A Base-Controlled Reaction of 2-Cyanoacetamidines (3,3-Diaminoacrylonitriles) with Sulfonyl Azides as a Route to Nonaromatic 4-Methylene-1,2,3-triazole-5-imines

Article abstract of DOI:10.1002/ejoc.202000453

Reactions of 2-cyanoacetamidines with sulfonyl azides were shown to take place via two different pathways to form a mixture of 1-substituted 5-amino-1,2,3-triazoles 3 and novel 4-methylene-1H-1,2,3-triazole-5(4H)-imine derivatives 4–14. In the absence of

Full text of DOI:10.1002/ejoc.202000453

European Journal of Organic Chemistry
Accepted Article
Accepted Article
Title: A Base-controlled Reaction of 2-Cyanoacetamidines (3,3-
Diaminoacrylonitriles) with Sulfonyl Azides as a Route to
Nonaromatic 4-Methylene-1,2,3-triazole-5-imines
Authors: Pavel S. Silaichev, Tetyana Beryozkina, Mikhail S. Novikov,
Wim Dehaen, and Vasiliy A. Bakulev
This manuscript has been accepted after peer review and appears as an
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of the final Version of Record (VoR). This work is currently citable by
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to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
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To be cited as: Eur. J. Org. Chem. 10.1002/ejoc.202000453
Link to VoR: https://doi.org/10.1002/ejoc.202000453
01/2020

10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
A Base-controlled Reaction of 2-Cyanoacetamidines (3,3-
Diaminoacrylonitriles) with Sulfonyl Azides as a Route to
Nonaromatic 4-Methylene-1,2,3-triazole-5-imines
Pavel S. Silaichev,[a,b] Tetyana V. Beryozkina,*[a] Mikhail S. Novikov,[c] Wim Dehaen,*[d] and Vasiliy A.
Bakulev[a]
[a]
Dr. P. S. Silaichev, Dr. T. V. Beryozkina, Prof. Dr. V. A. Bakulev
Ural Federal University named after the first President of Russia B. N. Yeltsin
19 Mira st. Yekaterinburg 620002, Russia
E-mail: t.v.berezkina@urfu.ru
[b]
[c]
[d]
Dr. P. S. Silaichev
Department of Chemistry, Perm State University
15 Bukireva st., Perm 614990, Russia
Prof. Dr. M. S. Novikov
St. Petersburg State University, Institute of Chemistry
7/9 Universitetskaya nab., St. Petersburg 199034, Russia
Prof. Dr. W. Dehaen
Molecular Design and Synthesis, Department of Chemistry, KU Leuven
Celestijnenlaan 200F, B-3001 Leuven, Belgium
E-mail: wim.dehaen@chem.kuleuven.be
Supporting information for this article is given via a link at the end of the document.
Abstract: Reactions of 2-cyanoacetamidines with sulfonyl azides
were shown to take place via two different pathways to form a
mixture of 1-substituted 5-amino-1,2,3-triazoles 3 and novel 4-
methylene-1H-1,2,3-triazole-5(4H)-imine derivatives 4-14. In the
absence of a base, 5-amino-1,2,3-triazoles 3 are formed as the only
products. The presence of 1.2 equiv of sodium ethoxide or DBU
switches the reaction outcome while involving the cyano group,
resulting (after a 1,5-protic shift) in triazoles 4-14 as the only
products. The methods were elaborated for the selective and
efficient synthesis of triazoles 3 and 4-methylene-1,2,3-triazole-5-
imines 4-14 including one-pot synthesis from sodium azide and
sulfonyl chlorides. The unusual structure of 4-14 compounds was
1,2,3-triazoles remains
Because few 5-amino-1,2,3-triazole derivatives were
synthesized from the reaction of 2-
ethoxycarbonylacetamidines[10] and from malonodinitrile with
benzenesulfonyl azide[13] we turned our attention to the reactivity
of 2-cyanoacetamidines towards sulfonyl azides to prepare
derivatives of 5-amino-1,2,3-triazole-4-carbimidamides (Scheme
1).
a subject worthy of investigation.
a
confirmed by X-ray data and 2D H‒15N and H‒13C NMR spectra.
The formation of the products was explained by the presence of two
strong hydrogen bonds N···H and O···H in these molecules.
1
1
Introduction
Since the beginning of this millennium, 1,2,3-triazoles have
become very fashionable and rather available compounds due
to the landmark discovery of copper catalyzed alkyne azide
cycloaddition (CuAAC)[1] giving access to various types of 1,2,3-
triazoles and facilitating their use in medicinal chemistry,[2] in
organic synthesis as building blocks,[3] in chemical biology,[4] and
in material chemistry.[5] Apart from the CuAAC reaction, the
transformation of functionalized hydrazones,[6] the reactions of
azides with enamines,[7] and carbonyl active methylene
compounds,[6,8]
reactions
of
NH-1,2,3-triazoles
with
electrophiles,[6,9] intra-[10] and intermolecular reactions of diazo
compounds with aldimines,[6] and transformations of other
heterocyclic compounds[11] are the main synthetic methods
towards 1,2,3-triazoles of various structures. However, these
methods are not applicable to the synthesis of 1,2,3-triazoles
bearing both sulfonylamido and amidino groups which are of
interest for medicinal chemistry.[12] Hence, the search of new
effective methods for the synthesis of variously substituted
Scheme 1. Reactions of methylene active amidines with sulfonyl azides.
1
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It is worth noting that in contrast to the well-studied 2-
cyanothioacetamides,[11a,14] the chemistry of their aza analogs,
2-cyanoacetamidines is poorly described in the literature[15] and
their reactions with azides presented in only one report.[15e] It
was shown there that the formation of intermediate diazo
compounds took place as a result of diazo group transfer (Regitz
reaction), which then cyclized to 5-amino-1,2,3-triazole-4-
carbonitriles (Scheme 1). The generally accepted opinion on the
single diazo group transfer direction of methylene active
amidines with sulfonyl azides has been held for the long
time.[16,20]
of 4a and can be considered an alternative protocol of the
synthesis of compounds 4 (Table 1, Supporting Info, Table S1).
Table 1. Optimization of the Reaction Conditions for the Synthesis of Triazole
4a[a]
Combined experimental and theoretical studies of the reaction of
amidines 1 with azides 2 have now demonstrated two different
pathways for this reaction, leading to 5-amino-4-cyano-1,2,3-
triazoles 3 and novel 5-sulfonylimido-4-methylene-1,2,3-triazoles
4-14 (Scheme 1). Depending on the presence and amount of
base used, the direction of the reaction can be switched in favor
of either compound. Thus, proper conditions were found and
methods were elaborated for the selective and efficient
Entry
T,
°C
Solvent
Base
Time
(min)
Ratio
4a/3a
Isolated
yield,
4a (%)
synthesis of 4-cyano-5-cycloamino-1,2,3-triazoles
3 and 4-
1
2
rt
rt
EtOH (95%)
EtOH (95%)
EtOH (95%)
EtOH (anh.)
EtOH (anh.)
i-PrOH (anh.)
1,4-dioxane
EtOH (anh.)
1,4-dioxane
‒
30
30
30
30
30
30
30
30
30
2/98
17/83
69/31
92/8
95/5
94/6
95/5
99/1
‒
‒
methylene-1,2,3-triazole-5-imines 4-14 (Scheme 1). The
pathway to triazoles 4-14 represents a novel method of the
synthesis of 1,2,3-triazoles based on tandem heterocyclization
of 2-cyanoacetamidines and sulfonyl azides to 1-sulfonyl-1,2,3-
triazoles and their subsequent rearrangement followed by a 1,5-
protic shift to form the final products.
Et3N
‒
3
rt
DBU
‒
4
rt
EtONae
EtONae
i-PrONae
DBU
87f
89f
89f
90f
93f
91f
5c
6
rt
rt
Results and Discussion
7
rt
Usually, reactions of active methylene compounds with azides
take place in the presence of various bases.[11a,17,18] In this work,
we have found that 2-cyanoacetamidines 1 can react with mesyl
azide even in the absence of an external base to form 4-
cyanotriazoles 3 confirming the Regitz diazo-group-transfer
course for this reaction.[18] The use of mesyl azide allows to
easily separate the triazoles 3 from the by-product, mesyl amide
by washing out the latter with water. It should be noted that
mesyl azide is potentially explosive, and all reactions should be
carried out behind blast shields. At the more available and
considerable less expensive than 2-morpholinoethylsulfonyl
azide which has been used previously[15e] to prepare compounds
3. Furthermore the LCMS analysis of the sample 3a showed,
next to same time, mesyl azide is the major products 3a the
presence of a very small impurity of triazole 4a.
