Synthesis and pharmacological properties of phosphoryl acetohydrazones and acetohydrazines

Full text of DOI:10.1023/A:1020872422070

Pharmaceutical Chemistry Journal
Vol. 36, No. 6, 2002
SYNTHESIS AND PHARMACOLOGICAL PROPERTIES OF PHOSPHORYL
ACETOHYDRAZONES AND ACETOHYDRAZINES
R. I. Tarasova,1 O. V. Voskresenskaya,1 I. I. Semina,2 T. V. Kurmysheva,3 V. P. Balashov,3
and V. V. Moskva1
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 36, No. 6, pp. 17 – 20, June, 2002.
Original article submitted March 18, 2000.
Nitrogen-containing derivatives of phosphorylcarboxylic
acids constitute a new class of compounds possessing high
biological activity [1]. One active representative of this
class – diphenylphosphorylacetic acid hydrazide (fosenazid,
Ia) – was recommended for clinical testing as a tranquilizer
and an antialcoholic agent [2]. Another compound,
2-chloroethoxy-p-N-dimethylaminophenyl phosphoryl ace-
tohydrazide (CAPAH, Ib), was shown to have neuroprotector
action with an antidepressant component and to improve
memory function [3]. At present, CAPAH as a nootropic
agent is in the final stage of preclinical testing.
Ib involve a considerable membranotropic component [5], it
was of interest to seek new effective psychotropic and
antiarrhythmic agents among their analogs and derivatives.
For this purpose, we have synthesized and studied a series of
phosphoryl acetohydrazones II and N-substituted phosphoryl
acetohydrazines III based on compounds Ia and Ib.
Hydrazones II were synthesized via interaction of
unsubstituted hydrazides I with aldehydes or ketones [6, 7]:
A(B)P(O)CH2C(O)NHNH2 + RC(O)R¢ ®
Ia, Ib
Besides the psychotropic action, fosenazid exhibited a
significant antiarrhythmic effect comparable with that of
dimephosphon and etmozin [4]. Since mechanisms of the
pharmacological action of the aforementioned drugs Ia and
® A(B)P(O)CH2C(O)NHN=C(R)R¢
IIa – IIm
1
Ia: A = B = Ph;
Ib: A = p-Me2NC6H4, B = OCH2CH2Cl;
IIa – IIm: for A, B, R, and R¢, see Table 1.
Kazan State Technological University, Kazan, Tatarstan, Russia.
Kazan State Medical University, Kazan, Tatarstan, Russia.
Mordovian State University, Saransk, Russia
2
3
TABLE 1. Yields and Characteristics of Phosphoryl Acetohydrazones A(B)P(O)CH2C(O)NHN=CRR¢ (II)
Compound
A
B
R
R¢
Yield, %
M.p., °C
Empirical formula
IIa
IIb
IIc
IId
IIe
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
H
H
H
H
H
CH3
C6H5
98
92
94
89
97
resin
201 – 203
218
C16H17N2O2P
C21H19N2O2P
C21H19N2O3P
C23H21N2O2P
C36H32N4O4P2
C6H4OH-2
CH=CHC6H5
212
C6H4CH=
320 (decomp.)
NNHC(O)CH2P(O)Ph2
IIf
IIg
IIh
IIi
C6H5
C6H5
H
CH3
H
3,5-Br2–2-OH–C6H2
94
88
95
52
80
60
97
82
226 – 228
177 – 178
resin
C21H17Br2N2O3P
C17H19N2O2P
C6H5
C6H5
CH3
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
OC2H4Cl
OC2H4Cl
OC2H4Cl
OC2H4Cl
OC2H4Cl
OC2H4Cl
CH3
C6H5
C14H21ClN3O3P
C19H23ClN3O3P
C20H23ClN3O5P
C20H23ClN3O5P × C7H9N
C15H23ClN3O3P
C15H21ClN3O5P
H
155 – 156
205 – 207
153 – 154
resin
IIj
H
C6H4COOH-4
C6H4COO–N+H3CH2C6H5
CH3
IIk
IIl
H
CH3
CH3
IIm
COOH
169 – 170
298
0091-150X/02/3606-0298$27.00 © 2002 Plenum Publishing Corporation

Synthesis and Pharmacological Properties of Phosphoryl Acetohydrazones and Acetohydrazines
299
In contrast to the reaction with aldehydes proceeding
readily even at room temperature, the interaction of
hydrazides I with acetone required prolonged (1 – 7 h) heat-
ing at a boiling point of acetone. The yields and physicoche-
mical characteristics of hydrazones II are listed in Table 1.
