (300 MHz,
CD3OD) d ppm: 1.57 (bm, 1H, Hax-16), 1.81e2.03 (m, 5H, Heq-16, H-
15, 150), 2.50 (d, J ¼ 1.0 Hz, 3H, H-9), 2.68 (s, 3H, H-11), 3.10 (bm, 2H,
H-14), 3.68 (bt, J ¼ 4.8 Hz, 2H, H-13), 3.73 (bs, 2H, H-140), 4.60 (bt,
J ¼ 4.8 Hz, 2H, H-12), 6.28 (d, J ¼ 1.0 Hz, 1H, H-3), 7.17 (s, 1H, H-8),
H-4); 13C NMR (75 MHz, DMSO-d6) ppm: 7.64 (C-15, 150), 47.27 (C-
d
16), 56.47 (C-14, 140), 58.40 (C-13), 61.89 (C-12), 101.62 (C-8), 112.81
(C-46), 112.89 (C-3), 112.93 (C-4a), 129.54 (C-5), 144.21 (C-4), 155.19
(C-8a), 160.11 (C-2), 160.35 (C-7).
8.14 (s, 1H, H-5); 13C NMR (75 MHz, CD3OD)
d ppm: 18.66 (C-9),
22.63 (C-16), 24.43 (C-15, 150), 31.17 (C-11), 55.39 (C-14,140), 57.17
(C-13), 65.14 (C-12), 103.07 (C-8), 114.07 (C-3), 115.07 (C-4a), 126.73
(C-6), 129.43 (C-5), 155.17 (C-4), 158.71 (C-8a), 160.86 (C-7), 162.26
(C-2), 200.17 (C-10).
4.4.3. 7-[2-(N,N-Diethyl-N-methylamino)ethoxy]4-
methylchromen-2-one iodide (3bm)
Yield 79%; m.p.: 206.5e207.5 (dec.) ꢀC; IR (KBr) cmꢁ1: 3033
(nCeHarom), 2978, 2937 (nCeHasym), 2878 (nCeHsym), 1702 broad (nC]
4.3.19. 8-Acetyl-7-[2-piperidylethoxy]4-methylchromen-2-one
hydrochloride (6dh)
O), 1626, 1612, 1510, 1448 (nC]C), 1461 (dCeHasym), 1389 (dCeHsym),
1281 (nCeOeCasym), 1054 (nCeOeCsym), 843 (gCeH); 1H NMR (300 MHz,
Yield 79%; m.p.: 231e233 (dec.) ꢀC; C19H23NO4$HCl$H2O
(383.87 g/mol): calcd. C 59.45, H 6.83, N 3.65, Cl 9.24%; found C
59.32, H 6.54, N 3.77, Cl 9.90%; IR (KBr) cmꢁ1: 3076 (nCeHarom), 2949
þ
DMSO-d6)
d
ppm: 1.30 (t, J ¼ 7.2 Hz, 6H, H-15, 150), 2.42 (s, 3H, H-9),
3.05 (s, 3H, H-16), 3.43 (q, J ¼ 7.2 Hz, 4H, H-14, 140), 3.76 (bt,
J ¼ 6.0 Hz, 2H, H-13), 4.55 (bt, J ¼ 6.0 Hz, 2H, H-12), 6.26 (bq, 1H, H-
3), 7.02 (dd, J1 ¼2.4 Hz, J2 ¼ 8.7 Hz, 1H, H-6), 7.10 (d, J ¼ 2.4 Hz, 1H,
H-8), 7.74 (d, J ¼ 8.7 Hz, 1H, H-5); 13C NMR (75 MHz, DMSO-d6)
(
nCeHasym), 2863 (nCeHsym), 2650e2300 ðnN eHÞ, 1744, 1699 (nC]O),
1599, 1492, 1452 (nC]C), 1469 (dCeHasym), 1385 (dCeHsym), 1287
nCeOeCasym), 1052 (nCeOeCsym), 867 (gCeH); 1H NMR (300 MHz,
CD3OD) ppm: 1.59 (bm,1H, Hax-16), 1.80e2.03 (m, 5H, Heq-16, H-
(
d
ppm: 7.62 (C-15, 150), 18.13 (C-9), 47.25 (C-16), 56.44 (C-14, 140),
d
58.43 (C-13), 61.85 (C-12), 101.63 (C-8), 111.54 (C-3), 112.54 (C-6),
113.71 (C-4a), 126.56 (C-5), 153.34 (C-4), 154.58 (C-8a),159.98 (C-2),
160.28 (C-7).
