Synthesis of 4-(5-Nitrophenylfur-2-yl)-1,2,3-thia- and Selenadiazoles

Article abstract of DOI:10.1134/S1070363219040108

Arylation of 2-acetylfuran with o-, m-, and p-nitrophenyldiazonium salts under the conditions of the Gomberg-Bachmann reaction has afforded the corresponding 5-(nitrophenyl)-2-acetylfurans. Their carbo-ethoxyhydrazones have undergone the cyclization into stable 4-(5-nitrophenylfur-2-yl)-1,2,3-thiadiazoles under the conditions of the Hurd-Mori reaction. Analogous semicarbazones have afforded the corresponding selenadiazoles upon oxidation with selenium dioxide. The analysis of electronic absorption spectra of the obtained hybrid heterocycles has shown that the conjugation of the phenyl and the furan ring in o-nitrophenyl derivatives is distorted due to steric hindrance, whereas the effect of direct polar conjugation leading to strong bathochromic shift of the absorption band has been observed in the case of the p-nitro derivatives. The position and intensity of the bands in the electronic absorption spectra of the studied compounds are determined by electronic as well as steric factors. The difference in the length of conjugation chain determined by the position of the nitro group in the phenyl fragment also contributes to the observed trend. The introduction of selenadiazole fragment instead of thiadiazole one has caused slight bathochromic shift of the band in the electron absorption spectra.

Full text of DOI:10.1134/S1070363219040108

ISSN 1070-3632, Russian Journal of General Chemistry, 2019, Vol. 89, No. 4, pp. 701–707. © Pleiades Publishing, Ltd., 2019.
Russian Text © The Authors(s), 2019, published in Zhurnal Obshchei Khimii, 2019, Vol. 89, No. 4, pp. 566–573.
Synthesis of 4-(5-Nitrophenylfur-2-yl)-1,2,3-thia-
and Selenadiazoles
V. V. Dmiterkoa, L. M. Pevznera*, M. L. Petrova, and V. S. Zavgorodniia
a St. Petersburg State Institute of Technology (Technical University), Moskovskii pr. 26, St. Petersburg, 190013 Russia
*e-mail: pevzner_lm@list.ru
Received December 7, 2018; revised December 7, 2018; accepted December 13, 2018
Abstract—Arylation of 2-acetylfuran with o-, m-, and p-nitrophenyldiazonium salts under the conditions of the
Gomberg–Bachmann reaction has afforded the corresponding 5-(nitrophenyl)-2-acetylfurans. Their carbo-
ethoxyhydrazones have undergone the cyclization into stable 4-(5-nitrophenylfur-2-yl)-1,2,3-thiadiazoles under
the conditions of the Hurd–Mori reaction. Analogous semicarbazones have afforded the corresponding
selenadiazoles upon oxidation with selenium dioxide. The analysis of electronic absorption spectra of the
obtained hybrid heterocycles has shown that the conjugation of the phenyl and the furan ring in o-nitrophenyl
derivatives is distorted due to steric hindrance, whereas the effect of direct polar conjugation leading to strong
bathochromic shift of the absorption band has been observed in the case of the p-nitro derivatives. The position
and intensity of the bands in the electronic absorption spectra of the studied compounds are determined by
electronic as well as steric factors. The difference in the length of conjugation chain determined by the position
of the nitro group in the phenyl fragment also contributes to the observed trend. The introduction of
selenadiazole fragment instead of thiadiazole one has caused slight bathochromic shift of the band in the
electron absorption spectra.
Keywords: 2-acetylfuran, arylation, hydrazones, Hurd–Mori reaction, 1,2,3-thidiazoles, 1,2,3-selenadiazoles
DOI: 10.1134/S1070363219040108
We have recently demonstrated that phenyl
substituent containing nitro or ester group and located
at position 5 of the furan ring of 4-(3-furyl)-1,2,3-
thiadiazole makes this hybrid system thermally stable
[1]. This study aimed to verify whether it was possible
to stabilize labile 4-(2-furyl)-1,2,3-thia- and selena-
diazole systems [2] via the same approach and to
elucidate the features of electron density distribution in
such molecules.
phenyldiazonium salts in a water–acetone medium
under the conditions of the Gomberg–Bachmann reac-
tion, as described elsewhere [3] (Scheme 1).
Compounds 1-3 were obtained in 62, 30, and 70%
yield, respectively. The difference in the yields was in
line with electrophilicity of aryl carbocations formed
via elimination of nitrogen from the nitrophenyldia-
zonium salts, suggesting that the arylation of acetyl-
furan proceeded according to the electrophilic mechanism.
The first step of the target products synthesis was
Nitrophenylketones 1–3 were crystalline substances
the arylation of 2-acetylfuran with o-, m-, or p-nitro-
with distinct melting points. Synthetic protocol and
Scheme 1.
Cl−
N2+
CuCl2
+
O
O
O2N
O2N
O
O
1−3
2-NO2 (1), 3-NO2 (2), 4-NO2 (3).
