Synthesis and properties of substituted benzaldehyde phenylhydrazones

Article abstract of DOI:10.1134/S1070363209050144

Phenylhydrazones containing hydroxy, alkoxy and acyloxy groups are synthesized from aromatic aldehydes of vanillin series by reaction with phenylhydrazine.

Full text of DOI:10.1134/S1070363209050144

ISSN 1070-3632, Russian Journal of General Chemistry, 2009, Vol. 79, No. 5, pp. 953–956. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © E.A. Dikusar, V.I. Potkin, 2009, published in Zhurnal Obshchei Khimii, 2009, Vol. 79, No. 5, pp. 781–784.
Synthesis and Properties
of Substituted Benzaldehyde Phenylhydrazones
E. A. Dikusar and V. I. Potkin
Institute of Physical Organic Chemistry, National Academy of Sciences of Belarus,
ul. Surganova 13, Minsk, 220072 Belarus
e-mail: evgen_58@mail.ru
Received November 24, 2008
Abstract―Phenylhydrazones containing hydroxy, alkoxy and acyloxy groups are synthesized from aromatic
aldehydes of vanillin series by reaction with phenylhydrazine.
DOI: 10.1134/S1070363209050144
We reported earlier on the syntheses of thiosemi-
carbazides and Е-3-alkoxy-4-hydroxy(alkoxy, acyl-
oxy)phenylmethylenephenylamines (azomethines) by
reaction of substituted aromatic aldehydes of vanillin
series with hydrazinothiocarboxylic acid amide (thio-
semicarbazone) or aniline [1, 2]. These compounds
turned out to be promising objects for preparation of
nanofilms and nanomaterials [3].
phenylhydrazones IIIa–IIIt, IVa–IVk can be stored
for a long period when sealed in glass ampoules under
argon atmosphere, in the dark at the temperature below
–5°С . Structures of phenylhydrazones IIIa–IIIt, IVa–
IVk were proved by elemental analysis, cryoscopic
determination of molecular weight (Table 1), data of
IR and 1Н NMR spectroscopy.
In the IR spectra of phenylhydrazones IIIa–IIIt,
IVa–IVk) absorption bands were observed of groups
NН in the region of 3313±2; С–Har at 3100–3000,
880–610; С–Нalk at 2980–2840; C=N at 1600±2; С–Сar
at 1600–1390; C–O at 1270–1025 cm–1. The presence
of OH group in phenols IIIb and IVa is confirmed by
the absorption band at 3495±5 cm–1 in their IR spectra.
The IR spectra of esters IIId–IIIt, IVc–IVk contain
bands of С=О group in the region of 1770–1740 cm–1.
The presence of nitro group in the nitro derivative IIIq
is confirmed by characteristic absorption bands at 1539
and 1352 cm–1.
The aim of this work was the synthesis and study
of properties of phenylhydrazones of substituted aro-
matic aldehydes from the vanillin series, containing
hydroxy, alkoxy and acyloxy groups. By a reaction of
substituted aromatic aldehydes (I) with phenylhyd-
razine (II) in anhydrous diethyl ether we prepared in
80–90% yield the corresponding phenylhydrazones
(IIIa–IIIt, IVa–IVm), possessing hydroxy, alkoxy
and acyloxy groups. The reaction was completed in 8–
30 h, proceeded under mild conditions (ratio of rea-
gents 1:1, temperature –5°С, protection against light)
without catalysts. According to the data of 1Н NMR spec-
troscopy the purity of obtained compounds was 92±2 %.
