Synthesis of Isomeric Dinitro and Diamino Derivatives of Polycyclic Crown Ethers: Dibenzo-18-crown-6 and Dibenzo-24-crown-8

Article abstract of DOI:10.1134/S1070363218080078

Specific features of the synthesis of polycyclic crown ethers dibenzo-18-crown-6 and dibenzo-24-crown-8 and their dinitro and diamino derivatives have been studied. A mixture of isomers of dibenzocrown ether derivatives was obtained and separated. The spectral and thermal characteristics of the synthesized compounds and the kinetics of synthesis of dibenzo-24-crown-8 by the two-component condensation of pyrocatechol with 1-chloro-2-[2-(2-chloroethoxy)ethoxy]ethane in an alcoholic medium in the presence of a KOH template agent were studied.

Full text of DOI:10.1134/S1070363218080078

ISSN 1070-3632, Russian Journal of General Chemistry, 2018, Vol. 88, No. 8, pp. 1595–1600. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © V.N. Glushko, N.Yu. Sadovskaya, L.I. Blokhina, M.Yu. Zhila, S.K. Belus’, E.S. Vashchenkova, I.A. Shmeleva, 2018, published in
Zhurnal Obshchei Khimii, 2018, Vol. 88, No. 8, pp. 1273–1279.
Synthesis of Isomeric Dinitro and Diamino Derivatives
of Polycyclic Crown Ethers: Dibenzo-18-crown-6
and Dibenzo-24-crown-8
V. N. Glushkoa*, N. Yu. Sadovskayaa, L. I. Blokhinaa, M. Yu. Zhilaa,
S. K. Belus’a, E. S. Vashchenkovaa, and I. A. Shmelevaa
a Institute of Chemical Reagents and High Purity Chemical Substances,
“Kurchatov Institute” National Research Center, Bogorodskii val 3, Moscow, 107076 Russia
*e-mail: tetrazoli@yandex.ru
Received April 5, 2018
Abstract—Specific features of the synthesis of polycyclic crown ethers dibenzo-18-crown-6 and dibenzo-24-
crown-8 and their dinitro and diamino derivatives have been studied. A mixture of isomers of dibenzocrown
ether derivatives was obtained and separated. The spectral and thermal characteristics of the synthesized
compounds and the kinetics of synthesis of dibenzo-24-crown-8 by the two-component condensation of
pyrocatechol with 1-chloro-2-[2-(2-chloroethoxy)ethoxy]ethane in an alcoholic medium in the presence of a
KOH template agent were studied.
Keywords: crown ether derivatives, regioisomers, dibenzo-18-crown-6, dibenzo-24-crown-8, separation of
isomers
DOI: 10.1134/S1070363218080078
Functional derivatives of dibenzocrown ethers are
promising candidates for application as building blocks
in supramolecular systems and polymer materials. The
known methods of synthesis of these derivatives
provide mixtures of isomers with unknown component
concentrations, and, therefore, research into the
separation of such mixtures is an urgent issue.
The methods of synthesis of functionally sub-
stituted aromatic crown ethers can be divided into two
main groups: syntheses starting from dihydric phenols
containing other functional groups and syntheses
involving functionalization of aromatic rings. We
chose the second synthetic approach, taking into
account that it makes use of usual reactions to
introduce substituents into the aromatic ring, and the
positions of the substituents are controlled by common
orientation rules (Scheme 1).
Amino and diamino derivatives of crown ethers can
be further functionalized. They can be immobilized on
various organic and inorganic substrates and then used
to construct nitrogen-containing structures, in parti-
cular, polymers of diaminocrown ethers [1–7]. Poly-
amide 18-crown-6 was used in a reverse osmosis
membrane, and polymers including crown ethers can
be used as proton-conducting cation exchange mem-
branes for proton-driven cation transport [6]. Macro-
cyclic ligands are introduced into membranes for metal
separation and ion-selective electrodes [6].
