GOLUBEV, SEN’
Thus the most efficient procedure for the synthesis
558
UV spectrum, λmax, nm (ε, l mol–1 cm–1): in EtOH: 495
(1020), 467 sh (1040), 456 (1130), 433 sh (1140), 407
(1340), 321 (21800), 294 sh (14300), 252 (3000); in
hexane: 572 sh (102), 539 sh (172), 510 sh (196),
480 sh (450), 442 sh (926), 428 sh (1030), 406 (1230),
319 (25000), 309 sh (21400), 300 sh (16200), 292 sh
(14400), 284 sh (12300), 254 (3100). IR spectrum
(CCl4), ν, cm–1: 3060 and 3040 (C–Harom), 2960, 2904,
2866 [C(CH3)3], 1590 and 1492 (C=Carom), 1420 (NO).
1H NMR spectrum (500 MHz, CDCl3), δ, ppm: 6.01 s
(18H, CH3); signals from aromatic protons were not
observed because of paramagnetic broadening. ESR
spectrum (toluene): 33 lines, aN = 0.99, ao-H = 0.186,
am-H = 0.09 mT.
c. A solution of 0.025 g (0.1 mmol) of CuSO4·
5H2O in 0.5 ml of water was added to a solution of
0.3 g (1 mmol) of hydroxylamine III in 5 ml of meth-
anol. The mixture was vigorously stirred (so that
a vortex cavity appeared) until complete consumption
of hydroxylamine III (~30 min), and 5 ml of water
was added. The precipitate was filtered off, washed
with 80% methanol, and dried under reduced pressure.
Yield 0.28 g (95%), red crystals, mp 105–125°C.
According to the HPLC data, the product contained
79% of I and 21% of II.
of radical I is oxidation of amine II and hydroxyl-
amine III with H2O2/WO42– in boiling methanol. These
conditions ensure short reaction time and high
selectivity.
EXPERIMENTAL
Bis(4-tert-butylphenyl)amine (II) was synthesized
according to the procedure reported in [10] and was
purified by recrystallization from methanol, mp 108°C.
Bis(4-tert-butylphenyl)hydroxylamine (III) was pre-
pared from 4-tert-butyl-1-nitrosobenzene and 4-tert-
butylphenylmagnesium bromide according Wieland
and Rosseu [1, 11] and was recrystallized from hexane,
mp 113–115°C. HPLC analyses were performed on
a Milikhrom chromatograph equipped with a 2×64-
mm column packed with Separon C18 (5 μm) and
a UV detector (λ 210 nm); eluent 80% acetonitrile;
retention volumes, μl: 570 (III), 785 (I), 900 (II).
Bis(4-tert-butylphenyl)aminoxyl (I). a. A solution
of 28.1 g (0.1 mol) of amine II in 450 ml of methanol
was heated to the boiling point, 34 ml (0.3 mol) of
30% hydrogen peroxide and a solution of 3.3 g
(10 mmol) of Na2WO4·2H2O in 7 ml of water were
added in succession, and the mixture was heated under
reflux on a water bath, the consumption of H2O2 being
monitored by the evolution of oxygen. When oxygen
no longer evolved (after ~3 h), a solution of 34 ml
(0.3 mol) of 30% hydrogen peroxide in 200 ml of
methanol was added, and the mixture was again heated
under reflux until evolution of oxygen ceased (~3.5 h).
Most part of methanol (420 ml) was distilled off, the
residue was cooled, and the precipitate was filtered off,
washed with 50% methanol, dried in air, and recrystal-
lized from methanol. Yield 23.8 g (80%), red crystals,
mp 134–135°C; published data: mp 134–135°C [1],
96–98°C [5]. According to the HPLC data, the product
contained 99% of I and 1% of amine II.
REFERENCES
1. Holt B. and Randel, D.R., FRG Patent Appl.
no. 2110627, 1971.
2. Kasaikina, O.T., Lobanova, T.V., Ivanov, Yu.A.,
Pokrovskaya, I.E., and Gagarina, A.B., Neftekhimiya,
1988, vol. 28, p. 552.
3. Jensen, R.K., Korcek, S., Zinbo, M., and Gerlock, J.L.,
J. Org. Chem., 1995, vol. 60, p. 5396.
4. Denisov, E.T., Usp. Khim., 1996, vol. 65, p. 547.
5. Ivanov, Yu.A., Kokorin, A.I., Shapiro, A.B., and
Rozantsev, E.G., Izv. Akad. Nauk SSSR, Ser. Khim.,
1976, p. 2217.
6. Rajka, A., Vale, M., and Rajka, S., J. Am. Chem. Soc.,
b. A solution of 1.49 g (5 mmol) of hydroxylamine
III in 25 ml of methanol was heated to the boiling
point, 1.7 ml (15 mmol) of 30% hydrogen peroxide
and a solution of 0.165 g (0.5 mmol) of Na2WO4·
2H2O in 0.5 ml of water were added in succession, and
the mixture was heated under reflux on a water bath
until complete consumption of initial hydroxylamine
III (~30 min) and treated with 5 ml of water. The mix-
ture was cooled, and the precipitate was filtered off,
washed with 80% methanol, and dried under reduced
pressure. Yield 1.41 g (95%), red crystals, mp 137°C.
2008, vol. 130, p. 9099.
7. Sen’, V.D., Golubev, V.A., and Efremova, N.N., Izv.
Akad. Nauk SSSR, Ser. Khim., 1982, p. 61.
8. Kamata, K., Kuzuya, S., Uehara, K., Yamaguchi, S., and
Mizuno, N., Inorg. Chem., 2007, vol. 46, p. 3768.
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Zh. Fiz. Khim., 1977, vol. 51, p. 1881.
10. Kostrab, G., Lovič, M., Janotka, I., Bajus, M., and
Mravec, D., Appl. Catal., A, 2008, vol. 335, p. 74.
11. Wieland, H. and Rosseu, A., Ber., 1912, vol. 45, p. 494;
ibid., 1915, vol. 48, p. 1117.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 4 2013