2414
BOGDANOV, MIRONOV
withdrawing substituents (bromine atom, a nitro
group) in the position 5 led only to the formation of
quinoxaline derivatives 6 and 7 (Scheme 1).
120.25 d (s) (С10а, 3JНС 5.8), 113.61 d.d (s) (С7, 1JНС 166.9,
2JНС 0.7). Mass spectrum (MALDI): m/z 253.8 [M]+.
9-Bromo-6H-indolo[2,3-b]quinoxaline (6). Yield
77%, yellow powder, mp 289°С (mp >300°С [9]). IR
spectrum, ν, cm–1: 3444, 1730, 1614, 1407, 1332,
An unexpected result was obtained by reacting o-
phenylenediamine with isatin 4 containing donor n-
butyl substituent. In this case, imidazo[1,2-c]quinazo-
linone 8 was obtained in a 79% yield and characterized
for the first time. Thus, in contrast to quinoxaline 5 the
IR spectrum of compound 8 contained an absorp-tion
at 1718 cm–1 due to the vibrations of the C=O bonds.
In the 13C NMR spectrum the carbonyl carbon atom
resonated as a singlet at 146.24 ppm that is charac-
teristic of an urea fragment. In addition, the composi-
tion of 8 was confirmed by the mass spectrometry
(MALDI).
1
1240, 1210, 1129, 1110, 1004, 948, 877, 823, 746. Н
NMR spectrum (DMSO-d6), δ, ppm (J, Hz): 7.33 br.d
3
3
3
(1H, Н7, JНН 8.7), 7.74 d.d.d (1H, ArН, JНН 6.9, JНН
6.8, JНН 1.4), 7.79 d.d (1H, Н8, JНН 8.7, JНН 2.3),
7.81–7.84 m (1H, ArН), 8.08 br.d.d (1H, ArН, JНН
4
3
4
3
4
3
8.3, JНН 0.8), 8.24 br.d (1H, ArН, JНН 8.3), 8.46 d
(1H, Н10, JНН 1.9), 12.17 br.s (1H, NН). Mass spec-
4
trum (MALDI): m/z 299.8 [М + Н]+.
9-Nitro-6H-indolo[2,3-b]quinoxaline (7). Yield 97%,
orange powder, mp 265°С. IR spectrum, ν, cm–1: 3327,
1748, 1716, 1659, 1614, 1518, 1338, 1274, 1165, 1121,
1072, 902, 831, 748, 686. Due to the low solubility of
this compound in wide range of the solvents NMR spectra
were not recordered. Mass spectrum (MALDI): m/z
297.3 [М + Na]+. Found, %: C 63.47; H 2.83; N 21.01.
Calculated, %: C14H8N4O2: C 63.64; H 3.05; N 21.20.
Finally, the structure of compounds 3 and 8 was
proved by X-ray diffraction analysis, whose details
will be provided later.
General procedure for the reactions of isatins 1–
4 with o-phenylenediamine. A solution of 1.08 g
(0.01 mol) of o-phenylenediamine in anhydrous
ethanol (50 mL) was added with stirring (20°C) to a
solution of 0.02 mol of the corresponding isatin in
100 mL of anhydrous ethanol. The reaction mixture
was maintained at reflux for 2 h. The solvent was
evaporated to 1/5 volume. The precipitate was filtered
off and heated in anhydrous chloroform to remove
impurities. The resulting precipitate was filtered off
and dried in a vacuum of 15 mmHg.
2-Butyl-5H-benzo[4,5]imidazo[1,2-c]quinazolin-
6-one (8). Yield 79%, orange powder, mp 235°С. IR
spectrum, ν, cm–1: 3437, 1718, 1615, 1594, 1543,
1498, 1337, 1248, 1200, 1125, 1062, 1009, 933, 829,
1
801, 758, 743. Н NMR spectrum (СDCl3), δ, ppm (J,
3
Hz): 0.87 t (3Н, CН3, JНН 7.4), 1.27–1.36 m (2Н,
3
CH2), 1.56–1.64 m (2Н, CH2), 2.65 t (2Н, CH2, JНН
3
7.5), 7.27 d (1Н, JНН 8.3), 7.32–7.36 m (2Н), 7.38–
3
4
7.42 m (1Н), 7.76 d (1Н, JНН 8.8), 8.11 d (1Н, JНН
9-Chloro-6H-indolo[2,3-b]quinoxaline (5). Yield
67%, yellow crystals, mp 223°C (mp 222–224°C [9]).