8b
9d
-10
rt
EtONae
DBU
[a]Unless noted, 1a (0.1 mmol), 2a (0.1 mmol), base (100 mol %) in the solvent
(0.4 mL) at the indicated temperature for the time given. Ratio 4/3 in mixtures
estimated by 19F NMR spectra for compound 4a and FBSA (concentration of
4a and FBSA are always equal). [b]Base (120 mol %). [c]Base (200 mol %).
[d]1a (1.0 mmol), 2a (1.0 mmol) in the solvent (4 mL). [e]Was used as freshly
prepared solution from sodium and anhydrous alcohol. [f]Isolated yield after
crystallization from ethanol.
Encouraged by these results, we used these optimized reaction
conditions for the reactions of tertiary 2-cyanoacetamidines 1a-f
with sulfonyl azides 2a-f. Their structures are shown in Scheme
2. We have shown that all amidines 1 smoothly react with azides
2 to form a series of 33 compounds 4-14 (Scheme 3).
In order to study the use of 2-cyanoacetamidine as a C‒C‒C‒N
building block and to involve the CN group in the process
leading to 4-methylene-1,2,3-triazole-5-imines from sulfonyl
azides, we screened the reaction conditions using 3-(azepane-1-
yl)-3-iminopropanenitrile (1a) and 4-fluorobenzenesulfonyl azide
2a as model reagents (Table 1 and Table SI1 of Supporting Info).
Our initial optimization studies revealed the fact that depending
on the presence and amount of base used, the direction of the
reaction can be switched in favor of either product. In the
absence of a base or in the presence of weak bases triazole 3a
is formed as major product. As it is seen from the Table 1 the
use of strong bases, low temperature favor the formation of
triazole 4a. The optimal conditions for the synthesis of the target
compound 4a include the use of ethanol as a solvent, 1.2 equiv
of a sodium ethoxide, and a temperature of -10 °C. The use of
DBU in either 1,4-dioxane or benzene gives a slightly less yield
The reaction tolerates different tertiary amine moieties in
amidine group of compounds 1 and 4-substituents in the aryl of
the arylsulfonyl azides 2. However, in contrast to other
compounds, the yields of 1,2,3-triazoles 4e-8e bearing a 4-
nitrobenzenesulfonyl group are only moderate (31‒38%).
Fortunately, the use of DBU in 1,4-dioxane allowed us to obtain
these compounds in high yields. Triazoles 14a-c bearing
methylsulfonimido group were also prepared by alternative
protocol. The formation of triazoles 4 took place with retention of
all the reagent atoms and therefore can be referred to as an
atom economic process, to be used for the design of a new
green chemistry process. Thus, we have elaborated a general
method for the synthesis of novel 5-sulfonylimino-1H-1,2,3-
triazole-4(5H)-ylidene)methanediamine derivatives 4-14 bearing
2
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10.1002/ejoc.202000453
European Journal of Organic Chemistry
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various tertiary methylenediamine moieties and sulfonylimino
groups in good to excellent yields (mainly 80‒95%) (Scheme 3).
narrow range of 131.6‒139 ppm,[14c] allowing to exclude the
tautomer form A from consideration.
Table 2. The yields of triazoles 4a,c, 5a,c, 8a,c according to the one-pot
protocol[a] compared to the yields involving isolation of azides.
Entry
ArSO2Cl
Amidine
Product
Yields of triazoles, %
2'
1
Ar
one-pot
with
synthesis
isolation of
azide 2
1
2
3
4
5
6
4-FC6H4 (2'a)
4-FC6H4 (2'a)
4-FC6H4 (2'a)
Tolyl (2'c)
1a
1b
1e
1a
1b
1e
4a
5a
8a
4c
5c
8c
80
88
85
88
87
88
79
81
81
80
81
80
Tolyl (2'c)
Tolyl (2'c)
[a]1) 2' (1.00 mmol), NaN3 (1.05 mmol), EtOH (2 mL), rt, 24 h. 2) 1 (0.90 mmol),
Na (1.08 mmol), EtOH (2 mL), 0 °C, 0.5 h.
Scheme 2. The structures of starting reagents used in this study.
The final prove of structure of 4-14 in the solid state was made
based on X-ray analysis for monocrystals of triazoles 4c, 5b, 7c
(Figs. S1-S3 of Supporting Info), and in the solution the
confirmation came from HSQC and HMBC 1H‒15N 2D NMR
spectra of 5c where there are cross peaks of the signals of both
protons of the NH2 group with the signal of 15N (Supporting Info).
The quantum chemical evaluation (DFT wB97XD/ccpvtz) of the
relative thermodynamic stability and bond lengths of all possible
tautomeric forms of compound 5b are shown in Figure 1.
The calculated bond lengths are close to those determined by X-
ray analysis for the 5b tautomer. Data of calculated energies
showed that tautomer 5b with the exocyclic C=C bond is more
stable than all other tautomers by more than 5 kcal/mol (Fig. 1).
The unexpectedly high thermodynamic stability of the non-
aromatic isomer 5b compared to its aromatic tautomers is due to
two very strong hydrogen bonds, N···H (1.854 Å) and O···H
Based on our knowledge that the reaction of sulfonyl azides 2
with 2-cyanoacetamidines 1 is leading to selective formation of
triazoles 4-14, to show the practical convenience of the
developed method we tried to synthesize these compounds in a
one-pot protocol starting from arylsulfonyl chlorides 2'a,c,
sodium azide and 2-cyanoacetamidines 1a,b,e (Table 2).
Sulfonyl chlorides 2' in EtOH were converted with sodium azide
to the sulfonyl azides, which were then treated with an ethanol-
alkali mixture of the corresponding amidine 1. After workup with
water and acetic acid pure triazoles 4a,c, 5a,c and 8a,c could be
filtered off in 80‒88% yield (Table 2). Table 2 demonstrates that
the yields of triazoles 4,5,8 using the one-pot procedure are
higher compared to the protocol involving the isolation of
sulfonyl azides 2. Thus, a convenient effective one-pot protocol
for the synthesis of triazoles 4,5,8 from readily available starting
reagents was elaborated. The method also allows to avoid
isolating the potentially explosive sulfonyl azides, increasing the
safety.
(2.059 Å).
A tentative mechanism for the formation of
compounds 3-14 is depicted in Scheme 4. We propose that the
triazenyl anion I1 generated by the addition of sulfonyl azide 2 to
the carbanion formed after deprotonation of 1 is a common
intermediate of the pathways leading to products 3-14. The
cyclization of anion I1 onto the cyano group leading to
triazolidine I2 (route a), and 1,4-prototropic shift in I1 leading to
NMR and HRMS of compounds 4-14 are consistent with the
proposed structure. Similar to other NH-triazoles, the 1H NMR
spectra of these compounds contain the signals of the NH
proton downfield in the range of 13.85‒14.29 ppm. Based on the
1H‒13C 2D NMR spectra of 11 we identified the signals of C4 and
C5 of 1,2,3-triazole ring at 117–119.5 and 146.1–147.7 ppm,
respectively. They are different from those for aromatic 5-
diazo compound I6 (route b)[14] are competitive reactions.
19
Cyclization of diazoimines I6 via heteroelectrocyclic
closure occurs to give final triazoles 3.
ring
sulfonamido-1,2,3-triazole which contain both signals in
a
3
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[a]Reaction condition: amidine 1 (1.0 mmol), sodium (28 mg, 1.2 mmol), anhydrous ethanol (4 mL), +10 °C, 5‒10 min → azide 2 (1.0 mmol), -10 °C, 1 h. [b]Isolated
yields. [c]With DBU (1.0 mmol) as the base, 1,4-dioxane (4 mL) as the solvent at room temperature for 10 min.
Scheme 3. Synthesis of triazole-4-carbonitriles 3 and triazoles 4-14.[a,b]
Alternatively addition of sulfonamide anion onto cyano group
and protonation of the latter by reaction by protic medium affords
1,2,3-triazoline I2. We propose that triazoline I2 easily
transforms in basic solution to aromatic triazole I3, and this is in
agreement with the isolation of stable 5-amino-1-aryl-1,2,3-
triazole-4-carbonitriles in reactions of malonodinitrile with
arylazides.[17] Then rearrangement of triazole I3, bearing strong
withdrawing sulfonyl group destabilizing the ring,[20] can
undergoes by either Dimroth type or double Cornforth type
resulting triazole I5 which are well known in the 1,2,3-triazole
series.[18]. An alternative for the transformation of I3 to I5 would
be intra- or intermolecular sulfonyl transfer similar to the report
of Watanabe et al.21 The final step includes unprecedented 1,5-
protropic shift for 1-sulfonylamino-3-iminopropenes leading to
Figure 1. Relative free energies (kcal/mol) and the bond lengths (Å) of
triazoles 5b,5b1,5b2,5b3 (bond lengths according RSA are in parentheses).
products 4-14.