A convenient pathway to compounds III is offered by hy-
drogenation of the corresponding II [6]. The reduction of
phosphoryl acetohydrazones II under the action of sodium
borohydride in methanol solutions readily proceeded at
0 – 5°C by the scheme
internal standard. The initial hydrazides Ia and Ib were syn-
thesized as described elsewhere [1, 3].
Phosphoryl acetohydrazones (II). To a solution of
20 mmole of unsubstituted phosphorylcarboxylic acid
hydrazide (Ia or Ib) in 20 ml of ethanol at room temperature
was added a solution of 20 mmole of the corresponding alde-
hyde in 10 ml of the same solvent and the reaction mixture
was allowed to stand at room temperature for 2 – 6 h. The
precipitate was filtered, washed with ethanol or chloroform,
and dried. The target compounds appear as white or slightly
yellowish powders insoluble in water, poorly soluble in etha-
nol, and soluble in DMSO or DMF. The yields and
physicochemical characteristics of hydrazones II are pre-
sented in Table 1.
A(B)P(O)CH2C(O)NHN = C(R)R¢ ®
II
® A(B)P(O)CH2C(O)NHNHCHRR¢
N-substituted phosphorylacetic acid hydrazines
(IIIa – IIIf). To a suspension of 25 mmole of the corre-
sponding phosphoryl acetohydrazone II in 20 ml of methanol
at 0 – 5°C was added by portions 25 mmole of sodium
borohydride, after which the reaction mixture was kept first
for 4 h at 3 – 5°C and then for 15 – 24 h at room temperature.
Then, the methanol was distilled off under reduced pressure
(water-jet pump) and the residue was dissolved in 1.0 ml of
water. The target product was extracted from this solution
with chloroform (2 ´ 10 ml). The chloroform solution was
dried over calcined magnesium sulfate and filtered, after
which the chloroform was distilled off under reduced pres-
sure (water-jet pump) and the residue was treated with ben-
zene to obtain the target product. The yields and
physicochemical characteristics of hydrazones III are pre-
sented in Table 2.
2-Chloroethoxy-4¢-dimethylaminophenylphosphoryla
cetic acid N-acetylhydrazine (IIIg). To 6.4 g (0.02 mole) of
(2-chloroethoxy-4¢-dimethylaminophenylphosphoryl)acetic
acid hydrazide (Ib) was added a solution of 2.22 ml of a 36%
hydrochloric acid solution in 60 ml of water. To this mixture,
slowly heated to 50°C, was gradually added with stirring
3.07 g (0.03 ml) of acetic anhydride and, upon cooling the
IIIa – IIIf
IIIa – IIIf: for A, B, and CHRR¢, see Table 2.
This process leads with a high yield to compounds
IIIa – IIIf representing N-substituted analogs of fosenazid (A
= B = Ph) and CAPAH (A = Me2NC6H4, B = OCH2CH2Cl)
(Table 2). The reduction of acetohydrazones to N-substituted
1
hydrazides was monitored by TLC and H NMR spectros-
copy. A characteristic sign of the formation of compounds III
is the appearance of high-field signals from methylene
(2 – 3 ppm) or methine (2.8 ppm) protons of CH(R)R¢ frag-
ments (R = H or CH3). The parameters of 1H NMR spectra of
hydrazones II and hydrazines III are listed in Table 3.
