Synthesis and investigation of ring-chain isomerism of the derivatives of N-amino-5-hydroxy-1,2,3-triazole-4-carboxylic acid

Article abstract of DOI:10.1023/A:1017598814562

A series of sodium salts of 4-substituted 1-amino-5-hydroxy-1,2,3-triazoles was obtained by the "diazo transfer" reaction to arylmethylene-protected α-ethoxycarbonyl- and α-(methylcarbamoyl)- acetohydrazides. In DMSO solution the corresponding neutral hyd

Full text of DOI:10.1023/A:1017598814562

Chemistry of Heterocyclic Compounds, Vol. 37, No. 3, 2001
SYNTHESIS AND INVESTIGATION
OF RING–CHAIN ISOMERISM OF THE
DERIVATIVES OF N-AMINO-5-HYDROXY-
1,2,3-TRIAZOLE-4-CARBOXYLIC ACID
Yu. A. Rozin, E. A. Vorob'ova, Yu. Yu. Morzherin, and V. A. Bakulev
A series of sodium salts of 4-substituted 1-amino-5-hydroxy-1,2,3-triazoles was obtained by the "diazo
transfer" reaction to arylmethylene-protected α-ethoxycarbonyl- and α-(methylcarbamoyl)-
acetohydrazides. In DMSO solution the corresponding neutral hydroxytriazoles exist in equilibrium
with the isomeric diazo compounds with an open chain. Electron-donating substituents stabilize the
cyclic form. A good correlation was obtained between the equilibrium constants and the Hammett
σ-constants. During the diazotization of benzaldehyde α-amino-α-cyanoacetylhydrazone the initially
formed diazo compound undergoes spontaneous cyclization in solution to hydroxytriazole. Removal of
the arylmethylene protection leads to N-unsubstituted sodium salts of 1-amino-5-hydroxytriazoles, but
acidification of the latter leads to diazoacetohydrazides with an open chain.
Keywords: diazomalonomonohydrazide, ring–chain isomerism, equilibrium constants, diazo-transfer
reaction, Hammett equation.
1,2,3-Triazoles and their benzo analogs have found widespread use in organic synthesis, medicine, and
industry [1]. N-Amino-1,2,3-triazoles are of particular interest. Of them, however, 5-H-, 5-alkyl-, and 5-aryl-
substituted derivatives are mainly known [2], while only individual representatives of N-amino-5-hydroxy-1,2,3-
triazoles (AHT) are known [1, 3]. A general method for the synthesis of AHT was not known before our
previous publication [4]. The present paper is devoted to the development of general method for the synthesis of
AHT and also investigation of stability of these compounds in relation to the opening of the triazole ring.
One approach to the synthesis of 5-hydroxy-1,2,3-triazoles is method involving the generation of
α
-diazoacetamides followed by their 1,5-electrocyclization in the presence of bases [5]. Base-catalyzed diazo
transfer to amides and amidines with an active α-methylene group by the action of sulfonyl azides followed by
electrocyclization has often been regarded as the most effective method for the production of triazoles [6].
We found that if diazo-transfer reaction is applied to O-ethylmalonylhydrazine 1 triazole is not formed
on account of a side reaction at the hydrazide group. Subsequently, therefore, hydrazides 1 and 2 were
transformed by the action of substituted benzaldehydes into arylmethylene-protected α-ethoxycarbonyl
- and
α
-methylcarbamoylacetohydrazides 3 and 4, which were brought into the diazo-transfer reaction (Scheme 1).
According to data from the 1H NMR spectra, these compounds exist as two conformers (Tables 1 and 2). During
their reaction with tosyl azide in ethanol in the presence of sodium ethoxide sodium salts of 5-hydroxytriazoles
5 and 6 are formed smoothly (Tables 3 and 4), as confirmed by the data from IR spectroscopy, i.e., by the
absence of an absorption band of the diazo group in the region of 2120-2160 cm-1.