15, 150), 2.49 (d, J ¼ 1.2 Hz, 3H, H-9), 2.64 (s, 3H, H-11), 3.10 (m, 2H,
H-14), 3.61 (bt, J ¼ 4.8 Hz, 2H, H-13), 3.62 (bm, 2H, H-140), 4.58 (bt,
J ¼ 4.8 Hz, 2H, H-12), 6.27 (d, J ¼ 1.2 Hz, 1H, H-3), 7.21 (d, J ¼ 9.0 Hz,
1H, H-6), 7.88 (d, J ¼ 9.0 Hz, 1H, H-5); 13C NMR (75 MHz, CD3OD)
4.4.4. 7-[2-(1,2-Dimethylpiperidinyl)ethoxy]chromen-2-one iodide
(4am)
d
ppm: 18.90 (C-9), 22.57 (C-16), 24.46 (C-15, 150), 32.91 (C-11),
55.50 (C-14,140), 57.16 (C-13), 65.37 (C-12), 110.76 (C-6), 113.61 (C-
3), 116.31 (C-4a),120.69 (C-8), 129.05 (C-5),152.18 (C-8a), 155.23 (C-
4), 157.90 (C-7), 161.80 (C-2), 201.82 (C-10).
Yield 27%; m.p.: 207.5e208 (dec.) ꢀC; IR (KBr) cmꢁ1: 3050, 3023
(nCeHarom), 2941 (nCeHasym), 2863 (nCeHsym), 1724 (nC]O), 1610, 1507
(nC]C), 1461 (dCeHasym), 1376 (dCeHsym), 1278 (nCeOeCasym), 1034
(
nCeOeCsym), 844 (gCeH); Diastereoisomers: 1H NMR (300 MHz,
DMSO-d6)
d
ppm: 1.31, 1.35 (2d, J ¼ 6.6 Hz, 3H, H-19), 1.47e1.93 (m,
6H, H-15,16,17), 3.02, 3.20 (s, 3H, H-20), 3.44e3.72 (m, 3H, H-14, H-
18), 3.89 (bt, 2H, H-13), 4.52-4.67 (bm, 2H, H-12), 6.34 (d, J ¼ 9.5 Hz,
1H, H-3), 7.02 (dd, J1 ¼8.5 Hz, J2 ¼ 2.0 Hz, 1H, H-6), 7.11 (d,
J ¼ 2.0 Hz, 1H, H-8), 7.70 (d, J ¼ 8.5 Hz, 1H, H-5), 8.04 (d, J ¼ 9.5 Hz,
4.4. General procedure for the preparation methiodides of coumarin
derivatives 2am, 3am, 3bm, 4am, 4bm
Compound 2a, 3a, 3b, 4a or 4b (0.5 mmol) was dissolved in
diethyl ether then methyl iodide (16 mmol, 1mL) was added. The
tightly closed and protected against light flask was stored in the
refrigerator for several days. The precipitate was filtered out and
dried. The analytical samples were crystallized from absolute
ethanol.
1H, H-4); 13C NMR (75 MHz, DMSO-d6)
d ppm: 14.60, 14.95 (C-19),
19.49, 19.79 (C-16), 20.90 (C-17), 26.99, 27.32 (C-15), 41.06, 50.31,
51.09 (C-20), 60.43, 60.80 (C-14), 61.63, 61.70 (C-12), 62.44 (C-13),
65.52 69.94 (C-18), 101.61, 101.64 (C-8), 112.83 (C-6), 112.89 (C-3),
112.94 (C-4a), 129.54 (C-5), 144.20 (C-4), 155.20 (C-8a), 160.12(C-2),
160.37 (C-7).

