Synthesis of 2-aminochromone-3-carbaldehyde hydrazones from 3-thiocarbamoylchromones and hydrazines

Article abstract of DOI:10.1007/s11172-018-2328-8

Reaction of 3-thiocarbamoylchromones with hydrazines is accompanied by recyclization affording 2-aminochromone-3-carbaldehyde hydrazones.

Full text of DOI:10.1007/s11172-018-2328-8

Russian Chemical Bulletin, International Edition, Vol. 67, No. 11, pp. 2054—2057, November, 2018
2054
Synthesis of 2-aminochromone-3-carbaldehyde hydrazones
from 3-thiocarbamoylchromones and hydrazines
D. Yu. Demin,a G. М. Rodionova,b V. N. Yarovenko,a and М. М. Krayushkina
aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
E-mail: mkray@ioc.ac.ru
bI. M. Sechenov First Moscow State Medical University
of the Ministry of Health of the Russian Federation,
8 str. 2 ul. Trubetskaya, 119991 Moscow, Russian Federation
Reaction of 3-thiocarbamoylchromones with hydrazines is accompanied by recyclization
affording 2-aminochromone-3-carbaldehyde hydrazones.
Key words: heterocyclization, chromones, hydrazines, hydrazones, thioamides, recyclization.
Scheme 1
Chromone motif forms a part of a variety of natural
and synthetic medicinal drugs1—3 and photoactive prod-
ucts.4,5 Moreover, chromones display a diverse reactivity.
Of considerable synthetic potential are chromones 3-sub-
stituted with electron-withdrawing substituents, which
enhance the push-pull activation of the pyrone С=С bond
and stimulate its tendency to transformations by the action
of nucleophiles. After nucleophilic addition to the double
bond of the γ-pyrone ring, various recyclization "ring
opening—ring closing" (RORC) reactions are typical for
the resulting compounds. Reactivity of chromones bearing
3-positioned electron-withdrawing groups such as formyl,
nitrile, ester, and carboxy, is well studied.6,7 Carbamoyl-
chromones8 are studied to a lesser extent, while thio-
carbamoyl derivatives are not studied at all due to the lack
of a convenient synthetic approach thereto. At the same
time the presence of thiocarbonyl moiety should effect
significantly the direction of recyclizations occurring fol-
lowed the nucleophilic attack, and consequently, the
structure of the resulting products.
Reagents and conditions: i. Me2NC(OMe)2, toluene, Δ. ii. ArNCS,
DMF, Δ.
ing (intermediate B), subsequent rotation around the C—C
bond (intermediate C), and cyclization involving the hydr-
oxyl group (intermediate D) to form a new pyrone ring
(intermediate E) take place, and the final step is a re-
arrangement resulting in the formation of hydrazono
aminochromones 4a—j. It should be noted that the
thiocarbonyl group is involved at the step of cyclization
proceeding by the action of the hydroxy group to yield
hydrazono aminochromones. There is no substitution of
the aniline moiety in our case as occurs in reactions be-
tween nucleophiles and carbamoylchromones.
Earlier9 we have developed a novel method to synthe-
size 3-thiocarbamoylchromones 1 based on the reaction
between o-hydroxyaryl amino enones 2 and isothiocyan-
ates (Scheme 1), allowing to start studying their transfor-
mation by the action of nucleophiles.
The aim of the present study was to investigate reactions
of 3-thiocarbamoylchromones with various hydrazines.
We have shown that 3-thiocarbamoylchromones 1a—c
react with hydrazines 3a—c in alcohol to produce
3-(R-hydrazono)methyl-2-arylamino-4H-chromen-4-
ones 4a—j (Scheme 2). The reaction comprises the con-
secutive processes such as the Michael reaction proceed-
ing at the С(2) position of γ-pyrone ring (intermediate A),
then the retro-Michael reaction with the pyrone ring open-
The structure of the resulting compounds was con-
firmed by the IR spectroscopy, mass spectrometry, and
NMR spectroscopy data. In the IR spectra of the com-
pounds, the C=O (1610 cm–1), hydrazone C=N (1570 cm–1
)
and the N—N bond (1440—1460 cm–1) absorptions were
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2054—2057, November, 2018.