4
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Scheme
4.
A
plausible
mechanism
for
the
formation
of
compounds
3-14.
shifts (δ) were expressed in ppm, and J values were given in Hz. High-
resolution mass spectra (HRMS) were obtained via electrospray
ionization source (ESI). The IR spectra were recorded with a FT-IR ATR
(attenuated total reflection, ZnSe) spectrometer in the 4000−500 cm-1
region. The reactions were monitored by analytical TLC on Sorbfil UV-
254 aluminum foil plates with 0.2 mm silica gel with a fluorescent
indicator visualized under UV light. Melting points were determined on
Stuart SMP10 melting point apparatus and are uncorrected.
Conclusion
In conclusion, an effective and flexible approach to
functionalized 1,2,3-triazoles from 2-cyanoacetamidines and
sulfonyl azides is described. The variation of the type of a
solvent and base allowed using the 2-cyanoacetamidines either
as C‒C‒N or C−C building blocks to form NH-1,2,3-triazoles 3
and 4-14, respectively, from the same reagents. The use of 1.2
equiv of sodium ethoxide in ethanol or in other alcohols and use
of DBU in either 1,4-dioxane of benzene changes the direction
of the reaction, allowing the construction of novel 5-
sulfonylimido-4-methylene-1,2,3-triazoles 4-14 as the only
products. This dramatic redirection of the reaction course is
explained by a plausible mechanism: a common intermediate
triazenide-anion resulting from cyanoacetamidine and sulfonyl
azides undergoes either 1,4-prototropic shift followed by 1,5-
cyclization or cyclization of azide involving the cyano group to
form triazoles 3 or 4-14, respectively. The unusual structure of
compounds 4-14 is rationalized by the presence of two hydrogen
bonds N···H and O···H in these molecules.
Preparation of Amidines. Amidines 1b-f were synthesized from ethyl 2-
cyanoacetimidate and corresponding amines according to the literature
procedures.[22,15e]
Preparation of Sulfonyl Azides. Sulfonyl azides 2a-f were prepared
from the corresponding sulfonyl chlorides[23] following the literature
procedures. Warning! Sulfonyl azides are potentially explosive, and all
reactions should be carried out behind blast shields. We recommend the
use of plastic spatulas for the handling of solid material.
(E)-3-Amino-3-(azepane-1-yl)acrylonitrile (1a).[24] A solution of ethyl 2-
cyanoacetimidate (6.08 g, 54.3 mmol) and azepane (5.37 g, 54.3 mmol)
in anhydrous EtOH (54 mL) was stirred at ambient temperature for 24 h.
Then the solution was kept in a cold place for 3 h. The formed precipitate
was filtered off and washed with dry Et2O to give 1a as a colorless solid;
mp 109‒110 °C (lit.[22] 108‒109 °C (PhH)). 1H NMR (400 MHz, DMSO-
d6): δ 1.44‒1.50 (m, 4H), 1.62 (br. s, 4H), 2.87 (s, 1H), 3.26‒3.29 (m, 4H),
5.45 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 26.2 (2C), 27.3 (2C),
37.3 (2C), 48.1, 124.3, 161.8.
Experimental Section
General
Starting materials and reagents were purchased from commercial
sources and used without further purification. Ethanol was dried and
distilled over CaO and magnesium shavings correspondingly prior to use.
1H and 13C NMR spectra were recorded at 400 and 100 MHz,
respectively, with SiMe4 as internal reference in DMSO-d6, the chemical
General Procedure for the Synthesis of Triazole-4-carbonitriles 3
Mesyl azide (2f) (121 mg, 1.0 mmol) was added to the solution of
amidine 1 (1.0 mmol) in ethanol (4‒8 mL) and the resulting mixture was
5
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10.1002/ejoc.202000453
European Journal of Organic Chemistry
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stirred at room temperature (at 50 ºC for 3d) for 30 min. Then the solvent
was removed under reduced pressure and water (4 mL) was added to
the residue. The resulting suspension was heated at reflux for 1 min and
then cooled to room temperature. The precipitate was filtered off, washed
with water, dried and crystallized from ethanol or DCM.
Method B
DBU (152 mg, 1.0 mmol) was added to the solution of amidine 1 (1.0
mmol) in 1,4-dioxane (4 mL) at room temperature was stirred for 5 min
and then azide 2 (1.0 mmol) was added. The reaction mixture was stirred
for 10 min at room temperature, then glacial acetic acid (0.6‒0.8 mL) was
added and the resulting solution was stirred for 15 min more. Then water
(15 mL) was added to the reaction mixture, formed precipitate was
filtered off, washed with water and dried in a desiccator over P4O10.
5-(Azepane-1-yl)-1H-1,2,3-triazole-4-carbonitrile (3a).[15e] Compound
3a was obtained in 96% yield (366 mg) according to the general
procedure (amidine 1a: 330 mg, 2.0 mmol; azide 2f: 252 mg, 2.0 mmol;
ethanol (8 mL)) as a colorless solid; mp 175‒176 °C (DCM) (lit.[15e]
174‒175 °C). 1H NMR (400 MHz, DMSO-d6): δ 1.44‒1.54 (m, 4H, 2CH2),
1.66‒1.76 (m, 4H, 2CH2), 3.43‒3.54 (m, 4H, 2CH2), 14.78 (br. s, 1H, NH).
13C NMR (100 MHz, DMSO-d6): δ 26.4 (CH2), 27.4 (CH2), 49.7 (CH2),
99.6 (C4), 115.2 (CN), 151.0 (C5).
Method C
A mixture of sulfonyl chloride 2' (1.00 mmol) and NaN3 (68.25 mg, 1.05
mmol) was stirred in ethanol (2 mL) for 24 h at room temperature.
Ethanol-alkali mixture of corresponding amidine 1, prepared from ethanol
(2 mL), Na (25 mg, 1.08 mmol) and amidine 1 (0.9 mmol) was added to
the reaction mixture at 0° C, and the resulting suspension was stirred at
0 °C for 30 min. Then water (10 mL) and glacial acid (0.8 mL) were
added to the reaction mixture. Formed precipitate was filtered off,
washed with water and dried in a desiccator over P4O10.
5-(Pyrrolidin-1-yl)-1H-1,2,3-triazole-4-carbonitrile (3b).[15e] Compound
3b was obtained in 94% yield (153 mg) according to the general
procedure (amidine 1b: 137 mg, 1.0 mmol; azide 2f: 121 mg, 1.0 mmol;
ethanol (4 mL)) as a colorless solid; mp 217‒219 °C (ethanol) (lit.[15e]
219‒220 °C). 1H NMR (400 MHz, DMSO-d6): δ 1.94 (br. s, 4H, 2CH2),
3.40 (br. s, 4H, 2CH2), 14.81 (br. s, 1H, NH). 13C NMR (100 MHz, DMSO-
d6): δ 25.0 (CH2), 48.7 (CH2), 100.0 (C4), 115.1 (CN), 149.6 (C5).
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)fluorobenzenesulfonamide (4a). Compound 4a was
obtained in 93% yield (340 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2a: 201
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 185‒186 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.53 (br. s, 4H), 1.77 (br. s, 4H), 3.61 (br. s,
2H), 4.21 (br. s, 2H), 7.27 (t, J = 9.0 Hz, 2H), 7.88 (dd, J = 9.0, 5.4 Hz,
2H), 8.19 (br. s, 1H), 8.54 (br. s, 1H), 14.18 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 25.1, 25.8, 25.9, 28.2, 50.0, 51.8, 115.4 (d, J = 22 Hz),
118.6, 128.4 (d, J = 9 Hz), 141.1 (d, J = 3 Hz), 146.9, 155.2, 163.2 (d, J =
248 Hz). IR (ATR, ZnSe, cm-1): ν 3313, 3171, 3110, 2935, 2857, 1650,
1587, 1550, 1368, 1219, 1043, 935. HRMS (ESI-TOF) m/z calcd. for
C15H20FN6O2S [M+H]+: 367.1347, found 367.1356.