2262
J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
4.4.5. 7-[2-(1,2-Dimethylpiperidinyl)ethoxy]4-methylchromen-2-
one iodide (4bm)
the hydrogen atoms were calculated in idealized positions and
refined as a riding model with their thermal parameters calculated
as 1.2 (1.5 for methyl group) times Ueq of the respective carrier
carbon atom. The deposition number CCDC 816034 for 5d contains
the supplementary crystallographic data for this paper. These data
can be obtained free of charge via www.ccdc.cam.ac.uk/data_
request/cif, or by emailing data_request@ccdc.cam.ac.uk, or by
contacting The Cambridge Crystallographic Data Centre, 12, Union
Road, Cambridge CB2 1EZ, UK; fax: þ44 1223 336033.
Yield 65%; m.p.: 223.5e224.5 (dec.) ꢀC; IR (KBr) cmꢁ1: 3011
(
nCeHarom), 2943 (nCeHasym), 2856 (nCeHsym), 1707 (nC]O), 1617, 1508,
1447 (nC]C), 1462 (dCeHasym), 1392 (dCeHsym), 1291 (nCeOeCasym),
1074 (nCeOeCsym), 832 (gCeH); 1H NMR (300 MHz, DMSO-d6)
ppm:
d
1.33 (2d, J ¼ 6.5 Hz, 3H, H-19), 1.51e1.93 (m, 6H, H-15, 16, 17), 2.42
(bs, 3H, H-9), 3.02, 3.20 (2 s, 3H, H-20), 3.44e3.99 (m, 5H, H-13,
H-14, H-18), 4.50e4.67 (bm, 2H, H-12), 6.26 (bq, 1H, H-3), 7.02 (bd,
J ¼ 9.0 Hz, 1H, H-6), 7.10 (bs, 1H, H-8), 7.74 (d, J ¼ 9.0 Hz, 1H, H-5);
13C NMR (75 MHz, DMSO-d6)
d ppm: 14.60, 14.95 (C-19),18.13 (C-9),
19.50, 19.80 (C-17), 20.91, 20.96 (C-16), 27.00, 27.33 (C-15), 41.05,
50.33, 51.07 (C-20), 60.44, 60.82 (C-13), 61.61, 61.68 (C-12), 62.16 (C-
14) 65.54, 69.95 (C-18), 101.61, 101.65 (C-8), 111.52 (C-3), 112.52,
112.56 (C-6), 113.67, 113.71 (C-4a), 126.55 (C-5), 153.33 (C-4), 154.57
(C-8a), 159.97 (C-2), 160.28(C-7).
4.6. Antibacterial evaluation
The following microbial strains with various cell wall structures
were chosen: bacteria Gram-positive: S. aureus ATCC 6538, S.
aureus ATCC 6538P, M. luteus ATCC 9341, M. luteus ATCC 10240, B.
subtilis ATCC 6633, B. cereus ATCC 11778, bacteria Gram-negative:
Escherichia coli ATCC 8739, E. coli ATCC 10536, Pseudomonas aer-
uginosa ATCC 27853, P. aeruginosa ATCC 15442 and fungi (yeast
strains): Candida albicans ATCC 10231, Candida parapsilosis ATCC
22019. The cylinder-plate method was used in the preliminary
4.5. X-ray diffraction measurements0 details
Crystals of 8-acetyl-7-[2-(1-morpholino)ethoxy]4-methylchro-
men-2-one (5d) suitable for X-ray analysis were grown by slow
evaporation from diethyl ether solution. All details of the
measurements, crystal data and structure refinement are given in
Table 3. The data were collected on an Oxford Diffraction KM4CCD
diffractometer [20] at 293 K, using graphite-monochromated MoKa
radiation. The unit cell parameters were determined by least-
squares treatment of setting angles of highest-intensity reflections
chosen from the whole experiment. Intensity data were corrected
for the Lorentz and polarization effects [21]. The structure was
solved by direct methods by use the SHELXS97 program [22] and
refined by the full-matrix least-squares method with the SHELXL97
program [23]. The function Sw(jFoj2 ꢁ jFcj2)2 was minimized with
antimicrobial activity tests [24]. The 100 mL of compound was
placed into the cylinder in suspension of 10% DMSO in a 0.08 M
phosphate buffer with pH 7.0. The cylinders were put on a Mul-
lereHinton 2 or Sabouraud agar plate inoculated with one of the
tested strains. The plates with bacterial strains were incubated at
37 ꢀC for 24 h and plates with yeast strains at 30 ꢀC for 48 h.
