Synthesis and crystal structures of N'-(5-bromo-2-hydroxy-3- methoxybenzylidene)-4-methoxybenzohydrazide and 4-{[1-(5-bromo-2-hydroxy3- methoxyphenyl)methylidene]amino}-1-methyl-2-phenyl-1,2-dihydropyrazol-3-one

Article abstract of DOI:10.1007/s10870-010-9839-y

Two Schiff bases, N'-(5-bromo-2-hydroxy-3-methoxybenzylidene)-4- methoxybenzohydrazide (1) and 4-{[1-(5-bromo-2-hydroxy3-methoxyphenyl) methylidene]-amino}-1-methyl-2-phenyl-1,2-dihydropyrazol-3-one (2), have been synthesized by the reaction of 5-bromo-3-methoxysalicylaldehyde with 4-methoxybenzohydrazide and 4-aminoantipyrine, respectively. The compounds were characterized by elemental analysis and X-ray single crystal determination. Compound (1) crystallizes in the monoclinic space group P2_1/c with unit cell dimensions a = 14.919(1), b = 8.249(2), c = 41.515(4) A, β = 111.054(2)°, V = 4768.1(13) A³, Z = 12, R₁ = 0.0765, and wR₂ = 0.1733. Compound (2) crystallizes in the monoclinic space group P2_1/c with unit cell dimensions a = 7.826(1), b = 13.791(1), c = 17.090(2) A, β = 100.137(2)°, V = 1815.7(3) A³, Z = 4, R₁ = 0.0334, and wR₂ = 0.0736. Both molecules of the compounds display E configuration with respect to the C=N double bonds. In the crystal structure of (1), molecules are linked via intermolecular N-H...O hydrogen bonds, forming chain structure along the a axis. In the crystal structure of (2), molecules are linked via weak Br...O interactions, forming chain structure along the c axis. Springer Science+Business Media, LLC 2010.

Full text of DOI:10.1007/s10870-010-9839-y

J Chem Crystallogr (2011) 41:69–72
DOI 10.1007/s10870-010-9839-y
ORIGINAL PAPER
Synthesis and Crystal Structures of N0-(5-Bromo-2-hydroxy-3-
methoxybenzylidene)-4-methoxybenzohydrazide and 4-{[1-
(5-bromo-2-hydroxy3-methoxyphenyl)methylidene]amino}-
1-methyl-2-phenyl-1,2-dihydropyrazol-3-one
•
Mei-An Zhu Xiao-Yang Qiu
Received: 17 April 2010 / Accepted: 21 June 2010 / Published online: 1 July 2010
Ó Springer Science+Business Media, LLC 2010
Abstract Two Schiff bases, N0-(5-bromo-2-hydroxy-3-
methoxybenzylidene)-4-methoxybenzohydrazide (1) and
4-{[1-(5-bromo-2-hydroxy3-methoxyphenyl)methylidene]-
amino}-1-methyl-2-phenyl-1,2-dihydropyrazol-3-one (2),
have been synthesized by the reaction of 5-bromo-3-
methoxysalicylaldehyde with 4-methoxybenzohydrazide
and 4-aminoantipyrine, respectively. The compounds were
characterized by elemental analysis and X-ray single
crystal determination. Compound (1) crystallizes in the
monoclinic space group P21/c with unit cell dimensions
Keywords Schiff base ꢀ Synthesis ꢀ Crystal structure ꢀ
Hydrogen bonds ꢀ Crystallography
Introduction
Schiff bases are readily synthesized by the condensation
reaction of aldehydes with primary amines. The compounds
have been widely investigated for their potential biological
activities [1–3] and versatile coordination modes [4–6]. The
Schiff bases derived from the salicylaldehyde have attracted
much attention in recent years [7–10], however, those
derived from the 5-bromo-3-methoxysalicylaldehyde have
seldom been reported. In the present work, two new Schiff
bases N0-(5-bromo-2-hydroxy-3-methoxybenzylidene)-4-meth
oxybenzohydrazide (1) and 4-{[1-(5-bromo-2-hydroxy3-
methoxyphenyl)methylidene]amino}-1-methyl-2-phenyl-1,
2-dihydropyrazol-3-one (2), have been synthesized and
characterized.