We previously studied the synthesis of dibenzo-18-
crown-6 1a [8]. According to GLC data, the reaction
was complete in 5–5.5 h. Along with compound 1a,
the postreaction mixture contained admixtures of benzo-
9-crown-3 2 and 1,2-bis[2-(2-chloroethoxy)ethoxy]-
benzene 3 and its reaction product with isopropanol
1-[2-(2-chloroethoxy)ethoxy]-2-[2-(2-propoxyethoxy)-
ethoxy]benzene 4, as well as semicrown diol 5.
We performed research into the synthesis of regio-
isomers of diaminodibenzo-18-crown-6 and diamino-
dibenzo-24-crown-8 from the presynthesized starting
compounds: dibenzocrown ethers and dinitrocrown
ethers.
To ensure selective cyclization to crown ethers and
prevent formation of linear polymers the reactions
were performed in highly diluted solutions, where
intramolecular cyclization to form a macrocyclic
product is more probable and occurs faster than
1595

1596
GLUSHKO et al.
Scheme 1.
O
O
O
O
O
O
nO
O
n
O2N
O
O
n O
O
n
HNO3
NO2
CH3CN, t°
1a, 1b
CH3COOH
t°
n = 1
n = 2
O
O
O
O
O
O
O
O2N
NO2
O
O
O2N
O
O
O
NO2
O
O
O
O
O
O
+
O2N
NO2
O
O
9a
9b
NH2NH2
NH2NH2
NH2NH2
DMF
Ni-Ra
DMF
Ni-Ra
DMF
Ni-Ra
O
O
O
O
O
O
NH2
H2N
O
O
O
O
H2N
O
O
O
O
NH2
H2N
O
O
O
O
NH2
O
O
cis-10a
trans-10a
n = 1 (a), 2 (b).
10b
O
O
O
OC3H7
Cl
OH
O
HO
O
O
O
O
O
O
Cl
Cl
O
O
O
O
5
2
3
4
polymerization which requires the two reagents to
collide with each other [9, 10].
ethoxy]ethane 7 in an alcoholic medium in the
presence of KOH as a template agent. The reaction
progress was followed and the molar concentrations of
compound 1b were determined by GLC. It was found
that the reaction mixtures contained, along with
compound 1b, minor amounts of compounds 8a‒8e
We studied the kinetics of the synthesis of dibenzo-
24-crown-8 1b by the two-component condensation of
pyrocatechol 6 with 1-chloro-2-[2-(2-chloroethoxy)-
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 88 No. 8 2018

SYNTHESIS OF ISOMERIC DINITRO AND DIAMINO DERIVATIVES
(Scheme 2). Admixtures of benzo-18-crown-6 8d and
1597
dibenzo-30-crown-10 8e were also detected in com-
pound 1b. The kinetic regularities of the synthesis of
compound 1b are illustrated in the figure.
Dinitro derivatives of dibezocrown ethers (dinitro-
dibenzo-18-crown-6 and dinitrodibenzo-24-crown-8) are
formed as mixtures of the trans and cis isomers.
Feigenbaum and Michel [11] described a long-term
isomers of dinitrodibenzo-18-crown-6 by the nitra-tion
of dibenzo-18-crown-6 with a mixture of nitric and
acetic acids in chloroform [11]. The synthesis gave the
cis (mp 208–236°С) and trans isomers (mp 236–252°С).
The broad ranges of melting points reported in the
cited work cast doubt upon the purity of these
products.
τ, h
Kinetic curves of the synthesis of dibenzo-24-crown-8 1b:
(1) pyrocatechol 6, (2) triethylene glycol dichloride, (3) di-
benzo-24-crown-8 1b, and (4–8) admixtures of compounds
8a‒8e.
isomer mixture obtained from dibenzo-18-crown-6
(mp 223–237°С) was separated into individual regio-
isomers by crystallization from acetic acid: trans-9а
(mp 242–249°С) and cis-9а (mp 210–213°С). Because
of the poor solubility of trans-9а, we could isolate the
regioisomers after the obtained synthesized nitro
compounds had been reduced to amino derivatives:
Dinitrodibenzo-18-crown-6 9а and dinitrodibenzo-
24-crown-8 9b were prepared by the reaction of the
corresponding dibenzocrown ethers with 58% nitric
acid in acetonitrile followed by crystallization of the
resulting dinitro derivatives from acetic acid. The
Scheme 2.