1
In the Н NMR spectra of phenylhydrazones IIIa–
IIIt, IVa–IVk the signals of protons С–Har (С6Н5 and
С6Н3) and of the NH group proton appear as a
multiplet in the region of 6.75–7.40 ppm. The proton
of HC=N group is observed as a singlet at 7.50–
7.75 ppm. The presence of OH group in phenols IIIb,
IVa is confirmed by a broad singlet in the region of
5.80–5.85 ppm. Groups MeO of phenylhydrazones
IIIa–IIIt, IVb, IVi give in 1Н NMR spectra singlets in
the range 3.85–4.00 ppm, in the spectra of compounds
IIIs, IVa–IVk the EtO group gives rise to a triplet in
the range 1.20–1.70 ppm (Ме) and a quadruplet at
4.00–4.50 ppm (CH2). In the spectra of acetates (IIId,
Freshly synthesized phenylhydrazones IIIa–IIIt,
IVa–IVk are colorless or slightly colored crystalline
substances with distinct melting points (Table 1). Un-
like semicarbazides [1] and azomethines [2] the
substituted aromatic aldehyde phenylhydrazones IIIa–
IIIt, IVa–IVk are unstable compounds rapidly
darkening when exposed to light and at the contact
with air oxygen. The phenylhydrazones IIIa–IIIt,
IVa–IVk transform readily via free radical isome-
rization into thermodynamically more stable azo
compounds V [4]. The substituted aromatic aldehyde
953

954
DIKUSAR, POTKIN
H
N
N
H
N
H
N
C
CHO
C
H
ν
h
H2NNH
+
R
R
R
R1
I
R1
R1
II
IIIa_IIIs, IVa_IVj
V
H
N
N
H
C
R
OCCH2
O
2
IIIt, IVk
III, R = H, R1 = MeO (a); R = MeO, R1 = HO (b), MeO (c), MeC(O)O (d), EtС(O)О (e), PrС(O)О (f), Me2CHС(O)О (g),
Me(CH2)6С(O)О (h), Me(CH2)8С(O)О (i), Me(CH2)16С(O)О (j), H2C=C(Me)С(O)О (k), С6Н5СН2С(O)О (l), С6Н5СН(Ме)СН2С(O)О
(m), С6Н5С(O)О (n), 2,4-Cl2C6H3С(O)О (o), 4-BrC6H4С(О)О (p), 3-O2NC6H4С(О)О (q), MeOС(О)О (r), EtOС(О)О (s); R = MeO (t);
IV, R1 = EtO, R1 = HO (a), MeO (b), MeC(O)O (c), EtС(O)О (d), PrС(O)О (e), Me2CHС(O)О (f), Me2CHCH2С(О)О (g), 4-
MeC6H4С(О)О (h), MeOС(О)O (i), EtOС(О)O (j); R = EtO (k).
IVc) the protons of МеС(О)О group give singlets at
of formation (Hf, kcal mol–1) of E–Z configuration
isomers of phenylhydrazones IIIa–IIId, IVa and IVd
and related isomeric trans and cis azo compounds V
(Table 2).
2.35 ppm.
1
The IR and Н NMR spectra of phenylhydrazones
IIIa–IIIt, IVa–IVk contain absorption bands and
proton signals confirming the presence of respective
structural fragments of ester groups.
The quantum-chemical calculations were per-
formed in the framework of semiempirical approxi-
mation MNDO PM3 [6, 7] using GAMESS program
[8]. We completely optimized all bond lengths, bond
angles and dihedral angles. From the calculations
follows that Е-configuration of phenylhydrazones
IIIa–IIId, IVa and IVd is by 0.1–0.7 kcal mol–1 more
stable thermodynamically that Z-configuration (ΔHE/Z),
and trans-configuration of azo compounds V is by
2.3–6.0 kcal mol–1 more advantageous than the cis-
configuration (ΔHtrans/cis). From the consideration of
the data for the most stable configurations of the
studied compounds Е-(IIIa–IIId, IVa, IVd) and trans-
V follows that at the isomerization of phenylhyd-
razones IIIa–IIIt and IVa–IVk into azo compounds V
the energy gain is 2.3–5.3 kcal mol–1 (ΔHЕ/trans) (Table 2).
In the IR spectra of the samples of phenyl-
hydrazones IIIa–IIId, IVa, IVd that have darkened or
strongly colored to red-brown due to the action of light
and air oxygen occurred a decrease in the intensity of
the absorption bands of groups NH and C=N. In the 1Н
NMR spectra of these samples a decrease was
registered in the intensity of the signal of HC=N
proton and a gradual increase in the intensity of the
singlet at 4.40 ppm corresponding to СН2 group of the
formed azo compounds V, that confirmed the proposed
scheme of isomerization [5].
To analyse the observed isomerization of phenyl-
hydrazones IIIa–IIIt, IVa–IVk into azo compounds V
we carried out quantum-chemical calculations of heat
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 5 2009

SYNTHESIS AND PROPERTIES OF SUBSTITUTED BENZALDEHYDE PHENYLHYDRAZONES
955
Table 1. Yields, melting points, and data of elemental analyses and molecular weight measurements of phenylhydrazones
(IIIa–IIIt, IVa–IVk)
Found, %
H
Calculated, %
H
М
Comp. Yield,
mp
Formula
no.
