Trifluoromethyl sulfones and perfluoroalkanesulfonamides of the azole series

Article abstract of DOI:10.1023/B:RUJO.0000034977.74026.b3

2-Phenyl-4-trifluoromethylsulfonylmethyl-2H-1,2,3-triazole was synthesized from 4-bromo-methyl-2-phenyl-2H-1,2,3-triazole and sodium trifluoromethanesulfinate CF₃SO₂Na. 1(2)-Ethyl-4-nitro- 1(2)H-1,2,3-triazoles and 4-nitro-2-phenyl-2H-1,2,3-triazole were reduced to the corresponding amines. Intermediate 1,2-bis(1-ethyl-1H-1,2,3-triazol-4-yl) diazene 1-oxide exists as a mixture of syn and anti isomers, the former being stabilized via formation of a strong intramolecular hydrogen bond. The reduction of 2-ethyl-4-nitro-2H-1,2,3-triazole in the presence of HCl afforded the target 4-amino-2-ethyl-2H-1,2,3-triazole and also 4-amino-5-chloro-2-ethyl-2H-1,2,3- triazole. Treatment of alkyl-substituted 4-amino-1,2,3-triazoles with trifluoromethanesulfonyl chloride and pentafluoroethanesulfonyl chloride gave N-triazolyl-substituted trifluoromethane- and pentafluoroethanesulfonamides and -imides.

Full text of DOI:10.1023/B:RUJO.0000034977.74026.b3

Russian Journal of Organic Chemistry, Vol. 40, No. 3, 2004, pp. 390–396. Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 3, 2004,
pp. 418–423.
Original Russian Text Copyright © 2004 by Meshcheryakov, Shainyan.
Trifluoromethyl Sulfones and Perfluoroalkanesulfonamides
of the Azole Series
V. I. Meshcheryakov and B. A. Shainyan
Favorskii Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences,
ul. Favorskogo 1, Irkutsk, 664033, Russia
e-mail: bagrat@irioch.irk.ru
Received November 26, 2002
Abstract—2-Phenyl-4-trifluoromethylsulfonylmethyl-2H-1,2,3-triazole was synthesized from 4-bromo-
methyl-2-phenyl-2H-1,2,3-triazole and sodium trifluoromethanesulfinate CF
1
1
3
SO
,2,3-triazoles and 4-nitro-2-phenyl-2H-1,2,3-triazole were reduced to the corresponding amines. Intermediate
,2-bis(1-ethyl-1H-1,2,3-triazol-4-yl)diazene 1-oxide exists as a mixture of syn and anti isomers, the former
2
Na. 1(2)-Ethyl-4-nitro-1(2)H-
being stabilized via formation of a strong intramolecular hydrogen bond. The reduction of 2-ethyl-4-nitro-2H-
,2,3-triazole in the presence of HCl afforded the target 4-amino-2-ethyl-2H-1,2,3-triazole and also 4-amino-5-
1
chloro-2-ethyl-2H-1,2,3-triazole. Treatment of alkyl-substituted 4-amino-1,2,3-triazoles with trifluoromethane-
sulfonyl chloride and pentafluoroethanesulfonyl chloride gave N-triazolyl-substituted trifluoromethane- and
pentafluoroethanesulfonamides and -imides.
Trifluoromethanesulfinic acid salts CF SO M (M =
methyl derivative Ib with sodium trifluoromethane-
sulfinate was slow, and chloride Ia failed to react at all
(Scheme 1). Triazoles having a chloromethyl group on
the nitrogen atom in position 1 or 2 did not react with
CF SO Na. With a view to enhance the nucleofugality
of the halogen atom, 1(2)-chloromethyl-4-nitro-1(2)H-
1,2,3-triazoles were converted into the corresponding
iodides via exchange reaction with NaI in acetone.
However, compounds V and VI also failed to replace
the iodine atom by trifluoromethylsulfonyl group
(Scheme 2).
3
2
K, Na) are known to behave as weak ambident
nucleophiles. They react with alkyl halides to give
products of either O- or S-alkylation, and the former
readily rearrange into the latter [1, 2]. Insofar as tri-
3
2
–
2
fluoromethanesulfinate ion CF SO is a weak nucleo-
3
phile, the formation of trifluoromethyl sulfones
CF SO R is a slow process which requires elevated
3
2
temperature, dipolar aprotic solvents, and the presence
of activating acceptor groups and good leaving groups
in the substrate [3].