5-(Piperidin-1-yl)-1H-1,2,3-triazole-4-carbonitrile (3c).[15e] Compound
3c was obtained in 91% yield (161 mg) according to the general
procedure (amidine 1c: 151 mg, 1.0 mmol; azide 2f: 121 mg, 1.0 mmol;
ethanol (4 mL)) as a colorless solid; mp 180‒183 °C (DCM) (lit.[15e]
180‒181 °C). 1H NMR (400 MHz, DMSO-d6): δ 1.57‒1.62 (m, 6H, 3CH2),
3.34‒3.41 (m, 4H, 2CH2), 15.03 (br. s, 1H, NH). 13C NMR (100 MHz,
DMSO-d6): δ 23.1 (CH2), 24.3 (2CH2), 48.5 (2CH2), 102.4 (C4), 114.6
(CN), 153.4 (C5).
5-(4-Benzylpiperidin-1-yl)-1H-1,2,3-triazole-4-carbonitrile
(3d).[15e]
Compound 3d was obtained in 93% yield (247 mg) according to the
general procedure (amidine 1d: 241 mg, 1.0 mmol; azide 2f: 121 mg, 1.0
mmol; ethanol (4 mL) as a colorless solid; mp 172‒174 °C (DCM) (lit.[15e]
Compound 4a was obtained in 80% yield (263.5 mg) according to the
general procedure C (4-fluorobenzenesulfonyl chloride (2'a): 194 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1a: 148.5 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
185‒186 °C.
1
173‒174 °C). H NMR (400 MHz, DMSO-d6): δ 1.23-1.33 (m, 2H, CH2),
1.64‒1.67 (m, 2H, CH2), 1.70‒1.80 (m, 1H, CH), 2.51-2.58 (m, 2H, CH2),
2.94‒2.99 (m, 2H, CH2), 3.80 (d, J = 12.0 Hz, 2H, CH2Ph), 7.16‒7.20 (m,
3H, Ph), 7.26‒7.30 (m, 2H, Ph), 15.00 (br. s, 1H, NH). 13C NMR (100
MHz, DMSO-d6): δ 30.2 (CH2), 36.2 (CH), 41.7 (CH2Ph), 47.8 (CH2),
102.7 (C4), 114.3 (CN), 125.6 (Cp-), 127.9 (Co-), 128.8 (Cm-), 139.7 (Ci-),
153.5 (C5).
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)benzenesulfonamide (4b). Compound 4b was
obtained in 86% yield (299 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2b: 183
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 198‒199 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.53 (br. s, 4H), 1.76 (br. s, 4H), 3.60 (m,
2H), 4.22 (br. s, 2H), 7.41‒7.48 (m, 3H), 7.81‒7.86 (m, 2H), 8.17 (br. s,
1H), 9.60 (br. s, 1H), 14.17 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ
25.0, 25.7, 25.9, 28.2, 50.0, 51.7, 118.3, 125.5, 128.4, 130.7, 144.7,
147.0, 155.2. IR (ATR, ZnSe, cm-1): ν 3301, 3110, 2922, 2853, 1652,
1591, 1554, 1124, 1084, 994. HRMS (ESI-TOF) m/z calcd. for
C15H21N6O2S [M+H]+: 349.1441, found 349.1443.
5-Morpholino-1H-1,2,3-triazole-4-carbonitrile (3e).[15e] Compound 3e
was obtained in 96% yield (171 mg) according to the general procedure
(amidine 3e: 153 mg, 1.0 mmol; azide 2f: 121 mg, 1.0 mmol; ethanol (4
mL)) as a colorless solid; mp 206‒207 °C (DCM) (lit.[15e] 207‒208 °C). 1H
NMR (400 MHz, DMSO-d6): δ 3.30‒3.39 (m, 4H, 2CH2), 3.68‒3.79 (m,
4H, 2CH2), 15.14 (br. s, 1H, NH). 13C NMR (100 MHz, DMSO-d6): δ 47.5
(CH2), 65.2 (CH2), 103.4 (C4), 114.3 (CN), 154.6 (C5).
General Procedure for the Synthesis of Triazoles 4-14
Method A
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methylbenzenesulfonamide (4c). Compound 4c was
obtained in 89% yield (322 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2c: 197
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 231‒232 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.53 (br. s, 4H), 1.77 (br. s, 4H), 2.31 (s,
3H), 3.60 (br. s, 2H), 4.23 (br. s, 2H), 7.24 (d, J = 8.3 Hz, 2H), 7.71 (d, J
= 8.3 Hz, 2H), 8.15 (br. s, 1H), 9.63 (br. s, 1H), 14.12 (br. s, 1H). 13C
NMR (100 MHz, DMSO-d6): δ 20.7, 25.1, 25.7, 25.9, 28.2, 50.0, 51.7,
118.1, 125.6, 128.8, 140.6, 141.8, 147.0, 155.1. IR (ATR, ZnSe, cm-1): ν
3272, 3147, 2930, 1658, 1594, 1542, 1134, 1084, 930. HRMS (ESI-TOF)
m/z calcd. for C16H23N6O2S: [M+H]+: 363.1598, found 363.1602.
Amidine 1 (1.0 mmol) was added into a solution of sodium ethoxide,
cooled to +10 °C, freshly prepared from sodium (28 mg, 1.2 mmol) and
anhydrous ethanol (4 mL), and the resulting mixture was stirred at +10 °C
for a further 5‒10 min. Then the reaction mixture was cooled to -10 °C
and the corresponding azide 2 (1.0 mmol) was added to the reaction
mixture and the resulting mixture were stirred at -10 °C for 1 h. The
solvent was removed under reduced pressure, the residue was dissolved
in water (4 mL) and acetic acid was added (72 mg, 1.2 mmol). The
formed precipitate was filtered off, washed with water, purified by
crystallization from ethanol and dried in a desiccator over P4O10.
6
This article is protected by copyright. All rights reserved.

10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
Compound 4c was obtained in 88% yield (287 mg) according to the
general procedure C (4-methylbenzenesulfonyl chloride (2'c): 190 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1a: 148.5 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
229‒230 °C.
938. HRMS (ESI-TOF) m/z calcd. for C13H17N6O2S [M+H]+: 321.1128,
found 321.1133.
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methylbenzenesulfonamide (5c). Compound 5c was
obtained in 89% yield (279 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2c: 197
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 238‒239 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.91‒1.99 (m, 4H), 2.30 (s, 3H), 3.46‒3.53
(m, 2H), 4.04-4.11 (m, 2H), 7.24 (d, J = 8.2 Hz, 2H), 7.71 (d, J = 8.2 Hz,
2H), 8.02 (br. s, 1H), 9.33 (br. s, 1H), 14.12 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 20.7, 23.4, 25.4, 48.7, 52.0, 118.5, 125.6, 128.9,
140.6, 141.9, 147.0, 153.1. IR (ATR, ZnSe, cm-1): ν 3387, 3220, 3103,
3085, 1605, 1550, 1496, 1359, 1266, 1129, 1078, 927. HRMS (ESI-TOF)
m/z calcd. for C14H19N6O2S [M+H]+: 335.1285, found 335.1291.
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methoxybenzenesulfonamide (4d). Compound 4d
was obtained in 92% yield (345 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2d:
213 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 190‒191 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.52 (br. s, 4H), 1.77 (br. s, 4H), 3.60
(br. s, 2H), 3.77 (s, 3H), 4.24 (br. s, 2H), 6.97 (d, J = 9.0 Hz, 2H), 7.77 (d,
J = 9.0 Hz, 2H), 8.14 (br. s, 1H), 9.66 (br. s, 1H), 14.11 (br. s, 1H). 13C
NMR (100 MHz, DMSO-d6): δ 25.1, 25.8, 25.9, 28.2, 50.0, 51.7, 55.3,
113.6, 118.0, 127.5, 136.7, 147.0, 155.1, 161.0. IR (ATR, ZnSe, cm-1): ν
3257, 3150, 3075, 2940, 1594, 1567, 1496, 1244, 1083, 1031, 908.
HRMS (ESI-TOF) m/z calcd. for: [M+H]+: C16H23N6O3S 379.1547, found
379.1557.
Compound 5c was obtained in 87% yield (261 mg) according to the
general procedure C (4-methylbenzenesulfonyl chloride (2'c): 190 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1b: 123 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
238‒240 °C.