O
O
O
O
OH
OH
O
O
O
O
KOH
ROH
+
Cl
O
Cl
2
6
7
1b
O
O
O
O
O
O
O
O
O
Cl
O
O
O
O
O
Cl
Cl
O
OH
8a
8b
8c
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
8d
8e
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GLUSHKO et al.
Thermal characteristics of dibenzocrown ethers and their dinitro and diamino derivatives
Compound
Endothermic peak, °C
Exothermic peak, °C
Weight loss at 400°C, %
Diaminodibenzo-18-crown-6 (10а)
Diaminodibenzo-24-crown-8 (10b)
Dibenzo-18-crown-6 (1a)
175
130
160
100
176
146
350
361
271
327
350
343
65
33
58
83
62
65
Dibenzo-24-crown-8 (1b)
Dinitrodibenzo-18-crown-6 (9a)
Dinitrodibenzo-24-crown-8 (9b)
cis-diaminodibenzo-18-crown-6 cis-10а (mp 170–172°С)
and trans-diaminodibenzo-18-crown-6 trans-10а (mp
197–198°С).
The thermoanalytical curves of these compounds show
endothermic peaks from 100 (1b) to 176°С (9a). These
temperature points correspond to melting of com-
pounds 1b and 9a. The exothermic peaks from 271 to
~400°С correspond to weight losses of 33 (1a) and
~65% (1b, 9, 10).
Attempted synthesis of isomeric dinitrodibenzo-24-
crown-8 9b both by the procedure in [12] and by the
nitration of compound 1b with nitric acid in
acetonitrile followed by crystallization of the resulting
nitro derivative from acetic acid afforded nitro
derivatives respectively of mp 148.5–149.5°С and mp
150–151.5°С; unlike dinitro derivative 9а they were
readily soluble in most organic solvents.
Comparison of the thermal characteristics of di-
benzocrown ethers and their derivatives is presented in
the table. The endothermic and exothermic peaks
makes it possible to determine the melting and decom-
position points, respectively.
A few methods of synthesis of diamino derivatives
of dibenzocrown ethers are known. Diaminodibenzo-
24-crown-8 10b were synthesized in a yield of 56% by
the reduction of dinitro derivative 9b with hydrogen on
Pd/C in ethanol [12] in an pressure reactor at 3.5 at or
in DMF, acetic acid, and ethylene glycol [13–15].
Thus, we synthesized and characterized the regio-
isomers of dinitrodibenzo-18-crown-6 and diamino-
dibenzo-18-crown-6 and determined the optimal condi-
tions of the preparation of the polycyclic ether dibenzo-
24-crown-8 and its dinitro and diamino derivatives.
EXPERIMENTAL
The mixture of regioisomers of compound 10b was
obtained by the procedure in [4, 16–18] by the
reduction of dinitrodibenzo-24-crown-8 9b (a mixture
of 4,4' and 4,5' isomers) with hydrazine hydrate in the
presence of Raney nickel. Diamino derivatives 10a and
10b were also prepared by the reduction of the
corresponding dinitrodibenzocrown ethers with
hydrazine hydrate in the presence of Pd or Ni catalysts
in DMF at 75–80°С. It was found that the diamino-
crown ether obtained in the presence of 10% Pd/C is
quite difficult to separate from the catalyst, because the
product forms a fairly strong complex with palladium.
The reduction catalyzed by the highly active Raney
nickel is much more facile.