˚
a = 14.919(1), b = 8.249(2), c = 41.515(4) A, b =
3
˚
111.054(2)°, V = 4768.1(13) A , Z = 12, R1 = 0.0765,
and wR2 = 0.1733. Compound (2) crystallizes in the
monoclinic space group P21/c with unit cell dimensions
˚
a = 7.826(1), b = 13.791(1), c = 17.090(2) A, b =
3
˚
100.137(2)°, V = 1815.7(3) A , Z = 4, R1 = 0.0334, and
wR2 = 0.0736. Both molecules of the compounds display
E configuration with respect to the C=N double bonds. In
the crystal structure of (1), molecules are linked via inter-
molecular N–HꢀꢀꢀO hydrogen bonds, forming chain struc-
ture along the a axis. In the crystal structure of (2),
molecules are linked via weak BrꢀꢀꢀO interactions, forming
chain structure along the c axis.
Br
Br
O
O
H
N
N
N
N
N
OH
O
O
O
OH
(1)
(2)
M.-A. Zhu
Department of Chemistry and Chemical Engineering, Fuyang
Normal University, Fuyang 236000, People’s Republic of China
Experimental
Materials and Methods
X.-Y. Qiu (&)
Department of Chemistry, Shangqiu Normal University,
Shangqiu 476000, People’s Republic of China
e-mail: xiaoyang_qiu@126.com
All chemicals were available commercially as AR grade
and were used without further purification. C, H and N
elemental analyses were performed on a Vario-EL-III
analyser.
X.-Y. Qiu
State Key Laboratory of Pharmaceutical Biotechnology, Nanjing
University, Nanjing 210093, People’s Republic of China
123

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J Chem Crystallogr (2011) 41:69–72
Synthesis of (1)
Table 1 Crystal and refinement data
Compound
(1)
(2)
5-Bromo-3-methoxysalicylaldehyde (1.0 mmol, 231.0 mg)
and 4-methoxybenzohydrazide (1.0 mmol, 166.2 mg) were
mixed in 50 mL methanol solution and then stirred and
refluxed for 30 min. The solvent was removed by distilla-
tion to give colorless product. The product was washed
with methanol and dried in air. Yield: 95%. Anal. Calcd.
(%) for C16H15BrN2O4: C, 50.7; H, 4.0; N, 7.4. Found (%):
C, 50.3; H, 4.1; N, 7.6. Single crystals suitable for X-ray
determination were formed by recrystallization of the
product in ethanol.
Molecular formula
Molecular weight
Temperature (K)
C16H15BrN2O4
379.2
C19H18BrN3O3
416.3
298(2)
298(2)
0.71073
´
˚
Radiation (MoKa), k (A) 0.71073
Crystal shape/color
Crystal size (mm3)
Crystal system
Block/colorless
Block/yellow
0.20 9 0.18 9 0.18 0.30 9 0.27 9 0.26
Monoclinic
P21/c
Monoclinic
P21/c
Space group
˚
a (A)
14.919(1)
8.249(2)
41.515(4)
111.054(2)
4768.1(13)
12
7.826(1)
13.791(1)
17.090(2)
100.137(2)
1815.7(3)
4
˚
b (A)
˚
c (A)
Synthesis of (2)
b (°)
3
˚
V (A )
5-Bromo-3-methoxysalicylaldehyde (1.0 mmol, 231.0 mg)
and 4-aminoantipyrine (1.0 mmol, 203.0 mg) were mixed
in 50 mL methanol solution and then stirred and refluxed
for 30 min. The solvent was removed by distillation to give
yellow product. The product was washed with methanol
and dried in air. Yield: 93%. Anal. Calcd. (%) for
C19H18BrN3O3: C, 54.8; H, 4.4; N, 10.1. Found (%): C,
54.3; H, 4.4; N, 10.3. Single crystals suitable for X-ray
determination were formed by recrystallization of the
product in methanol.