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)nitrobenzenesulfonamide (4e). Compound 4e was
obtained in 38% yield (149 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2e: 228
mg, 1.0 mmol; ethanol (4 mL)) as a light yellow solid; mp 258‒259 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.45‒1.60 (m, 4H), 1.66‒1.86 (m, 4H),
3.50‒3.73 (m, 2H), 4.00‒4.22 (m, 2H), 8.04 (d, J = 9.0 Hz, 2H), 8.28 (d, J
= 9.0 Hz, 3H), 9.33 (br. s, 1H), 14.37 (br. s, 1H). 13C NMR (100 MHz,
DMSO-d6): δ 25.0, 25.6, 26.0, 28.1, 49.9, 51.7, 119.5, 123.9, 127.0,
146.0, 148.5, 150.6, 155.5. IR (ATR, ZnSe, cm-1): ν 3211, 3160, 2944,
1662, 1605, 1558, 1520, 1342, 1088, 958. HRMS (ESI-TOF) m/z calcd.
for C15H20N7O4S [M+H]+: 394.1292, found 394.1302.
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methoxybenzenesulfonamide (5d). Compound 5d
was obtained in 95% yield (333 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2d:
213 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 182‒183 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.94‒1.97 (m, 4H), 3.48‒3.51 (m, 2H),
3.77 (s, 3H), 4.06‒4.09 (m, 2H), 6.96 (d, J = 9.0 Hz, 2H), 7.77 (d, J = 9.0
Hz, 2H), 8.02 (br. s, 1H), 9.35 (br. s, 1H), 14.10 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 23.4, 25.4, 48.7, 52.0, 55.3, 113.6, 118.4, 127.5,
136.7, 147.0, 153.1, 170.0. IR (ATR, ZnSe, cm-1): ν 3243, 3157, 3134,
1644, 1598, 1369, 1231, 1123, 1088, 944. HRMS (ESI-TOF) m/z calcd.
for C14H19N6O3S [M+H]+: 351.1234, found 351.1242.
Compound 4e was obtained in 94% yield (370 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1a: 165 mg, 1.0
mmol; azide 2e: 228 mg, 1.0 mmol; 1,4-dioxane (4 mL)) as a light yellow
solid; mp 258‒259 °C.
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)nitrobenzenesulfonamide (5e). Compound 5e was
obtained in 31% yield (113 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2e: 228
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)fluorobenzenesulfonamide (5a). Compound 5a was
obtained in 92% yield (311 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2a: 201
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 236‒237 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.94‒1.97 (m, 4H), 3.48‒3.52 (m, 2H),
4.06‒4.18 (m, 2H), 7.27 (t, J = 8.0 Hz, 2H), 7.86‒7.90 (m, 2H), 8.06 (br. s,
1H), 8.26 (br. s, 1H), 14.20 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ
23.5, 25.5, 48.8, 52.1, 115.4 (d, J = 22 Hz), 118.8, 128.3 (d, J = 9 Hz),
141.1 (d, J = 3 Hz), 146.8, 153.1, 163.2 (d, J = 248 Hz). IR (ATR, ZnSe,
cm-1): ν 3393, 3160, 3078, 2926, 1647, 1602, 1494, 1266, 1215, 1119,
1073, 947. HRMS (ESI-TOF) m/z calcd. for C13H16FN6O2S [M+H]+:
339.1034, found 339.1044.
1
mg, 1.0 mmol; ethanol (4 mL)) as a light yellow solid; mp 225‒226 °C. H
NMR (400 MHz, DMSO-d6): δ 1.92‒2.01 (m, 4H), 3.46‒3.51 (m, 2H),
4.01‒4.11 (m, 2H), 8.05 (d, J = 9.0 Hz, 2H), 8.13 (br. s, 1H), 8.28 (d, J =
9.0 Hz, 2H), 9.11 (br. s, 1H), 14.37 (br. s, 1H). 13C NMR (100 MHz,
DMSO-d6): δ 23.5, 25.4, 48.8, 52.1, 119.4, 123.9, 127.0, 146.2, 148.6,
150.4, 153.1. IR (ATR, ZnSe, cm-1): ν 3268, 3132, 2949, 1659, 1609,
1564, 1521, 1345, 1263, 1141, 1090, 966. HRMS (ESI-TOF) m/z calcd
for C13H16N7O4S [M+H]+: 366.0979, found 366.0989.
Compound 5e was obtained in 95% yield (348 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1b: 137 mg, 1.0
mmol; azide 2e: 228 mg, 1.0 mmol; 1,4-dioxane (4 mL)) as a light yellow
solid; mp 224‒226 °C.
Compound 5a was obtained in 88% yield (267.5 mg) according to the
general procedure C (4-fluorobenzenesulfonyl chloride (2'a): 194 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1b: 123 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
235‒237 °C.
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-fluorobenzenesulfonamide (6a). Compound 6a
was obtained in 88% yield (310 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2a:
201 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 194‒195 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.56‒1.71 (m, 6H), 3.65‒3.98 (m, 4H),
7.26 (t, J = 8.9 Hz, 2H), 7.86 (dd, J = 8.9, 5.4 Hz, 2H), 8.39 (br. s, 1H),
9.28 (br. s, 1H), 14.14 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 20.6,
23.1, 25.4, 48.9, 59.6, 115.3 (d, J = 22 Hz), 118.9, 128.3 (d, J = 9 Hz),
141.3 (d, J = 3 Hz), 146.5, 154.8, 163.1 (d, J = 248 Hz). IR (ATR, ZnSe,
cm-1): ν 3329, 3250, 3178, 2972, 1652, 1603, 1554, 1294, 1189, 1131,
1083, 1083, 946. HRMS (ESI-TOF) m/z calcd. for C14H18FN6O2S [M+H]+:
353.1190, found 353.1200.
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)benzenesulfonamide (5b). Compound 5b was
obtained in 94% yield (301 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2b: 183
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 267‒268 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.95 (t, J = 8.0 Hz, 4H), 3.48‒3.51 (m, 2H),
4.06‒4.09 (m, 2H), 7.42‒7.48 (m, 3H), 7.82‒7.84 (m, 2H), 8.04 (br. s,
1H), 9.32 (br. s, 1H), 14.17 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ
23.4, 25.4, 48.7, 52.0, 118.6, 125.5, 128.4, 130.7, 144.7, 146.9, 153.1. IR
(ATR, ZnSe, cm-1): ν 3452, 3277, 3171, 2966, 1634, 1605, 1219, 1078,
7
This article is protected by copyright. All rights reserved.

10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)benzenesulfonamide (6b). Compound 6b was
obtained in 92% yield (274 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2b: 183
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 197‒198 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.57‒1.69 (m, 6H), 3.66‒4.08 (m, 4H),
7.41‒7.47 (m, 3H), 7.81‒7.83 (m, 2H), 8.37 (br. s, 1H), 9.35 (br. s, 1H),
14.12 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 23.1, 25.4, 48.7,
118.7, 125.5, 128.4, 130.6, 144.8, 146.7, 154.8. IR (ATR, ZnSe, cm-1): ν
3269, 3111, 2943, 1655, 1605, 1552, 1495, 1443, 1365, 1127, 1084, 939.
HRMS (ESI-TOF) m/z calcd. for C14H19N6O2S [M+H]+: 335.1285, found
335.1288.
ZnSe, cm-1): ν 3356, 3160, 3059, 2926, 1651, 1594, 1556, 1494, 1133,
1087, 953. HRMS (ESI-TOF) m/z calcd. for C21H24FN6O2S [M+H]+:
443.1660, found 443.1673.
N-((4Z,5Z)-5-(Amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)benzenesulfonamide (7b). Compound 7b
was obtained in 76% yield (323 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1d: 241 mg, 1.0 mmol; azide 2b:
183 mg, 1.0 mmol; ethanol (8 mL)) as a colorless solid; mp 128‒129 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.24‒1.34 (m, 2H), 1.67‒1.70 (m, 2H),
1.83‒1.98 (m, 1H), 2.53‒2.54 (m, 2H), 3.19 (t, J = 12 Hz, 2H), 4.44 (br. s,
2H), 7.16‒7.20 (m, 3H), 7.27‒7.30 (m, 2H), 7.43‒7.45 (m, 3H), 7.82‒7.84
(m, 2H), 8.38 (br. s, 1H), 9.37 (br. s, 1H), 14.12 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 31.3, 36.4, 41.5, 48.0, 118.6, 125.5, 125.8, 128.1,
128.4, 128.9, 130.6, 139.7, 144.8, 146.9, 154.8. IR (ATR, ZnSe, cm-1): ν
3247, 3169, 2913, 1653, 1601, 1556, 1138, 1087, 945. HRMS (ESI-TOF)
m/z calcd. for C22H27N6O2S [M+H]+: 439.1911, found 439.1917.