In continuation of our studies on trifluoromethyl
sulfones of the azole series [4], in the present work we
made an attempt to introduce a trifluoromethylsulfonyl
group into the side chain of some 1,2,3-triazoles. We
have found that 4-halomethyl-2-phenyl-2H-1,2,3-
triazoles are weakly reactive toward sodium trifluoro-
methanesulfinate in acetone. The reaction of bromo-
Scheme 2.
NO2
NO2
NaI
CF SO K
3 2
N
N
N
N
N
N
ClCH2
ICH2
III, IV
V, VI
III, 1-CH
2
2 2 2
Cl; IV, 2-CH Cl; V, 1-CH I; VI, 2-CH I.
Scheme 1.
CH X
CH SO CF
2 2 3
2
We also tried to obtain trifluorosulfonamides of the
azole series via introduction of a trifluoromethyl-
sulfonyl group into exocyclic amino group of 1,2,3-
triazoles. For this purpose, we examined the reduction
of some nitro azoles under different conditions with
the goal of synthesizing the corresponding 1(2)-sub-
stituted 4-amino-1,2,3-triazoles. The reduction of
CF SO Na
acetone
3
2
N
N
N
N
N
N
Ph
Ph
Ia, Ib
II
X = Cl (a), Br (b).
1
070-4280/04/4003-0390 © 2004 MAIK “Nauka/Interperiodica”

TRIFLUOROMETHYL SULFONES AND PERFLUOROALKANESULFONAMIDES
391
Scheme 3.
Et
O
H
N
NO2
N
N
N
O
Al/NaOH
N
N
N
N
N
N
N
N
N
Et
Et
Et
N
N
N
N
N
Et
N
VII
anti-VIII
syn-VIII
1
-ethyl-4-nitro-1H-1,2,3-triazole (VII) with aluminum
both CH protons are involved in intermolecular
hydrogen bond with the solvent; therefore, the posi-
tions of their signals differ insignificantly, and they
appear in a weaker field than in the spectrum recorded
from a solution in chloroform. The transformation
in alkaline medium gave no desired 4-amino-1-ethyl-
1
1
H-1,2,3-triazole but incomplete reduction product,
,2-bis(1-ethyl-1H-1,2,3-triazol-4-yl)diazene 1-oxide
(
VIII) (Scheme 3). The formation of azoxy compound
1
13
VIII follows from the H and C NMR spectra which
contain two sets of signals from nonequivalent ethyl-
triazolyl fragments, as well as from the data of
elemental analysis. Compound VIII can exist as two
isomers, syn and anti, and the former could give rise to
a strong intramolecular hydrogen bond. In fact, from
the reaction mixture we isolated a yellow substance. Its
solution in chloroform quickly turned colorless, and
colorless crystals separated therefrom upon evapora-
anti-VIII
syn-VIII is reversible. This follows from
the fact that the solution in DMSO-d (syn-VIII) turns
6
yellow on storage as a result of displacement of the
equilibrium toward more polar anti isomer.
We succeeded in reducing 1-ethyl-4-nitro-1H-
1
,2,3-triazole (VII) to 4-amino-1-ethyl-1H-1,2,3-tri-
azole (IX) using zinc dust in ethanol. Aminotriazole
IX reacted with trifluoromethanesulfonyl chloride to
give N-(1-ethyl-1H-1,2,3-triazol-4-yl)trifluoromethane-
sulfonamide (X) (Scheme 4). The reaction of amino-
triazole IX with pentafluoroethanesulfonyl chloride
occurred in a similar way, but in this case both mono-
and disubstituted products XI and XII were formed
tion. The crystals were dissolved in CDCl , and in the
3
1
H NMR spectrum of the solution were observed
strongly different signals from the 5-H protons in the
two triazole rings, δ 8.36 and 8.80 ppm. On the other
hand, the positions of these signals in the spectra of
(
Scheme 5).
both products in DMSO-d were almost similar, δ 9.10
6
and 9.11 ppm for the colorless product and δ 9.10 and
Scheme 5.
9
.12 ppm for the yellow substance. These findings led
us to assign anti configuration to the yellow isomer
and syn configuration to the colorless isomer. Being
a weakly polar solvent, chloroform stabilizes the less
polar syn isomer with intramolecular hydrogen bond,
which is characterized by strongly different positions
of the 5-H signals. Polar DMSO destroys the
intramolecular hydrogen bond in the syn isomer, and
NHSO C F
2 2 5
C F SO Cl
2
5
2
IX
N
N
Et
N
XI
N(SO C F )
2 5 2
2
C F SO Cl
2
5
2
N
Et
N
N
Scheme 4.
