A mechanism for the hydrazinolysis of benzoic acid in the presence of ion-exchange catalyst

Article abstract of DOI:10.1134/S0036024413110083

A mechanism for the hydrazinolysis of benzoic acid via cyclic transition states is proposed on the basis of kinetic and IR spectroscopic studies.

Full text of DOI:10.1134/S0036024413110083

ISSN 0036ꢀ0244, Russian Journal of Physical Chemistry A, 2013, Vol. 87, No. 11, pp. 1943–1945. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © S.A. Dzhumadullaeva, M.O. Altynbekova, 2013, published in Zhurnal Fizicheskoi Khimii, 2013, Vol. 87, No. 11, pp. 1978–1980.
SHORT
COMMUNICATIONS
A Mechanism for the Hydrazinolysis of Benzoic Acid
in the Presence of Ionꢀexchange Catalyst
S. A. Dzhumadullaeva and M. O. Altynbekova
Yasavi International Kazakh–Turkish University, Kentau, 160400 Kazakhstan
eꢀmail: Jumadullaeva_00@mail.ru
Received February 26, 2013
Abstract—A mechanism for the hydrazinolysis of benzoic acid via cyclic transition states is proposed on the
basis of kinetic and IR spectroscopic studies.
Keywords: hydrazinolysis, benzoic acid, hydrazine hydrate, anion exchange resin, benzhydrazide, adsorpꢀ
tion, active site, fixed cation of resin.
DOI: 10.1134/S0036024413110083
–
3
–3
INTRODUCTION
rate constants were 0.25
1
×
10 , 2.8
×
10 , 2.9
×
⎯
3
0 L/(mol min), respectively. The order of the reacꢀ
The hydrazinolysis of carboxylic acids over polyꢀ
meric ion exchange resin catalysts is a promising method
for synthesizing aromatic and pyridinecarboxylic acid
hydrazides, which are used as drugs, accelerators of rubꢀ
tion with respect to benzoic acid was 1 (Fig. 1). It was
similarly established that the reaction was of the first
order with respect to the second component, hydraꢀ
ber vulcanization, modifiers, and curing agents for polyꢀ zine hydrate (HH). For HH concentrations c' = 0.81,
0
meric materials. However, there is no clear idea of the 0.93, and 1.06 mol/L, the rate constant values were
–
3
–3
–3
mechanism of the hydrazinolysis reaction [1]. In this 2.9
work, we attempt to fill this gap by investigating hydraziꢀ
×
10 , 3.0
×
10 , 3.1
×
10 L/(mol min).
The low activation energy, the high negative
nolysis of benzoic acid into benzhydrazide in the presꢀ entropy of activation, and the first order with respect
ence of AVꢀ17ꢀ8 anion exchange resin.
to benzoic acid and hydrazine hydrate indicate that
the reaction occurs via a cyclic transition state. These
kinetic data are consistent with the results from IR
spectroscopic studies.
RESULTS AND DISCUSSION
Our investigations were performed by kinetic
means and IR spectroscopy. The experimental proceꢀ interaction with the anion exchange resin (
dure was described in [2, 3].
The spectra of benzoic acid (
1
) and the product of its
), respecꢀ
tively, are shown in Fig. 2. Comparing them to each
2
We found that benzoic acid reacts quite readily with other, we can see there are no absorption bands that are
hydrazine to form benzhydrazide (BH) in the presence characteristic of acids (the very strong stretching vibraꢀ
–
1
of AVꢀ17ꢀ8 anion exchange resin in the OHꢀform:
tion band of the C=O group at 1700 cm and the
–1
absorption band at 940 cm referring to the outꢀofꢀ
plane deformation vibration of the OHꢀgroup) in the
spectrum 2. The continuous absorption characteristic of
both acid and the anion exchange resin disappeared. The
intensity of the band in the region of deformation vibraꢀ
С H COOH + H N–NH
2
6
5
2
→
С H CONHNH + H O.
6 5 2 2
The dependence of the BH concentration (
time at various temperatures is shown in Fig. 1. The
reaction rate constants at 65, 75, 80, and 95 are
с) on
–1
°C
tions of water (1600–1700 cm ) is reduced dramatically.
–
3
–3
–3
2.9
×
10 , 3.0
×
10 , and 4.2
×
10 L/(mol min), At the same time, a very intense pair of bands at 1370 and
–1
respectively. The activation energy found from the 1615 cm appeared for the reaction product of benzoic
Arrhenius dependence was 20.1 kJ/mol. The entropy acid with anion exchange resin. This pair of bands can be
of activation, calculated using the method in [4], was attributed, respectively, to the symmetric stretching
–
–
198.2 J/(mol K). At different initial concentrations vibrations of carboxylate anions (СOO ), which become
of benzoic acid (c0 = 0.10, 0.30, and 0.51 mol/L), the fixed counterions of the resin according to [5, 6]:
O
O
O
−
+
+
–
N (CH ) + 2H O
.
2
R C
+ N (CH
3
)
3
OH · H
2
O
RC
3 3
OH
1943