The Fourier transform IR spectra were measured on
a Bruker Vertex 70 instrument with an ATR unit
1
(Miracle ATR, PIKE, ZnS crystal). The Н and 13С
NMR spectra were registered on a Bruker Avance III
NanoBay spectrometer [300.28 (1Н) and 75.51 МHz
(13С)] in the thermostabilization mode at 25°С.
The reaction products were identified on a
Khromatek-Kristall 500.2 chromatograph coupled to a
Thermo ISQ mass spectrometer, using a TR-5MS
quartz capillary column (l 15 m, d 0.25 mm, film
thickness 0.25 µm, carrier gas helium, split ratio 1 : 25,
oven temperature 150–280°С, ramp rate 20 deg/min).
The mass spectra were obtained at the ionization
energy 70 eV and ion source temperature 280°С. The
products were identified by library search on NISTUSA
database (2008), as well as by the molecular ions based
on mass spectrum–structure correlations.
In view of the fact that diaminodibenzocrown
ethers can be used to obtain high-temperature poly-
mers, we assessed the thermal stability of dibenzo-
crown ethers 1a and 1b and derivatives 9a, 9b and
10a, 10b. The thermal degradation of compounds 1, 9,
and 10 involves two steps: melting and decomposition.
Isomeric dinitrodibenzo-18-crown-6 ethers 9a.
Dibenzo-18-crown-6 1a, 36 g (0.1 mol), in 160 mL of
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 88 No. 8 2018

SYNTHESIS OF ISOMERIC DINITRO AND DIAMINO DERIVATIVES
1599
acetonitrile was heated to 70°С, after which 40 mL
(1.5 mol) of 58% nitric acid was added with stirring
over the course of 0.5 h. The reaction mixture was
stirred for 40 min at 70°С and then poured into 1000 g
of ice or ice water. In 0.5 h the precipitate was filtered
off and washed with 500 mL of water. The reaction
product was dried in air to constant weight to obtain
42.5 g (94.8%) of the isomer mixture, mp 220–224°С.
The mixture was recrystallized from acetic acid to
obtain 2.87 g of trans-dinitrodibenzo-18-crown-6, mp
240–249°С, and 2.49 g of cis-dinitrodibenzo-18-crown-6,
mp 208.1–213.8°С.
cis-Diaminodibenzo-18-crown-6 (cis-10а). Yield
93.2%, mp 167.0–170.5°С. IR spectrum, ν, cm–1: 602
w, 655 w, 722 w, 743 w, 783 m (NH2), 795 m (NH2),
828 m, 849 w, 905 w, 928 w, 956 w, 984 m, 1040 w,
1060 w, 1080 w, 1129 s (С–О–С), 1187 m, 1232 s,
1345 m, 1449 m, 1489 w, 1512 s (СН2), 1592 w
(С–СAr), 1614 w (NH2), 2874 w (С–Н), 2920 w (С–Н),
1
3228 w (NH2), 3326 w (NH2). Н NMR spectrum
(CD3CN), δ, ppm: 3.76–3.84 m (8Н, СН2), 3.94–4.05
m (8Н, СН2), 6.14 д. d (2НAr, J = 8.5, J = 2.5 Hz), 6.31
d (2НAr, J = 2.5 Hz), 6.66 d (2НAr, J = 8.5 Hz). 13C
NMR spectrum (CD3CN), δC, ppm: 68.44, 69.13,
70.27, 70.40, 101.70, 106.57, 114.42, 141.24, 143.19,
149.82. Found, %: C 61.71; H 7.26; N 7.27.
C20H26N2O6. Calculated, %: C 61.53; H 6.71; N 7.17.
cis-Dinitrodibenzo-18-crown-6 (cis-9а). Yield 2.49 g,
mp 208.1–213.8°С. IR spectrum, ν, cm–1: 624 w, 653
m, 722 w, 742 s (NO2), 784 w, 806 m, 863 w, 867 m,
898 w, 929 w, 956 m, 972 m, 998 w, 1043 m, 1055 m,
1082 m, 1100 s (С–N), 1135 s (С–О–С), 1221 s, 1237
s, 1261 s, 1274 s, 1343 s (NO2), 1405 w, 1426 w, 1451
m, 1505 s (СН2), 1512 sh (NO2), 1588 m (С–СAr),
trans-Diaminodibenzo-18-crown-6 (trans-10а).