Diacylhydrazine IIIg was obtained as described previ-
ously [8], via interaction of hydrazide Ib with acetic anhy-
dride:
[CH3CO]2O
p-Me2NC6H4P(O)(OC2H4Cl)CH2C(O)NHNH2 ®
Ib
® Me2NC6H4P(O)(OC2H4Cl)CH2C(O)NH NHC(O)CH3
IIIg
mixture to room temperature,
a solution of 3.28 g
(0.04 mole) of sodium acetate in 14 ml of water. A crystal-
line product, precipitated from the reaction mixture upon
cooling, was filtered, washed with ice-cold water, dried, and
recrystallized from water (Table 2).
EXPERIMENTAL CHEMICAL PART
The 1H NMR spectra were recorded on a Bruker WP-80
spectrometer using DMSO-d6 as the solvent and TMS as the
TABLE 2. Yields and Characteristics of Phosphoryl Acetohydrazines A(B)P(O)CH2C(O)NHNHCRR¢ (III)
Yield,
%
Compound
A
B
CHRR¢
M.p., °C
Empirical formula
IIIa
IIIb
IIIc
IIId
IIIe
IIIf
IIIg
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C2H5
97
90
80
95
93
81
78
143 – 145
C16H19N2O2P
C3H7-i
137 – 141
200 – 203
resin
C17H21N2O2P
CH2C6H5
C2H5
C21H21N2O2P
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
(CH3)2NC6H4
OC2H4Cl
OC2H4Cl
OC2H4Cl
OC2H4Cl
C14H23ClN3O3P
C15H25ClN3O3P
C19H25ClN3O3P
C14H21ClN3O4P
C3H7-i
resin
CH2C6H5
C(O)CH3
158 – 160
119

300
R. I. Tarasova et al.
EXPERIMENTAL PHARMACOLOGICAL PART
with an electrode floor. The effect was evaluated by the
change in the latent period before the first visit to the dark
compartment. The compounds to be tested were introduced
to animals 40 min before learning on the first day of experi-
ment.
The antihypoxant properties of the synthesized com-
pounds were studied on a model of acute hypobaric hypoxia
in mice, which was reproduced in an altitude chamber by
simulating ascent to an altitude of 10,000 m at a velocity of
25 m/sec. The results were evaluated by determining the sur-
vival lifetime of experimental animals from the beginning of
ascent. The drugs were introduced 40 min before onset of the
hypoxic factor [11].
The antidepressant activity of the synthesized com-
pounds was studied using the “behavioral despair” test on
mongrel male mice weighing 17 – 21 g. The effect was as-
sessed by measuring the duration of the immobilization pe-
riod [9]. The drugs were introduced 40 min before test, in a
single intraperitoneal dose of 0.01LD50.
The effects of compounds II and III on memory and
learning were assessed on a model of passive avoidance con-
ditioned reflex (PACR) [10]. The reflex was developed in
mice with the aid of a special chamber containing two com-
partments – light and dark ones, the latter being equipped
TABLE 3. Parameters of the 1H NMR Spectra of Substituted Phosphoryl Acetohydrazones A(B)P(O)CH2C(O)NHN=CRR¢(II) and
Acetohydrazines A(B)P(O)CH2C(O)NHNHCRR¢ (III)
Proton chemical shift d, ppm
Compound
A
B
R
R¢
C(O)NH