____________________________________________________________________________________________
Urals State Technical University, Ekaterinburg, Russia; e-mail: vab@htf.ustu.ru. Translated from Khimiya
Geterotsiklicheskikh Soedinenii, No. 3, pp. 323-333, March, 2001. Original article submitted July 23, 1999.
294
0009-3122/01/3703-0294$25.00©2001 Plenum Publishing Corporation

Scheme 1
O
O
O
O
ArCHO
N
Ar
X
N
H
X
NHNH2
ONa
1, 2
3, 4 a–j
H
TsN3
EtONa
O
O
H
N
X
NaO
Ar
N
N
N
N
N
N
N
H
Me
N
Ar
7
5, 6 a–j
H
O
ONa
EtO
O
O
+H+
–H+
N
Ar
EtO
N
5
N
N
N
H
N
N2
H
Ar
Ar = 4-R1-3-R2-C6H3
H
9
8
X= EtO;
X= MeNH
2, 4, 6
1, 3, 5
g
3–12
a
b
c
d
e
f
h
i
j
R1
R2
Me2N NO2
H
H
Cl
H
F
Me
H
H
MeO MeO
Br
H
NO2
H
H
MeO
H
H
1
A characteristic feature of the H NMR spectra of triazololates 5 and 6 is the shift of the signals from
the protons of the azomethine fragment (9.20-9.43 ppm) downfield by 1.0-1.5 ppm compared with their position
in the initial hydrazones 3 and 4.
In the case of the reaction of the carbamoyl derivatives 4 with tosyl azide the formation of the isomeric
could be expected on account of cyclization of α-diazo compound
triazoles 6 and 7
via the nitrogen atom of the
amide or hydrazide groups. However, only the last possibility was realized, as indicated by the position of the
1
signals from the protons of the N=CH and CH3 groups in the H NMR spectra, located at 9.25-9.48 and
2.60-2.75 ppm respectively and not at 8.3 and 3.75 ppm as for the isomer 7 [7]. In solutions 5-hydroxy-1,2,3-
triazoles are in equilibrium with their chain isomers, α-diazoacetamides (DAA), while in the presence of bases
they exist in the form of triazol-5-olates [7-9].
During treatment of aqueous solutions of salts 5 with one equivalent of HCl 5-hydroxytriazoles 8, which
are in equilibrium with the open-chain diazo compounds, are obtained. In the solid state these products largely
represent the diazo compounds 9 (Table 5), as shown by the strong absorption band of the diazo group in the IR
spectra in the region of 2140-2155 cm-1. On treatment with sodium ethoxide diazo compounds 9 undergo
irreversible cyclization to triazolates 5.
.
In solutions of the products from acidification of compounds 5 in DMSO an equilibrium 8
9,
detected by means of the 1H NMR spectra, is observed. The content of triazole 8 in the equilibrium mixture is in
the range of 4-80% depending on the substituents, and the thermodynamic stability of the cyclic form increases
with increase in the electron-donating activity of substituent. The discovered relationships agree with data on
the effect of substituents at position 1 of the triazole ring of 5-hydroxy-1,2,3-triazoles [8]. The calculated
equilibrium constants (Table 5) correlate well with the σ-constants of the substituents in the phenyl ring:
295

lg Ki = -0.867* ΣσR – 0.613; r2 = 0.959.
On acidification of sodium salts of hydroxytriazoles 6 products that are also predominantly diazo
compounds (with the exception of hydroxytriazole 10a, the IR spectrum of which does not contain the
1
absorption band of the diazo group) separate from the aqueous solution. According to the H NMR spectra, the
solutions of the mentioned compounds in DMSO under the equilibrium conditions contain diazo compound 11
and the two isomeric hydroxytriazoles 10 and 12 (Scheme 2).