Yield 89.3%, mp 197.0–198.5°С. IR spectrum, ν, cm–1:
622 w, 663 w, 698 w, 720 w, 752 w, 767 w, 784 w,
792 w, 802 w, 836 m (NH2), 905 w, 929 w, 947 w, 956
w, 987 w, 1062 m, 1087 w, 1130 s (С–О–С), 1184 m,
1228 s, 1281 m, 1346 w, 1356 w, 1384 w, 1444 w,
1455 w, 1511 s (СН2), 1592 w (С–СAr), 1615 w (NH2),
1673 w, 2833 w (С–Н), 2884 w (С–Н), 2928 w (С–Н),
2968 w (С–Н), 3357 w (NH2), 3382 w (NH2), 3422 w
1
2883 w (С–Н), 2926 w (С–Н). Н NMR spectrum
(DMSO-d6), δ, ppm: 3.79–3.93 m (8Н, СН2), 4.16–
4.30 m (8Н, СН2), 7.16 d (2НAr, J = 8.9 Hz), 7.72 d
(2НAr, J = 1.7 Hz), 7.88 dd (2НAr, J = 8.9, J = 1.7 Hz).
13C NMR spectrum (DMSO-d6), δC, ppm: 68.05,
68.30, 68.39, 106.77, 111.31, 117.44, 140.51, 147.63,
153.74. Found, %: C 52.10; H 5.33; N 6.19.
C20H22N2O10. Calculated, %: C 53.33; H 4.92; N 6.22.
1
(NH2), 3433 w (NH2). Н NMR spectrum (DMSO-d6),
δ, ppm: 3.72 m (8Н, СН2), 3.88–4.02 m (8Н, СН2),
4.62 br.s (4Н, NН2), 6.06 д. d (2НAr, J = 8.4, J =
2.0 Hz), 6.24 d (2НAr, J = 2.0 Hz), 6.63 d (2НAr, J =
8.4 Hz). 13C NMR spectrum (DMSO-d6), δC, ppm:
67.77, 69.01, 69.29, 69.39, 100.80, 105.37, 115.99,
139.11, 143.52, 149.28. Found, %: C 60.46; H 7.52; N
7.17. C20H26N2O6. Calculated, %: C 61.53; H 6.71; N 7.17.
trans-Dinitrodibenzo-18-crown-6 (trans-9а). Yield
2.87 g, mp 240–249°С. IR spectrum, ν, cm–1: 616 w,
649 w, 722 w, 744 s (NO2), 798 m, 849 w, 883 w, 898
m, 923 w, 967 m, 995 m, 1035 w, 1048 w, 1096 m,
1118 w, 1140 s (С–О–С), 1235 s, 1247 m, 1275 s
(NO2), 1346 s (NO2), 1399 w, 1417 w, 1428 w, 1454
w, 1474 w, 1492 w, 1512 s (СН2), 1591 (С–СAr), 2887
w (С–Н), 2955 w (С–Н), 3079 w (С–Н), 3093 w (С–Н).
1Н NMR spectrum (DMSO-d6), δ, ppm: 3.79–3.91 m
(8Н, СН2), 4.11–4.20 m (8Н, СН2), 7.16 d (2НAr, J =
9.0 Hz), 7.72 d (2НAr, J = 2.6 Hz). 13C NMR spectrum
(DMSO-d6), δC, ppm: 68.02, 68.35, 68.41, 106.62,
111.26, 117.53, 140.53, 147.65, 153.74. Found, %: C
53.36; H 5.44; N 6.20. C20H22N2O10. Calculated, %: C
53.33; H 4.92; N 6.22.