(1H)
P(O)CH2
(2H)
Ar, CH = N
CHRR¢ or R¢
IIa
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
H
H
CH3
CH3
C6H5
C6H5
CH3
CH3
CH3
CH3
C6H5
C6H5
CH3
CH3
11.0 d
8.2 s
7.4 – 7.7 (m, 11H)
7.4 – 7.8 (m, 10H)
7.3 – 8.2 (m, 16H)
7.4 – 8.0 (m, 15H)
7.4 – 7.8 (m, 10H)
7.4 – 7.8 (m, 10H)
6.7 – 7.3 (m, 5H)
6.7 – 7.3 (m, 4H)
6.7 – 7.9 (m, 10H)
6.7 – 7.3 (m, 9H)
6.7 – 7.5 (m, 4H)
6.7 – 7.5 (m, 4H)
3.5 d 3.3 d 1.75 dd (CH3)
IIIa
IIb
IIIc
IIg
IIIb
IIh
IIId
IIi
3.6 d
3.8 d 4.1 d
3.8 d
2.6 q (CH2) 1.0 t (CH3)
H
11.8 d
8.2 s
–
H
2.0 d (CH2)
CH3
CH3
H
10.3 s
9.5 s
3.8 d 3.9 d 1.8 dd. (CH3)
3.6 d
3.05 dd
3.3 d
2.8 m (CH) 0.8 d (CH3)
Me2NC6H4 OC2H4Cl
Me2NC6H4 OC2H4Cl
Me2NC6H4 OC2H4Cl
Me2NC6H4 OC2H4Cl
Me2NC6H4 OC2H4Cl
Me2NC6H4 OC2H4Cl
10.6 d
7.9 s
1.38 dd (CH3)
2.2 q (CH2) 0.5 t (CH3)
–
H
H
11.7 d
8.0 s
3.2 dd
3.4 d
IIIf
IIl
H
2.2 d (CH2)
CH3
CH3
9.8 s
3.25 dd
3.3 d
1.75 dd (CH3)
2.8 m (CH) 0.8 d (CH3)
IIIe
8.2 s
Note: the spectra of compounds II and III with A = Me2NC6H4 and B = OC2H4Cl also contain signals at (d, ppm) 2.9 (s, 6H, Me2NC6H4), 4.0
(q, 2H, OCH2CH2Cl), and 3.7 (d, 2H, OCH2CH2Cl).
TABLE 4. Acute Toxicity and the Psychotropic and Antihypoxant Activity of Phosphoryl Acetohydrazones (II) and N-Substituted Phosphoryl
Acetohydrazines (III) in Mice
Antidepressant activity (immobilization
time in behavioral despair test;
dose, 0.01LD50)
Antihypoxant activity (lifetime
in hypobaric hypoxia test; dose,
0.01LD50)
Mnemotropic activity (latent avoidance
period in PACR test; dose, 0.01LD50)
LD50 (i.p.),
mg/kg
Compound
sec (M m )
% of control
sec (M m )
% of control
sec (M m )
% of control
IIb
IId
IIi
97.5
87
92
130
217*
182
325*
212*
89
–
–
5200 ± 310
5170 ± 150
4960 ± 210
5110 ± 190
5180 ± 36
229.3 ± 9.3
216.5 ± 21.9
184.2 ± 25.4
179.6 ± 21.8
151.4 ± 17.1
166.6 ± 14.2
205.0 ± 15.7
185.5 ± 22.3*
180.9 ± 19.3
144.9 ± 24.9
127.1 ± 19.7
37.4 ± 5.2*
31.4 ± 15.7
52.7 ± 10.1*
34.4 ± 5.2*
108.8 ± 26.2
131.6 ± 28.6
38.7 ± 7.8
–
–
102
97.5
87
139*
93
404.2 ± 30.2*
187.4 ± 34.5
209.4 ± 37.1
215.7 ± 21.5
226.0 ± 38.7
382.5 ± 22.6
299.0 ± 29.4
IIj
IIk
IIm
IIIe
IIIf
IIIg
108
111
110
104
136
90
5250 ± 286
4950 ± 13.6
5100 ± 26.4
3120 ± 160
100
80.5
90
84
199
* Differences from control reliable for p < 0.05.

Synthesis and Pharmacological Properties of Phosphoryl Acetohydrazones and Acetohydrazines
301
The antiarrhythmic activity was studied on a group of
male and female mongrel cats weighing 2.0 – 4.0 kg,
narcotized with ethaminal sodium (50 mg/kg, i.p.). The
models of acute occlusive and reperfusive violations of the
heart rhythm were induced as described in [12]. The com-
pounds to be tested were slowly infused intravenously in a
dose amounting to 1/100 of the molecular weight, 3 min be-
fore occlusion of the coronary artery.