Scheme 2
O
O
OH
MeHN
O
O
H
N
N
+H+
-H+
HO
Ar
N
Ar
6
MeHN
N
H
N
N
N
N
N
N
N2
H
H
Me
N
Ar
12
H
11
10
To determine the structure of the products it is possible to use the position of the signals for the protons
of the methyl group and the protons of the azomethine fragment, which are shifted downfield by 0.93-0.94 ppm
on closure of the triazole ring via the nitrogen atom of the carboxamide group and by 0.86-0.99 ppm on closure
via the nitrogen atom of the hydrazide group. The content of components 10, 11, and 12, calculated from the
integral intensities of the indicated peaks, and also the equilibrium constants (the stability constants of triazoles)
(Table 6) indicate that the diazo compound predominates. The arylmethyleneamino group stabilizes the triazole
ring to a greater degree than the methyl group. Some tendency for the decrease of stability of triazoles with the
introduction of electron-withdrawing substituents into the phenyl ring is observed, but no strict Hammett
correlation is observed.
, in the reaction of α-cyanoacetylhydrazones
In contrast to acetylhydrazones 3 and 4
13 with tosyl azide
in the presence of sodium ethoxide the toluenesulfonamide group is not splitted off but takes part in
cycloaddition with the formation of benzylidenehydrazide of 5-amino-1-(p-toluenesulfonyl)-1,2,3-triazole-4-
carboxylic acid, which undergoes Dimroth rearrangement, giving 4(5)-tosylaminotriazole 14 (Scheme 3).
Diazotization of amine 15 by butyl nitrite in acetic acid gives diazohydrazone 16, which in solutions gradually
undergoes cyclization to 5-hydroxytriazole 17.
Scheme 3
O
O
O
N
N
CHPh
N
TsN3
CHPh
N
H
Ts
N
N
N
H
NC
N
N
N
N
H
CHPh
EtONa
N
H
N
H
13
NH2
14
Ts
NC
ONa
O
NC
OH
O
EtONa
NC
N
BuONO
HOAc
NC
N
N
H
CHPh
N
N
N
H
CHPh
N
N
N
N
N
18
N
17
NH2
15
N2
CHPh
CHPh
16
296

TABLE 1. The Characteristics of Hydrazones 3
1H NMR spectrum, δ, ppm (SSCC, J, Hz)*,*4
Com-
Empirical
Found N, %
——————
mp, °C
Yield, %
СН3CH2, t,
J = 7.1
СН3CH2, q,
pound formula
СН2(СО–)2, s
Нarom
N=CH, s+s
NH, s+s
Calculated N, %
J = 7.1
C12H14N2O3
11.95
11.96
112-113
160-163
163-168
163-165
117-121
180-181
163-165
110-111
145-147
1.17
1.15
1.17
1.16
1.17
1.17
1.18
1.18
1.14
4.09
4.13
4.10
4.10
4.09
4.11
4.11
4.09
4.08
3.34+3.64
3.65
7.44-7.70
m
7.97+8.18
7.96+8.18
7.92+8.2
7.80+8.20
7.83+8.30
8.8
11.55
11.61+11.57
11.42+11.46
11.40+11.44
11.18
83
83
86
87
63
84
84
74
65
3a
C12H13ClN2O3
C12H13FN2O3
C13H16N2O3
C14H19N3O2
C12H13N3O4
C12H13N3O4
C13H16N2O4
C14H18N2O5
11.06
7.48+7.68
3b
(8.5)*2
10.43
11.26
11.11
3.27
7.22+7.51
m+m
3c
11.38
3.26+3.30
2.95
7.30+7.55
3d
(8.4) *2
11.28
15.50
15.15
6.70+7.44
(8.4) *2
3e
15.32
3.41+3.71
3.41+3.70
3.34+3.62
3.33+3.61
7.89+8.26
11.82
3f
(8.9) *2
15.05
15.34
15.05
7.68-8.55
m
8.09+8.31
7.92+8.12
7.88+8.09
11.75
3g
10.30
6.98+7.57
11.39+11.44
11.40+11.41
3h
(8.8)*2
10.60
3
9.37
9.50
*
3i
_______
* Two conformers are present.
*2 4H, dd.
