Synthesis, characterization and crystal structures of 2-cyano-N′-(2- chlorobenzylidene)acetohydrazide and 2-cyano-N′-(4- dimethylaminobenzylidene)acetohydrazide

Article abstract of DOI:10.1007/s10870-012-0372-z

Two new benzohydrazone derivatives, 2-cyano- N′-(2-chlorobenzylidene) acetohydrazide (1) and 2-cyano- N′-(4-dimethylaminobenzylidene) acetohydrazide (2), were prepared and characterized by elemental analysis, 1H and 13C NMR, and single crystal X-ray diffr

Full text of DOI:10.1007/s10870-012-0372-z

J Chem Crystallogr (2012) 42:1138–1141
DOI 10.1007/s10870-012-0372-z
ORIGINAL PAPER
Synthesis, Characterization and Crystal Structures of 2-Cyano-
N0-(2-chlorobenzylidene)acetohydrazide and 2-Cyano-
N0-(4-dimethylaminobenzylidene)acetohydrazide
•
Xin Zhou Jing-Jun Ma
Received: 8 April 2012 / Accepted: 20 September 2012 / Published online: 26 September 2012
Ó Springer Science+Business Media New York 2012
Abstract Two new benzohydrazone derivatives, 2-cyano-
N0-(2-chlorobenzylidene)acetohydrazide (1) and 2-cyano-
N0-(4-dimethylaminobenzylidene)acetohydrazide (2), were
for analytical applications [7, 8]. The compounds are
readily prepared by the condensation reaction between
hydrazides and carbonyl-containing compounds. In the past
decade, a number of benzohydrazone derivatives were
prepared and investigated for their structure–activity rela-
tionships [9–11]. The detailed study on the crystal structures
seems to be essential for the understanding of the biological
and medicinal activities and analytical applications of the
compounds. However, to the best of our knowledge, the
hydrazone compounds derived from cyanoacetohydrazide
have seldom been reported. In this study, the author reports
the synthesis, characterization, and crystal structures of two
new hydrazone compounds derived from the reaction of
cyanoacetohydrazide with 2-chlorobenzaldehyde and
4-dimethylaminobenzaldehyde, respectively.
1
prepared and characterized by elemental analysis, H and
13C NMR, and single crystal X-ray diffraction. Compound 1
crystallizes in the monoclinic space group P21/c with unit
˚
cell dimensions a = 9.925(1) A, b = 7.045(1) A, c =
˚
3
˚
˚
15.117(2) A, b = 91.479(2)°, V = 1056.7(2) A , Z = 4,
R1 = 0.0447, and wR2 = 0.0930. Compound 2 crystallizes
in the monoclinic space group P21/c with unit cell dimen-
˚
˚
˚
sions a = 13.714(2) A, b = 8.938(1) A, c = 10.883(1) A,
3
˚
b = 112.628(2)°, V = 1231.3(3) A , Z = 4, R1 = 0.0578,
and wR2 = 0.1122. X-ray diffraction indicated that the
molecules of the compounds display trans configurations
with respect to the C=N double bonds. The crystal struc-
tures of the compounds are stabilized by N–HꢀꢀꢀO hydrogen
bonds and weak pꢀꢀꢀp interactions.
Experimental
Keywords Benzohydrazone ꢀ Synthesis ꢀ Crystal
structure ꢀ X-ray diffraction ꢀ Hydrogen bonding
Materials and Measurements
2-Chlorobenzaldehyde, 4-dimethylaminobenzohydrazide,
and cyanoacetohydrazide were purchased from Aldrich.
The methanol solvent was commercially available and used
without further purification. Elemental analyses (C, H and
N) were performed on a Perkin-Elmer 2400 CHN Ele-
Introduction
Benzohydrazone derivatives containing the functional
groups –CH=N–NH–C(O)– are a kind of important Schiff
base compounds which have been intensively investigated
in recent years for their coordination ability [1–3], biolog-
ical and medical activities [4–6], and promising properties
1
mental Analyzer. H and 13C NMR spectra were obtained
from solution in DMSO-d6 with Me4Si as internal standard
using a Bruker AVANCE 500 MHz analyzer.
Synthesis of 2-Cyano-N0-(2-chlorobenzylidene)
acetohydrazide (1)
X. Zhou ꢀ J.-J. Ma (&)
Hebei Key Laboratory of Bioinorganic Chemistry, College of
Sciences, Agricultural University of Hebei, Baoding 071001,
People’s Republic of China
2-Chlorobenzaldehyde (1.0 mmol, 0.14 g) and cya-
noacetohydrazide (1.0 mmol, 0.10 g) were dissolved in
e-mail: majingjun71@yahoo.cn
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J Chem Crystallogr (2012) 42:1138–1141
1139
methanol (20 mL). The mixture was stirred at room tem-
perature for 30 min to give a colorless solution. After
keeping the solution in air for a few days, colorless block-
shaped single crystals, suitable for X-ray diffraction, were
formed. The crystals were isolated by filtration, washed
with methanol and dried in air. Yield 0.17 g (77 %). Anal.