A(B)P(O)CH2C(O)NHNH2 > A(B)P(O)CH2C(O)NHN =
II
I
=CHR¢ > A(B)P(O)CHC(O)NHNHCH2R¢
III
The results of tests for the antiarrhythmic activity also in-
dicate that the effect depends on the hydrazine fragment
structure. However, in this case, the order of compounds I
and II changes as compared to the above sequence:
RESULTS AND DISCUSSION
Ph2P(O)CH2C(O)NHN = CHR¢ >
Among the series of substances studied, only compound
IIi produced a reliable antihypoxant effect on the hypobaric
hypoxia model (Table 4). Compounds IIi, IIk, and IIm ad-
ministered in the doses indicated above improved memory
and learning in the test mice under the PACR conditions,
which can be considered as evidence of nootropic activity.
Substituted phosphoryl acetohydrazines (III) either exhibited
a less pronounced effect in this test (compound IIIg) or
showed no such activity at all.
II
Ph2P(O)CH2C(O)NHNH2 @
I
Ph2P(O)CH2C(O)NHNHCH2R
III
As for the structure of the phosphoryl fragment, both
previous data [13] and the results of this experiment indicate
that replacement of the aryl substituent at the phosphorus
atom increases the psychotropic and antiarrhythmic activity
of hydrazines.
A significant antidepressant activity (estimated at
19.5%) was observed only for compound IIIf.
Most compounds (except for IIi) exhibited
antiarrhythmic activity on the model of acute occlusive ar-
rhythmia. The effect with respect to reperfusive violations of
the heart rhythm was less pronounced (Table 5).
A comparative analysis of the psychotropic activity of
compounds II and III, on the one hand, and the previously
studied unsubstituted phosphoryl acetohydrazines [13]
showed that substituents in the hydrazide fragment reduce
the activity in the following order:
ACKNOWLEDGMENTS
This study was supported by the Ministry of Education
of the Russian Federation within the framework of the Pro-
gram “Basic Research in Natural Sciences” (project No.
TOO-9.3-554).
TABLE 5. Antiarrhythmic Activity of Phosphoryl Acetohydrazones (II) and N-Substituted Phosphoryl Acetohydrazines (III) in Occlusive and
Reperfusive Arrhythmia Models in Cats
Number of animals
Dose,
mg/kg
Compound
occlusion test
arrhythmia
reperfusion test
arrhythmia
Total
VF**
Total
VF**
Control
–
31
7
31 (100 %)
4 (57.1 %)*
2 (33.3 %)*
2 (40 %)*
1 (14 %)*
3 (43 %)*
9 (29 %)
23
7
23 (100 %)
6 (85.7 %)
6 (100 %)
3 (60 %)*
5 (71 %)*
6 (86 %)
15 (65 %)
4 (57.1 %)
2 (33.3 %)
2 (40 %)
IIb
3.6
3.7
6.5
5.3
4.5
3.9
3
0
0
0
0
0
IIc
6
6
IIe
5
5
IIf
7
7
4 (57 %)
IIj
7
7
1 (14 %)*
IIm
2
Fibrillation 5 min after occlusion of coronary artery
IIIa
6
3 (50 %)*
3 (50 %)*
2 (20 %)*
3 (43 %)*
3 (30 %)*
2 (33 %)
4
6
4 (100 %)
4 (67 %)*
7 (70 %)*
5 (71 %)
7 (70 %)
2 (50 %)
3 (50 %)
2 (20 %)*
2 (29 %)
2 (20 %)
IIIb
3.1
3.6
200
2.0
6
0
0
0
0
IIIg
10
7
10
7
Dimephosphon
Etmozin
10
10
* Differences from control reliable for p < 0.05; ** VF = ventricular fibrillation.

302
R. I. Tarasova et al.
6. G. G. Zhuravleva,
R. K. Ismagilov,
and
V. E. Kolla,
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