*3 7.32-6.92 (3H, ABC system, Jo = 8.3, Jm = 1.8, Harom).
*4 Signals of the methyl groups of compounds 3d: 2.32 (3H, s, MeAr); 3e: 2.95 (6H, s, Me2N); 3h: 3.80 (3H, s, MeO); 3i: 3.789 +
3.793 + 3.80 (6H, s + s + s, MeO).

TABLE 2. The Characteristics of Hydrazones 4
Com-
Empirical
1H NMR spectrum, δ, ppm (SSCC, J, Hz)
Yield,
%
Found N, %
——————
mp, °C
pound formula
Calculated N, %
CH3N
2.61 (4.5)
2.62+2.66 (4.8)
2.61 (4.7)
2.62 (4.8)
2.63 (4.3)
2.60 (4.8)
CH2
MeNH
7.88
7.94
8.20
8.10
7.78
8.13
Harom
N=CH
7.96+8.22
7.94+8.19
7.93+8.18
7.95
C=NNH
11.32+11.22
11.51+11.41
11.28+11.42
11.30
C11H13N3O2
19.30
19.17
206-208
222-224
130-133
210-215
153-155
180-185
3.14+3.48
3.14+3.48
3.14+3.49
3.15+3.50
3.09+3.45
3.14+3.48
7.44+7.63
50
80
54
75
73
54
4a
4b
4d
4f
C11H12ClN3O2
C12H15N2O2
C11H12N4O4
C12H15N3O3
C11H12BrN3O2
16.31
7.71+7.67 (8.6)*
7.22+7.52 (8.1)
7.22+7.49 (8.4)
6.84+6.89 (8.7)*2
7.35+7.52 (8.5)
16.56
17.68
18.01
20.74
20.20
18.29
16.86
7.87+8.10
7.89
11.15+11.21
11.35
4h
4j
15.57
13.97
_______
* 7.71 (2Н, d, J = 8.6); 7.67 (2Н, d, J = 8.6 ); isomers at 7.49 and 7.77 (J = 8.6 ).
*2 6.84 (2Н, d, J = 8.7); 6.89 (2Н, d, J = 8.7); isomers at 7.54 and 7.61 ( J = 8.7).

TABLE 3. The Characteristics of Sodium Salts of 5-Hydroxytriazoles
1H NMR spectrum, δ, ppm (SSCC, J, Hz)
Com-
Empirical
Found N, %
——————
mp, °C
Yield, %
СН3CH2, t
J = 6.9-7.1
CH3СН2, q
pound formula
N=CH, s
Нarom
Calculated N, %
J = 6.9-7.1
С12H11N4NaO3
19.45
19.85
225 (decomp.)
>300 (decomp.)
>300 (decomp.)
250-255
1.25
1.26
1.26
1.26
1.28
1.24
1.25
1.24
1.25
4.16
4.17
4.16
4.16
4.18
4.13
4.15
4.14
4.15
9.30
9.27
9.30
9.26
9.06
9.43
9.42
9.25
9.22
7.6-7.9, m
72
60
56
56
66
72
75
88
76
5a
5b
5c
5d
5e
5f
C12H10ClN4NaO3
C12H10FN4NaO3
C13H13N4NaO3
C14H16N5NaO3
C12H10N5NaO5
C12H10N5NaO5
C13H14N5NaO4
C14H15N4NaO5
17.29
7.52+7.87 (8.5)*
7.30+7.88, m
17.69
18.13
18.66
18.31
7.28+7.72 (8.0)*
6.77+7.50 (8.9)*
8.06+8.31 (8.8)*
18.91
21.08
21.53
240-242
21.22
>250 (decomp.)
305-311 (decomp.)
207-209 (decomp.)
>250 (decomp.)
21.40
2
21.31
21.40
*
5g
5h
5i
17.60
7.45+7.01 (8.6)*
17.94
3
16.20
16.37
*
_______
* 4Н, dd.
*2 5g: 8.65 (1Н, m, 2-Н); 8.3-8.2 (2Н, м, 4,6-Н); 7.76 (1Н, dd, J = 8.0, 5-Н).