XII
NO2
NH2
Zn/EtOH
N
N
N
N
Unfortunately, we failed to isolate analytically
pure samples of compounds XI and XII; nevertheless,
Et
Et
N
N
VII
IX
the obtained elemental compositions, C:N:F:S =
6.1:4:4.7:0.8 and C:N:F:S = 8:4:10.6:2.1 for amide
NHSO CF
2
3
XI and imide XII, respectively, are fairly consistent
with the assumed structures. The structure of XI and
XII was also confirmed by the NMR spectra. The H
CF SO Cl
3
2
N
N
Et
1
N
X
NMR spectrum of imide XII lacks NH signal, while
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004

3
92
MESHCHERYAKOV, SHAINYAN
signals from the other protons are displaced downfield
relative to the corresponding signals of amide XI; the
downfield shift is the stronger the closer the proton is
located to the electron-acceptor N(SO C F ) group. In
the C NMR spectrum of imide XII, the C signal
appears strongly downfield relative to the correspond-
mixture by gas chromatography–mass spectrometry
showed the presence of two compounds in approx-
imately equal amounts. Compound XVI gave the
molecular ion peak with m/z 146, whose isotope
composition corresponded to the presence of one
chlorine atom in the molecule.
2
2 5 2
13
4
ing signal of amide XI (∆δ = 16 ppm); as a result, the
С
Scheme 8 shows a probable reaction sequence
which rationalizes the formation of compound XVI
using the reaction of nitrotriazole XIII with HCl as an
example. Obviously, an analogous scheme may be
proposed for the reaction of HCl with partially reduced
intermediates, e.g., those containing a nitroso or
hydroxylamino group. This scheme explains the
formation of just 2-ethyl-5-chloro-1,2,3-triazole, but
it is hardly applicable to 1-ethyl- and 2-phenyl-sub-
stituted analogs (see below). 1-Ethyl derivative could
not give rise to a resonance-stabilized structure, while
the formation of such structure from 2-phenyl deriva-
tive requires rupture of conjugation between the
benzene and triazole rings. According to Scheme 8,
product XVI cannot be obtained via chlorination of
completely reduced compound XIV. In fact, no prod-
uct XVI was detected in the reaction mixture (by TLC)
obtained in a special experiment with pure amino-
triazole XIV.
4
C signal in the spectrum of XI is located in a stronger
field than those of the C F group, and in the spectrum
2
5
of XII, in a weaker field.
2-Ethyl-4-nitro-2H-1,2,3-triazole (XIII) was reduced
with zinc dust in boiling ethanol in the presence of
CaCl according to the procedure described in [5]. The
2
resulting 4-amino-2-ethyl-2H-1,2,3-triazole (XIV) was
treated with trifluoromethanesulfonyl chloride to ob-
tain N-(1-ethyl-1H-1,2,3-triazol-4-yl)trifluoromethane-
sulfonamide (XV) (Scheme 6).
Scheme 6.
NO2
NH2
Zn/EtOH
N
N
N
N
N
N
Et
Et
XIII
XIV
NHSO CF3
2
Scheme 8.
CF SO Cl
3
2
H
N
N
O
HO
HCl
H
N
N+ O–
H
N+ O–
Cl
Et
N
N
N–
N
XV
N
N+
Et
Et
When triazole XIII was reduced with tin(II)
chloride or zinc dust in ethanol in the presence of
hydrochloric acid, apart from compound XIV we
isolated 4-amino-5-chloro-2-ethyl-2H-1,2,3-triazole
XVI) (Scheme 7). The structure of product XVI is
confirmed by the presence in the H NMR spectrum
of a singlet from protons of the amino group and
HO
HO
N
H
N
N+ O–
H
N
O–
Cl
Cl
(
N–
N
1
N+
N+
Et
Et
1
3
the absence of 5-H signal. The C NMR spectrum
J-modulated) of XVI contained two signals from
(
H
N
NO
Cl
NO
Cl
quaternary carbon atoms of the triazole ring at δ 135
H+
C
4
5
(
C ) and 149 ppm (C ). Analysis of the reaction
–H+
–
H O
N
N
N
2
N+
Et
N
Scheme 7.
Et
Cl
NH2
The reduction of 4-nitro-2-phenyl-2H-1,2,3-triazole
XVII with zinc dust in ethanol gave a mixture of 1,2-
bis(2-phenyl-2H-1,2,3-triazol-4-yl)-hydrazine (XVIII)
SnCl or Zn, EtOH, HCl
2
N
N
XIII
XIV
+
N
Et
(
partial reduction product) and the desired 4-amino-
XVI
2-phenyl-2H-1,2,3-triazole (XIX) (Scheme 9).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004

TRIFLUOROMETHYL SULFONES AND PERFLUOROALKANESULFONAMIDES
393
Scheme 9.
trifluoromethanesulfinate under conditions of phase-
transfer catalysis in the presence of potassium carbo-
nate was proved by thin-layer chromatography using
an authentic sample.
