Reactions of 2-Arylthio-and 2-Arylsulfonyl-1-nitro-1-phenylethenes with Amines

Article abstract of DOI:10.1023/A:1023494629499

2-Arylthio- and 2-arylsulfonyl-1-nitro-1-phenylethenes react with amines to give the corresponding nitroenamines whose configuration (E or Z) depends on the amine structure. Primary amines gives rise to Z-nitroenamines, secondary cyclic amines with 2-aryl

Full text of DOI:10.1023/A:1023494629499

Russian Journal of Organic Chemistry, Vol. 39, No. 1, 2003, pp. 82 86. Translated from Zhurnal Organicheskoi Khimii, Vol. 39, No. 1, 2003,
pp. 91 95.
Original Russian Text Copyright
2003 by Kuz’mina, Lipina, Kropotova, Berkova, Pavlova.
Reactions of 2-Arylthio-
and 2-Arylsulfonyl-1-nitro-1-phenylethenes with Amines
N. V. Kuz’mina, E. S. Lipina, T. Yu. Kropotova, G. A. Berkova, and Z. F. Pavlova
Gertsen Russian State Pedagogical University, nab. r. Moiki 48, St. Petersburg, 191186 Russia
e-mail: chemis@herzen.spb.ru
Received April 25, 2001
Abstract 2-Arylthio- and 2-arylsulfonyl-1-nitro-1-phenylethenes react with amines to give the corresponding
nitroenamines whose configuration (E or Z) depends on the amine structure. Primary amines gives rise to
Z-nitroenamines, secondary cyclic amines with 2-arylthio-1-nitroalkenes form E-nitroenamines, and with more
reactive 2-arylsulfonyl-1-nitroalkenes E/Z-isomeric mixtures are obtained.
The presence of a readily departing group in the
-position with respect to the nitro group determines
the high reactivity of 2-arylthio- and 2-arylsulfonyl-
1-nitro-1-phenylethenes toward nucleophilic reagents
and formation of the corresponding substitution prod-
ucts [1]. We previously described reactions of sulfur-
containing nitroalkenes with alkoxide and thiolate
ions [2, 3], as well as with some amines (e.g., aniline
and morpholine [2]). In addition, reactions of R-thio-
nitroalkenes with pyrrolidine [4] and three aliphatic
amines [5] were reported. The products of these reac-
tions were the corresponding nitroenamines; however,
neither the reactivity of various R-thio- and R-sul-
fonyl-substituted substrates nor the relations between
the product configuration and initial amine structure
were examined.
With the goal of studying in more detail the reac-
tivity of 1-nitro-2-R-thio(sulfonyl)ethenes toward
various amines and revealing the relations between
the amine nature and steric structure of the resulting
nitroenamines, 2-(4-chlorophenylthio)-1-nitro-1-
phenylethene (I) and 2-arylsulfonyl-1-nitro-1-phenyl-
ethenes II and III were brought into reactions with
primary and secondary amines. The reactions with
such aliphatic amines as diethylamine, dipentylamine,
and benzylamine were carried out for the the first
time. As secondary cyclic amines we used piperidine
and morpholine. As a result, nitroenamines IV XVI
were obtained (Tables 1 3; Scheme 1).
As expected, ammonia and aliphatic amines (ben-
zylamine, dialkylamines) reacted with compounds
I III more readily than did aromatic amines (aniline
Scheme 1.
I, R1 = H, R2 = 4-ClC6H4, n = 0; II, R1 = H, R2 = 4-CH3C6H4, n = 2; III, R1 = Ph, R2 = 4-CH3C6H4, n = 2; IV, R1 = R5 = H;
V, R1 = H, R5 = PhCH2; VI, R1 = H, R5 = 4-NO2C6H4; VII, R1 = H, R3 = R4 = Et; VIII, R1 = H, R3 = R4 = C5H11; IX, R1 = H,
X = CH2; X, R1 = H, X = O; XI, R1 = Ph, R5 = H; XII, R1 = Ph, R5 = PhCH2; XIII, R1 = Ph, R3 = R4 = Et; XIV, R1 = Ph, R3 =
R4 = C5H11; XV, R1 = Ph, X = CH2; XVI, R1 = Ph, X = O.