701

702
DMITERKO et al.
Scheme 2.
SOCl2
H2N−NHCOOEt
1−3
O
N
O
O2N
O2N
N
N
NHCOOEt
S
4−6
2-NO2 (4, 7), 3-NO2 (5, 8), 4-NO2 (6, 9).
7−9
spectral parameters of the obtained compounds are
presented in the Experimental.
acetylfurans with semicarbazide hydrochloride in the
presence of sodium acetate in 2-propanol gave semi-
carbazones 10–12 (Scheme 3). The reaction was
performed at the ketone : semicarbazide hydro-
chloride : sodium acetate molar ratio of 1 : 1.2 : 2 at
80°C during 10 h. The yields of the target products
after crystallization from ethanol were 87, 89, and
90%, respectively. Oxidation of compounds 10–12
with selenium dioxide in acetic acid at 66°C led to the
formation of selenadiazoles 13–15 (Scheme 3). The
reaction was carried out at the semicarbazone :
selenium dioxide molar ratio of 1 : 1.1 during 6 h. The
target products were obtained in 82, 65, and 77% yield,
respectively. The formation of 1,2,3-selenadiazole ring
was confirmed by the presence of the proton signal at
Carbethoxyhydrazones of compounds 1–3 were
synthesized via the reaction with carboethoxyhyd-
razine in 2-propanol in the presence of sulfuric acid at
the ketone to hydrazine molar ratio 1 : 1.05 (Scheme 2).
The reaction duration was 10 h at 80°C. Yields of
o- (4) and p-nitrophenyl compounds 6 were practically
equal (56 and 57%, respectively), while the m-isomer
1
was prepared in 65% yield. According to H and 13C
spectral data, those compounds existed in solutions in
a single form rather than as a mixture of syn- and anti-
isomers as in the case of hydrazones of methyl
derivatives of acetylfuran [2] and acetylfurancarbo-
xylates [4].
2
9.3–9.6 ppm in CDCl3 (satellite with JHSe = 39.2 Hz)
2
The transformation of carboethoxyhydrazones 4–6
into 1,2,3-thiadiazoles 7–9 was carried out under the
conditions of the Hurd–Mori reaction, in boiling
chloroform via treating with 3–4-fold molar excess of
thionyl chloride (Scheme 3). Yields of thiadiazoles 7–9
were 40, 35, and 76%, respectively. The formation of
thiadiazole ring was confirmed by the presence of the
H5 proton signal (8.6–8.8 ppm) in the 1H NMR spectra.
The signals of 1,2,3-thiadiazole C5 and C4 carbon
atoms were located at about 129 and 149–152 ppm,
respectively. Compounds 7–9 were crystalline substances
with mp 107, 102, and 160°C, respectively.
or at 10.2 ppm in DMSO-d6 (satellite with JHSe
=
37.2 Hz) in the 1H NMR spectra. The signals of the C5
and C4 carbon atoms were observed at 135–141 and
149–151 ppm, respectively.
The obtained compounds 13–15 were crystalline
substances with mp 120, 127, and 116°C, respectively.
Hence, the introduction of nitrophenyl fragment in
the structure of 4-(2-furyl)-1,2,3-thiadiazole as well as
of 4-(2-furyl)-1,2,3-selenadiazole led to thermal
stabilization of the system. The yields of the target
products in the Hurd–Mori reaction were significantly
stronger dependent on the location of the nitro group in
the phenyl ring as compared with the reaction leading
to the formation of selenadiazole heterocycle.
Two-stage synthesis of 1,2,3-selenadiazoles from
acetylfurans 1–3 was carried out similarly to the
procedure described elsewhere [5]. The treatment of
Scheme 3.
SeO2
H2N−NHCONH2
N
O
O
1−3
O2N
O2N
CH3COOH
CH3COONa
N
N
NHCONH2
Se
13−15
10−12
2-NO2 (10, 13), 3-NO2 (11, 14), 4-NO2 (12, 15).
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SYNTHESIS OF 4-(5-NITROPHENYLFUR-2-YL)-1,2,3-THIA- AND SELENADIAZOLES
703
Electronic absorption spectral data for 5-(nitrophenyl)-2-
acetylfurans 1–3, 4-[5-(nitrophenyl)fur-2-yl]-1,2,3-thiadi-
azoles 7–9, and 4-[5-(nitrophenyl)fur-2-yl]-1,2,3-selenadi-
azoles 13–15 (chloroform, 20°C).
To elucidate the effect of the structure of chromo-
phore groups and their mutual influence, we examined
the electronic absorption spectra of ketones 1–3,
thiadiazoles 7–9, and selenadiazoles 13–15 in chloro-
form. The positions of the absorption maximums and
the extinction coefficients of the above-mentioned com-
pounds at room temperature are listed in the table.
λmax,
Formula
nm
Analysis of the obtained data revealed that the
substituion at positions 2 and 5 of the furan ring led to
significant bathochromic shift and the increase in the
extinction coefficient as compared to the unsubstituted
furan (λmax = 200 nm, εmax 1000 L mol–1 cm–1 [6]).