%
оС
C
N
C
N
found
calculated
86
80
82
88
90
86
84
85
87
88
83
86
85
87
88
90
89
85
86
85
82
80
84
84
86
88
85
88
86
84
88
114–115
64–65
74.86
69.90
70.45
67.92
68.84
69.53
69.37
71.84
73.02
75.91
69.96
73.67
74.60
73.06
60.97
59.64
64.83
64.25
65.12
68.06
70.56
71.45
68.73
69.50
70.14
70.19
70.65
73.98
65.20
66.03
68.92
6.28
6.03
6.34
5.70
6.19
6.48
6.52
7.73
8.26
9.67
5.89
5.67
6.33
5.25
3.95
4.18
4.54
5.46
5.81
5.48
6.43
6.85
6.09
6.50
6.88
6.92
7.23
6.02
5.85
6.28
5.93
12.07
11.19
10.58
9.49
9.07
8.65
8.60
7.32
6.84
5.23
8.65
7.48
7.04
7.82
6.47
6.20
10.28
8.99
8.58
9.60
10.54
10.00
8.98
8.62
8.63
8.34
7.88
7.12
8.73
8.18
9.22
C14H14N2О
C14H14N2О2
C15H16N2О2
C16H16N2О3
C17H18N2О3
C18H20N2О3
C18H20N2О3
C22H28N2О3
C24H32N2О3
C32H48N2О3
C18H18N2О3
C22H20N2О3
C24H24N2О3
C21H18N2О3
C21H16Cl2N2О3
C21H17BrN2О3
C21H17N3О5
C16H16N2О4
C17H18N2О4
C32H30N4О6
C15H16N2О2
C16H18N2О2
C17H18N2О3
C18H20N2О3
C19H22N2О3
C19H22N2О3
C20H24N2О3
C23H22N2О3
C17H18N2О4
C18H20N2О4
C34H34N4О6
74.31
69.41
70.29
67.59
68.44
69.21
69.21
71.71
72.70
75.55
69.96
73.32
74.21
72.82
60.74
59.31
64.45
63.99
64.96
67.83
70.29
71.09
68.44
69.21
69.92
69.92
70.57
73.78
64.96
65.84
68.67
6.24
5.82
6.29
5.67
6.08
6.45
6.45
7.66
8.13
9.51
5.85
5.59
6.23
5.24
3.88
4.03
4.38
5.37
5.77
5.34
6.29
6.71
6.08
6.45
6.79
6.79
7.11
5.92
5.77
6.14
5.76
12.38
11.56
10.93
9.85
9.39
8.97
8.97
7.60
7.06
5.51
9.03
7.77
7.21
8.09
6.75
6.59
10.74
9.33
8.91
9.89
10.93
10.36
9.39
8.97
8.58
8.58
8.23
7.48
8.91
8.53
9.42
218.0
234.3
241.8
268.5
290.2
304.1
301.2
352.4
388.4
480.7
298.6
350.1
374.3
333.8
405.7
434.5
380.4
289.6
303.2
541.9
243.3
259.0
291.4
301.5
317.7
314.8
328.5
362.6
301.8
319.2
583.0
226.3
242.3
256.3
284.3
298.3
312.4
312.4
368.5
396.5
508.7
310.4
360.4
388.5
346.4
415.3
452.3
391.4
300.3
314.3
566.6
256.3
270.3
298.3
312.4
326.4
326.4
340.4
374.4
314.3
328.4
594.7
IIIa
IIIb
IIIc
IIId
IIIe
IIIf
IIIg
IIIh
IIIi
94–95
93–94
114–115
104–105
98–99
84–85
67–68
62–63
IIIj
IIIk
IIIl
53–54
97–98
47–48
IIIm
IIIn
IIIoa
IIIpb
IIIq
IIIr
IIIs
IIIt
IVa
IVb
IVc
IVd
IVe
IVf
209–210
128–129
153–154
152–153
113–114
132–133
203–204
132–133
115–116
108–109
107–108
110–111
111–112
106–107
137–138
110–111
53–54
IVg
IVh
IVi
IVj
196–197
IVk
а Found Сl, %: 16.81. Calculated Cl, %: 17.07. b Found Br, %: 18.43. Calculated Br, %: 18.79.
Table 2. Results of quantum-chemical calculations of heat of formation (Hf, kcal mol–1) of phenylhydrazones IIIa–IIId, IVa,
IVd E- and Z-isomers and related isomeric trans and cis azo compounds V
Comp. no.