1070-4280/03/3901-0082$25.00 2003 MAIK Nauka/Interperiodica

REACTIONS OF 2-ARYLTHIO- AND 2-ARYLSULFONYL-1-NITRO-1-PHENYLETHENES
83
Table 1. Melting points and spectral parameters of 2-amino-1-nitroethenes IV XVI
1
IR spectrum, , cm
1H NMR spectrum, , ppm
R1 R2
UV spectrum,
max, nm ( ,
Comp.
no.
mp,
C
Isomer
1
NOO (NO2) C C, C N
Ph
R3
l mol 1 cm )
IV
V
92 93
84 85
Z
Z
Z
1380, 1280,
1180
1385, 1365,
1175
1335, 1175, 1650, 1630
1120
1640
1640
7.11 7.27 m
9.00 br
4.59 d,a
7.45 7.50 m 368 [12000]
11.10 br 7.19 7.69 m
245 [9500]
368 [12000]
262 [10000]
7.45 7.50 m 7.14 s 9.69 br
VI
224 225
7.19 7.69 m
VII
VIII
67 69
52 53
E
E
1375, 1285 1620, 1595 7.30 7.42 m 8.50 s
1380, 1275 1660, 1590 7.29 7.40 m 8.45 s
1.09 t, 3.07 q
364 [16000]
0.90 t, 1.25 q,
1.59 m, 3.15 q
1.52 s, 3.09 m
IX
X
135 136
Oil
160 161
Oil
Eb
Zd
Eb
Zd
Z
1385, 1265c
1170
1370, 1170 1640, 1590
1625
8.47 s
7.26 7.38 m 7.85 s
8.40 s
257 [9300]
368 [20000]
410 [10000]
3.09, 3.19, 3.46,
3.70 m
6.85 7.30 m 7.80 s
7.10 7.28 m
XI
XII
157 158
1393, 1291
1600
10.00 br
240 [9200]
360 [12000]
257 [5200]
370 [13500]
160 161
Z
Z
Z
Z
Z
1375, 1180, 1590, 1570
7.32 m
7.11 m 11.34 s
4.32 d,
7.00 m
1.15 t, 3.18 q
1135
XIII 130 131
1375, 1285, 1595, 1580
7.26 m
7.26 m
7.31 m
7.15 m
7.12 m
7.11 m
1180
XIV
XV
69 70
1375, 1240, 1595, 1580
0.89 t, 1.23 q,
1.57 m, 3.12 t
1.68 s, 3.02 s
262 [4200]
420 [4400]
257 [12000]
424 [10500]
1180
167 168
1290, 1230, 1595, 1590
1180
XVI 204 205
1305, 1120 1600, 1570 7.10 7.20 m 6.95 m
2.55, 3.18, 3.81 m 257 [7700]
414 [7000]
a
b
c
J = 10 Hz.
From compound I.
In KBr.
d
From compound II.
1
and p-nitroaniline; Table 2). Arylsulfonyl-substituted
compounds II and III turned out to be more reactive
than I, and the styrene derivative was more reactive
than stilbene III (Table 2). Styrene I and stilbene
III failed to react with such a weak nucleophile as
p-nitroaniline in boiling acetonitrile (24 h).
1300 1170 cm ( N O). The UV spectra contain
s
a long-wave charge-transfer band at 340 410 nm.
The configuration of nitroenamines was determined
on the basis of the H NMR spectra. It is known that
1
in the absence of deshielding effect of the nitro group
(through space) the signal from the olefinic proton of
the Z isomer appears in a stronger field relative to
the corresponding signal of the E isomer [7]. The
position of the -vinyl proton signal in the spectra
of secondary aminonitrostyrenes IV VI ( 7.14
7.80 ppm) suggests that their molecules have Z con-
figuration. The structure of tertiary aminonitroalkenes
depends on the amine nature. Compounds VII and
The structure of previously unknown 2-amino-1-
nitroethenes was confirmed by spectral data (Table 1).
