Synthesis and optical properties of new coumarin derivatives based on 2-(2-chlorobenzylidene)malononitrile

Article abstract of DOI:10.1134/S1070428017010080

A procedure has been developed for the conversion of the CS gas [2-(2-chlorobenzylidene)-malononitrile] to new 3-cyanocoumarin derivatives, 4-(2-chlorophenyl)-2-oxo-2H-chromene-3-carbonitriles. Study of the optical properties of the synthesized compounds

Full text of DOI:10.1134/S1070428017010080

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2017, Vol. 53, No. 1, pp. 47–50. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © I.N. Bardasov, N.L. Malyshkina, A.Yu. Alekseeva, O.V. Ershov, D.V. Timrukova, A.O. Grigor’eva, 2017, published in Zhurnal
Organicheskoi Khimii, 2017, Vol. 53, No. 1, pp. 53–55.
Synthesis and Optical Properties of New Coumarin Derivatives
Based on 2-(2-Chlorobenzylidene)malononitrile
I. N. Bardasov,* N. L. Malyshkina, A. Yu. Alekseeva, O. V. Ershov,
D. V. Timrukova, and A. O. Grigor’eva
I.N. Ul’yanov Chuvash State University, Moskovskii pr. 15, Cheboksary, 428015 Russia
*e-mail: bardasov.chem@mail.ru
Received July 14, 2016
Abstract—A procedure has been developed for the conversion of the CS gas [2-(2-chlorobenzylidene)-
malononitrile] to new 3-cyanocoumarin derivatives, 4-(2-chlorophenyl)-2-oxo-2H-chromene-3-carbonitriles.
Study of the optical properties of the synthesized compounds has revealed strong fluorescence in the violet and
blue regions.
DOI: 10.1134/S1070428017010080
Coumarin derivatives are known as organic fluoro-
phores [1]. They have found wide application as
optical bleaching agents [2], active media of tunable
lasers [3], and luminescent labels [4]. Furthermore,
many coumarin derivatives exhibit anti-inflammatory
[5, 6], antitubercular [7], and anticoagulant activity [8].
continuation of studies in this line, herein we propose
a procedure for the disposal of 2-(2-chlorobenzylidene)-
malononitrile (CS gas). This compound is a complex
action irritant produced on a large scale. Due to its
teratogenic properties [11], the use of CS as a riot
control agent is restricted in some countries. Therefore,
development of efficient methods for utilization of CS
is a topical problem.
We have recently developed a new synthetic
approach to coumarin derivatives, which is based on
oxidation of cyano-substituted 4H-chromenes [9]; the
latter can be prepared in turn by reaction of benzyli-
denemalononitriles with activated phenols [10]. In
Herein, we propose a procedure for the synthesis of
2-amino-4-(2-chlorophenyl)-4H-chromene-3-carbo-
nitriles 1 by reaction of 2-(2-chlorobenzylidene)-
Scheme 1.
Cl
OR
Cl
CN
Base
CN
+
CN
OH
RO
O
NH2
1a, 1b
Cl
Cl
[O], H+/H2O
Ac2O
CN
CN
RO
O
2a, 2b
O
AcO
O
O
3
R = H (a), Me (b).
47

BARDASOV et al.
48
Table 1. Solvent effect on the electronic absorption and
fluorescence spectra of compound 2a
Of particular interest are optical properties of
coumarins [1–4] which are known to absorb in the UV
region and show fluorescence. Therefore, we examined
the absorption and luminescence spectra of coumarin
derivatives 2 and 3. Table 1 contains parameters of the
electronic absorption and fluorescence spectra of 2a in
different solvents. Polar protic solvents such as ethanol
and acetic acid ensured the maximum fluorescence
quantum yield of 2a as compared to aprotic and non-
polar solvents. Pyridine induced fluorescence quench-
ing and change of the color of the solution and
absorption region, presumably as a result of formation
of pyridinium salt 4 (Scheme 2).
a
Solvent
Ethanol
λabs, nm Amax
εmax
λfl, nm
φF
,375, ,0.3354, ,14581, 482
0.47
429
353
355
354
356
0.2886 12547
0.2920 12696
0.3876 16854
0.4326 18809
0.4560 19825
Ethyl acetate
Benzene
415
416
414
417
0.22
0.16
0.27
0.43
0.08
Acetonitrile
Acetic acid
Pyridine
,366, ,0.4073, ,17707, 502
448 0.2257 09814
a
The fluorescence quantum yields were determined using 4-meth-
ylumbelliferone (4-Me-umb) as reference.
Scheme 2.
Table 2. Optical properties of compounds 2 and 3 in ethanol
Cl
Compound λabs, nm. Amax
εmax
0.3713 15469
,375, ,0.3354, ,14581,
λfl, nm
φF
+
CN
N
4-Me-umb
358
447
482
0.63
0.47
2a
HO
O
O
429
0.2886 12547
2a
2b
3
358
0.3632 15793
418
410
0.42
0.49
,305, ,0.2839, ,12345,
341 0.2640 11478
Cl
CN
N
H
malononitrile with resorcinol or its monomethyl ether
(Scheme 1). The subsequent oxidation of compounds
1a and 1b with chromium(VI) oxide gave 4-(2-chloro-
phenyl)-2-oxo-2H-chromene-3-carbonitriles 2a and 2b
in 68 and 74% yield, respectively. The acylation of 2a
with acetic anhydride afforded 88% of 4-(2-chloro-
phenyl)-3-cyano-2-oxo-2H-chromen-7-yl acetate (3).
The structure of chromenes 1 and coumarins 2 and 3
was confirmed by spectral data.
–O
O
O
4
The spectral properties of 2 and 3 were studied in
ethanol (Table 2; Figs. 1, 2). It is seen (Table 2) that
the substituent on C8 strongly affects the positions of
the absorption and emission maxima, but the fluores-
cence quantum yield almost does not change.
2b
2b
0.35
12
2a
2a
3
0.30
0.25
0.20
0.15
0.10
0.05
0.00
10
8
6
4
2
3
0
300
250
300
350
400
450
λ, nm
350
400
450
500
550
600 λ, nm
Fig. 1. Electronic spectra of compounds 2 and 3 in ethanol.
Fig. 2. Fluorescence spectra of compounds 2 and 3 in ethanol.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 53 No. 1 2017