Minimal inhibitory concentration (MIC) was obtained by mixed
with 19 mL of a MuellereHinton 2 Agar, cooled to 56 ꢀC with 1 mL
of appropriate dilution of the tested compound. Then 2 mL of
a particular cell suspension of optical density 0.5 unit on the
McFarland scale was applied to the surface of the agar. The lowest
concentration of tested compound which totally inhibited growth
of examined strain was evaluated as MIC value [25]. In control
samples, MIC values of ciprofloxacin ranging between 0.08 and
1.36 ꢂ 10ꢁ3 mmol/mL for bacterial strains.
wꢁ1 ¼ [
s
2(Fo)2 þ (0.0655P)2], where P ¼ (Fo2 þ 2Fc2)/3. All non-
hydrogen atoms were refined anisotropically. The coordinates of
Appendix. Supplementary data
Table 3
Crystal data, data collection and structure refinement for compound 5d.
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.ejmech.2011.03.006.
Compound
5d
Empirical formula
Formula weight
T (K)
C18H21NO5
331.36
293(2)
0.71073
Monoclinic, P21/c
ꢁ
Wavelength (A)
References
Crystal system, space group
Unit cell dimensions
[1] M. Gabor, The Pharmacology of Benzopyrone Derivatives and Related
Compounds. Akademiai Kiado, Budapest, 1988.
[2] L. Wu, X. Wang, W. Xu, F. Farzaneh, R. Xu, The structure and pharmacological
functions of coumarins and their derivatives, Curr. Med. Chem. 16 (2009)
4236e4260.
[3] I. Kostova, Synthetic and natural coumarins as cytotoxic agents, Curr. Med.
Chem., Anticancer Agents 5 (2005) 29e46.
[4] J.T. Goldberg, Aminoalkyl ethers of phenols as anticancer agents for the breast
and colon, in: C. Winnipeg (Ed.), The University of Manitoba, United States
Patent 4803227, 1989.
ꢁ
a (A)
7.6038(4)
21.734(1)
10.3668(5)
103.408(5)
1666.5(1)
4, 1.321
ꢁ
b (A)
ꢁ
c (A)
b
(ꢀ)
Volume (Å3)
Z, Dx (mg/m3)
m
(mmꢁ1
)
0.097
F(000)
q
704
range for data collection (ꢀ)
4.12e26.02
ꢁ9 ꢃ h ꢃ 9
ꢁ19 ꢃ k ꢃ 26
ꢁ12 ꢃ l ꢃ 9
[5] O. Kayser, H. Kolodziej, Antibacterial activity of simple coumarins: struc-
hkl range
tural requirements for biological activity, Z. Naturforsch.
C 54 (1999)
169e174.
[6] C. Montagner, S.M. de Souza, C. Groposoa, F. Delle Monache, E.F. Smania,
A. Smania Jr., Antifungal activity of coumarins, Z. Naturforsch. C 63 (2008)
21e28.
[7] E. Hejchman, D. Maciejewska, I. Wolska, Microwave-assisted synthesis of
derivatives of khellinone under phase-transfer catalytic conditions, Monatsh.
Chem. 139 (2008) 1337e1348.