IIIa
Е
50.6
9.0
Z
ΔHE/Z
0.1
trans-V
48.3
cis-V
50.6
9.7
ΔHtrans/cis
2.3
ΔHЕ/trans
2.3
50.7
9.3
0.3
5.3
4.4
3.7
IIIb
16.3
–27.7
4.5
17.0
–27.0
5.0
0.7
13.9
17.1
–25.5
5.2
3.2
2.4
IIIc
0.7
–30.5
–0.8
5.0
2.8
IIId
0.5
6.0
5.3
IVa
–37.1
–36.7
0.4
–40.5
–35.2
5.3
3.4
IVd
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956
DIKUSAR, POTKIN
H
C
N
N
N
N
N
H
C
N
H
H
H
N
H
H
N
H
C
C
R
R
R
R
R1
R1
cis
R1
R1
trans
E
Z
Phenylhydrazones of the substituted aromatic
ACKNOWLEDGMENTS
This work was financially supported by the
aldehydes IIIa–IIIt and IVa–IVk owing to their high
light sensitivity can be used for thermal vacuum
spraying of nano films for formation on the films of a
relief with submicro elements by the methods of laser
ablation lithography [3].
Foundation for Basic Research of Belarus, grant Х08-227.
REFERENCES
1. Dikusar, E.A., Potkin, V.I., Kozlov, N.G., and
Ogorodnikova, M.M., Zh. Obshch. Khim., 2006, vol. 76,
no. 9, p. 1484.
EXPERIMENTAL
2. Dikusar, E.A., Zh. Obshch. Khim., 2008, vol. 78, no. 4,
p. 642.
The IR spectra were registered on an IR Fourier
spectrophotometer Protege-460 Nicolet in KBr pellets,
1Н NMR spectra were obtained on a BS-587A 100
MHz Tesla instrument from 5% solutions in CDCl3,
chemical shifts were measured from internal TMS.
Elemental analysis was carried out on a C, H, N, O, S-
analyzer Vario EL-III Elementar, the measurements
error 0.1%. Molecular weight was determined by
cryoscopy in benzene.
3. Azarko, V.A., Dikusar, E.A., Potkin, V.I., Kozlov, N.G.,
and Yuvchenko, A.P., Proc. of Int. Sci. and Practical
Conf. “Optika neodnorodnykh struktur–2007” (Optics
of Non-Uniform Structures–2007), October 2–3, 2007,
Mogilev (Belarus’): Kuleshov Mogilev State Univ.,
2007, p. 27.
4. Kitaev Yu.P. and Buzykin B.I., Gidraziny (Hydrazines),
Moscow: Nauka, 1974.
5. Comprehensive Organic Chemistry, Barton, D. and
Ollis, U.D., Eds., vol. 3, Nitrogen Compounds, Moscow:
Khimiya, 1982, p. 268.
Vanillin and vanillal esters I were obtained along
the procedures in [9–12]. Phenylhydrazine II of
“analytically pure” grade, purity 99%, mp 19–20°С
was used in the syntheses.
6. Stewart, J.J.P., J. Comput. Chem., 1989, vol. 10, no. 2,
p. 209.
7. Stewart, J.J.P., J. Comput. Chem., 1989, vol. 10, no. 2,
p. 221.
Substituted aromatic aldehydes phenylhyd-
razones (IIIa–IIIt and IVa–IVk). A 5 mmol portion
of a substituted aromatic aldehyde I and 5 mmol of
phenylhydrazine II were dissolved in 10 ml of
anhydrous diethyl ether at –5°С at protection against light,
under argon atmosphere (in the synthesis of succinates
IIIt and IVk was taken 10 mmol of phenylhydrazine
II per 5 mmol of the corresponding aldehyde I). The
formed homogenous solution or suspension was kept
under the above conditions for 8–30 h. Excess of ether
was carefully (without heating) removed in a vacuum
and the formed crystals of compounds IIIa–IIIt, IVa–
IVk were separated by filtration on a porous glass filter
and dried in a vacuum.
8. Shmidt, M.W., Baldridge, K.K., Boatz, J.A., Elbert, S.T.,
Gordon, M.S., Jensen, J.H., Koseki, S., Matsunaga, N.,
Nguyen, K.A., Su, S.J., Midus, T.L., Dupnis, M., and
Montgomery, J.A., J. Comput. Chem., 1993, vol. 14, no. 7,
p. 1347.
9. Dikusar, E.A., Vyglazov, O.G., Moiseichuk, K.L.,
Zhukovskaya, N.A., and Kozlov, N.G., Zh. Prikl.
Khim., 2005, vol. 78, no. 1, p. 122.
10. Dikusar, E.A. and Kozlov, N.G., Khin. Prirod. Soed.,
2005., no. 1, p. 74.
11. Dikusar, E.A. and Kozlov, N.G., Zh. Org. Khim., 2005,
vol. 41, no. 7, p. 1015.
12. Dikusar, E.A., Zh. Prikl. Khim., 2006, vol. 79, no. 6,
p. 1043.
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