*3 5i: 7.47 (1Н, d, Jм = 1.8, 2-Н); 7.32 (1Н, dd, Jo=8.5, Jм = 1.8, 6-Н); 7.04 (1Н, t, Jo = 8.5, 5-Н).
*4 Signals of methyl groups - 5d: 2.36 (3Н, s, MeAr); 5e: 2.99 (6Н, s, Me2N); 5h: 3.82 (3Н, s, МеО); 5i: 3.83
(6Н, s, (МеО)2).

TABLE 4. The Characteristics of Sodium Salts of 5-Hydroxy-4-methylcarbamoyltriazoles
Com-
Empirical
1H NMR spectrum, δ, ppm (SSCC, J, Hz)
Found N, %
——————
mp, °C
Yield, %
pound formula
Calculated N, %
СН3N*
Harom
NH
N=CH
9.33
9.31
9.32
9.48
9.25
9.33
С11H10N5NaO2
26.13
26.21
240-245 (decomp.)
>300 (decomp.)
>250 (decomp.)
>250 (decomp.)
>250 (decomp.)
>250 (decomp.)
2.75 (4.8)
2.77 (4.8)
2.65 (4.7)
2.62 (4.8)
2.75 (5.0)
2.60 (4.7)
7.83+7.47
7.89 (4.8)
7.82 (4.8)
7.59 (4.7)
7.51 (4.8)
7.94 (5.0)
7.53 (4.7)
94
83
94
95
86
93
6a
6b
6d
6f
C11H9ClN5NaO2
C12H12N5NaO2
C11H9N6NaO4
C12H12N5NaO3
C11H9BrN5NaO2
23.08
7.53+7.88 (8.6)
7.21+7.58 (8.1)
7.22+7.49 (8.4)
7.03+7.77 (8.9)
7.33+7.51 (4.7)
23.22
24.42
24.90
26.91
26.92
23.70
23.56
6h
6j
19.87
20.23
_______
* Other signals of methyl groups – 6d: 2.33 (3Н, s, CH3Ph); 6h: 3.82 (3Н, s, СН3О).
TABLE 5. The Characteristics of the Products from Neutralization of Sodium Salts of AHT 5
1H NMR spectrum, δ, ppm (DMSO-d6)
IR spectrum (KBr),
Initial
Content of 8, %
Keq·103
lg K
9
ν
, cm-1
N2
compound
8, N=CH
N=CH
NH
9.31
9.35
9.36
9.27
9.09
9.48
9.50
9.26
9.22
8.35
8.36
8.36
8.30
8.15
8.49
8.51
8.28
8.25
10.81
10.84
10.79
10.73
10.51
11.04
10.98
10.68
10.70
16.88
14.87
15.27
24.42
80.26
7.00
4.21
36.00
22.94
212±18
919±16
245±21
288±24
1514±130
60±5
39±3
463±40
380±33
-0.67
-0.72
-0.61
-0.54
0.18
-1.25
-1.41
-0.34
-0.42
2142
2145
2140
2150
2140
2150
2145
2155
2142
5a
5b
5c
5d
5e
5f
5g
5h
5i

TABLE 6. The Ring–Chain Equilibrium in the Series of Hydroxytriazoles
10 and 12
IR spectrum
Com-
pound
1H NMR spectrum, δ, ppm (DMSO-d6)
Content,
%
Kst
(KBr), νN2, cm-1
CH3N
CH3NH
CONHN
N=CH
2.81
2.81
3.75
2.81
2.81
3.74
2.81
2.81
3.75
2.81
2.81
3.74
8.05
8.05
—
8.40
8.40
—
8.00
8.35
—
8.03
8.03
—
—
9.35
8.43
8.43
9.36
8.40
8.40
9.30
8.49
8.49
9.34
8.42
8.42
11.3
79.9
8.8
12
73
15
15.3
83.3
4.2
13.1
77.1
9.8
0.14
—
0.11
0.16
—
0.20
0.20
—
10a
11a
12a
10b
11b
12b
10d
11d
12d
10j
11.73
11.73
—
11.80
11.75
—
12.01
12.01
—
11.73
11.73
2118
2130
2140
2110
0.05
0.17
—
11j
0.13
12j
The cyclic structure of the compound 17 is confirmed by the absence of the absorption band of the diazo
group in the region of 2060-2160 cm-1 and by the downfield shift of the peak for the proton of the N=CH group
compared with the initial hydrazone. In contrast to hydroxytriazoles 8, 10, and 12, it was not possible to detect
the presence of diazo compound 16 in the DMSO solution by means of the 1H NMR spectra. Hydroxytriazole 17
forms sodium salt 18 with sodium ethoxide.