[8] J. Trykowska, E. Hejchman, I. Wolska, D. Maciejewska, Solid state structure by
X-ray and 13C CP/MAS NMR of new 7-[2-(N,N-diisopropulamino)ethoxy]
coumarins, J. Mol. Struct. 930 (2009) 195e200.
[9] E. Hejchman, J. Trykowska Konc, D. Maciejewska, H. Kruszewska, Conven-
tional and microwave-assisted synthesis and solid-state structure of new
coumarins and angelicin, Synth. Commun, in press.
Reflections
Collected
5915
Unique (Rint
Observed (I > 2s(I))
)
3183(0.012)
2193
Data/restraints/parameters
Absorption correction
Goodness-of-fit on F2
3183/0/217
Multi-scan
1.07
R(F) (I > 2
s
(I))
0.0393
0.1140
0.274/ꢁ0.210
wR(F2) (all data)
3
ꢁ
Max/min. Dr (e/A )

J. Trykowska Konc et al. / European Journal of Medicinal Chemistry 46 (2011) 2252e2263
2263
[10] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor,
M. Towler, J. van de Streek, Mercury: visualization and analysis of crystal
structures, J. Appl. Crystallogr. 39 (2006) 453e457.
[18] E. Massarani, D. Nardi, P. Mantegazza, M. Riva, G. Cavallini, New orally active
derivatives of alpha-pyrone possessing anti-capillary fragility activity. III,
J. Med. Pharm. Chem. 3 (1961) 231e240.
[11] P. Toffoli, P. Khodadad, N. Rodier, R. Céolin, J. Astoin, Méthyl-4 (propyn-2 yloxy)-
7 chroménone-2 (giparmène), C13H10O3, Acta Crystallogr., Sect. C 41 (1985)
933e935.
[12] J.P. Jasinski, R.C. Wondenberg, 7-hydroxy-4-methylcoumarin monohydrate,
Acta Crystallogr., Sect. C 50 (1994) 1952e1953.
[13] B.-C. Yip, O.-L. Yaw, L.-H. Ong, H.-K. Fun, K. Sivakumar, Coumarin 311, Acta
Crystallogr., Sect. C 51 (1995) 2087e2089.
[14] I. Fujii, N. Hirayama, Crystal structure of 5,7-dihydroxy-3-methylcoumarin,
Anal. Sci. 17 (2001) 803e804.
[15] S.-P. Yang, L.-J. Han, D.-Q. Wang, T.-Z. Ding, 7-acetamido-4-methyl-2H-1-
benzopyran-2-one, Acta Crystallogr., Sect. E 62 (2006) 5196e5198.
[16] D.K. Chatterjee, K. Sen, Indian J. Appl. Chem. 32 (1969) 65.
[17] B.S. Joshi, N. Viswanathan, C.L. Kaul, R.S. Grewal, Evaluation of some naturally
occurring and synthetic coumarins for hypotensive activity, Indian J. Chem.,
Sect. B 19 (1980) 495e499.
[19] E. Massarani, Alpha-pyrone derivatives with action on capillary fragility. I,
Farmaco Sci. 12 (1957) 691e694.
[20] Oxford Diffraction Poland, CrysAlisCCD, CCD data collection GUI, version
1.171.33.36d, 2009.
[21] Oxford Diffraction Poland, CrysAlisRED, CCD data reduction GUI, version
1.171.33.34d, 2009.
[22] G.M. Sheldrick, Phase annealing in SHELX-90: direct methods for larger
structures, Acta Crystallogr., Sect. A 46 (1990) 467e473.
[23] G.M. Sheldrick, SHELXL97, Program for the Refinement of Crystal Structures.
University of Göttingen, Germany, 1997.
[24] European Pharmacopoeia, 20702 (2.7.2) Microbial assay of antibiotics,
2008.
[25] National Committee for Clinical Laboratory Standards, Approved Standard
M7-A6, Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria
That Grow Aerobically, sixth ed. NCCLS, Wayne, PA, 2003.