346
374
3
9
O2N
O2N
13452
8934
O
O
O
A transition from orto- to meta- and para-nitro
group in the phenyl fragment in the series of acetyl-
furans, 1,2,3-thia- and -selenadiazoles increased the
bathochromic shift in the electronic absorption spectra.
The analysis of the Stewart–Brigleb models of
nitrophenylfuryl derivatives showed that coplanar
location of phenyl and furyl rings was impossible for
the orto-nitrophenyl-substituted furans 1, 7, and 13.
That decreased the degree of conjugation between
those structural units and led to shorter-wave absorp-
tion maximums as compared to the para-substituted
derivatives 3, 9, and 15. The para-nitrophenyl
derivatives 3, 9, and 15 exhibited longer-wave
absorption due to effect of direct polar conjugation
with the electron-accepting para-nitro group. The
strongest bathochromic shift in the absorption spectra
was observed for the furans containing 1,2,3-selena-
diazole fragment at position 2 (Δλmax = 75 and 65 nm
between p- and o-, m-nitro derivatives, respectively).
The weakest shift was observed for the acetylfuran
series (Δλmax = 51 and 36 nm between p- and o-, m-nitro
derivatives, respectively). The transition from thiadi-
azole to selenadiazole caused slight bathochromic shift
of the absorption maximum for all three (orto-, meta-,
and para-nitro) chromophore systems, somewhat
depending on the structure. Therefore, it could be con-
cluded that 1,2,3-thia- and -selenadiazole cycles
similarly affected the electron density distribution in
the studied molecules, and the heavy atom effect was
minor. Hence, the bands location in the electronic
absorption spectra of the studied compounds was
determined mainly by the steric factors determined by
the position of the nitro group in the phenyl fragment.
S
N N
385 16673
295 17966
15
1
O2N
Se
N N
O
O
O
O
O
NO2
NO2
NO2
300 14368
310 21911
310 22378
7
S
N N
13
2
Se
N N
O
O
O
O
O2N
O2N
O2N
315 14560
320 25680
8
S
N N
14
Se
N N
between the planes of phenyl and furyl rings [7]). Such
behavior was most probably connected with the more
prominent influence of the electronic factors as
compared to the steric ones. The presence of strong
electron-accepting substituents at the opposite sides of
The change in the extinction coefficient of the
described compounds was nonpredictable. It did not
follow the Braude rule (the decrease in the extinction
coefficient should be enhanced along with the angle
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704
DMITERKO et al.
the π-excessive furan led to the change in the molecule
polarity. Overall electron-accepting effect of the
nitrophenyl fragment at position 5 and the π-deficient
substituents at position 2 (ketones 1–3 and hetero-
cycles 7–9, 13–15) on furan possessing the electron-
donating character showed complex outcome in the
absorption intensity. The molar absorptivity was
decreased for the thiadiazole derivatives in comparison
with the acetyl and increased in the case of the
selenadiazoles. Hence, the position and intensity of the
band in the electronic absorption spectra of the studied
compounds was determined by electronic as well as
steric factors. Further effect was caused by the dif-
ference in the length of the conjugation chain caused
by different location of the nitro group in the phenyl
fragment.
7.6 Hz), 7.65 t (1H, H5-phenyl, J = 7.6 Hz), 7.77 br. d
(1H, Н3,6-phenyl, J = 7.6 Hz), 7.78 br. d (1H, Н3,6-
13
phenyl, J = 7.6 Hz). C NMR spectrum (CDCl3), δC,
ppm: 26.07 (CH3–C=O-furan), 111.71 (С4-furan),
118.20 (С3-furan), 123.02 (С1-phenyl), 124.16 (С3-
phenyl), 129.70 (С4-phenyl), 129.98 (С6-phenyl),
132.27 (С5-phenyl), 147.95 (С5-furan), 151.68 (С2-
furan), 153.08 (С2-pheny), 186.48 (C=O).
5-(m-Nitrophenyl)-2-acetylfuran (2). 12.2 mL of
15% hydrochloric acid was added at stirring to a
suspension of 2.50 g (20.3.4 mmol) of m-nitroaniline
in 16 mL of water. The mixture was heated until
complete dissolution of m-nitroaniline hydrochloride
and cooled to 0°C, 5.5 mL of 30% aqueous solution of
sodium nitrite was then added dropwise at 0–3°C.
After that, the solutions of 2.30 g (17.4 mmol) of
2-acetylfuran in 10.2 mL of acetone and of 0.51 g
(3.0 mmol) of copper chloride dihydrate in 2 mL of
water were added at the same temperature. The
mixture was stirred for 20 min, heated to 40°C, and
stirred at that temperature for 5 h. The evolved organic
phase was boiled with ethanol and small amount of
silica gel; the solution was filtered and left for
crystallization. The formed precipitate was filtered off,
washed with ethanol, and dried in air. Yield 1.45 g
EXPERIMENTAL
1H and 13C NMR spectra were recorded using a
Bruker DPX-400 spectrometer [400.13 (1H), 100.61 MHz
(13C)] in CDCl3 and DMSO-d6. Electronic absorption
spectra were obtained using an SF-2000 device in 1 cm
quartz cells. High-resolution mass spectra were
obtained using a Bruker MicrOTOF mass spectro-
meter. Melting points were measured with a Boёtius
apparatus.