The benzylidene protection in triazolates 5a, 6a, and 18 was removed by boiling them in ethanol with
one equivalent of hydrazine or by boiling for many hours in water with distillation of benzaldehyde as an
azeotrope with water (Scheme 4). The structure of the obtained sodium salts of the derivatives of 1-amino-5-
hydroxy-1,2,3-triazole-4-carboxylic acid 19, 20, and 21 is confirmed by the absence of the absorption band of
the diazo group in the IR spectra and by the magnitude of the chemical shift of the amino group, typical of N-
aminotriazoles [2].
Scheme 4
O
R
ONa
R
OH
+
+H
H2NNH2
R
NH2
5a, 6a, 18
N
H
N
N
N
N
or
NH2
NH2
N
N2
N
+H2O
-PhCHO
25–27
21, 24, 27
R = CN
19 21
22 24
–
–
19, 22, 25
20, 23, 26
R = MeNHCO;
R = EtOCO;
The products obtained during acidification of sodium salts of hydroxytriazoles 19-21 are mostly diazo
compounds 25-27, formed as a result of opening of the triazole ring in the supposed intermediate
5-hydroxytriazoles 22-24. This is indicated by the presence of a strong absorption band of the diazo group at
2145 cm-1 in the IR spectrum and a broad one-proton singlet, corresponding to the proton of the C(O)NH group
at 9.95 ppm in the 1H NMR spectra.
Thus, an accessible general method has been developed for the production of N-amino-5-hydroxy-1,2,3-
triazoles. A correlation was obtained between their thermodynamic stability and the nature of the substituents.
301

EXPERIMENTAL
The IR spectra were recorded on an UR-20 instrument in tablets with potassium bromide. The 1H NMR
spectra in DMSO-d6 solution were obtained on a Bruker WM-250 instrument with TMS as internal standard.
.
The AHT
DAA equilibrium constants were determined in DMSO-d6 solution at 23±2°C from the integral
1
intensities of the peaks in the H NMR spectra measured 24, 48, and 72 h after dissolution. The equilibrium
constants were calculated as the ratio of the integral intensities of the signals from the protons of the azomethine
(or methyl) groups of hydroxytriazoles 8 (10 or 12) and the respective diazo compounds 9 (or 11). The
parameters of the correlation equation for the dependence of the equilibrium constant on the σ-constants of the
substituents were obtained by the method of least squares. The Jaffe σ-constants were used [11].
O-Ethylmalonylhydrazine 1 was obtained by the method [12].
Methylcarbamoylacetohydrazide (2). Solution of hydrazide 1 (29.24 g, 0.2 mol) in ethanol (65 ml)
was saturated at 10-15°C with gaseous methylamine, produced from methylamine hydrochloride (53.8 g,
0.8 mol) and potassium hydroxide (44.7 g, 0.8 mol), and was left at room temperature overnight. The solvent
and the excess of methylamine were removed under vacuum at a temperature not exceeding 50°C. The residue
was diluted with equal volume of ethanol and left at 0-5°C for 2-3 h. The precipitate was filtered off,
recrystallized from a small amount of ethanol, and dried under vacuum at room temperature. Yield 19.8 g
(50%); mp 104-106°C. Found, %: N 31.65. C4H9N3O2. Calculated, %: N 32.04.