Calcd for C10H8ClN3O: C 54.2, H 3.6, N 19.0 %; found: C
methanol (20 mL). The mixture was stirred at room tem-
perature for 30 min to give a colorless solution. After
keeping the solution in air for a few days, colorless block-
shaped single crystals, suitable for X-ray diffraction, were
formed. The crystals were isolated by filtration, washed
with methanol and dried in air. Yield 0.19 g (83 %). Anal.
Calcd for C12H14N4O: C 62.6, H 6.1, N 24.3 %; found: C
1
1
54.0, H 3.7, N 18.9 %. H NMR (ppm): d: 3.29 (s, 2H),
62.5, H 6.1, N 24.4 %. H NMR (ppm): d: 3.05 (s, 6H),
7.40–7.55 (m, 3H), 7.76 (d, 1H), 9.00 (s, 1H), 11.54 (s,
1H). 13C NMR (ppm): d: 27.2, 125.3, 126.8, 127.5, 130.0,
132.2, 133.7, 134.9, 138.3, 170.6.
3.29 (s, 2H), 6.78 (d, 2H), 7.51 (d, 2H), 8.53 (s, 1H), 11.27
(s, 1H). 13C NMR (ppm): d: 27.2, 41.5, 111.6, 123.2, 125.5,
128.0, 144.0, 153.1, 170.8.
Synthesis of 2-Cyano-N0-(4-
dimethylaminobenzylidene)acetohydrazide (2)
X-Ray Crystallography
Suitable single crystals were carefully selected under a
microscope. Crystal data for the two compounds were col-
lected on a Bruker SMART APEX II-CCD diffractometer
4-Dimethylaminobenzaldehyde (1.0 mmol, 0.15 g) and
cyanoacetohydrazide (1.0 mmol, 0.10 g) were dissolved in
Table 1 Crystallographic data
Compounds
1
2
for 1 and 2
CCDC deposit no.
Color/shape
873422
873423
Colorless/block
Colorless/block
C12H14N4O
230.27
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
C10H8ClN3O
221.64
298(2)
298(2)
Monoclinic
P21/c
Monoclinic
P21/c
Unit cell dimensions
´
˚
a (A)
9.925(1)
7.045(1)
15.117(2)
91.479(2)
1056.7(2)
4
13.714(2)
8.938(1)
10.883(1)
112.628(2)
1231.3(3)
4
´
˚
b (A)
´
˚
c (A)
b (°)
Volume (A )
´
3
˚
Z
Density (calculated)
(g/cm3)
1.393
1.242
Absorption coefficient (mm-1
)
0.337
0.084
F(000)
456
488
T
min, Tmax
0.925, 0.935
0.23 9 0.20 9 0.20
2.70–26.49
0.983, 0.986
0.20 9 0.20 9 0.17
2.79–25.49
Crystal size (mm3)
Theta range for data
collection (°)
Limiting indices
-12 B h B 12, -8 B k B 8,
-18 B l B 18
-16 B h B 16, -8 B k B 10,
-11 B l B 13
Reflections collected
2182
2167
Independent reflections
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I C 2r(I)]
R indices (all data)
1362 [Rint = 0.0374]
2182/1/139
1104 [Rint = 0.0518]
2167/1/159
1.020
0.931
R1 = 0.0447, wR2 = 0.0930
R1 = 0.0820, wR2 = 0.1075
0.144, -0.217
R1 = 0.0578, wR2 = 0.1122
R1 = 0.1212, wR2 = 0.1355
0.148, -0.187
Largest diff. peak and hole
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1140
J Chem Crystallogr (2012) 42:1138–1141
at 298(2) K using graphite monochromated MoKa radia-
tion (k = 0.71073 A). Cell parameters were obtained by
Results and Discussion
˚
the global refinement of the positions of all collected
reflections. An empirical absorption correction was
applied. The structures were solved by direct method and
refined by full-matrix least-squares on F2 using the
SHELXL-97 software [12]. All the non-hydrogen atoms
were refined anisotropically. The amino H atoms in the
compounds were located from difference Fourier maps and
refined isotropically, with N–H distances restrained to
The two compounds were readily prepared by the reaction
of equimolar quantities of cyanoacetohydrazide with
2-chlorobenzaldehyde and 4-dimethylaminobenzaldehyde,
respectively, in methanol. They elemental analyses are in
agreement with the empirical formulae given by the single
crystal X-ray determination. The colorless single crystals
of the compounds are soluble in methanol, ethanol, ace-
tonitrile, and chloroform.