1
(30%), mp 117°C. H NMR spectrum (CDCl3), δ,
ppm: 2.59 s (3H, CH3–C=O-furan), 6.97 d (1H, H4-
furan, J = 3.6 Hz), 7.32 d (1H, H3-furan, J = 3.6 Hz),
7.66 t (1H, H5-phenyl, J = 8.0 Hz), 8.14 d (1H, H6-
phenyl, J = 8.0 Hz), 8.24 d (1H, H4-phenyl, J =
8.0 Hz), 8.61 s (1H, H2-phenyl). 13C NMR spectrum
(CDCl3), δC, ppm: 26.14 (CH3-C=O-furan), 109.37
(С4-furan), 119.18 (С3-furan), 119.72 (С4-phenyl),
121.70 (С1-phenyl), 123.53 (С2-phenyl), 130.12 (С5-
phenyl), 130.39 (С6-phenyl), 148.78 (С5-furan), 152.66
(С3-phenyl), 154.77 (С2-furan), 186.59 (C=О).
5-(o-Nitrophenyl)-2-acetylfuran (1). 10.4 mL of
15% hydrochloric acid was added at stirring to a
suspension of 2.40 g (17.4 mmol) of o-nitroaniline in
14 mL of water. The mixture was heated until
complete dissolution of o-nitroaniline hydrochloride
and cooled to 0°C, 4.2 mL of 30% aqueous solution of
sodium nitrite was then added dropwise at 0–3°C.
After that, the solutions of 1.91 g (17.4 mmol) of
2-acetylfuran in 9 mL of acetone and of 0.44 g
(2.6 mmol) of copper chloride dihydrate in 2 mL of
water were added at the same temperature. The
obtained mixture was stirred for 20 min, heated to 40°C,
and stirred at that temperature for 5 h. Then it was
extracted with chloroform, and the extract was dried
with calcium chloride. The drying agent was filtered
off, and the filtrate was evaporated. The residue was
triturated with ethanol, and water was added until the
onset of precipitation. The mixture was kept during
several hours, the precipitate was filtered off and dried
5-(p-Nitrophenyl)-2-acetylfuran (3). 16.2 mL of
15% hydrochloric acid was added at stirring to a
suspension of 3.28 g (20.3.4 mmol) of p-nitroaniline in
21.6 mL of water. The mixture was heated until
complete dissolution of p-nitroaniline hydrochloride
and cooled to 0°C, 6.5 mL of 30% aqueous solution of
sodium nitrite was then added dropwise at 0–3°C.
After that, the solutions of 2.93 g (27.0 mmol) of
2-acetylfuran in 13.5 mL of acetone and of 0.69 g
(4.0 mmol) of copper chloride dihydrate in 2 mL of
water were added at the same temperature. The
mixture was stirred for 20 min, heated to 40°C, and
stirred at that temperature for 5 h. The evolved organic
phase was boiled with ethanol; the solution was
1
in air. Yield 2.48 g (62%), mp 116°C. H NMR
spectrum (CDCl3), δ, ppm: 2.48 s (3H, CH3–C=O-
furan), 6.76 d (1H, H4-furan, J = 3.6 Hz), 7.24 d (1H,
H3-furan, J = 3.6 Hz), 7.54 t (1H, H4-phenyl, J =
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SYNTHESIS OF 4-(5-NITROPHENYLFUR-2-YL)-1,2,3-THIA- AND SELENADIAZOLES
705
filtered and left for crystallization. The formed preci-
pitate was filtered off, washed with ethanol, and dried
Carboethoxyhydrazone of 5-(m-nitrophenyl)-2-
acetylfuran (6). Yield 57%, mp 166°С. H NMR
1
1
in air. Yield 3.84 g (70%), mp 196oC. H NMR spec-
spectrum (DMSO-d6), δ, ppm: 1.27 t (3H, СН3-ethyl,
J = 7.0 Hz), 2.21 s (3H, CH3-hydrazone), 4.19 q (2H,
OCH2-ethyl, J = 7.0 Hz), 7.02 d (1H, H4-furan, J =
2.8 Hz), 7.39 d (1H, H3-furan, J = 3.6 Hz), 7.96 d (2H,
H2,6-phenyl, J = 8.4 Hz), 8.29 d (2H, H3,5-phenyl, J =
8.4 Hz), 10.23 s (1H, NH). 13C NMR spectrum
(DMSO-d6), δC, ppm: 13.75 (СН3C=N), 15.04 (CH3-
ethyl), 61.18 (OCH2-ethyl), 112.38 (С4-furan), 113.11
(С3-furan), 124.71 (С3,5-phenyl), 125.95 (С2,6-phenyl),
135.95 (С1-phenyl), 141.27 br (C=N), 146.51 (С5-furan),
151.78 (С2-furan), 154.03 (С4-phenyl), 154.39 (C=O).