Z
Dc (g/cm3)
1.585
1.523
l (mm-1
)
2.608
2.288
F(000)
2304
848
h range (°)
Index ranges (h, k, l)
1.46/26.12
1.91/27.00
-18/17, -10/10,
-42/50
-9/9, -13/17,
-21/20
Measured reflections
25482
0.0902
4000
10969
0.0297
2748
Rint
Observed reflections
I [ 2r(I)
Min. and max.
transmission
0.624/0.651
9130/3/637
0.547/0.588
3944/0/239
X-Ray Crystallography
Data/restraints/
parameters
The suitable single crystals of the compounds were
mounted on glass fibers for data collection performed on a
Bruker SMART 1000 CCD area diffractometer equipped
with a graphite-monochromatic Mo Ka radiation (k =
Goodness-of-fit on F2
R1, wR2 [I [ 2r(I)]a
R1, wR2 (all data)a
Large diff. peak
1.031
1.006
0.0765, 0.1733
0.1820, 0.2115
0.0334, 0.0736
0.0605, 0.0829
˚
0.490 and -0.476 0.325 and -0.379
0.71073 A) at 298 K. The unit cell dimensions were
3
˚
and hole (e/A )
obtained with the least-squares refinements and the struc-
ture was solved by direct methods using SHELXTL-97
program [11]. The final refinement was performed by full-
matrix least-squares methods with anisotropic thermal
parameters for the non-hydrogen atoms on F2. H2, H4A,
and H6A in (1) were located from a difference Fourier map
and refined isotropically, with N–H distances restrained to
P
Results and Discussion
P
P
P
R1 = ||Fo| - |Fc||/ |Fo|, wR2 = [ w(F2o - F2c)2/ w(Fo2)2]1/2
a
The colorless single crystals of (1) and yellow single
crystals of (2) are stable in air at room temperature, soluble
in most polar organic solvents, such as MeOH, EtOH and
MeCN, but insoluble in water and non-polar organic sol-
vents such as Et2O.
˚
0.90(1) A. Other hydrogen atoms in both compounds were
placed in calculated positions and constrained to ride on
their parent atoms. Multi-scan absorption correction was
applied by using the SADABS program [12]. The crystal-
lographic data and experimental details for structural
analysis of the compounds are summarized in Table 1.
Selected bond lengths and angles are given in Table 2.
Hydrogen bonds are listed in Table 3.
Structure Description of (1)
The compound consists of three independent molecules
linked by N–HꢀꢀꢀO hydrogen bonds, as shown in Fig. 1.
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J Chem Crystallogr (2011) 41:69–72
71
˚
Table 2 Selected bond lengths (A) and angles (°) for the compounds
(1)
˚
Distances (A)
N1–C7
N2–C8
1.266(9)
1.371(10)
1.278(9)
1.377(10)
1.286(10)
1.354(10)
N1–N2
O3–C8
N3–N4
O7–C24
N5–N6
O11–C40
1.352(8)
1.222(9)
1.370(8)
1.231(9)
1.333(8)
1.234(9)
N3–C23
N4–C24
N5–C39
N6–C40
Angles (°)
C7–N1–N2
121.3(7)
115.9(7)
116.1(7)
114.5(7)
118.9(7)
120.7(8)
N1–N2–C8
O3–C8–N2
N3–N4–C24
O7–C24–N4
N5–N6–C40
N6–C40–C41
118.5(6)
119.9(7)
117.7(6)
121.1(7)
117.7(7)
117.9(7)
N2–C8–C9
C23–N3–N4
N4–C24–C25
C39–N5–N6
O11–C40–N6
(2)
Fig. 1 View of the molecular structure of (1) with 30% thermal
ellipsoids. Intramolecular O–HꢀꢀꢀN hydrogen bonds are drawn as
dashed lines
˚
Distances (A)
N1–C7
1.281(3)
1.223(3)
N1–C8
1.391(3)
O3–C9
Angle (°)
C7–N1–C8
121.9(2)
Table 3 Geometrical parameters for hydrogen bonds
D–HꢀꢀꢀA