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-methylbenzenesulfonamide (6c). Compound 6c
was obtained in 87% yield (303 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2c:
197 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 217‒218 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.58‒1.69 (m, 6H), 2.31 (s, 3H),
3.63‒4.09 (m, 4H), 7.23 (d, J = 8.0 Hz, 2H), 7.71 (d, J = 8.0 Hz, 2H), 8.35
(br. s, 1H), 9.39 (br. s, 1H), 14.06 (br. s, 1H). 13C NMR (100 MHz,
DMSO-d6): δ 20.7, 23.1, 25.4, 48.8, 118.5, 125.6, 128.8, 140.5, 142.0,
146.9, 154.8. IR (ATR, ZnSe, cm-1): ν 3363, 3224, 3048, 2943, 2854,
1662, 1605, 1556, 1487, 1371, 1119, 1084, 948. HRMS (ESI-TOF) m/z
calcd. for C15H21N6O2S [M+H]+: 349.1441, found 349.1447.
N-((4Z,5Z)-5-(Amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)methylbenzenesulfonamide
(7c).
Compound 7c was obtained in 74% yield (325 mg) according to the
general procedure A (sodium: 28 mg, 1.2 mmol; amidine 1d: 241 mg,
1.0 mmol; azide 2c: 197 mg, 1.0 mmol; ethanol (8 mL)) as a colorless
solid; mp 186‒187 °C. 1H NMR (400 MHz, DMSO-d6): δ 1.23‒1.33 (m,
2H), 1.65‒1.68 (m, 2H), 1.82‒1.96 (m, 1H), 2.30 (s, 3H), 2.53 (d, J = 8.0
Hz, 2H), 3.14‒3.20 (m, 2H), 4.03 (br. s, 1H), 4.97 (br. s, 1H), 7.16‒7.30
(m, 7H), 7.70 (d, J = 8.0 Hz, 2H), 8.40 (br. s, 1H), 9.37 (br. s, 1H), 14.14
(br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 20.8, 31.4, 36.6, 41.7, 46.5,
49.6, 118.6, 125.7, 126.0, 128.2, 128.9, 129.0, 139.9, 140.7, 142.0,
146.8, 154.8. IR (ATR, ZnSe, cm-1): ν 3300, 3261, 3167, 2924, 2852,
1651, 1600, 1555, 1494, 1132, 1084, 941. HRMS (ESI-TOF) m/z calcd.
for C22H27N6O2S [M+H]+: 439.1911, found 439.1917.
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-methoxybenzenesulfonamide (6d). Compound 6d
was obtained in 95% yield (346 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2d:
213 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 185‒186 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.59‒1.70 (m, 6H), 3.75‒4.05 (m, 4H),
3.78 (s, 3H), 6.96 (d, J = 8.0 Hz, 2H), 7.76 (d, J = 8.0 Hz, 2H), 8.34 (br. s,
1H), 9.40 (br. s, 1H), 14.06 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ
23.1, 25.4, 48.7, 55.3, 113.5, 118.3, 127.5, 136.8, 146.9, 154.7, 160.9.
HRMS (ESI-TOF) m/z calcd. for C15H21N6O3S [M+H]+: 365.1390, found
365.1398.
N-((4Z,5Z)-5-(Amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)methoxybenzenesulfonamide
(7d).
Compound 7d was obtained in 81% yield (369 mg) according to the
general procedure A (sodium: 28 mg, 1.2 mmol; amidine 1d: 241 mg,
1.0 mmol; azide 2d: 213 mg, 1.0 mmol; ethanol (8 mL)) as a colorless
solid; mp 126‒127 °C. 1H NMR (400 MHz, DMSO-d6): δ 1.23‒1.32 (m,
2H), 1.66‒1.69 (m, 2H), 1.82‒1.97 (m, 1H), 2.53 (d, J = 8.0 Hz, 2H),
3.10‒3.25 (m, 2H), 3.76 (s, 3H), 4.03 (br. s, 1H), 5.01 (br. s, 1H), 6.96 (d,
J = 8.7 Hz, 2H), 7.16‒7.20 (m, 3H), 7.26‒7.30 (m, 2H), 7.74 (d, J = 8.7
Hz, 2H), 8.43 (br. s, 1H), 9.42 (br. s, 1H), 14.14 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 31.5, 36.6, 41.6, 46.8, 49.3, 55.4, 113.6, 118.4, 125.9,
127.6, 128.2, 129.0, 136.8, 139.8, 146.9, 154.8, 161.0. IR (ATR, ZnSe,
cm-1): ν 3302, 3226, 3094, 2921, 2838, 1661, 1595, 1543, 1495, 1171,
1133, 1054, 1024, 938. HRMS (ESI-TOF) m/z calcd. for C22H27N6O3S
[M+H]+: 455.1860, found 455.1871.
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-nitrobenzenesulfonamide (6e). Compound 6e was
obtained in 38% yield (144 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2e: 228
1
mg, 1.0 mmol; ethanol (4 mL)) as a light yellow solid; mp 241‒242 °C. H
NMR (400 MHz, DMSO-d6): δ 1.54‒1.73 (m, 6H), 3.50‒4.10 (m, 4H),
8.02 (d, J = 8.9 Hz, 2H), 8.27 (d, J = 8.9 Hz, 2H), 8.46 (br. s, 1H), 9.09
(br. s, 1H), 14.29 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 23.1, 25.4,
49.4, 119.9, 123.9, 127.0, 145.9, 148.5, 150.9, 155.2. IR (ATR, ZnSe,
cm-1): ν 3208, 3099, 3049, 2933, 2853, 1668, 1603, 1559, 1522, 1454,
1344, 1265, 1188, 998. HRMS (ESI-TOF) m/z calcd. for C14H18N7O4S
[M+H]+: 380.1135, found 380.1146.
N-((4Z,5Z)-5-(amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)-4-nitrobenzenesulfonamide
(7e).
Compound 6e was obtained in 89% yield (338 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1c: 151 mg, 1.0
mmol; azide 2e: 228 mg, 1.0 mmol; 1,4-dioxane (4 mL)) as a light yellow
solid; mp 241‒243 °C.
Compound 7e was obtained in 79% yield (186 mg) according to the
general procedure B (DBU: 76 mg, 0.5 mmol; amidine 1d: 120 mg, 0.5
mmol; azide 2e: 114 mg, 0.5 mmol; 1,4-dioxane (2 mL)) as a light yellow
solid, mp 219‒220 °C. 1H NMR (400 MHz, DMSO-d6): δ 1.20‒1.35 (m,
2H), 1.62‒1.72 (m, 2H), 1.85‒1.95 (m, 1H), 2.54‒2.58 (m, 2H), 3.1‒3.23
(m, 2H), 4.08 (br. s, 1H), 4.57 (br. s, 1H), 7.14‒7.22 (m, 3H), 7.25‒7.32
(m, 2H), 8.01 (d, J = 9.0 Hz, 2H), 8.26 (d, J = 9.0 Hz, 2H), 8.48 (br. s, 1H),
9.09 (br. s, 1H), 14.30 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 31.3,
36.3, 41.5, 46.9, 49.5, 119.8, 123.8, 125.8, 126.9, 128.1, 128.9, 139.7,
145.8, 148.4, 150.8, 155.0. IR (ATR, ZnSe, cm-1): ν 3301, 3156, 2913,
2725, 1659, 1600, 1567, 1518, 1463, 1377, 1346, 1233, 1125, 1090,
1056, 840. HRMS (ESI-TOF) m/z calcd. for C21H24N7O4S [M+H]+:
470.1605, found 470.1611.
N-((4Z,5Z)-5-(Amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)fluorobenzenesulfonamide (7a). Compound
7a was obtained in 83% yield (368 mg) according to the general
procedure A (sodium: 28 mg, 1.2 mmol; amidine 1d: 241 mg, 1.0 mmol;
azide 2a: 201 mg, 1.0 mmol; ethanol (8 mL)) as a colorless solid, mp
175‒176 °C. 1H NMR (400 MHz, DMSO-d6): δ 1.20‒1.35 (m, 2H),
1.60‒1.74 (m, 2H), 1.89 (m, 1H), 2.50‒2.57 (m, 2H), 3.10‒3.26 (m, 2H),
4.02 (br. s, 1H), 4.90 (br. s, 1H), 7.13‒7.22 (m, 3H), 7.22‒7.32 (m, 4H),
7.87 (dd, J = 8.4, 5.7 Hz, 2H), 8.45 (br. s, 1H), 9.29 (br. s, 1H), 14.21 (br.
s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 31.4, 36.5, 41.6, 46.5, 49.5,
115.4 (d, J = 22 Hz), 118.9, 125.9, 128.2, 128.4 (d, J = 9 Hz), 129.0,
139.8, 141.3 (d, J = 3 Hz), 146.5, 154.9, 163.2 (d, J = 248 Hz). IR (ATR,
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-fluorobenzenesulfonamide (8a). Compound 8a
was obtained in 91% yield (322 mg) according to the general procedure
8
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10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
A (sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2a:
201 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 224‒225 °C.