SYNTHESIS AND OPTICAL PROPERTIES OF NEW COUMARIN DERIVATIVES
49
In summary, we have synthesized some coumarin
derivatives on the basis of CS gas and studied their
optical properties.
spectrum, ν, cm–1: 3385 (OH), 2218 (C≡N), 1730
(C=O). H NMR spectrum (DMSO-d6), δ, ppm:
1
6.86 d.d (1H, CH, J = 2.2, 8.8 Hz), 6.90 d (1H, CH, J =
2.1 Hz), 6.92 d (1H, CH, J = 9.3 Hz), 7.56 d.d (1H,
C6H4, J = 1.6, 7.5 Hz), 7.62 t (1H, C6H4, J = 7.4 Hz),
7.67 t.d (1H, C6H4, J = 1.6, 8.1 Hz), 7.77 d (1H, C6H4,
J = 8.0 Hz), 11.47 s (1H, OH). Mass spectrum, m/z
(Irel, %): 299 (31) [M]+, 297 (100) [M]+, 262 (93) [M –
35]+. Found, %: C 64.74; H 2.62; N 4.76. C16H8ClNO3.
Calculated, %: C 64.55; H 2.71; N 4.71. M 297.69.
EXPERIMENTAL
The IR spectra were recorded on an FSM-1202
spectrometer with Fourier transform from samples
1
dispersed in mineral oil. The H NMR spectra were
recorded on a Bruker DRX-500 instrument from solu-
tions in DMSO-d6 using tetramethylsilane as internal
standard. The mass spectra (electron impact, 70 eV)
were obtained on a Finnigan MAT INCOS-50 mass
spectrometer. The elemental compositions were deter-
mined with a Vario Micro cube CHN analyzer. The
melting points were measured with an OptiMelt
MPA100 automated melting point apparatus. The prog-
ress of reactions and the purity of products were
monitored by TLC on Sorbfil PTSKh-AF-A-UF plates
using ethyl acetate as eluent; spots were visualized
under UV light, by treatment with iodine vapor, or by
thermal decomposition.
4-(2-Chlorophenyl)-7-methoxy-2-oxo-2H-chro-
mene-3-carbonitrile (2b) was synthesized in a similar
way. Yield 74%, mp 175–176°C. IR spectrum, ν, cm–1:
1
2227 (C≡N), 1735 (C=O). H NMR spectrum
(DMSO-d6), δ, ppm: 3.93 s (3H, OCH3), 6.98 d (1H,
CH, J = 9.0 Hz), 7.01 d.d (1H, CH, J = 1.8, 9.0 Hz),
7.25 d (1H, CH, J = 1.7 Hz), 7.57 d (1H, C6H4, J =
7.3 Hz), 7.64 t (1H, C6H4, J = 7.4 Hz), 7.68 t (1H,
C6H4, J = 7.4 Hz), 7.78 d (1H, C6H4, J = 8.0 Hz). Mass
spectrum, m/z (Irel, %): 313 (35) [M]+, 311 (100) [M]+,
276 (55) [M – Cl]+. Found, %: C 65.58; H 3.29;
N 4.40. C17H10ClNO3. Calculated, %: C 65.50; H 3.23;
N 4.49. M 311.72.
2-Amino-4-(2-chlorophenyl)-7-hydroxy-4H-chro-
mene-3-carbonitrile (1a). A suspension of 0.188 g
(1 mmol) of 2-(2-chlorobenzylidene)malononitrile,
0.110 g (1 mmol) of resorcinol, 0.101 g (1 mmol) of
triethylamine, and 0.046 g (0.15 mmol) of OKSIPAV
AP in a mixture of 2.5 mL of water and 2.5 mL of
ethanol was vigorously stirred for 2 h at room tempera-
ture. The mixture was then neutralized with 5% aque-
ous HCl, and the precipitate was filtered off, washed
with 10 mL of water, recrystallized from ethanol, and
dried in a vacuum desiccator. Yield 0.275 g (92%),
mp 187–189°C (decomp.); published data [12]:
mp 188–190°C (decomp.).
4-(2-Chlorophenyl)-3-cyano-2-oxo-2H-chromen-
7-yl acetate (3). A solution of 0.298 g (1 mmol) of
compound 2a in 2 mL of acetic anhydride was refluxed
for 2 h. The solvent was distilled off, the residue was
ground with 5 mL of propan-2-ol, and the precipitate
was filtered off, washed with propan-2-ol, and dried in
a vacuum desiccator. Yield 0.299 g (88%), mp 193–
194°C. IR spectrum, ν, cm–1: 2229 (C≡N), 1747
1
(C=O). H NMR spectrum (DMSO-d6), δ, ppm: 2.33 s
(3H, CH3), 7.59 d (1H, CH, J = 8.7 Hz), 7.23 d.d (1H,
CH, J = 2.2, 8.7 Hz), 7.55 d (1H, CH, J = 2.2 Hz),
7.59 d.d (1H, C6H4, J = 1.8, 7.5 Hz), 7.66 t.d (1H,
C6H4, J = 1.0, 7.5 Hz), 7.70 t.d (1H, C6H4, J = 1.8,
7.6 Hz), 7.80 d (1H, C6H4, J = 7.9 Hz). Mass spectrum,
m/z (Irel, %): 341 (5) [M]+, 339 (12) [M]+, 299 (100)
[M – 32]+, 297 (30) [M – 32]+. Found, %: C 63.75;
H 3.05; N 4.02. C18H10ClNO4. Calculated, %: C 63.64;
H 2.97; N 4.12. M 339.73.
2-Amino-4-(2-chlorophenyl)-7-methoxy-4H-
chromene-3-carbonitrile (1b) was synthesized in
a similar way. Yield 94%, mp 179–181°C (decomp.);
published data [13]: mp 178–180°C (decomp.).
4-(2-Chlorophenyl)-7-hydroxy-2-oxo-2H-chro-
mene-3-carbonitrile (2a). A suspension of 0.299 g
(1 mmol) of compound 1a in 5 mL of acetic acid was
heated to 60°C, 0.100 g (1 mmol) of chromium(VI)
oxide was added in portions with stirring over a period
of 10 min, and the mixture was stirred for 30 min at
that temperature. The mixture was cooled and diluted
with 15 mL of water, and the precipitate was filtered
off, washed with 10 mL of water, recrystallized from
water–propan-2-ol, and dried in a vacuum desiccator.
Yield 0.202 g (68%), mp 239–240°C (decomp.). IR
This study was performed under financial support
by the Russian Foundation for Basic Research and
by the Cabinet of Ministers of Chuvash Republic
(research project no. 16-43-210540 r_a).
REFERENCES
1. Fourati, M.A., Maris, Th., Skene, W.G., Bazuin, C.G., and
Prud’homme, R.E., J. Phys. Chem. B, 2011, vol. 115,
p. 12362.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 53 No. 1 2017