˚
0.90(1) A. The remaining H atoms were added theoreti-
cally. Crystals of 2 were very weakly diffracting and this is
reflected in the low completeness (0.948). Some relevant
crystallographic data and structure determination parame-
ters are summarized in Table 1. Selected bond lengths and
angles for the compounds are given in Table 2. Hydrogen
bonding interactions are listed in Table 3.
Crystal Structure Description
Figures 1 and 2 give perspective views of the compounds 1
and 2, respectively, with the atomic labeling systems. All
the bond lengths in the compounds are within normal
ranges [13], and are comparable to those of the similar
benzohydrazone compounds [14–18]. The C7–N1 bond
˚
length of 1.267(2) A in 1 and the C9–N2 bond length of
˚
1.283(3) A in 2 confirm them as double bonds. The C8–N2
´
˚
Table 2 Selected bond lengths (A) and angles (°) for 1 and 2
˚
bond (1.335(2) A) and the N1–N2 bond (1.372(2) A) in 1
˚
˚
and the C10–N3 bond (1.332(3) A) and the N2–N3 bond
1
˚
(1.395(3) A) in 2 are relatively short, suggesting some
Bond distances
degree of delocalization in each of the acetohydrazide
systems. It is notable that the C7–N1 and N1–N2 bonds in
1 are shorter than the corresponding bonds in 2, which is
caused by the electron withdrawing effect of the Cl atom in
C7–N1
1.267(2)
1.335(2)
N1–N2
C8–O1
1.372(2)
1.220(2)
N2–C8
Bond angles
C7–N1–N2
N2–C8–O1
C9–C10–N3
115.5(2)
121.8(2)
178.5(3)
N1–N2–C8
N2–C8–C9
119.9(2)
115.7(2)
2
Bond distances
C9–N2
1.283(3)
1.332(3)
N2–N3
1.395(3)
1.226(3)
N3–C10
C10–O1
Bond angles
C9–N2–N3
N3–C10–O1
C11–C12–N4
114.4(2)
125.1(3)
178.6(3)
N2–N3–C10
N3–C10–C11
120.5(2)
113.5(2)
Fig. 1 Molecular structure of 1 showing 30 % probability displace-
ment ellipsoids
˚
Table 3 Hydrogen-bond geometry (A, °) of 1 and 2
˚
D–HꢀꢀꢀA
d(D–H)
˚
(A)
d(HꢀꢀꢀA)
d(DꢀꢀꢀA) (A)
Angle(D–
HꢀꢀꢀA) (°)
˚
(A)
1
N2–
0.90(1)
0.90(1)
1.97(1)
1.93(1)
2.879(2)
2.833(3)
176(2)
174(2)
H2ꢀꢀꢀO1i
2
N3–
H3ꢀꢀꢀO1ii
Fig. 2 Molecular structure of 2 showing 30 % probability displace-
ment ellipsoids
Symmetry codes: (i) -x, 1 - y, -z; (ii) 1 - x, -1/2 ? y, 1/2 - z
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J Chem Crystallogr (2012) 42:1138–1141
1141
In the crystal structure of 1, adjacent two molecules are
linked through two N–HꢀꢀꢀO hydrogen bonds, forming a
dimer (Fig. 3). In the crystal structure of 2, molecules are
linked through N–HꢀꢀꢀO hydrogen bonds, forming 1D
chains running along the b axis (Fig. 4). Moreover, there
are also pꢀꢀꢀp interactions [19] with centroid to centroid
˚
distance of 3.827(2) A in 1.
Supplementary Material
Crystallographic data for the structures reported in this
study have been deposited with the Cambridge Crystallo-
graphic Data Centre as supplementary publication no.
873422 (1) and 873423 (2). Copies of available material can
be obtained, free of charge, on application to the Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK, (fax:
?44-(0) 1223-336033 or e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgments Project supported by the Agricultural Univer-
sity of Hebei.
Fig. 3 Molecular packing of 1, viewed along the b axis. Intermolec-
ular hydrogen bonds are shown as dashed lines
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Fig. 4 Molecular packing of 2. Intermolecular hydrogen bonds are
shown as dashed lines
1, and the electron donating effect of the dimethylamino
group in 2. In 1, the dihedral angle between the C1–C6
benzene ring and the plane defined by O1–C8–C9–C10–N3
is 7.1(2)°. In 2, the dihedral angle between the C3–C8
benzene ring and the plane ring defined by O1–C10–C11–
C12–N4 is 26.4(3)°.
123