1066-5285/18/6711-2054 © 2018 Springer Science+Business Media, Inc.

2-Amino-3-formylchromone hydrazones
Russ. Chem. Bull., Int. Ed., Vol. 67, No. 11, November, 2018
2055
Scheme 2
1
a
b
c
d
R1
Ph
R2
H
H
H
F
3
a
b
c
R3
Ph
R4
H
4-EtO2CC6H4
3,5-Cl2C6H3
Ph
—(CH2)2—O—(CH2)2—
—(CH2)2—N(Me)—(CH2)2—
4
a
b
c
d
e
R1
Ph
Ph
R2
H
H
H
H
H
R3
Ph
R4
H
4
f
R1
R2
H
H
H
H
F
R3
—(CH2)2—N(Me)—(CH2)2—
Ph
—(CH2)2—O—(CH2)2—
—(CH2)2—N(Me)—(CH2)2—
R4
4-EtO2CC6H4
3,5-Cl2C6H3
3,5-Cl2C6H3
3,5-Cl2C6H3
Ph
—(CH2)2—O—(CH2)2—
—(CH2)2—N(Me)—(CH2)2—
g
h
i
H
Ph
4-EtO2CC6H4
4-EtO2CC6H4
Ph
H
—(CH2)2—O—(CH2)2—
j
Ph
H
observed. In mass spectra of the products, the parent peaks
are accompanied with the peaks of comparable intensities
([M – 92]+ for compounds 4a,d,g,j, [М – 86]+ for com-
pounds 4b,e,h, and [M – 99]+ for compounds 4c,f), which
are supposedly formed upon the N—N bond cleavage in
hydrazone moieties. Also, in all instances, peaks of
2-anilino-3-methylchromone and 2-hydroxyacetophenone
were observed.
Structure of the products was unambiguously estab-
lished by the example of compound 4j using NMR spectro-
scopy wherein a complete assignement of all signals in 1H
and 13C NMR spectra was carried out. Signals of phenyl
protons as well as those of the chromone benzylidene ring
appear as characteristic multiplets and were found at
δ 6.7—7.8 corresponding to the area of aromatic protons.
Three singlet peaks at δ 8.48, 10.37, and 11.78 are shifted
downfield. The signals pertain to a proton on the sp2-
hybridized carbon atom and two NH groups, respectively.
It is unclear from the one-dimensional 1H NMR spectrum
whether the CH moiety forms a part of a linear structure
or a chromone heterocycle. Using a two-dimensional
1H—13C HSQC experiment, a correlation between the
proton (δ 8.48) and the carbon atom having the chemical
shift at δ 134.5, was revealed. Such chemical shift can not
be attributed to C(2) and C(3) atoms, therefore the above
CH moiety is a part of the linear structure. Consequently,
2- and 3-positions of chromone are substituted. From the
1H—1H COSY spectrum (Fig. 1), low-intensity correla-
tions between NH-protons and ortho-protons on the
phenyl rings were revealed testifying that benzene rings
are bonded to the residie of the molecule through NH
groups. Also, in the COSY spectrum, an interaction be-
tween one of the NH protons and the CH proton was found
Fig. 1. Spin interaction found in a COSY experiment for com-
pound 4j.

2056 Russ. Chem. Bull., Int. Ed., Vol. 67, No. 11, November, 2018
Demin et al.
J = 17.2 Hz, J = 7.5 Hz); 7.34—7.20 (m, 3 H, J = 16.2 Hz,
J = 8.0 Hz); 6.94 (d, 2 H, J = 7.8 Hz); 6.77 (t, 1 H, J = 7.2 Hz).