NO2
HN
NH
N
NH2
Zn/EtOH
+
N
N
N
N
N
N
N
N
N
N
N
Ph
Ph
Ph
Ph
EXPERIMENTAL
XVII
XVIII
XIX
The NMR spectra were recorded on a Bruker DPX-
1
13
4
(
00 spectrometer at 400 ( H), 100 ( C), and 376 MHz
Compounds XVIII and XIX were separated by
column chromatography; they are characterized by
very similar elemental compositions and positions of
signals in the H and C NMR spectra (except for the
NH signal). However, the melting point of substituted
hydrazine XVIII is much higher than that of amine
XIX, the NH signal of the former in the H NMR
spectrum (CDCl ) appears 2.1 ppm downfield relative
to the corresponding signal of XIX, and its relative
intensity is twice as low.
1
9
1
13
F) using HMDS as internal reference for H and C;
1
9
the F chemical shifts were measured relative to
1
13
CCl F. Gas chromatographic–mass spectrometric
3
analysis was performed on a Hewlett-Packard HP 5890
gas chromatograph coupled with an HP 5971A mass-
selective detector (70 eV); Ultra-2 column (5% of
phenylmethylsilicone); injector temperature 250°C;
oven temperature programming from 70 to 280°C at
1
3
2
0 deg/min.
2
-Phenyl-4-trifluoromethylsulfonylmethyl-2H-
Unexpectedly, our attempt to introduce one or two
trifluoromethylsulfonyl groups to one or both nitrogen
atoms in 1,2-disubstituted hydrazine XVIII via reac-
tion with trifluoromethanesulfonyl chloride resulted in
isolation of the oxidation product, (Z)-1,2-(2-phenyl-
1
,2,3-triazole (II). To a solution of 2 g (8.4 mmol) of
bromomethyltriazole Ib in 20 ml of acetone we added
in portions 2.62 g (16.8 mmol) of sodium trifluoro-
methanesulfinate. The mixture was stirred for 50 h on
heating under reflux, poured into cold water, and
treated with diethyl ether. The extract was dried over
MgSO and evaporated, and the residue was purified
by passing through a column charged with Al O3
(eluent diethyl ether–hexane, 1:2). The crystalline
product was washed with hexane and dried. Yield
0.5 g (20%), mp 78–80°C. H NMR spectrum
1
,2,3-triazol-4-yl)diazene (XX) (Scheme 10). Prob-
ably, the first reaction stage is replacement of one NH
proton by trifluoromethylsulfonyl group; the inter-
mediate thus formed can be regarded as an N,N'-di-
substituted trifluoromethanesulfonic acid hydrazide.
Published data on perfluoro-alkanesulfonic acid
hydrazides are very limited [6–8]; moreover, these
compounds were neither isolated nor characterized. It
is known that they are relatively stable only at reduced
temperature (below –30°C) and that at room tem-
perature they decompose with liberation of nitrogen
and formation of perfluoroalkanesulfinic acids R SO H.
4
2
1
(acetone d ), δ, ppm: 5.35 s (2H, CH ), 7.45 m (1H,
6
2
p-H), 7.58 m (2H, m-H), 8.08 m (2H, o-H), 8.18 s
1
3
(1H, 5-H). C NMR spectrum (acetone-d ), δ , ppm:
6
C
o
1
47.86 (CH ), 119.27 (C ), 120.27 q ( J = 327.3 Hz),
2
p
CF
m
i
F
2
128.83 (C ), 130.13 (C ), 135.83 (C ), 137.97 (CH=N),
39.96 (C=N). F NMR spectrum (acetone-d ):
1
9
As applied to our case, elimination of potassium
1
6
δ –75.09 ppm. Found, %: C 41.11; H 2.87; F 19.50;
F
Scheme 10.
N 14.75; S 10.88. C H F N O S. Calculated, %:
1
0
8
3
3
2
C 41.24; H 2.77; F 19.57; N 14.43; S 11.01.
SO CF
2
3
HN
N
N
1-Iodomethyl-4-nitro-1H-1,2,3-triazole (V). A mix-
ture of 2.5 g (0.015 mol) of 1-chloromethyl-4-nitro-
1H-1,2,3-triazole (III), 3.14 g (0.017 mol) of NaI·
CF SO Cl
3
2
XVIII
N
N
N
–HCl
N
N
2
H O, and 20 ml of acetone was stirred at 50°C until
2
Ph
Ph
NaCl no longer precipitated. The salt was filtered off,
the filtrate was evaporated, and the residue was
recrystallized from alcohol with addition of hexane.