Dinitrodibenzo-24-crown-8 ethers 9b. Acetonitrile,
80 mL, was added to 26.88 g (0.06 mol) of a mixture
of 4,4'- and 4,5'-isomers of dibenzo-24-crown-8. The
mixture was heated to 70°С, after which 19 mL (26 g,
0.24 mol) of 58% nitric acid was added over the course
of 0.5 h. The reaction mixture was stirred for 20 min at
70°С and then poured into 400 g of ice water. The
precipitate was filtered off, washed with 100–200 mL
of water, dried, and recrystallized from 40 mL of
acetic acid. Yield 31.7 g (98.5%, mixture of regio-
isomers), mp 152.5–155.0°С. IR spectrum, ν, cm–1:
655 m, 722 w, 743 s (NO2), 797 w, 813 m, 873 m, 906
w, 941 w, 967 w, 992 m, 1017 m, 1043 m, 1080 m,
1095 m, 1130 s (С–О–С), 1140 s, 1236 s, 1265 s, 1280
s, 1338 s (NO2), 1375 w, 1426 w, 1450 w, 1470 w,
1482 w, 1508 s (СН2), 1510 sh (NO2), 1590 (С–СAr),
2879 (С–Н), 2904 (С–Н), 2942 (С–Н). 1Н NMR spec-
trum (CDCl3), δ, ppm: 3.80–3.85 m (8Н, СН2), 3.91–
Isomeric diaminodibenzo-18-crown-6 ethers 10а.
A suspension of 2.0 g (4.4 mmol) of dinitrodibenzo-18-
crown-6 in 30 mL of DMF was heated with stirring to
110°С and then 1.6 g of Raney Ni was added, followed
by dropwise addition of 3.3 g (66 mmol) of hydrazine
hydrate at 75–80°С. The catalyst was filtered off, the mother
liquor was evaporated, and the residue was washed
with 50 mL of ethanol and dried to a constant weight.
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GLUSHKO et al.
3.98 m (8Н, СН2), 4.18–4.25 m (8Н, СН2), 6.86 d
(2НAr, J = 8.9 Hz), 7.71 t (2НAr, J = 2.4 Hz), 7.86 d.t
(2НAr, J = 8.9, J = 2.4 Hz). 13C NMR spectrum (CDCl3),
δC, ppm: 69.67, 69.79, 69.86, 69.90, 71.12, 71.79, 108.42,
108.44, 111.41, 111.44, 118.19, 118.21, 141.66, 141.70,
148.56, 148.60, 154.47, 154.48. Found, %: C 53.58; N
5.18. C24H30N2O12. Calculated, %: С 53.50; N 5.20.
CONFLICT OF INTEREST
No conflict of interest was declared by the authors.
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at 60°С to 31.7 g (0.075 mol) of dinitrodibenzo-24-
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mixture of regioisomers), mp 132.0–133.7°С. IR
spectrum, ν, cm–1: 627 m, 667 w, 763 w, 775 w, 828 m
(NH2), 844 m (NH2), 891 m, 945 m, 979 m, 1051 s,
1080 s, 1118 s (C–O–C), 1182 m, 1225 s, 1274 m,
1326 w, 1349 w, 1443 m, 1509 s (CH2), 1586 s (C–CAr),
1617 m (NH2), 2868 m (С–Н), 2923 m (С–Н), 3366 m
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ppm: 3.66 t (8Н, СН2, J = 2.9 Hz), 3.70–3.80 m (8Н,
СН2), 3.85 br.s (4Н, NH2), 3.94–4.05 m (8Н, СН2),
6.14 д. д. d (2НAr, J = 8.4, J = 2.5, J = 0.7 Hz), 6.29 d
(2НAr, J = 2.5 Hz), 6.68 d (2НAr, J = 8.4 Hz). 13C NMR
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102.87, 107.28, 107.31, 141.58, 141.62, 144.17, 144.22,
151.07, 151.11. Found, %: С 60.18; N 5.85. C24H34N2O8.
Calculated, %: С 60.25; N 5.86.
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