trum (CDCl3), δ, ppm: 2.58 s (3H, CH3–C=O-furan),
7.00 d (1H, H4-furan, J = 3.6 Hz), 7.31 d (1H, H3-
furan, J = 3.6 Hz), 7.95 d (2H, H2-phenyl, J = 9.0 Hz),
8.31 d (2H, H3-phenyl, J = 9.0 Hz). 13C NMR spectrum
(CDCl3), δC, ppm: 26.16 (CH3–C=O-furan), 110.62 (С4-
furan), 119.18 (С3-furan), 124.40 (С3,5-phenyl), 125.40
(С2,6-phenyl), 134.95 (С1-phenyl), 147.65 (С2-furan), 153.06
(С4-phenyl), 154.71(С5-furan), 186.50 (C=O-furan).
5-Nitrophenyl-2-acetylfuran carboethoxyhydrazones
(general procedure). 6 mmol of 5-nitrophenyl-2-acetyl-
furan 1–3 and 6.3 mmol of carboethoxyhydrazine were
dissolved in a mixture of 50 mL of 2-propanol and
0.25 mL of concentrated sulfuric acid. The solution
was refluxed with stirring for 10 h. The formed
precipitate was filtered off at cooling, washed with
small amount of 2-propanol, and crystallized from ethanol.
4-[5-(o-Nitrophenyl)fur-2-yl]-1,2,3-thiadiazole (7).
0.84 mL (11.6 mmol) of thionyl chloride was added at
stirring to a suspension of 0.92 g (2.9 mmol) of 5-(o-
nitrophenyl)-2-acetylfuran carboethoxyhydrazone in
20 mL of chloroform. The mixture was stirred for 10 h
at 64–66°C and left overnight. On the next day, the
formed precipitate was filtered off, and the filtrate was
evaporated. The residue was dissolved in ethyl acetate
and precipitated with hexane. The formed precipitate
was removed, the filtrate was boiled with silica gel, the
solid phase was removed, and the filtrate was slowly
evaporated. The formed precipitate was filtered off and
crystallized from ethanol. Yield 0.43 g (40%), mp 106°C.
1H NMR spectrum (CDCl3), δ, ppm: 6.88 d (1H, H4-
furan, J = 3.6 Hz), 7.27 d (1H, H3-furan, J = 3.6 Hz),
7.49 t (1H, H4-phenyl, J = 7.6 Hz), 7.64 t (1H, H5-
phenyl, J = 7.6 Hz), 7.75 d (1H, H6-phenyl, J =
7.6 Hz), 7.78 d (1H, H3-phenyl, J = 7.6 Hz), 8.77 s
Carboethoxyhydrazone of 5-(o-nitrophenyl)-2-
1
acetylfuran (4). Yield 56%, mp 119°C. H NMR
spectrum (DMSO-d6), δ, ppm: 1.26 t (3H, СН3-ethyl,
J = 7.0 Hz), 2.14 s (3H, CH3-hydrazone), 4.18 q (2H,
OCH2-ethyl, J = 7.0 Hz), 6.94 d (1H, H4-furan, J =
3.6 Hz), 6.99 d (1H, H3-furan, J = 3.6 Hz), 7.59 t (1H,
H4-phenyl, J = 7.6 Hz), 7.74 t (1H, H5-phenyl, J =
7.6 Hz), 7.89 d (1H, H6-phenyl, J = 7.6 Hz), 7.91 d
(1H, H3-phenyl, J = 7.6 Hz), 10.18 s (1H, NH). 13C
NMR spectrum (DMSO-d6), δC, ppm: 13.43 (СН3C=N),
15.00 (CH3-ethyl), 61.14 (OCH2-ethyl), 111.51 (С4-
furan), 112.36 (С3-furan), 122.79 (С1-phenyl), 124.39
(С3-phenyl), 129.17 (С4-phenyl), 129.82 (С6-phenyl),
132.91 (С5-phenyl), 141.37 (С=N), 147.38 (С5-furan),
148.65 (С2-furan), 153.77 (С2-phenyl), 154.37 br (С=О).
13
(1H, H5-thiadiazole). C NMR spectrum (CDCl3), δC,
ppm: 111.34 (С4-furan), 111.71 (С3-furan), 123.28
(С1-phenyl), 123.99 (С3-phenyl), 128.83 (С4-phenyl),
128.93 (С6-phenyl), 129.39 (С5-thiadiazole), 131.98
(С5-phenyl), 147.67 (С5-furan), 149.27 (С2-furan), 150.90
(С4-thiadiazole), 153.99 (С2-phenyl). Mass spectrum:
found m/z: 274.0290, calculated for C12H7N3O3S:
274.0281 [M + H].