1944
DZHUMADULLAEVA, ALTYNBEKOVA
log
2
c
×
10 , mol/L
4
−
c
BH
3
.0
.8
.6
.4
2
c
×
10 , mol/L
3
−
logcBH
2.8
(a)
0
.7
(b)
0
.7
2
3
1
2
0
0
0
.5
.3
.1
0.5
0.3
0.1
2
1
2
2
2
.6
.4
2
2
1
3
4
1
2
3
~
~
~
~
40
80
40
80
t, min
t, min
Fig. 1. Kinetics of the hydrazinolysis of benzoic acid over ABꢀ17ꢀ8 anion exchange resin: (a) at с0 = 0.51 M, c0' = 0.81 M, KT
=
2
g/g BH and different temperatures: (
) 0.51, ( ) 0.30, and ( ) 0.10 M.
1) 65, (
2) 75, (3) 80, and (4) 95°C
; (b) at 95°
C
,
c'
0
=
1.6 M and different values of с0
:
(1
2
3
1370 1615
2
1
1300
940
, cm−
1
400 600 700 1100 1500
2200 2600 3000
ν
Fig. 2. IR absorption spectra of benzoic acid (
), respectively.
1) and the product of its interaction with ABꢀ17ꢀ8 anion exchange resin in OHꢀform
(2
The IR spectrum of the anion exchange resin upon assume that the complex of carboxylate anion with the
contact with hydrazine hydrate does not differ from the catalyst decomposes under the action of hydrazine from
spectrum of the fresh anion exchange resin, indicating the reaction volume, leading to the formation of the tarꢀ
there was no adsorption of hydrazine. We may therefore get hydrazide and the regeneration of the active site:
O
O
−
+
+
−
RC
H N HN
N (CH )
RC
+
N (CH ) OH
.
3 3
3
3
O
NHNH2
2
H
CONCLUSIONS
A plausible mechanism of hydrazinolysis of carꢀ
boxylic acids over an anion exchange resin thus
involves the formation of the cyclic transition state.
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 87
No. 11 2013

A MECHANISM FOR THE HYDRAZINOLYSIS OF BENZOIC ACID
1945
REFERENCES
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1
. K. Kh. Dzhumakaev, K. A. Ayapbergenov, I. I. Mai,
and S. A. Dzhumadullaeva, Kinet. Katal. 30, 488
(1989).
5
. L. H. Little, Infrared Spectra of Adsorbed Molecules
Academic, London, 1966).
(
2
. K. Kh. Dzhumakaev, S. A. Dzhumadullaeva, and
K. M. Akhmetov, Catalytic Reactions of Monomers and
Polymers (Cheboks. Gos. Univ., Cheboksary, 1988),
p. 64 [in Russian].
6
. K. Kh. Dzhumakaev, I. I. Mai, S. A. Dzhumadullaeva,
et al., Zh. Fiz. Khim. 64, 2811 (1990).
3
. S. A. Dzhumadullaeva, L. K. Abulyaisova, and
K. Kh. Dzhumakaev, Zh. Fiz. Khim. 67, 1083 (1993).
Translated by S. Mikhailichenko
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 87
No. 11 2013