13C NMR (75 MHz, DMSO-d6), δ: 173.26, 157.60, 154.60,
152.80, 145.55, 136.70, 135.37, 133.42, 130.14, 129.78, 125.75,
125.61, 125.44, 122.38, 119.03, 117.60, 112.02, 95.10. HRMS,
found: m/z 356.1405 [M]+. Calculated for C22H17N3O2: M =
= 356.1394.
3-[(Morpholinoimino)methyl]-2-phenylamino-4H-chromen-
4-one (4b). Yield 47%, yellowish powder, m.p. 159—161 °C. IR,
ν/cm–1: 3491, 3011, 2973, 2938, 2879, 2825, 1649, 1604, 1559,
1469, 1445, 1370, 1333, 1274, 1223, 1187, 1114, 1092, 1004, 947,
932, 865, 820, 759, 720, 665. 1H NMR (300 MHz, DMSO-d6),
δ: 12.29 (s, 1 H); 8.26 (s, 1 H); 8.10—8.02 (m, 1 H); 7.70 (dd, 1 H,
J = 11.2 Hz, J = 4.3 Hz); 7.55 (d, 3 H, J = 6.1 Hz); 7.46 (dd,
3 H, J = 14.2 Hz, J = 7.1 Hz); 7.25 (t, 1 H, J = 7.3 Hz); 3.86—3.76
(m, 4 H); 3.15—3.07 (m, 4 H). 13C NMR (75 MHz, DMSO-d6),
δ: 173.28, 157.97, 152.85, 136.89, 134.85, 133.47, 130.01, 125.78,
125.44, 125.38, 122.50, 121.98, 117.62, 94.64, 66.04, 52.62.
HRMS, found: m/z 350.1502 [M]+. Calculated for C20H19N3O3:
M = 350.1499.
(δNH/δCH = 10.37/8.48). Spin splitting was not observed
in a one-dimensional spectrum, hence the COSY spectrum
shows interactions over just four chemical bonds, and
nitrogen atom is a linker. As a result, chromone is substi-
tuted at 2- and 3-positions with aniline and phenylhydr-
azonomethyl residues, respectively. Cross peaks being the
evidence of this fact were found in a 1H—13C HMBC
spectrum. Solution concentrations and time of 1D-exper-
iments were chosen according to the known guidelines.10
To conclude, we have proposed a convenient procedure
to obtain functionalized 2-aminochromone-3-carbalde-
hyde hydrazone derivatives. The reported11,12 synthetic
approach to hydrazones based on the reaction between
hydrazines and 2-amino-3-formylchromones is more
laborious and multi-step. It gave rise to the limited amount
of hydrazones; 2-anilino-3-formylchromones were mostly
used as starting compounds.
3-[(4-Methylpiperazin-1-yl)imino]methyl-2-phenylamino-
4H-chromen-4-one (4c). Yield 53%, white powder, m.p. 178—
180 °C. IR, ν/cm–1: 3483, 3016, 2946, 2881, 2841, 2826, 2796,
2762, 2662, 1655, 1622, 1571, 1499, 1466, 1446, 1375, 1335, 1290,
1279, 1228, 1216, 1143, 1102, 1076, 1028, 1000, 937, 899, 834,
794, 750, 699, 688, 669. 1H NMR (300 MHz, DMSO-d6), δ:
12.27 (s, 1 H); 8.19 (s, 1 H); 8.05 (d, 1 H, J = 6.9 Hz); 7.72—7.62
(m, 1 H); 7.48 (d, 6 H, J = 13.5 Hz); 7.27—7.18 (m, 1 H); 3.10
(s, 4 H); 2.61 (s, 4 H); 2.30 (s, 3 H). 13C NMR (75 MHz, DMSO-d6),
δ: 173.24, 157.84, 152.78, 136.91, 134.65, 133.36, 129.98, 125.70,
125.41, 125.28, 122.48, 121.85, 117.53, 94.74, 54.07, 51.45, 45.58.