1H NMR (400 MHz, DMSO-d6): δ 3.73‒4.02 (m, 8H), 7.27 (t, J = 8.0 Hz,
2H), 7.88 (dd, J = 8.0, 4.0 Hz, 2H), 8.54 (br. s, 1H), 9.44 (br. s, 1H),
14.19 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 48.0, 65.5, 115.3 (d,
J = 22 Hz), 118.6, 128.4 (d, J = 9 Hz), 141.2 (d, J = 3 Hz), 146.8, 155.5,
163.1 (d, J = 248 Hz). IR (ATR, ZnSe, cm-1): ν 3301, 3210, 3107, 3049,
2930, 2838, 1657, 1588, 1547, 1489, 1174, 1104, 1082, 831. HRMS
(ESI-TOF) m/z calcd. for C13H16FN6O3S [M+H]+: 355.0983, found
355.0984.
1H). 13C NMR (100 MHz, DMSO-d6): δ 48.0, 65.5, 119.5, 125.9, 127.0,
146.1, 148.5, 150.7, 155.8. IR (ATR, ZnSe, cm-1): ν 3316, 3240, 3150,
3034, 1662, 1592, 1566, 1510, 1306, 1228, 1187, 1088, 950, 856. HRMS
(ESI-TOF) m/z calcd. for C13H16N7O5S [M+H]+: 382.0928, found
382.0935.
Compound 8e was obtained in 76% yield (290 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1e: 153 mg, 1.0
mmol; azide 2e: 228 mg, 1.0 mmol; 1,4-dioxane (4 mL)) as a light yellow
solid; mp 250‒253 °C.
Compound 8a was obtained in 85% yield (271 mg) according to the
general procedure C (4-fluorobenzenesulfonyl chloride (2'a): 194 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1e: 137.7 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
223‒226 °C.
N-((4Z,5Z)-5-(Amino(pyrrolidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methanesulfonamide (9). Compound 9 was obtained
in 59% yield (152 mg) according to the general procedure A (sodium:
28 mg, 1.2 mmol; amidine 1b: 137 mg, 1.0 mmol; azide 2f: 121 mg, 1.0
mmol; ethanol (4 mL)) as a colorless solid, mp 256‒257 °C. 1H NMR
(400 MHz, DMSO-d6): δ 1.91‒2.04 (m, 4H), 2.81 (s, 3H), 3.51 (br. s, 2H),
4.11 (br. s, 2H), 8.07 (br. s, 1H), 9.32 (br. s, 1H), 14.16 (br. s, 1H). 13C
NMR (100 MHz, DMSO-d6): δ 23.6, 25.6, 40.5, 48.6, 52.1, 117.9, 147.5,
153.2. IR (ATR, ZnSe, cm-1): ν 3333, 3254, 3135, 2958, 1633, 1594,
1566, 1325, 1221, 1094, 965. HRMS (ESI-TOF) m/z calcd. for
C8H15N6O2S [M+H]+: 259.0972, found 259.0979.
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)benzenesulfonamide (8b). Compound 8b was
obtained in 93% (313 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2b: 183
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid mp 196‒197 °C. 1H
NMR (400 MHz, DMSO-d6): δ 3.60‒4.22 (m, 8H), 7.44‒7.46 (m, 3H),
7.82‒7.84 (m, 2H), 8.55 (br. s, 1H), 9.49 (br. s, 1H), 14.24 (br. s, 1H). 13
C
N-((4Z,5Z)-5-(Amino(piperidin-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methanesulfonamide (10). Compound 10 was
obtained in 50% yield (136 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1c: 151 mg, 1.0 mmol; azide 2f: 121
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 216‒217 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.60‒1.75 (m, 6H), 2.82 (s, 3H), 3.80‒4.10
(m, 4H), 8.33 (br. s, 1H), 9.42 (br. s, 1H), 13.85 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 23.1, 25.4, 40.6, 48.7, 117.9, 147.4, 154.8. IR (ATR,
ZnSe, cm-1): ν 3326, 3260, 3148, 3084, 2927, 1656, 1595, 1572, 1243,
1109, 951. HRMS (ESI-TOF) m/z calcd. for C9H17N6O2S: [M+H]+:
273.1128, found 273.1136.
NMR (100 MHz, DMSO-d6): δ 47.9, 65.6, 118.5, 125.6, 128.6, 130.8,
144.7, 147.0, 155.5. IR (ATR, ZnSe, cm-1): ν 3319, 3164, 2956, 2868,
1651, 1577, 1550, 1175, 1140, 1081, 1007, 949. HRMS (ESI-TOF) m/z
calcd. for C13H17N6O3S [M+H]+: 337.1077, found 337.1080.
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-methylbenzenesulfonamide (8c). Compound 8c
was obtained in 90% yield (315 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2c:
197 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 219‒220 °C.
1H NMR (400 MHz, DMSO-d6): δ 2.32 (s, 3H), 3.69‒4.16 (m, 8H), 7.24 (d,
J = 8.0 Hz, 2H), 7.71 (d, J = 8.0 Hz, 2H), 8.49 (br. s, 1H), 9.53 (br. s, 1H),
14.12 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 20.7, 47.9, 65.5,
118.2, 125.6, 128.8, 140.6, 141.9, 147.0, 155.5. IR (ATR, ZnSe, cm-1): ν
3304, 3223, 3142, 2913, 2864, 1658, 1592, 1546, 1493, 1232, 1171,
1106, 1086, 938. HRMS (ESI-TOF) m/z calcd. for C14H19N6O3S [M+H]+:
351.1234, found: 351.1236.
N-((4Z,5Z)-5-(Amino(azepane-1-yl)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methanesulfonamide (11). Compound 11 was
obtained in 66% yield (189 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1a: 165 mg, 1.0 mmol; azide 2f: 121
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 242‒243 °C. 1H
NMR (400 MHz, DMSO-d6): δ 1.47‒1.61 (m, 4H), 1.73‒1.87 (m, 4H),
2.83 (s, 3H), 3.55‒3.72 (m, 2H), 4.21‒4.38 (m, 2H), 8.17 (br. s, 1H), 9.67
(br. s, 1H), 14.12 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 25.2, 25.8,
26.0, 28.4, 40.5, 50.1, 51.8, 117.6, 147.7, 155.1. IR (ATR, ZnSe, cm-1): ν
3311, 3257, 3173, 3093, 2924, 2866, 1650, 1603, 1572, 1109, 974.
HRMS (ESI-TOF) m/z calcd. for C10H19N6O2S: [M+H]+: 287.1285, found
287.1294.
Compound 8c was obtained in 88% yield (277.5 mg) according to the
general procedure C (4-methylbenzenesulfonyl chloride (2'c): 190 mg,
1.0 mmol; NaN3: 68.3 mg, 1.05 mmol; amidine 1e: 137.7 mg, 0.9 mmol;
Na: 25 mg, 1.08 mmol, EtOH (4 mL)) as a colorless solid; mp
219‒221 °C.
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-methoxybenzenesulfonamide (8d). Compound 8d
was obtained in 86% yield (315 mg) according to the general procedure
A (sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2d:
213 mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid; mp 205‒206 °C.
1H NMR (400 MHz, DMSO-d6): δ 3.73‒3.74 (m, 4H), 3.78 (s, 3H),
3.80‒4.15 (m, 4H), 6.97 (d, J = 12.0 Hz, 2H), 7.76 (d, J = 12.0 Hz, 2H),
8.48 (br. s, 1H), 9.56 (br. s, 1H), 14.11 (br. s, 1H). 13C NMR (100 MHz,
DMSO-d6): δ 48.0, 55.3, 65.6, 113.6, 118.1, 127.5, 136.7, 147.0, 155.4,
161.0. IR (ATR, ZnSe, cm-1): ν 3269, 3150, 2964, 2904, 2816, 1653,
1590, 1172, 1107, 1083, 940. HRMS (ESI-TOF) m/z calcd. for
C14H19N6O4S [M+H]+: 367.1183, found 367.1181.