Carboethoxyhydrazone of 5-(m-nitrophenyl)-2-
1
acetylfuran (5). Yield 65%, mp 110°C. H NMR
spectrum (CDCl3), δ, ppm: 1.39 br. t (3H, СН3-ethyl,
J = 7.0 Hz), 2.26 s (3H, CH3-hydrazone), 4.36 br. q
(2Н, OCH2-ethyl, J = 7.0 Hz), 6.88 d (1H, H4-furan,
J = 3.6 Hz), 6.93 d (1H, H3-furan, J = 3.6 Hz), 7.57 t
(1H, H5-phenyl, J = 8.0 Hz), 8.11 d (1H, H6-phenyl,
J = 8.0 Hz), 8.35 d (1H, H4-phenyl, J = 8.0 Hz), 8.50 s
(1H, H2-phenyl, J = 8.0 Hz). 13C NMR spectrum
(CDCl3), δC, ppm: 12.14 (СН3C=N), 14.54 (CH3-ethyl),
62.37 (OCH2-ethyl), 109.42 (С4-furan), 112.16 (С3-
furan), 118.73 (С4-phenyl), 121.62 (С1-phenyl), 122.18
(С2-phenyl), 129.60 (С5-phenyl), 129.81 (С6-phenyl),
143.33(С= N), 148.70 (С2-furan), 148.70 (С5-furan),
152.18 (С2-furan), 152.28 (C3-phenyl), 152.46 (С=О).
4-[5-(m-Nitrophenyl)fur-2-yl]-1,2,3-thiadiazole (8)
was obtained similarly from 0.74 g (2.33 mmol) of
5-(m-nitrophenyl)-2-acetylfuran carboethoxyhydrazone
and 0.7 mL (9.65 mmol) of thionyl chloride. The
precipitate was filtered off, and the filtrate was
evaporated. The residue was triturated with hexane, the
formed precipitate was filtered off and recrystallized
from ethanol. Yield 0.22 g (35%), mp 101°C. 13C
NMR spectrum (CDCl3), δC, ppm: 109.56 (С4-furan),
111.92 (С3-furan), 118.70 (С4-phenyl), 122.37 (С2-
phenyl), 123.07 (С1-phenyl), 129.17 (С5-thiadiazole),
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706
DMITERKO et al.
1
129.51 (С5-phenyl), 129.98 (С6-phenyl), 147.29 (С2-furan),
148.26 (С5-furan), 148.83 (С4-thiadiazole), 152.24 (С3-
phenyl). Mass spectrum: found m/z: 274.0289,
calculated for C12H7N3O3S: 274.0281 [M + H].
mp 124°C. H NMR spectrum (DMSO-d6), δ, ppm:
2.20 s (3H, CH3-semicarbazone), 6.54 br. s (2H, NH2),
7.10 d (1H, H4-furan, J = 3.4 Hz), 7.36 d (1H, H3-
furan, J = 3.4 Hz), 7.73 t (1H, H5-phenyl, J = 7.2 Hz),
8.12 d (1H, H6-phenyl, J = 7.2 Hz), 8.22 d (1H, H4-
phenyl, J = 7.2 Hz), 8.50 s (1H, H2-phenyl), 9.52 s
(1H, NH). 13C NMR spectrum (DMSO-d6), δC, ppm:
12.84 (СН3C=N), 110.96 (С4-furan), 111.82 (С3-
furan), 118.20 (С4-phenyl), 122.39 (С2-phenyl), 124.32
(С1-phenyl),130.10 (С5-phenyl), 131.16 (С6-phenyl),
136.57 (C=N), 147.65 (С2-furan), 148.96 (С5-furan),
151.16 (С3-phenyl), 157.42 (C=O).
4-[5-(p-Nitrophenyl)fur-2-yl]-1,2,3-thiadiazole (9)
was obtained similarly from 1.19 g (3.75 mmol) of
5-(p-nitrophenyl)-2-acetylfuran carboethoxyhydrazone
and 1.0 mL (15 mmol) of thionyl chloride. Tar-like
precipitate was filtered off, and the filtrate was
evaporated. The residue was triturated with hexane, the
formed precipitate were filtered off and recrystallized
1
from ethanol. Yield 0.78 g (76%). H NMR spectrum
(CDCl3), δ, ppm: 7.08 d (1H, H4-furan, J = 3.6 Hz),
7.33 d (1H, H3-furan, J = 3.6 Hz), 7.91 d (2H, H2,6-
phenyl, J = 8.8 Hz), 8.31 d (2H, H3,5-phenyl, J =
8.8 Hz), 8.77 s (1H, H5-thiadiazole). 13C NMR
spectrum (CDCl3), δC, ppm: 111.13 (С4-furan), 112.20
(С3-furan), 124.25 (С3,5-phenyl), 124.47 (С2,6-phenyl),
129.37 (С5-thiadiazole), 135.16 (С1-phenyl), 146.82
(С5-furan), 147.96 (С2-furan), 152.42 (С4-thiadiazole),
154.01 (С4-phenyl). Mass spectrum: found m/z:
274.0290, calculated for C12H7N3O3S: 274.0281 [M + H].