HRMS, found: m/z 363.1816 [M]+. Calculated for C21H22N4O2:
M = 363.1816.
Ethyl 4-{[4-oxo-3-(2-phenylhydrazonomethyl)-4H-chromen-
2-yl]amino}benzoate (4d). Yield 37%, yellow powder, m.p.
221—223 °C. IR, ν/cm–1: 3431, 3249, 3039, 2979, 2903, 1718,
1655, 1603, 1561, 1541, 1509, 1493, 1466, 1425, 1365, 1333, 1300,
1275, 1229, 1182, 1106, 1025, 944, 902, 845, 751, 690. 1H NMR
(300 MHz, DMSO-d6), δ: 11.85 (s, 1 H); 10.19 (s, 1 H); 8.50
(s, 1 H); 8.07 (d, 3 H, J = 6.6 Hz); 7.76—7.56 (m, 4 H,
J = 22.8 Hz); 7.45 (t, 1 H, J = 7.5 Hz); 7.26 (t, 2 H, J = 6.1 Hz);
6.95 (d, 2 H, J = 6.1 Hz); 6.78 (t, 1 H, J = 7.6 Hz); 4.34 (q, 2 H,
J = 6.6 Hz); 1.36 (t, 3 H, J = 5.6 Hz). 13C NMR (75 MHz,
DMSO-d6), δ: 173.52, 165.55, 156.97, 152.81, 145.36, 141.17,
134.79, 133.61, 131.31, 129.82, 125.92, 125.43, 122.29, 121.36,
121.21, 119.21, 117.78, 112.14, 96.03, 61.12, 14.62. HRMS, found:
m/z 428.1595 [M]+. Calculated for C25H21N3O4: M = 428.1605.
Ethyl 4-[(3-morpholinoiminomethyl-4-oxo-4H-chromen-2-
yl)amino]benzoate (4e). Yield 46%, yellowish powder, m.p.
181—183 °C. IR, ν/cm–1: 3434, 2976, 2840, 1718, 1655, 1607,
1561, 1510, 1459, 1434, 1408, 1365, 1307, 1277, 1233, 1180, 1107,
1007, 901, 845, 762, 701, 673. 1H NMR (300 MHz, DMSO-d6),
δ: 12.43 (s, 1 H); 8.18 (s, 1 H); 8.08—7.94 (m, 3 H); 7.76—7.53
(m, 4 H); 7.48—7.37 (m, 1 H); 4.33 (q, 2 H, J = 6.3 Hz); 3.80
(s, 4 H); 3.29 (s, 4 H); 1.34 (t, 3 H, J = 6.0 Hz). 13C NMR
(75 MHz, DMSO-d6), δ: 173.47, 165.52, 157.30, 152.78, 141.39,
134.10, 133.54, 131.10, 125.85, 125.63, 125.40, 122.38, 120.70,
117.69, 95.52, 65.97, 61.05, 52.40, 14.60. HRMS, found: m/z
422.1715 [M]+. Calculated for C23H23N3O5: M = 422.1710.
Ethyl 4-({3-[(4-methylpiperazin-1-yl)iminomethyl]-4-oxo-
4H-chromen-2-yl}amino)benzoate (4f). Yield 52%, white powder,
m.p. 140—142 °C. IR, ν/cm–1: 3449, 2986, 2938, 2881, 2825,
Experimental
NMR spectra of compounds 4a—j were recorded on a Bruker
AM-300 spectrometer (300 (1H) and 75 MHz (13C)) in DMSO-d6.
Chemical shifts were measured relative to the deuterated solvent
residual signals. IR spectrum were recorded on a Bruker ALPHA
spectrometer in KBr pellets. Mass spectra were recorded on
a Varian MAT CH-6 instrument with a direct sample injection
into radiation source, ionization energy 70 eV, control voltage
1.75 kV. High resolution mass spectra (HRMS) were obtained on
a Bruker micrOTOF II instrument using electrospray ionization
technique. Melting points were measured on a Boetius apparatus
and were uncorrected. The reaction was monitored by the TLC
technique using TLC plates Merck 60 F254 UV-254.