N
N
N
1
Yield 2.54 g (65%), mp 112°C. H NMR spectrum
N
N
N
–
CF SO H
3 2
N
N
(acetone-d ), δ, ppm: 6.54 s (2H, CH ), 9.28 s (1H,
6
2
1
3
Ph
Ph
CH). C NMR spectrum (acetone-d ), δ , ppm: 9.94
6
C
5 4
XX
(CH ), 124.86 (C ), 154.43 (C ). Found, %: C 14.74;
2
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004

3
94
MESHCHERYAKOV, SHAINYAN
H 0.63; I 50.21; N 21.51. C H IN O . Calculated, %:
C 14.19; H 1.19; I 49.96; N 22.06.
5 ml of anhydrous methanol was added dropwise over
a period of 30 min to a solution of 1 g (8.9 mmol) of
compound IX in 20 ml of anhydrous methanol. The
mixture was stirred for 2 h at 40°C and for 30 min at
60°C until the initial amine disappeared (TLC). The
most part of the solvent was distilled off, the residue
was poured into ice water, and the precipitate was
filtered off, washed with a small amount of ice water,
and dried in air. Yield 0.51 g (24%). The product was
3
3
4
2
2
-Iodomethyl-4-nitro-2H-1,2,3-triazole (VI) was
synthesized in a similar way. Yield 81%, mp 92–93°C.
1
H NMR spectrum (acetone-d ), δ, ppm: 6.54 s (2H,
6
13
CH ), 8.57 s (1H, CH). C NMR spectrum (acetone-d ),
2
6
5
4
δ , ppm: 16.29 (CH ), 133.13 (C ), 154.67 (C ). Found,
C
2
%
: C 14.70; H 0.48; I 51.37; N 22.31. C H IN O .
3 3 4 2
Calculated, %: C 14.19; H 1.19; I 49.96; N 22.06.
,2-Bis(1-ethyl-1H-1,2,3-triazol-4-yl)diazene
-oxide (VIII). To a mixture of 5 g (0.0352 mol) of
recrystallized from alcohol with addition of hexane.
1
1
mp 133–135°C. H NMR spectrum (DMSO-d ), δ,
6
1
ppm: 1.43 t (3H, CH ), 4.40 q (2H, CH ), 8.01 s/br.s
3
2
compound VII, 2.85 g (0.106 mol) of aluminum
powder, and 50 ml of ethanol we added dropwise
under vigorous stirring 52 ml of a 20% solution of
sodium hydroxide. The mixture warmed up to 50°C
and gradually divided into layers, and crystals
separated from the organic phase. The mixture was
stirred until the initial nitrotriazole disappeared (TLC),
the organic phase was separated, washed with
a saturated solution of sodium chloride, and partially
evaporated, and the yellow crystals were filtered off,
(
2H, CH, NH); the CH and NH signals are resolved in
chloroform [δ, ppm: 1.58 (CH ), 4.42 (CH ), 7.61
3
2
13
(
CH), 10.07 (NH)]. C NMR spectrum (DMSO-d ),
6
δ , ppm: 14.78 (CH ), 46.53 (CH ), 117.42 (CH),
C
3
2
1
4
19
1
20.23 q (CF , J = 324.3 Hz), 142.17 (C ). F NMR
3 CF
spectrum (DMSO-d ): δ –74.25 ppm. Found, %:
6
F
C 25.20; H 2.85; N 22.56; S 13.27. C H F N O S.
5
7
3
4
2
Calculated, %: C 24.59; H 2.89; N 22.94; S 13.13.
The reaction of 4-amino-1-ethyl-1H-1,2,3-triazole
IX) with pentafluoroethanesulfonyl chloride was
(
dried in air, and recrystallized from ethanol. Yield
1
carried out in a similar way. However, the reaction did
not come to completion even on prolonged heating
under reflux. After removal of methanol and unreacted
pentafluoroethanesulfonyl chloride, the residue con-
taining the initial amine and products XI and XII was
separated by column chromatography on silica gel
using diethyl ether–hexane (3:1) as eluent. We failed
to isolate pure compounds; therefore, the products
were identified by the NMR spectra of fractions en-
riched in compound XI (liquid) and XII (crystalline).