Their IR spectra are typical of strongly polarized
nitroenamine systems [6]: a strong enamine band is
1
observed in the region 1660 1570 cm , and stretch-
ing vibrations of the nitro group give rise to absorp-
1
tion at 1510 1440 cm
( asN O, weak band) and
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 1 2003

84
KUZ’MINA et al.
Table 2. Reaction of nitroalkenes I III with amines; given are product no., configuration, reaction time, and yield
Comp. no.
Solvent
Ammoniaa
Benzylamine
p-Nitroanilineb
I
Diethyl ether
IV (Z),
V (Z),
I, 4 h,
90 min, 34%
100 min, 60%
60 C, 95%
II
Diethyl ether
IV (Z),
5 min, 39%
V (Z),
25 min, 57%
VI (Z),
20 min,c 73%
III
Methanol
XI (Z),
XII (Z),
III,
Acetonitrile
30 min, 20 C, 52%
20 min, 50 C, 87%
24 h, 60 C, 98%
Comp. no.
Solvent
Diethylamine
Dipentylamine
Piperidine
Morpholine
I
Diethyl ether
VII (E),
VIII (E),
IX (E),
X (E),
40 min, 41%
40 min, 40%
45 min, 46%
50 min, 75%
II
Diethyl ether
VII (E),
VIII (E),
IX (E/Z),
X (E/Z),
15 min, 30%
15 min, 27%
10 min, 57%
25 min, 70%
III
Methanol
XIII (Z),
XIV (Z),
XV (Z),
XVI (Z),
Acetonitrile
15 min, 50 C, 64% 15 min, 50 C, 43% 5 min, 50 C, 82% 10 min, 50 C, 68%
a
b
c
The reaction was carried out in MeOH/H2O at 18 20 C.
The reaction with aniline in methanol at room temperature was complete in 3 h [2].
The reaction was carried out in acetonitrile.
VIII derived from secondary aliphatic amines are
E isomers; the chemical shifts of the olefinic protons
therein are 8.50 and 8.45 ppm, respectively. Nitro-
enamines IX and X obtained from arylsulfonylalkene
and cyclic amines were isolated as mixtures of E
and Z isomers (Table 1), whereas the reaction with
less reactive arylthioethene I gave only more stable
E isomer.
data of [9], 1-nitro-2-piperidino-1,2-diphenylethene
has also Z configuration.
The reaction of 2-arylthio- and 2-arylsulfonyl-1-
nitroethenes with alkylamines may be regarded as
a preparative route to 2-alkylamino-1-nitroethenes,
taking into account that the other -functionalized
nitroalkenes are less accessible and that their reactions
with strongly basic aliphatic amines are accompanied
by considerable tarring.
1
According to the TLC and H NMR data, nitro-
enamines XI XVI of the stilbene series were isolated
as single isomers. The Z configuration of XI and
XII was assigned by analysis of the 1H chemical shifts
of both -phenyl protons and proton on the amino
nitrogen atom. Their signals are displaced downfield
( 10.0 and 11.50 ppm, respectively) due to deshield-
ing effect of the nitro group in the cis-position. Like-
wise, the NH proton signal in the spectra of Z-styrene
derivatives IV and V is observed at > 9.00 ppm
(Table 1), in keeping with published data for (Z)- and
EXPERIMENTAL
The IR spectra were recorded on a Specord-75IR
spectrometer in chloroform (unless otherwise stated).
The H NMR spectra were obtained on a Tesla BS-
1
487C instrument (80 MHz) in CDCl3. The UV spectra
were measured on a Specord M-40 spectrophotometer.
The progress of reactions was monitored, and the
purity of products was checked, by TLC on Silufol
UV-254 plates using hexane acetone (2:1) as eluent.
Some products were isolated and purified by column
chromatography on silica gel (L 100/250 m,
Czechia); eluents were selected according to the
Trappe series. 2-(4-Chlorophenylthio)-1-nitro-1-
phenylethene (I) [10], 1-nitro-1-phenyl-2-(4-tolylsul-
fonyl)ethene (II), and 1-nitro-1,2-diphenyl-2-(4-tolyl-
sulfonyl)ethene (III) [11] were synthesized by known
methods.