5-(p-Nitrophenyl)-2-acetylfuran semicarbazone
(12) was prepared similarly from 1.72 g (7.6 mmol) of
5-(p-nitrophenyl)-2-acetylfuran, 1.00 g (9.00 mmol) of
semicarbazide hydrochloride, and 1.50 g (18.3 mmol)
1
of sodium acetate. Yield 1.93 g (90%), mp 126°C. H
NMR spectrum (DMSO-d6), δ, ppm: 2.20 s (3H, CH3-
semicarbazone), 6.59 br. s (2H, NH2), 7.14 d (1H, H4-
furan, J = 3.4 Hz), 7.39 d (1H, H3-furan, J = 3.4 Hz),
8.02 d (2H, H2.6-phenyl, J = 8.8 Hz), 8.26 d (2H, H3,5-
phenyl, J = 8.8 Hz), 9.62 s (1H, NH). 13C NMR
spectrum (DMSO-d6), δC, ppm: 13.16 (СН3C=N), 112.13
(С4-furan), 112.89 (С3-furan), 124.66 (С3,5-phenyl),
124.86 (С2,6-phenyl), 136.10 (С1-phenyl), 136.41
(C=N), 146.51 (С5-furan), 151.34 (С2-furan), 154.03
(С4-phenyl), 157.40 (C=О).
5-(o-Nitrophenyl)-2-acetylfuran semicarbazone (10).
A mixture of 0.92 g (3.98 mmol) of 5-(o-nitrophenyl)-
2-acetylfuran and 0.52 g (4.70 mmol) of semicarbazide
hydrochloride was dissolved at stirring and cooling in
12 mL of 2-propanol. After complete dissolution of the
reagents, 0.79 g (9.60 mmol) of sodium acetate was
added. The mixture was refluxed with stirring for 10 h
and left overnight. The formed precipitate was filtered
off, washed with small amount of 2-propanol, and
recrystallized from ethanol. Yield 1.00 g (87%), mp
4-[5-(o-Nitrophenyl)fur-2-yl]-1,2,3-selenadiazole
(13). 0.35 g (3.15 mmol) of selenium dioxide was
added at stirring to a suspension of 0.82 g (2.85 mmol)
of 5-(o-nitrophenyl)-2-acetylfuran semicarbazone in
12.3 mL of glacial acetic acid. The mixture was heated
for 6 h at 66°C protecting from light. After the process
was complete, 10 mL of warm water was added, the
formed precipitate was filtered off and washed with
warm water. Yield 0.75 g (82%), mp 119°C. 1H NMR
spectrum (CDCl3), δ, ppm: 6.90 d (1H, H4-furan, J =
3.6 Hz), 7.23 d (1H, H3-furan, J = 3.6 Hz), 7.49 t (1H,
H4-phenyl, J = 8.0 Hz), 7.64 t (1H, H5-phenyl, J =
8.0 Hz), 7.74 d (1H, H6-phenyl, J = 8.0 Hz) 7.81 d
(1H, H3-phenyl, J = 8.0 Hz), 9.38 s (1H, H5-selena-
1
121°C. H NMR spectrum (DMSO-d6), δ, ppm: 2.09 s
(3H, CH3-semicarbazone), 6.53 br. s (2H, NH2), 7.05
br. s (1H, H4-furan), 7.10 br. s (1H, H3-furan), 7.55 br.
t (1H, H4-phenyl, J = 7.2 Hz), 7.71 br. t (1H, H5-
phenyl, J = 7.2 Hz), 7.83 d (1H, H6-phenyl, J = 7.2 Hz),
7.93 d (1H, H3-phenyl, J = 7.2 Hz), 9.55 s (1H, NH).
13C NMR spectrum (CDCl3), δC, ppm: 12.84 (СН3C=N),
111.16 (С4-furan), 112.19 (С3-furan), 122.21 (С1-phenyl),
124.05 (С3-phenyl), 128.41 (С4-phenyl), 129.50 (С6-
phenyl), 132.46 (С5-phenyl), 135.89 (C=N), 147.26
(С5-furan), 148.18 (С2-furan), 153.90 (С2-phenyl),
157.45 (C=O).
2
13
diazole, satellite JHSe = 39.2 Hz). C NMR spectrum
(CDCl3), δC, ppm: 111.23 (С4-furan), 111.74 (С3-
furan), 123.38 (С1-phenyl), 123.97 (С3-phenyl), 128.74
(С4-phenyl), 128.77 (С6-phenyl), 131.93 (С5-phenyl),
136.12 (С5-selenadiazole), 147.58 (С5-furan), 148.78
(С2-furan),148.88 (С4-selenadiazole), 154.23 (С2-phenyl).
Mass spectrum: found m/z: 321.9710, calculated for
C12H7N3O3Se: 321.9725 [M + H].