1H NMR and 2D-correlational spectra for compound 4j were
recorded on a Bruker Avance 600 spectrometer (600 (1Н) and
150 MHz (13С)) in CDCl3 at 293 К. 13C NMR spectra were
obtained on a Bruker DRX500 spectrometer (125 MHz) in CDCl3
at room temperature. The residual solvent signals were used as
an internal standard. Two-dimensional correlation spectrum was
obtained using the standard Bruker software.
Synthesis of 3-thiocarbamoylchromones 1a—d (general pro-
cedure). A mixture of amino enone 2 (15 mmol) and a corres-
ponding isothiocyanate (33 mmol, 2.2 equiv.) in dried DMF
(3 mL) was heated for 3—5 h at 110 °С (TLC monitoring). The
solvent was evaporated and the product was purified on a silica
gel column (eluent — CH2Cl2).
Synthesis of 2-amino-3-formylchromone hydrazones 4a—j
(general procedure). A mixture of hydrazine 3a—c (0.5 mmol)
and thiocarbamoylchromone 1a—d (0.5 mmol) in alcohol (5 mL)
was stirred for 3 h at room temperature (for phenylhydrazine) or
heated for 2 h at 60 °С (for aliphatic hydrazines). The precipitate
was filtered and recrystallized from ethyl acetate (for phenyl-
hydrazine) or rinsed with alcohol (for aliphatic hydrazines).
2-Phenylamino-3-[(2-phenylhydrazono)methyl]-4H-chrom-
en-4-one (4a). Yield 35%, yellow powder, m.p. 155—157 °C. IR,
ν/cm–1: 3433, 3231, 3041, 1654, 1622, 1600, 1567, 1542, 1498,
1465, 1434, 1331, 1299, 1264, 1228, 1215, 1159, 1102, 1026, 994,
943, 897, 754, 686. 1H NMR (300 MHz, DMSO-d6), δ: 11.74
(s, 1 H); 10.21 (s, 1 H); 8.55 (s, 1 H); 8.08 (d, 1 H, J = 7.6 Hz);
7.70 (t, 1 H, J = 7.5 Hz); 7.65—7.39 (m, 6 H, J = 24.0 Hz,

2-Amino-3-formylchromone hydrazones
Russ. Chem. Bull., Int. Ed., Vol. 67, No. 11, November, 2018
2057
2803, 1709, 1657, 1625, 1604, 1567, 1511, 1459, 1432, 1408, 1364,
1281, 1231, 1215, 1181, 1138, 1108, 1027, 1002, 937, 899, 843, 796,
765, 701, 673, 628. 1H NMR (300 MHz, DMSO-d6), δ: 12.45
(s, 1 H); 8.08 (s, 1 H); 8.05—7.92 (m, 3 H, J = 14.0 Hz, J = 8.1 Hz);
7.68 (t, 1 H, J = 7.3 Hz); 7.56 (d, 3 H, J = 7.9 Hz); 7.41 (t, 1 H,
J = 7.2 Hz); 4.31 (dd, 2 H, J = 14.0 Hz, J = 7.0 Hz); 3.11 (s, 4 H);
2.59 (s, 4 H); 2.29 (s, 3 H); 1.34 (t, 3 H, J = 7.0 Hz). 13C NMR
(75 MHz, DMSO-d6), δ: 173.41, 165.50, 157.14, 152.71, 141.38,
133.86, 133.44, 131.07, 125.77, 125.49, 125.36, 122.34, 120.50,
117.61, 95.59, 61.03, 53.98, 51.24, 45.58, 14.58. HRMS, found:
m/z 435.2022 [M]+. Calculated for C24H26N4O4: M = 435.2027.