3
.1 g (75%), mp 216–218°C. H NMR spectrum
(
4
8
CDCl ), δ, ppm: 1.63 t (3H, CH ), 1.46 t (3H, CH ),
3
3
3
.51 q (2H, CH ), 4.53 q (2H, CH ), 8.36 s (1H, =CH),
2 2
1
3
.80 s (1H, =CH). C NMR spectrum (CDCl ), δ ,
3
C
ppm: 15.14 (CH ), 15.26 (CH ), 45.88 (CH ), 46.53
3
3
2
(
CH ), 113.86 (C), 118.82 (CH), 119.44 (CH), 148.45
2
(
C). Found, %: C 40.16; H 5.10; N 47.37. C H N O.
8
12
8
Calculated, %: C 40.67; H 5.12; N 47.43.
4-Amino-1-ethyl-1H-1,2,3-triazole (IX). A mix-
ture of 10 g (0.07 mol) of compound VII, 75 g of zinc
dust, and 5 g of calcium chloride in 200 ml of
N-(1-Ethyl-1H-1,2,3-triazol-4-yl)-1,1,2,2,2-penta-
1
fluoro-1-ethanesulfonamide (XI). H NMR spectrum
(
7
7
8% ethanol was stirred for 2–3 h on heating under
CDCl ), δ, ppm: 1.46 t (3H, CH ), 4.30 q (2H, CH ),
reflux (the progress of the reaction was monitored by
TLC). The mixture was filtered while hot, and the
precipitate of zinc dust was washed with hot alcohol.
The solvent was distilled off, and the residue was dis-
tilled under reduced pressure. A fraction with bp 108–
3
3
2
1
3
.48 s (1H, CH), 8.82 br.s (1H, NH). C NMR
spectrum (CDCl ), δ , ppm: 14.15 (CH ), 48.09 (CH ),
3
C
3
2
1
2
1
3
3
10.52 (CH), 114.61 t.q (CF , J = 303.94, J
5.78 Hz), 119.16 q.t (CF , J = 286.9, J
3.0 Hz), 146.38 (C ). F NMR spectrum (CDCl ), δ ,
=
=
2
CF
CF
1
2
3
CF
CF
4
19
1
10°C (2 mm) crystallized on cooling to give a color-
3
F
1
ppm: –77.87 (3F, CF ), –116.45 (2F, CF ).
less solid with mp 56–58°C. H NMR spectrum
3
2
(
DMSO-d ), δ, ppm: 1.34 t (3H, CH , J = 7.3 Hz),
6
3
1
-Ethyl-4-bis(perfluoroethylsulfonyl)amino-1H-
1
4
.18 q (2H, CH ), 4.71 s (2H, NH ), 7.12 s (1H, =CH).
2 2
1
(
(
(
,2,3-triazole (XII). mp 140°C. H NMR spectrum
13
C NMR spectrum (DMSO-d ), δ , ppm: 15.32 (CH ),
6
C
3
acetone-d ), δ, ppm: 1.56 t (3H, CH ), 4.57 q
6
3
1
3
4
4.53 (CH ), 106.83 (=CH), 152.19 (C). Found, %:
2
2H, CH ), 8.09 s (1H, CH). C NMR spectrum
2
C 42.74; H 7.51; N 49.79. C H N . Calculated, %:
C 42.85; H 7.19; N 49.96.
4
8
4
DMSO-d ), δ , ppm: 14.58 (CH ), 50.28 (CH ),
6
C
3
2
1
2
1
11.83 t.q (CF , J = 287.5, J = 36.6 Hz),
2 CF CF
1
2
N-(1-Ethyl-1H-1,2,3-triazol-4-yl)trifluoro-
methanesulfonamide (X). A solution of 2.26 g
(
119.00 q.t (CF , JCF = 286.6, JCF = 33.8 Hz), 126.84
(CH), 140.27 (C ). F NMR spectrum (DMSO-d
ppm: –77.18 (3F, CF ), –116.17 (2F, CF ).
3
4
19
), δ,
6
13.4 mmol) of trifluoromethanesulfonyl chloride in
3
2
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004

TRIFLUOROMETHYL SULFONES AND PERFLUOROALKANESULFONAMIDES
395
1
3
o
4
-Amino-2-ethyl-2H-1,2,3-triazole (XIV) was
C NMR spectrum (CDCl ), δ , ppm: 117.46 (C ),
3
C
5
p
m
i
synthesized by the procedure described in [5]. Yield
2%, bp 86-87°C (5 mm). H NMR spectrum (CDCl ),
123.41 (C ), 125.98 (C ), 128.97 (C ), 139.64 (C ),
152.25 (C ). Found, %: C 60.07; H 5.17; N 34.42.
1
4
3
3
δ, ppm: 1.22 t (3H, CH , J = 7.3 Hz), 3.90 br.s (2H,
C H N . Calculated, %: C 59.99; H 5.03; N 34.98.