5-(m-Nitrophenyl)-2-acetylfuran semicarbazone
(11) was prepared similarly from 0.44 g (1.90 mmol)
of 5-(m-nitrophenyl)-2-acetylfuran, 0.25 g (2.25 mmol)
of semicarbazide hydrochloride, and 0.37
g
(4.60 mmol) of sodium acetate. Yield 0.49 g (89%),
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 4 2019

SYNTHESIS OF 4-(5-NITROPHENYLFUR-2-YL)-1,2,3-THIA- AND SELENADIAZOLES
707
4-[5-(m-Nitrophenyl)fur-2-yl]-1,2,3-selenadiazole
(14) was prepared similarly from 0.46 g (1.59 mmol)
of 5-(m-nitrophenyl)-2-acetylfuran semicarbazone and
0.2 g (1.80 mmol) of selenium dioxide. Yield 0.33 g
FUNDING
The study was performed in scope of the basic part
of State Project of the Ministry of Education and
Science of Russia (project no 4.5554.2017/6.7) with
financial support from the Russian Foundation of
Basic Research (project no 16-08-01299).
1
(65%), mp 127°C. H NMR spectrum (CDCl3), δ,
ppm: 7.01 d (1H, H4-furan, J = 3.6 Hz), 7.28 d (1H,
H3-furan, J = 3.6 Hz), 7.63 t (1H, H5-phenyl, J = 8
Hz), 8.06 d (1H, H6-phenyl, J = 8.0 Hz), 8.17 d (1H,
H4-phenyl, J = 8.0 Hz), 8.60 s (1H, H2-phenyl), 9.53 s
CONFLICT OF INTEREST
No conflict of interest was declared by the authors.
REFERENCES
2
(1H, H5-selenadiazole, satellite JHSe = 39.2 Hz). 13C
NMR spectrum (CDCl3), δC, ppm: 109.56 (С4-furan),
111.79 (С3-furan), 118.64 (С4-phenyl), 122.23 (С2-
phenyl), 129.41 (С5-phenyl), 129.92 (С6-phenyl),
131.69 (С1-phenyl), 135.76 (С5-selenadiazole), 148.39
(С2-furan), 148.84 (С5-furan), 151.86 (С4-selena-
diazole), 154.37 (С3-phenyl). Mass spectrum: found
m/z: 321.9733, calculated for C12H7N3O3Se: 321.9725
[M + H].
1. Remizov, Yu.O., Pevzner, L.M., and Petrov, M.L.,
Russ. J. Gen. Chem., 2018, no. 7, p. 1402. doi 10.1134/
S1070363218070095
2. Remizov, Yu.O., Pevzner, L.M., and Petrov, M.L.,
Russ. J. Gen. Chem., 2015, no. 1, p. 61. doi 10.1134/
S1070363215010119
4-[5-(p-Nitrophenyl)fur-2-yl]-1,2,3-selenadiazole
(15) was obtained similarly from 1.05 g (3.64 mmol)
of 5-(p-nitrophenyl)-2-acetylfuran semicarbazone and
0.44 g (3.96 mmol) of selenium dioxide. Yield 0.9 g
3. Frimm, R., Kovac, J., and Krutosikova, A., Chem.
Zvesti, 1973, vol. 27, no. 1, p. 101.
4. Maadadi, R., Pevzner, L.M., and Petrov, M.L., Russ. J.
Gen. Chem., 2015, no. 11, p. 21. doi 10.1134/
S1070363215110110
1
(77%), mp 116°C. H NMR spectrum (DMSO-d6), δ,
ppm: 7.35 br. d (1H, H4-furan, J = 2.4 Hz), 7.54 br. d
(1H, H3-furan, J = 2.4 Hz), 8.13 d (2H, H2,6-phenyl,
J = 8.2 Hz), 8.32 d (2H, H3,5-phenyl, J = 8.2 Hz), 10.17
s (1H, H5-selenadiazole, satellite 2JHSe = 37.2 Hz ). 13C
NMR spectrum (DMSO-d6), δC, ppm: 112.20 (С4-
furan), 112.88 (С3-furan), 124.85 (С3,5-phenyl), 124.94
(С2,6-phenyl), 135.92 (С1-phenyl), 140.60 (С5-selena-
diazole), 146.62 (С5-furan), 149.31 (С2-furan), 151.80
(С4-selenadiazole), 153.97 (С4-phenyl). Mass spec-
trum: found m/z: 321.9710, calculated for C12H7N3O3Se:
321.9725 [M + H].
5. Petrov, M.L., Lyapunova, A.G., and Androsov, D.A.,
Russ. J. Org. Chem., 2012, vol. 48, no. 1, p. 147. doi
10.1134/S1070428012010625
6. Kazitsina, L.A., Primenenie UF-, IK-, YaMR-spektro-
skopii v organicheskoi khimii (The Use of UV, IR,
NMR Spectroscopy in Organic Chemistry), Moscow:
Ripol Klassik, 2013.
7. Stern, E.S. and Timmons, C.J., Introduction to Electronic
Absorption Spectroscopy in Organic Chemistry, London:
Arnold, 1970, 3rd ed.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 4 2019