d
d
d
Angle
˚
˚
˚
(D–H, A) (HꢀꢀꢀA, A) (DꢀꢀꢀA, A) (D–HꢀꢀꢀA, °)
(1)
O5–H5ꢀꢀꢀN3
O9–H9ꢀꢀꢀN5
N2–H2ꢀꢀꢀO7
0.82
0.82
1.84
1.87
2.552(8)
2.571(8)
2.942(8)
2.960(8)
2.850(8)
2.587(8)
145
142
0.898(10) 2.13(5)
150(8)
168(9)
163(9)
149
N6–H6AꢀꢀꢀO3#1 0.899(10) 2.08(2)
N4–H4AꢀꢀꢀO11 0.903(10) 1.97(3)
O1–H1ꢀꢀꢀN1
(2)
O1–H1ꢀꢀꢀN1
0.85
1.82
0.82
1.87
2.594(2)
147
Symmetry code for #1: 1 ? x, y, z
Each molecule adopts an E configuration about the C=N
bond. The main difference amongthe molecules is the degree
of the distortion. The dihedral angles between the two ben-
zene rings in A, B, and C are 8.7(7)°, 66.2(7)°, and 21.8(7)°,
respectively. In each molecule, there is an intramolecular
O–HꢀꢀꢀN hydrogen bond, forming an six-membered ring.
The torsion angles N1–N2–C8–C9, N3–N4–C24–C25, and
N5–N6–C40–C41 are 3.5(7)°, 7.4(7)°, and 2.5(7)°, respec-
tively. The bond distances and angles in the compound
are typical, and are comparable to the similar compounds
[13, 14]. The bond distances of N2–C8, N4–C24, and
N6–C40 are intermediate between those of the C–N single
bonds and the C=N double bonds, because of the conjugation
effects in the molecules.
Fig. 2 The one-dimensional chain structure of (1). Hydrogen bonds
are drawn as dashed lines
In the crystal structure, molecules are linked via inter-
molecular N–HꢀꢀꢀO hydrogen bonds, forming chain struc-
ture along the a axis, as shown in Fig. 2.
Structure Description of (2)
The molecule of the compound adopts an E configuration
about the C7=N1 bond, as shown in Fig. 3. The least
squares plane of C8–C9–N2–N3–C10 forms dihedral
123

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J Chem Crystallogr (2011) 41:69–72
Supplementary Information
CCDC-767876 for (1) and 767877 for (2) contain the
supplementary crystallographic data for this paper. These
data can be obtained free of charge at http://www.ccdc.
cam.ac.uk/const/retrieving.html or from the Cambridge
Crystallographic Data Centre (CCDC), 12 Union Road,
Cambridge CB2 1EZ, UK; fax: ?44-1223-336033 or
e-mail: data_request@ccdc.cam.ac.uk.
Fig. 3 View of the molecular structure of (2) with 30% thermal
ellipsoids. Intramolecular O–HꢀꢀꢀN hydrogen bond is drawn as a
dashed line
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Fig. 4 The one-dimensional chain structure of (2). Hydrogen bonds
and weak BrꢀꢀꢀO interactions are drawn as dashed lines
angles of 5.1(2)° and 56.8(2)°, respectively, with the
C1–C6 and C13–C18 benzene rings. The dihedral angles
between the two benzene rings is 61.7(2)°. There is an
intramolecular O1–H1ꢀꢀꢀN1 hydrogen bond, forming an
six-membered ring. The torsion angles C1–C7–N1–C8,
C7–N1–C8–C9, and C9–N2–C13–C14 are 2.0(2)°, 2.0(2)°,
and 73.0(2)°, respectively. The bond distances and angles
in the compound are typical, comparable to those in (1) and
other similar compounds [15, 16].
´
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375–389
In the crystal structure, molecules are linked via weak
˚
BrꢀꢀꢀO interactions [3.296(3) A], forming chain structure
along the c axis, as shown in Fig. 4.
123