2-(3,5-Dichlorophenylamino)-3-(2-phenylhydrazonomethyl)-
4H-chromen-4-one (4g). Yield 34%, yellow powder, m.p. 238—
240 °C. IR, ν/cm–1: 3425, 3273, 1655, 1628, 1598, 1587, 1561,
1542, 1509, 1497, 1465, 1449, 1421, 1329, 1299, 1266, 1226, 1194,
1159, 1117, 10 40, 993, 955, 927, 843, 809, 749, 735, 685, 670.
1H NMR (300 MHz, DMSO-d6), δ: 11.80 (s, 1 H); 10.15 (s, 1 H);
8.49 (s, 1 H); 8.08 (d, 1 H, J = 7.2 Hz); 7.80—7.67 (m, 1 H); 7.61
(s, 2 H); 7.54—7.38 (m, 3 H); 7.31—7.17 (m, 2 H); 6.96 (d, 2 H,
J = 6.3 Hz); 6.80 (s, 1 H). 13C NMR spectrum could not be
obtained because of poor solubility of the substance. HRMS,
found: m/z 424.0615 [M]+. Calculated for C22H15Cl2N3O2:
M = 424.0614.
2-(3,5-Dichlorophenylamino)-3-morpholinoiminomethyl-4H-
chromen-4-one (4h). Yield 49%, yellowish powder, m.p. 176—
178 °C. IR, ν/cm–1: 3441, 3232, 2951, 2924, 2869, 2826, 1656,
1625, 1585, 1561, 1542, 1465, 1432, 1372, 1320, 1272, 1211, 1142,
1116, 1063, 1005, 955, 926, 890, 839, 803, 755, 721, 699, 662,
602. 1H NMR (300 MHz, DMSO-d6), δ: 12.14 (s, 1 H); 8.21
(s, 1 H); 8.04 (s, 1 H); 7.71 (s, 1 H); 7.57—7.33 (m, 5 H); 3.81
(s, 4 H); 3.30 (s, 4 H). 13C NMR spectrum could not be obtained
because of poor solubility of the substance. HRMS, found: m/z
418.0713 [M]+. Calculated for C20H17Cl2N3O3: M = 418.0720.
2-(3,5-Dichlorophenylamino)-3-[(4-methylpiperazin-1-yl)-
iminomethyl]-4H-chromen-4-one (4i). Yield 50%, white powder,
m.p. 196—198 °C. IR, ν/cm–1: 3448, 3233, 3024, 2941, 2875,
2823, 2800, 2768, 1665, 1624, 1587, 1560, 1465, 1434, 1375, 1326,
1290, 1254, 1215, 1145, 1110, 1077, 1002, 957, 925, 887, 837, 806,
759, 698, 671, 604. 1H NMR (300 MHz, DMSO-d6), δ: 12.19
(s, 1 H); 8.15 (s, 1 H); 8.04 (d, 1 H, J = 7.3 Hz); 7.71 (t, 1 H,
J = 7.2 Hz); 7.44 (dd, 5 H, J = 27.0 Hz, J = 18.3 Hz); 3.28
(s, 4 H); 2.55 (s, 4 H); 2.26 (s, 3 H). 13C NMR spectrum could
not be recorded because of poor solubility of the substance. HRMS,
found: m/z 431.1042 [M]+. Calculated for C21H20Cl2N4O2:
M = 431.1008.