3
8
8
4
1
3
NH ), 4.01 q (2H, CH ), 6.69 s (1H, CH). C NMR
2
2
1
,2-Bis(2-phenyl-2H-1,2,3-triazol-4-yl)-hydra-
spectrum (CDCl ), δ , ppm: 14.05 (CH ), 48.69 (CH ),
3
C
3
2
4
zine (XVIII). Compound XVII, 3 g (0.016 mol), was
added over a period of 1 h under vigorous stirring to
a cooled mixture of 10.5 g of zinc dust and 1.2 g of
1
%
20.16 (=CH), 150.88 (C ). Mass spectrum, m/z (I ,
rel
): 112 (70) [M] , 97 (100) [M – CH ] , 70 (38) [M –
CH – HCN] , 42 (42) [NH CN] . Found, %: C 41.83;
+
+
3
+
+
3
2
CaCl in 50 ml of 78% ethanol. The mixture was
2
H 7.65; N 50.26. C H N . Calculated, %: C 42.85;
4
8
4
stirred for 30 min at room temperature, carefully
heated to 50°C (self-heating), and heated for 4 h under
reflux (the progress of the reaction was monitored by
TLC). The mixture was filtered while hot, and the
precipitate was washed with hot ethanol. The filtrate
was cooled, and the yellow crystals were filtered off.
H 7.19; N 49.96.
N-(2-Ethyl-2H-1,2,3-triazol-4-yl)trifluoro-
methanesulfonamide (XV) was synthesized as
1
described above for compound X. H NMR spectrum
(
7
CDCl ), δ, ppm: 1.52 t (3H, CH ), 4.46 q (2H, CH ),
3
3
2
1
3
.63 s (1H, CH), 10.26 s (1H, NH). C NMR spectrum
1
Yield 0.86 g (34%), mp 185–187°C. H NMR
(
CDCl ), δ , ppm: 14.57 (CH ), 50.67 (CH ), 119.57 q
3
C
3
2
spectrum, δ, ppm: DMSO-d : 7.26 t (1H, p-H), 7.47 t
6
1
4
(
CF , J = 320.3 Hz), 125.56 (CH), 140.90 (C ).
3 CF
(
(
7
2H, m-H), 7.53 s (1H, =CH), 7.87 d (2H, o-H), 8.43 s
1
9
F NMR spectrum (CDCl ): δ –76.20 ppm. Found,
3
F
1H, NH); CDCl : 6.14 s (1H, NH), 7.25 t (1H, p-H),
3
%
: C 25.31; H 2.87; N 23.13; S 13.55. C H F N O S.
13
5
7
3
4
2
.41 m (3H, =CH, m-H), 7.93 d (2H, o-H). C NMR
Calculated, %: C 24.59; H 2.89; N 22.94; S 13.13.
-Amino-5-chloro-2-ethyl-2H-1,2,3-triazole
XVI). Concentrated hydrochloric acid, 18.5 ml, was
o
spectrum (DMSO d ), δ , ppm: 117.05 (C ), 123.17
6
C
5
p
m
i
4
(C ), 126.16 (C ), 129.48 (C ), 139.42 (C ), 156.97
4
(
(C ). Found, %: C 60.29; H 4.41; N 35.01. C H N .
16
14
8
added dropwise to a mixture of 5 g (0.035 mol) of
Calculated, %: C 60.37; H 4.43; N 35.20.
compound XIII, 36 g of SnCl ·2H O, 50 ml of water,
2
2
The mother liquor was evaporated, and the residue
was subjected to column chromatography to isolate
and 10 ml of ethanol, heated to 40°C. The mixture was
heated for 2 h at the boiling point, cooled, poured into
excess 10% aqueous NaOH, and extracted with diethyl
0
.88 g (35%) of amine XIX.
ether. The extract was dried over MgSO and
(Z)-1,2-Bis(2-phenyl-2H-1,2,3-triazol-4-yl)di-
4
evaporated, and the residue (2.3 g) was distilled under
reduced pressure; bp 88-90°C (5 mm). We thus
isolated 1.36 g of a mixture of approximately equal
amounts of 4-amino-2-ethyl-2H-1,2,3-triazole (XIV)
and 4-amino-5-chloro-2-ethyl-2H-1,2,3-triazole (XVI).
The reduction of XIII with zinc dust in methanol in the
presence of HCl occurred in a similar way. Products
XIV and XVI were separated by column chromatog-
azene (XX). A solution of 0.57 g (3.4 mmol) of
trifluoromethanesulfonyl chloride in 3 ml of methanol
was added dropwise to a suspension of 0.43 g
(1.4 mmol) of compound XIX in 10 ml of methanol.