(E)-2-amino-1-nitroethenes:
9.00 11.50 ppm (Z)
and < 9 ppm (E) [6 8]. This conclusion is supported
by the upfield position of signals from the -phenyl
protons ( 7.11 ppm) relative to those of the -phenyl
protons ( 7.28 and 7.32 ppm). The assignment of
tertiary nitroenamines XIII XVI to the Z series is
less reliable. It was made on the basis of the chemical
shifts of the phenyl protons, which are similar to those
observed for Z isomers XI and XII. According to the
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 1 2003

REACTIONS OF 2-ARYLTHIO- AND 2-ARYLSULFONYL-1-NITRO-1-PHENYLETHENES
85
Table 3. Elemental analyses of aminonitroethenes IV XVI
Found, %
H
Calculated, %
H
Compound
no.
Formula
C
N
C
N
IV
V
VI
VII
VIII
IX
X
XI
XII
XIII
XIV
XV
XVI
58.49
70.79
59.07
65.39
69.98
67.33
57.99
70.01
76.08
72.83
75.40
74.20
61.98
4.83
5.61
3.91
7.33
13.78
6.71
5.53
4.95
5.61
6.91
8.69
6.62
12.09
17.18
11.05
14.68
12.80
13.70
12.13
17.00
11.58
8.46
9.38
7.59
9.08
11.98
C8H8N2O2
58.54
70.87
58.94
65.45
71.05
67.24
58.06
70.00
76.36
72.97
75.79
74.03
62.07
4.88
5.52
3.85
7.27
13.79
6.89
5.65
5.00
5.46
6.76
8.42
6.49
12.07
17.07
11.02
14.73
12.73
13.79
12.07
16.94
11.67
8.49
9.46
7.37
9.09
12.07
C15H14N2O2
C14H11N3O4
C12H16N2O2
C18H28N2O2
C13H16N2O2
C12H14N2O3
C14H12N2O2
C21H18N2O2
C18H20N2O2
C24H32N2O2
C13H30N2O2
C12H28N2O3
(Z)-2-Amino-1-nitro-1-phenylethene (IV). To
a solution of 0.30 g (1 mmol) of 1-nitro-1-phenyl-2-
(4-tolylsulfonyl)ethene (II) in 10 ml of methanol we
added dropwise 2 ml (1 mmol) of 25% aqueous
ammonia. The mixture instantaneously turned bright
creamson, and 5 min after it became lemon yellow.
The solvent was distilled off on a rotary evaporator,
and the residue was subjected to column chromatog-
raphy on silica gel. By elution with chloroform we
isolated 0.064 g of nitroenamine IV as yellow crystals
with mp 92 93 C; published data [12]: mp 96 C.
The same product was obtained from 2-(4-chloro-
phenylthio)-1-nitro-1-phenylethene (I) under similar
conditions.
(Z)-2-Amino-1-nitro-1,2-diphenylethene (XI) was
synthesized following the above procedure with the
use of a double excess of ammonia.
phenyl-2-(4-tolylsulfonyl)ethene (II) we added drop-
wise a solution of 0.08 g (1 mmol) of diethylamine
in 5 ml of dry diethyl ether. After 15 min, the mixture
became yellow, and diethylammonium sulfinate pre-
cipitated as a colorless solid. The mixture was filtered,
the filtrate was concentrated, 5 ml of anhydrous
ethanol was added to the residue, the mixture was
cooled to 0 C, and the yellow cubic crystals were
filtered off. Yield 0.066 g.
Under analogous conditions, from nitrostyrenes I
and II we obtained (E)-2-dipentylamino-1-nitro-1-
phenylethene (VIII), 1-nitro-1-phenyl-2-piperidino-
ethene (IX), and (E)-2-morpholino-1-nitro-1-phenyl-
ethene (X). From nitrostyrene II we also synthesized
1-nitro-2-(4-nitrophenylamino)-1-phenylethene (VI),
and from nitrostilbene III, 1-nitro-1,2-diphenyl-2-
piperidinoethene (XV).