Compound 11 was obtained in 76% yield (218 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1a: 165 mg, 1.0
mmol; azide 2f: 121 mg, 1.0 mmol; 1,4-dioxane (4 mL)) as a colorless
solid, mp 242‒243 °C.
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)methanesulfonamide (12). Compound 12 was
obtained in 61% yield (167 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2f: 121
mg, 1.0 mmol; ethanol (4 mL)) as a colorless solid, mp 221‒222 °C. 1H
NMR (400 MHz, DMSO-d6): δ 2.82 (s, 3H), 3.76-3.79 (m, 4H), 3.87‒4.15
(m, 4H), 8.48 (br. s, 1H), 9.55 (br. s, 1H), 13.97 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 40.6, 48.1, 65.6, 117.7, 147.6, 155.4. IR (ATR, ZnSe,
cm-1): ν 3245, 3028, 2861, 1654, 1566, 1183, 1100, 957. HRMS (ESI-
TOF) m/z calcd. for C8H15N6O3S [M+H]+: 275.0921, found 275.0926.
N-((4Z,5Z)-5-(Amino(morpholino)methylene)-3,5-dihydro-4H-1,2,3-
triazol-4-ylidene)-4-nitrobenzenesulfonamide (8e). Compound 8e was
obtained in 34% yield (129 mg) according to the general procedure A
(sodium: 28 mg, 1.2 mmol; amidine 1e: 153 mg, 1.0 mmol; azide 2e: 228
N-((4Z,5Z)-5-(amino(4-benzylpiperidin-1-yl)methylene)-3,5-dihydro-
4H-1,2,3-triazol-4-ylidene)methanesulfonamide (13). Compound 13
was obtained in 68% yield (123 mg) according to the general procedure
B (DBU: 76 mg, 0.5 mmol; amidine 1d: 120 mg, 0.5 mmol; azide 2f: 67
1
mg, 1.0 mmol; ethanol (4 mL)) as a light yellow solid; mp 252‒253 °C. H
NMR (400 MHz, DMSO-d6): δ 3.74‒3.95 (m, 8H), 8.03 (d, J = 9.0 Hz, 2H),
8.27 (d, J = 9.0 Hz, 2H), 8.61 (br. s, 1H), 9.27 (br. s, 1H), 14.34 (br. s,
9
This article is protected by copyright. All rights reserved.

10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
mg, 0.55 mmol; 1,4-dioxane (2 mL)) as a colorless solid, mp 204‒205 °C.
1H NMR (400 MHz, DMSO-d6): δ 1.25‒1.38 (m, 2H), 1.69‒1.77 (m, 2H),
1.85‒2.00 (m, 1H), 2.55‒2.57 (m, 2H), 2.81 (s, 3H), 3.21‒3.25 (m, 2H),
4.62 (br. s, 2H), 7.16‒7.22 (m, 3H), 7.27‒7.32 (m, 2H), 8.36 (br. s, 1H),
9.42 (br. s, 1H), 13.95 (br. s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 31.5,
36.5, 40.6, 41.6, 47.9, 117.8, 125.8, 128.1, 128.9, 139.7, 147.4, 154.7. IR
(ATR, ZnSe, cm-1): ν 3103, 2920, 2852, 2725, 1661, 1601, 1462, 1377,
1257, 1112, 1017. HRMS (ESI-TOF) m/z calcd. for C16H23N7O2S [M+H]+:
363.1598, found 363.1605.
Keywords: 2-cyanoacetamidines • sulfonyl azides • 1,2,3-
triazoles • rearrangement • diazo group transfer
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N-((4Z,5Z)-5-(Amino(dimethylamino)methylene)-3,5-dihydro-4H-
1,2,3-triazol-4-ylidene)-4-methylbenzenesulfonamide
(14a).
Compound 14a was obtained in 72% yield (221 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1f: 111 mg, 1.0
mmol; azide 2c: 197 mg, 1.0 mmol; 1,4-dioxane (3 mL)) as a colorless
solid, mp 232‒233 °C. 1H NMR (400 MHz, DMSO-d6): δ 2.30 (s, 3H),
3.15 (br.s, 3H), 3.56 (br. s, 3H), 7.23 (d, J = 8.0 Hz, 2H), 7.71 (d, J = 8.0
Hz, 2H), 8.15 (br. s, 1H), 9.46 (br. s, 1H), 14.10 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 20.7, 39.6 (from HSQC), 42.3, 118.5, 125.6, 128.8,
140.6, 141.9, 146.9, 156.0. IR (ATR, ZnSe, cm-1): ν 3592, 3455, 3327,
3113, 1659, 1632, 1556, 1496, 1461, 1377, 1254, 1138, 1085, 1062,
1036, 1021. HRMS (ESI-TOF) m/z calcd. for C12H16N6O2S [M+H]+:
309.1128, found 309.1137.
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N-((4Z,5Z)-5-(Amino(dimethylamino)methylene)-3,5-dihydro-4H-
1,2,3-triazol-4-ylidene)-4-methoxybenzenesulfonamide
(14b).
Compound 14b was obtained in 84% yield (272 mg) according to the
general procedure B (DBU: 152 mg, 1.0 mmol; amidine 1f: 111 mg, 1.0
mmol; azide 2d: 213 mg, 1.0 mmol; 1,4-dioxane (3 mL)) as a colorless
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1
solid, mp 130‒131 °C. H NMR (400 MHz, DMSO-d6): δ 3.16 (br.s, 3H),
3.56 (br.s, 3H), 3.78 (s, 3H), 6.96 (d, J = 8.8 Hz, 2H), 7.75 (d, J = 8.8 Hz,
2H), 8.15 (br. s, 1H), 9.47 (br. s, 1H), 14.08 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 39.5 (from HSQC), 42.2, 55.3, 113.6, 118.4, 127.5,
136.7, 147.0, 156.0, 160.9. IR (ATR, ZnSe, cm-1): ν 3571, 3437, 3327,
3259, 3096, 1656, 1631, 1594, 1576, 1557, 1499, 1466, 1437, 1376,
1310, 1254, 1181, 1137, 1089, 1063, 1033, 1016. HRMS (ESI-TOF) m/z
calcd. for C12H16N6O3S [M+H]+: 325.1077, found 325.1085.
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N-((4Z,5Z)-5-(Amino(dimethylamino)methylene)-3,5-dihydro-4H-
1,2,3-triazol-4-ylidene)methanesulfonamide (14c). Compound 14c
was obtained in 70% yield (326 mg) according to the general procedure
B (DBU: 304 mg, 2.0 mmol; amidine 1f: 222 mg, 2.0 mmol; azide 2f: 242
mg, 2.0 mmol; 1,4-dioxane (6 mL)) as a colorless solid, mp 235‒236 °C.
1H NMR (400 MHz, DMSO-d6): δ 2.81 (s, 3H), 3.24 (br.s, 3H), 3.58 (br.s,
3H), 8.15 (br. s, 1H), 9.46 (br. s, 1H), 14.02 (br. s, 1H). 13C NMR (100
MHz, DMSO-d6): δ 39.4 (from HSQC), 40.6, 42.2, 118.0, 147.5, 156.0. IR
(ATR, ZnSe, cm-1): ν 3317, 3244, 3159, 3116, 3028, 1650, 1631, 1571,
1463, 1417, 1377, 1334, 1255, 1234, 1165, 1115, 1062, 1040. HRMS
(ESI-TOF) m/z calcd. for C6H12N6O2S [M+H]+: 233.0815, found 233.0814.
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Crystallographic Data Center (CCDC 1959386 (4c), 1959374 (5b),
1959375 (7c)).
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Acknowledgements
We gratefully acknowledge financial support of this work by the
Russian Science Foundation (18-13-00161).
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European Journal of Organic Chemistry
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11
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10.1002/ejoc.202000453
European Journal of Organic Chemistry
FULL PAPER
Entry for the Table of Contents
The generally accepted opinion on the single diazo group transfer direction of methylene active amidines with sulfonyl azides has
been disproved by this study. Thus two products for reaction of 2-cyanoacetamidines with sulfonyl azides were found to afford
different types of 1,2,3-triazoles. Mesyl azide reacts with 2-cyanoacetamidines in the absence of a base to afford 5-amino-4-cyano-
1,2,3-triazole. The use of strong base switches the direction of the reaction in favor of nonaromatic 4-methylene-1,2,3-triazole-5-
imines.
Key Topic Nonaromatic NH-1,2,3-triazoles
12
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