Hydrazones of Ethoxycarbonyl- and Methylcarbamoylacetohydrazide (3) and (4). Mixture of
equimolar amounts of hydrazide 1 (or 2) and the respective substituted benzaldehyde was heated in ethanol at
50-60°C for 2-3 h and cooled to 5-10°C. The precipitate was filtered off, washed with ethanol, and recrystallized
from ethanol (Tables 1 and 2).
Sodium Salts of 1-Arylmethylideneamino-4-ethoxycarbonyl- and 1-Arylmethylideneamino-4-
methylcarbamoyl-5-hydroxy-1,2,3-triazoles (5) and (6). To suspension of hydrazone 3 (or 4) (0.01 mol) in
absolute ethanol (20 ml) under stirring at 5-10°C we added sodium ethoxide (0.01 mol) in ethanol (6 ml) and
over 15 min p-tosyl azide (1.97 g, 0.01 mol) in ethanol (10 ml). The mixture was stirred at 5-10°C for 3 h and
kept for further 24 h at room temperature. The precipitate was filtered off, washed with ethanol, and crystallized
from ethanol (Tables 3 and 4).
Acidification of Sodium Salts 5 and 6. Salt 5 (or 6) was dissolved in a small amount of water, and the
solution was acidified at 5-10°C with one equivalent of dilute hydrochloric acid. The precipitate was filtered
off, washed with water, and dried under vacuum at room temperature over calcium chloride (Tables 4 and 6).
4(5)-Tosylamino[1,2,3]triazole-5(4)-benzylidenecarbohydrazide (14). The compound was obtained
1
under conditions similar to those described for compounds 5 and 6. The yield was 81%; mp >290°C. H NMR
), δ, ppm,
spectrum (DMSO-d6
J, Hz: 13.67 (1H, br. s, 1-H); 11.80 (1H, br. s, SO2NH); 8.14 (1H, s, N=CH); 7.87
(2H, m, Harom); 7.75 + 7.30 (4H, d + d, J = 8.2, AB system); 7.50 (3m, Harom); 2.32 (3H, s, CH3). Found, %:
N 21.46; S 8.17. C17H16N6O3S. Calculated, %: N 21.86; S 8.34.
Aminocyanoacetobenzylidenehydrazide (15). The compound was obtained by analogy with
. Equimolar amounts of α-amino-α-cyanoacetohydrazide [13] and benzaldehyde were stirred for 2
compound 3
h
1
), δ, ppm: 13.67 (1H,
in ethanol at room temperature. Yield 78%; mp 123-125°C. H NMR spectrum (DMSO-d6
br. s, CONH); 8.37 + 8.06 (1H, s + s, N=CH); 7.8-7.3 (5H, m, Harom); 5.17 + 4.86 (2H, s + s, NH2). Found, %: N
27.4. C10H10N4O. Calculated, %: N 27.7.
α-Diazo-α-cyanoacetobenzylidenehydr
azide (16) and 1-Benzylideneamino-5-hydroxy-1,2,3-
triazole-4-carbonitrile (17). To solution of amine 15 (4 g, 0.02 mol) in glacial acetic acid (12 ml) we added
dropwise with stirring and cooling (10-15°C) butyl nitrite (3 ml, 2.65 g, 0.025 mol). After stirring at 0-5°C for
1 h the precipitate of 16 was filtered off and washed with acetic acid and then with ether. IR spectrum, , cm-1:
ν
2218 (CN), 2148 (N=N), 1658 (CO). Recrystallization of hydrazide 16 from acetonitrile gave triazole 17.
302

1
), δ, ppm: 9.31 (1H, s, N=CH); 12.31 (1H,
Yield 2.22 g (52%); mp 164°C (expl.). H NMR spectrum (DMSO-d6
s, NH). IR spectrum, , cm-1: 2217 (C N), 1705, 1687 sh, 1665 sh (C=O). Found, %: N 33.1. C10H7N5O.
