AMINATION OF SOME 1,3-DINITROBENZENES
831
column chromatography. Preparative thin-layer
chromatography was performed using standard Silica
gel 60 PF-254 plates (20×40 cm, Merck).
M + (100). Found, %: C 36.28; H 2.97; N 28.30.
C6H6N4O4. Calculated, %: C 36.37; H 3.05; N 28.27.
M 198.1.
Commercial 1,3-dinitrobenzene and its 2-amino,
2-chloro, 2-methyl, 4-ethoxy, 4-fluoro-, 4-formyl, and
4-methyl derivatives were used. 2-Ethoxy-1,3-dinitro-
benzene [15], 4-chloro-1,3-dinitrobenzene [16], and
2,4-dinitrobenzamide [17] were synthesized according
to known procedures.
Amination of 2-chloro-1,3-dinitrobenzene (Ic).
Compound Ic, 0.5 g (2.47 mmol), was subjected to
amination according to the general procedure. The
residue was recrystallized from methanol to obtain
2,4-dinitro-1,3-phenylenediamine (IIb). The mother
liquor was evaporated, and the residue was separated
by column chromatography (2.5×25 cm) using chloro-
form as eluent. From the first fraction (100 ml) 0.27 g
(54%) of the initial compound was recovered. The
second fraction (150 ml) was evaporated, and the
residue was recrystallized from chloroform to afford
86 mg (16%) of 3-chloro-2,4-dinitroaniline (IIc),
yellow needles, mp 145–145.5°C. IR spectrum, ν,
Amination of 1,3-dinitrobenzenes with the
system liquid ammonia–potassium permanganate
(general pocedure). 1,3-Dinitrobenzene I, 0.5 g, and
potassium permanganate, 0.8–1.0 g, were added to 25–
30 ml of liquid ammonia, and the mixture was stirred
for 0.5–2.0 h at –33°C. After evaporation of ammonia,
~30 ml of water was added to the residue, and the
mixture was continuously extracted with chloroform
for 15–30 h. The solvent was removed from the
extract, and the residue was treated as described below.
1
cm–1: 3470 m and 3380 m (NH2). H NMR spectrum
(DMSO-d6), δ, ppm: 8.08 d (5H), 7.32 br.s (NH2),
6.93 d (5-H), J5,6 = 9.5 Hz. Mass spectrum (70 eV),
m/z (Irel, %): 219 (26), 217 (78) [M+], 187 (100)
[M – NO]+. Found, %: C 32.71; H 1.71; N 19.13.
C6H4ClN3O4. Calculated, %: C 33.12; H 1.85; N 19.30.
M 217.59.
Amination of 1,3-dinitrobenzene (Ia). The amina-
tion was carried out according to the general procedure
using 0.5 g (2.98 mmol) of compound Ia. The residue
was subjected to chromatographic separation on
a 3×35-cm column using chloroform as eluent. From
the first fraction (100 ml) 25 mg (5%) of the initial
compound was recovered. The second fraction
(350 ml) was evaporated, and the residue was recrys-
tallized from aqueous acetone to obtain 0.38 g (70%)
of 2,4-dinitroaniline (IIa); yellow crystals, mp 177–
178°C; published data [18]: mp 176°C. The product
was identical in Rf value and spectral parameters
(1H NMR, IR) to an authentic sample (commercially
available). The residue isolated from the third fraction
(200 ml) was washed with cold hexane; it was
2,4-dinitro-1,3-phenylenediamine (IIb), yield 12 mg
(2%), orange crystals, mp 256–257°C; published data:
mp 253–254°C [19], 260°C [20]. Compound IIb was
identical in Rf value and spectral parameters (1H NMR,
IR) to a sample obtained by amination of Ib.
The residue obtained after evaporation of the third
fraction (100 ml) was washed with hexane to obtain
an additional amount of pure compound IIb; overall
yield 54 mg (11%). The product was identified by
comparing with a sample prepared as described above
by the melting point, Rf, and 1H NMR and IR spectra.
Amination of 2-ethoxy-1,3-dinitrobenzene (Id).
The reaction was carried out with 0.5 g (2.36 mmol) of
compound Id according to the general procedure. The
product was recrystallized from methanol; 0.13 g
(28%) of 2,4-dinitro-1,3-phenylenediamine (IIb) was
thus isolated. It was identical in the melting point,
Rf value, and IR spectrum to a sample obtained by
amination of Ib.
Amination of 2,6-dinitrotolune (Ie). The reaction
was carried out with 0.5 g (2.75 mmol) of compound
Ie according to the general procedure. The residue was
dissolved in chloroform, and the solution was applied
to a 3.0×30-cm column for chromatographic separa-
tion using chloroform as eluent. From the first fraction
(200 ml) we isolated 0.42 g (84%) of the initial com-
pound. The second fraction (150 ml) was evaporated,
and the residue was washed with hexane to obtain
54 mg (10%) of 3-methyl-2,4-dinitroaniline (IId),
yellow crystals, mp 133°C; published data [21]:
Amination of 2,6-dinitroaniline (Ib). Compound
Ib, 0.5 g (2.73 mmol), was subjected to amination
according to the general procedure. The residue was
recrystallized from methanol to obtain 0.16 g (30%) of
2,4-dinitro-1,3-phenylenediamine (IIb) as orange crys-
tals with mp 259–260°C; published data: mp 253–
254°C [19], 260°C [20]. IR spectrum, ν, cm–1: 3395 m
and 3290 m (2-NH2), 3435 m and 3320 m (4-NH2).
1H NMR spectrum (DMSO-d6), δ, ppm: 9.44 br.s
(NH2), 9.05 br.s (NH2), 8.09 d (5-H), 6.29 d (6-H),
1
mp 132.5°C. H NMR spectrum (DMSO-d6), δ, ppm:
J
5,6 = 9.5 Hz. Mass spectrum (70 eV), m/z (Irel, %): 198
8.02 d (5-H), 7.06 br.s (NH2), 6.87 d (6H), 2.39 s
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 6 2004