BARDASOV et al.
50
2. The Chemistry of Synthetic Dyes, Venkataraman, K., Ed.,
8. Coumarin
Anticoagulant
Research
Progress,
Edardes, J.P., Ed., New York: Nova Biomedical Books,
2008.
New York: Academic, 1971, vol. 5, p. 535.
3. Jones, G. and Rahman, M.A., J. Phys. Chem., 1994,
9. Bardasov, I.N., Alekseeva, A.U., Ershov, O.V., Surazh-
skaya, M.D., Churakov, A.V., and Grishanov, D.A.,
Tetrahedron Lett., 2015, vol. 56, p. 6145.
vol. 98, p. 13028.
4. Vemula, V., Ni, Zh., and Fedorova, M., Redox Biol.,
2015, vol. 5, p. 195.
10. Kolla, S.R. and Lee, Y.R., Tetrahedron, 2011, vol. 67,
5. Kontogiorgis, Ch.A. and Hadjipavlou-Litina, D.J.,
p. 8271.
J. Med. Chem., 2005, vol. 48, p. 6400.
11. Bauchinger, M. and Schmid, E., Mutat. Res., 1992,
6. Witaicenis, A., Seito, L.N., da Silveira Chagas, A., de
Almeida, L.D., Jr., Luchini, A.C., Rodrigues-Orsi, P.,
Cestari, S.H., and Di Stasi, L.C., Phytomedicine, 2014,
vol. 21, p. 240.
vol. 282, p. 231.
12. Dekamin, M.G., Eslami, M., and Maleki, A., Tetra-
hedron, 2013, vol. 69, p. 1074.
7. Keri, R.S., Sasidhar, B.S., Nagaraja, B.M., and
13. Han, G., Du, J., Chen, L., and Zhao, L., J. Heterocycl.
Chem., 2014, vol. 51, p. 1094.
Santos, M.A., Eur. J. Med. Chem., 2015, vol. 100, p. 257.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 53 No. 1 2017