ν
≡
Calculated, %: N 32.8.
Sodium Salt of Hydroxynitrile 17 (18). Suspension of compound 17 in absolute ethanol was treated
1
with one equivalent of sodium ethoxide. The salt was precipitated with ether. H NMR spectrum (DMSO-d6),
δ,
ppm: 9.30 (1H, s, N=CH); 7.93 + 7.54 (5H, m + m, Harom). Found, %: N 29.25. C10H6N5NaO. Calculated, %:
N 29.78.
Sodium 1-Amino-4-R-1,2,3-triazol-5-olates (19-21). A. Mixture of salt 5a (or 6a or 18) (10 mmol),
100% hydrazine (0.35 g, 11 mmol), and ethanol (150 ml) was boiled for 15 h. The reaction mass was evaporated
under vacuum to 20-30 ml and cooled at 0-5°C for 2 h. The precipitate was filtered off, washed with ethanol,
1
), δ, ppm,
and dried at 50-60°C. Compound 19: yield 81%; mp >250°C. H NMR spectrum (DMSO-d6
J, Hz:
5.25 (2H, br. s, NH2); 4.13 (2H, q, J = 7.0 Hz, CH2); 1.23 (3H, t, J = 7.0). Found, %: N 28.25. C5H7N4NaO3.
1
), δ, ppm,
Calculated, %: N 28.85. Compound 20: yield 90%; mp 300-305°C. H NMR spectrum (DMSO-d6
J, Hz: 7.86 (1H, q, J = 4.7, CONH); 5.30 (2H, s, NH2); 2.72 (3H, d, J = 4.7, CH3). Found, %: N 38.70.
C4H6N5NaO2. Calculated, %: N 39.10. Compound 21: yield 50%; mp >250°C. Found, %: N 47.22. C3H2N5NaO.
Calculated, %: N 47.62.
B. For compound 19. Solution of salt 5a (3 g) in distilled water (200 ml) was filtered and boiled with
distillation of the azeotropic mixture of benzaldehyde and water. Water was added from time to time, and the
process took about 50 h. The reaction mixture was evaporated to dryness. The residue was suspended in the
minimum amount of ethanol and cooled to 0-5°C. The precipitate was filtered off and dried. Yield 70%. The
product was identical with that obtained in method A.
α-Diazo-α-R-acetohydrazides (25-27).
Solution of salt 19 (20 or 21) in water was acidified with one
equivalent of hydrochloric acid and evaporated to dryness under vacuum. The product was dissolved in boiling
ethanol, sodium chloride was filtered off, and the filtrate was evaporated to dryness under vacuum. The
precipitate was suspended in ether and filtered off. Compound 25: yield 55%; mp 157-160°C. H NMR
1
), δ, ppm,
spectrum (DMSO-d6
J, Hz: 9.94 (1H, br. s, NH); 5.5-7.5 (2H, br. s, NH2); 4.28 + 4.23 (2H, q + q,
J = 7.2, CH2); 1.27 (3H, t, J = 7.2, CH3). IR spectrum, , cm-1: 2145 (N2). Found, %: N 33.03. C5H8N4O3.
ν
1
Calculated, %: N 33.25. Compound 26: yield 65%; mp 200-203°C (decomp.). H NMR spectrum (DMSO-d6),
δ,
ppm, J, Hz: 7.87 (1H, br. s, NH); 4.25 (2H, br. s, NH2); 2.75 (3H, d, J = 4.0, CH3). Found, %: N 44.02.
C4H7N5O. Calculated, %: N 44.57. Compound 27: yield 50%; mp 150°C (decomp.) IR spectrum, , cm-1:
ν
2250 (CN), 2150 (N=N). Found, %: N 55.27. C3H3N5O. Calculated, %: N 55.99.
The work was carried out with financial support from the Russian Fundamental Research Fund (grant
98-03-33045a) and the fund of the Russian Ministry of Education of the Russian Federation, grant 97-0-9.4-235.
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