After stirring for 1 h at room temperature, the mixture
contained only initial hydrazine XVIII (TLC). Phase-
transfer catalysts, dicyclohexyl-18-crown-6 (0.03 g,
0
.07 mmol), KF·2H O (7 mg, 0.07 mmol), and K CO
2 2 3
raphy on Al O using diethyl ether–hexane (2:1) as
2
3
(0.1 g, 0.7 mmol), were added, and the mixture was
heated for 3 days under reflux, new portions of tri-
fluoromethanesulfonyl chloride being added as the
mixture boiled away. The dark yellow precipitate was
1
eluent. H NMR spectrum (CDCl ), δ, ppm: 1.45 t (3H,
3
1
3
CH ), 3.76 br.s (2H, NH ), 4.20 q (2H, CH ). C NMR
3
2
2
spectrum (CDCl ), δ, ppm: 14.49 (CH ), 50.11 (CH ),
3
3
2
4
5
1
1
21.13 (C ), 146.81 (C ). Mass spectrum, m/z (I , %):
rel
46 (54) [M] , 131 (100) [M – CH ] , 118 (5) [M –
C H ] , 42 (30) [NH CN] .
filtered off and washed with cold methanol. Yield
+
+
1
3
0.34 g (80%), mp 230°C. H NMR spectrum (CDCl ),
3
+
+
2
4
2
δ, ppm: 7.42 t (1H, p-H), 7.53 t (2H, m-H), 8.20 d (2H,
1
3
4
-Amino-2-phenyl-2H-1,2,3-triazole (XVII) was
synthesized by the procedure reported in [9]. Yield
6% (cf. no more than 73% in [9]), mp 70°C;
o-H), 8.24 s (1H, =CH). C NMR spectrum (CDCl ),
3
o
5
p
δ, ppm: 119.22 (C ), 126.28 (C ), 128.50 (C ), 129.49
m
i
4
5
p
8
(C ), 139.66 (C ), 160.86 (C ); the C and C signals
were assigned using two-dimensional { H– C} NMR
technique. Found, %: C 60.32; H 3.71; N 35.43.
1
1
13
published data [9]: mp 68–69°C. H NMR spectrum
(
7
CDCl ), δ, ppm: 4.02 s (2H, NH ), 7.13 s (1H, =CH),
3
2
.18 t (1H, p-H), 7.36 t (2H, m-H), 7.88 d (2H, o-H).
C H N . Calculated, %: C 60.75; H 3.82; N 35.42.
16 12 8
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004

3
96
MESHCHERYAKOV, SHAINYAN
The mother liquor was evaporated, and the residue
4. Shainyan, B.A. and Meshcheryakov, V.I., Russ. J. Org.
Chem., 2001, vol. 37, p. 1797.
was recrystallized from ethanol–hexane to obtain white
crystals which were identified as potassium trifluoro-
methanesulfinate (by TLC using an authentic sample).
5. Organic Syntheses, Blatt, A.H., Ed., New York: Wiley,
1943, collect. vol. 2. Translated under the title Sintezy
organicheskikh preparatov, Moscow: Inostrannaya
Literatura, 1949, collect. vol. 2, p. 385.
The authors are grateful to Yu.A. Chuvashev for
performing GC–MS analyses.
6
. Brown, H.A., US Patent no. 2950317, 1960; Ref. Zh.,
Khim., 1961, no. 17L103.
REFERENCES
7
. Roesky, H.W., Niederpruem, H., and Wechsberg, M.,
FRG Patent no. 2148597, 1973; Chem. Abstr., 1973,
vol. 78, no. 158922.
1
2
. Hendrickson, J.B. and Skipper, P.L., Tetrahedron, 1976,
vol. 32, p. 1627.
8
9
. Harzdorf, C., Meuβdoerffer, J.-N., Niederprum, H., and
Wechsberg, M., Justus Liebigs Ann. Chem., 1973, p. 33.
. Hendrickson, J.B., Bair, K.W., Bergeron, R., Giga, A.,
Skipper, P.L., Sternbach, D.D., and Wareing, J.A., Org.
Prep. Proced. Int., 1977, vol. 9, p. 173.
. Eugene, F., Langlois, B., and Laurent, E., J. Fluorine
Chem., 1994, vol. 66, p. 301.
. Nikitin, V.M., Zavodov, A.V., Vereshchagin, A.L., and
Vereshchagin, L.I., Zh. Org. Khim., 1992, vol. 28,
p. 2334.
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 3 2004