(Z)-2-Benzylamino-1-nitro-1,2-diphenylethene
(XII). To a suspension of 0.38 g (1 mmol) of 1-nitro-
1,2-diphenyl-2-(4-tolylsulfonyl)ethene (III) in 3 ml of
methanol we added a solution of 0.22 g (2 mmol) of
benzylamine in 5 ml of acetonitrile, and the mixture
was heated for 20 min to 60 C until it became homo-
geneous. The mixture was kept for 15 min at 18 20 C
and cooled to 0 C, and the precipitate of (Z)-nitro-
aminostilbene XII was filtered off. Yield 0.29 g,
yellow crystals.
2-Dipentylamino-1-nitro-1,2-diphenylethene (XIV)
and 2-morpholino-1-nitro-1,2-diphenylethene (XVI)
were synthesized in a similar way. Following the
above procedure (reaction time 40 min), 2-benzyl-
(Z)-2-Benzylamino-1-nitro-1-phenylethene (V).
To a suspension of 0.15 g (5 mmol) of nitrostyrene II
in 10 ml of dry diethyl ether we added dropwise
a solution of 0.1 g (1 mmol) of benzylamine in 5 ml
of dry diethyl ether. After several minutes, the
mixture became homogeneous and gradually turned
yellow, and a colorless solid (benzylammonium sul-
finate) separated. The precipitate was filtered off, and
the filtrate was kept for 25 min at 18 20 C and cooled
to 0 C. Large bright yellow crystals separated and
were filtered off. Yield 0.07 g. The same product was
obtained from nitrostyrene I.
2-Diethylamino-1-nitro-1-phenylethene (VII). To
a suspension of 0.15 g (0.5 mmol) of 1-nitro-1-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 1 2003

86
KUZ’MINA et al.
amino-1-nitro-1-phenylethene (V) was obtained from
nitrostyrene I.
3. Kuz’mina, N.V., Lipina, E.S., Kropotova, T.Yu.,
Berkova, G.A., and Pavlova, Z.F., Russ. J. Org.
Chem., 2001, vol. 37, p. 1259.
4. Ono, N., Kamimura, A., and Kaji, A., J. Org. Chem.,
1986, vol. 51, p. 2139.
5. Kamimura, A. and Ono, N., Synthesis, 1988, p. 921.
6. Chiara, H., Gomez-Sanchez, A., and Bellanato, J.J.,
J. Chem. Soc., Perkin Trans. 2, 1992, p. 78.
7. Fetell, A.I. and Feuer, H., J. Org. Chem., 1978,
Reaction of 2-(4-chlorophenylthio)-1-nitro-1-
phenylethene (I) and 1-nitro-1,2-diphenyl-2-(4-
tolylsulfonyl)ethene (III) with p-nitroaniline. To
a suspension of 0.29 g (1 mmol) of nitrostyrene I in
5 ml of acetonitrile we added a solution of 0.14 g
(1 mmol) of p-nitroaniline in 5 ml of acetonitrile.
The resulting suspension was heated for 4 h at 60 C
(with a reflux condenser). The mixture was cooled,
and the yellow precipitate of initial compound I,
0.35 g (95%), was filtered off.
vol. 43, p. 1238.
8. Gate, E.N., Meek, M.A., Schwalbe, C.H., Ste-
vens, M.F.G., and Threadgill, M.D.. J. Chem. Soc.,
Perkin Trans. 2, 1985, p. 251.
9. Todres, Z.V., Dyusengaliev, K.I., and Kosni-
kov, A.Yu., Izv. Akad. Nauk SSSR, Ser. Khim., 1990,
p. 791.
Under analogous conditions, 98% of the initial
nitrostilbene was recovered from the reaction of
p-nitroaniline with compound III.
10. Mukhina, E.S., Berkova, G.A., Pavlova, Z.F.,
Lipina, E.S., and Perekalin, V.V., Zh. Org. Khim.,
1990, vol. 26, p. 1447.
11. Mukhina, E.S., Pavlova, Z.F., Berkova, G.A.,
Lipina, E.S., and Mostyaeva, L.V., Zh. Org. Khim.,
1991, vol. 27, p. 910.
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