7.71 (dd, 1 H, H(5), J = 8.4 Hz, J = 3.1 Hz); 7.64 (dd, 1 H, H(8),
J = 9.1 Hz, J = 4.3 Hz); 7.61—7.55 (m, 3 H, o´-H, H(7)); 7.52
(t, 2 H, m´-H, J = 7.9 Hz); 7.29 (t, 1 H, p´-H, J = 7.4 Hz); 7.24
(t, 2 H, m-H, J = 7.9 Hz); 6.90 (d, 2 H, o-H, J = 7.4 Hz); 6.76
(t, 1 H, p-H, J = 7.3 Hz). 13C NMR (100 MHz, DMSO-d6), δ:
172.0 (C(4)), 159.1 (d, C(6), J = 243.4 Hz), 157.3 (C(2)), 148.6
(C(8a)), 145.0 (i-C), 136.1 (i´-C), 134.5 (CHN), 129.8 (m´-C),
129.4 (m-C), 125.4 (p´-C), 123.3 (d, C(4a), J = 7.1 Hz), 122.1
(o´-C), 120.6 (d, C(7), J = 25.2 Hz), 119.9 (d, C(8), J = 8.5 Hz),
118.8 (p-C), 111.6 (o-C), 110.0 (d, C(5), J = 24.0 Hz), 94.5 (C(3)).
HRMS, found: m/z 374.1406 [M]+. Calculated for C22H16FN3O2:
M = 374.1401.
The work was financially supported by the Russian
Science Foundation (Project No. 14-50-00126).
References
1. R. S. Keri, S. Budagumpi, R. K. Pai, R. G. Balakrishna, Eur.
J. Med. Chem., 2014, 78, 340.
2. A. Gaspar, M. J. Matos, J. Garrido, E. Uriarte, F. Borges,
Chem. Rev., 2014, 114, 4960.
3. M. J. Matos, S. Vazquez-Rodriguez, E. Uriarte, L. Santana,
F. Borges, Expert Opin. Ther. Patents, 2015, 25, 1.
4. O. I. Kobeleva, T. M. Valova, V. A. Barachevsky, I. S.
Semenova, K. S. Levchenko, V. N. Yarovenko, M. M.
Krayushkin, Opt. Spectrosc., 2013, 114, 401.
5. I. Y. Martynov, V. A. Barachevsky, A. O. Ayt, O. I. Kobeleva,
T. M. Valova, K. S. Levchenko, V. N. Yarovenko, M. M.
Krayushkin, Opt. Mater., 2014, 37, 488.
6. M. Yu. Kornev, V. Ya. Sosnovskikh, Chem. Heterocycl. Compd.
(Engl. Transl.), 2016, 52, 71.
7. V. Y. Sosnovskikh, V. S. Moshkin, M. I. Kodess, J. Heterocycl.
Chem., 2010, 47, 629.
8. M. A. Ibrahim, Tetrahedron, 2009, 65, 7687.
9. D. Y. Demin, K. A. Myannik, P. A. Ermolich, V. N.
Yarovenko, M. M. Krayushkin, Mendeleev Commun., 2018,
5, DOI: 10.1016/j.mencom.2018.09.010.
10. A. M. Tsedilin, A. N. Fakhrutdinov, D. B. Eremin, S. S.
Zalesskiy, A. O. Chizhov, N. G. Kolotyrkina, V. P. Ananikov,
Mendeleev Commun., 2015, 25, 454.
11. G. Singh, L. Singh, M. P. S. Ishar, Tetrahedron, 2002,
58, 7883.
12. S. Maiti, S. K. Panja, C. Bandyopadhyay, Indian J. Chem.,
2009, 48B, 1447.
6-Fluoro-2-phenylamino-3-[(2-phenylhydrazono)methyl]-
4H-chromen-4-one (4j). Yield 37%, yellow powder, m.p. 142—
144 °C. IR, ν/cm–1: 3412, 3226, 3040, 1674, 1615, 1599, 1558,
1540, 1499, 1457, 1432, 1331, 1289, 1257, 1226, 1207, 1160, 1100,
1010, 989, 941, 885, 750, 646. 1H NMR (400 MHz, DMSO-d6),
δ: 11.78 (s, 1 H, NH); 10.37 (s, 1 H, NHN); 8.48 (s, 1 H, CHN);
Received July 2, 2018;
in revised form August 10, 2018;
accepted August 17, 2018