IR spectrum, ν, cm–1: 3444, 1615, 1405, 1335, 1239,
3
4
1.4), 8.36 br.d.d (1Н, JНН 7.8, JНН 0.5), 11.65 br.s
(1Н, NH). 13С NMR spectrum (CDCl3–DMSO-d6,
6 : 1, δС, ppm (J, Hz): 147.56 d.d (s) (3JНС 4.4, JНС
4
1
1207, 1126, 1107, 1005, 944, 875, 821, 748. Н NMR
0.7), 146.24 s (s) (С=О), 143.24 m (s), 137.53 m (s),
134.74 m (s), 132.19 d.m (s) (СHAr), 124.53 d.m (s)
(СHAr), 123.16 d.m (s) (СHAr), 123.12 d.m (s) (СHAr),
spectrum (DMSO-d6), δ, ppm (J, Hz): 7.62 d.d (1H,
Н7, 3JНН 8.6, 4JНН 0.5), 7.74 d.d (1H, Н8, 3JНН 8.6, 4JНН
3
3
4
2.2), 7.75 d.d.d (1H, Ar-Н, JНН 6.9, JНН 6.8, JНН
1
3
3
118.51 d.d.t (s) (СHAr, JНС 162.1, JНС 8.1, JНС 1.5),
115.56 d (s) (СHAr, 1JНС 163.2), 114.57 d.d.t (s) (СHAr,
1JНС 168.7, 3JНС 8.1, 3JНС 1.8), 111.27 m (s), 34.30 t.m
(s) (СН2), 32.90 t.m (s) (СН2), 21.49 t.m (s) (СН2, 1JНС
3
3
4
1.5), 7.84 d.d.d (1H, Ar-Н, JНН 6.9, JНН 6.8, JНН
3
4
5
1.5), 8.09 d.d.d (1H, Ar-Н, JНН 8.3, JНН 1.5, JНН
3
4
5
0.5), 8.26 d.d.d (1H, Ar-Н, JНН 8.3, JНН 1.5, JНН
0.5), 8.36 d.d (1H, Н10, JНН 2.2, JНН 0.5), 12.19 br.s
4
5
3
1
3
120.3, JНС 4.0), 13.40 q.t (s) (СН3, JНС 124.7, JНС
4.0). Mass spectrum (MALDI): m/z 291.8 [M]+.
(1H, NН). 13С NMR spectrum (DMSO-d6), δС, ppm
13
(J, Hz) (the data given in parentheses are for the C–
{1H} spectra): 146.03 s (s) (С5), 141.33 d.d (s) (С3,
REFERENCES
3JНС 9.5, JНС 9.5), 140.38 d.d (s) (С6а, JНС 9.9, JНС
9.5), 138.66 m (s) (С2, С11), 130.91 d.m (s) (СHAr),
129.19 d.m (s) (СHAr), 129.09 d.m (s) (СHAr), 127.53
3
3
3
1. Raj, V., Int. J. Curr. Pharm. Res., 2012, vol. 4, no. 4,
p. 1.
d.m (s) (СHAr), 126.27 d.d (s) (С8, JНС 162.1, JНССС
1
3
2. Jarrahpour, A., Khalili, D., De Clercq, E., Salmi, Ch.,
and Brunel, J.-M., Molecules, 2007, vol. 12, no. 8,
p. 1720. DOI: 10.3390/12081720.
9.2), 124.95 d.d.d (s) (С9, 3JНС 10.3, 2JНС 4.0, 2JНС 3.3),
121.43 d.d.d (s) (С10, JНС 168.0, JНС 5.5, JНС 1.1),
1
3
4
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 10 2015