Synthesis of nitroso- and aminopyrazoles containing an adamantane fragment

Full text of DOI:10.1134/S1070428010040342

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2010, Vol. 46, No. 4, pp. 608–609. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © S.A. Kon’kov, I.K. Moiseev, 2010, published in Zhurnal Organicheskoi Khimii, 2010, Vol. 46, No. 4, pp. 614–615.
SHORT
COMMUNICATIONS
Synthesis of Nitroso- and Aminopyrazoles Containing
an Adamantane Fragment
S. A. Kon’kov and I. K. Moiseev
Samara State Technical University, ul. Molodogvardeiskaya 244, Samara, 443100 Russia
e-mail: ikmoiseev@mail.ru
Received June 25, 2009
DOI: 10.1134/S1070428010040342
In the recent years, chemistry of nitrogen-contain-
ing heterocyclic compounds attracts researchers’ atten-
tion due to their practical importance and biological
activity. On the other hand, a number of effective
medicines with different kinds of activity contain
an adamantane fragment as pharmacophoric group.
The synthesis of pyrazoles having an adamantane frag-
ment was described in [1–3]. The goal of the present
work was to synthesize adamantane-containing
nitroso- and aminopyrazoles.
cooling over a period of 15 min to a solution of 1.5 g
(6.8 mmol) of diketone I in 12 ml of glacial acetic
acid, maintaining the temperature below 15°C. The
mixture was then stirred for 3 h at 25°C, poured into
200 ml of ice water, and extracted with chloroform
(3×100 ml). The organic extracts were combined and
dried over Na2SO4, the solvent was distilled off, and
the residue was recrystallized from petroleum ether
(bp 40–70°C). Yield 1.1 g (65%), yellow crystals,
mp 138–141°C. IR spectrum, ν, cm–1: 3356 (OH);
2904, 2849 (C−HAd); 1713, 1674 (C=O); 987 (N−O).
1H NMR spectrum, δ, ppm: 1.67–1.98 m (15H, Ad),
2.01 s (3H, CH3), 12.80 s (1H, OH). Mass spectrum,
m/z (Irel, %): 249 (6) [M]+, 163 (3.5), 135 (100), 107
(19.3), 93 (49.8), 79 (31.6), 67 (13.4), 55 (9), 43 (28.5).
Found, %: C 67.51; H 7.75; N 5.71. C14H19NO3. Cal-
culated, %: C 67.47; N 7.63; N 5.62. M 249.31.
For this purpose, 1-(1-adamantyl)butane-1,3-dione
(I) was treated with sodium nitrite in acetic acid to
obtain 1-(1-adamantyl)butane-1,2,3-trione 2-oxime
(II). Oxime II reacted with an equimolar amount of
hydrazine at room temperature to give 3-(1-adaman-
tyl)-5-methyl-4-nitroso-1H-pyrazole (III). By heating
oxime II with excess hydrazine we obtained 3-(1-ada-
mantyl)-5-methyl-1H-pyrazol-4-amine (IV).
3-(1-Adamantyl)-5-methyl-4-nitroso-1H-pyra-
zole (III). Hydrazine, 0.04 g (0.8 mmol), was added
dropwise on cooling to a solution of 0.2 g (0.8 mmol)
of compound II in 5 ml of ethanol, and the mixture
was kept for 2 h at room temperature; the solution
turned dark green. The green precipitate was filtered
1-(1-Adamantyl)butane-1,3-dione (I) was synthe-
sized according to the procedure described in [4].
1-(1-Adamantyl)butane-1,2,3-trione 2-oxime (II).
A solution of 0.94 g (13.6 mmol) of sodium nitrite in
2 ml of water was added dropwise under stirring and
NO
NH2NH2
Me
N
NOH
NH
III
NaNO2, AcOH
Me
Me
O
O
O
O
NH2
NH2NH2 (excess), Δ
I
II
Me
N
NH
IV
608

SYNTHESIS OF NITROSO- AND AMINOPYRAZOLES
609
off and recrystallized from ethanol. Yield 0.15 g
(77%), light green crystals, mp 237–238°C. IR spec-
trum, ν, cm–1: 3202 (N−H); 2908, 2851 (C−HAd); 1578
(N=O). 1H NMR spectrum, δ, ppm: 1.70–2.10 m (15H,
Ad), 2.28 s (3H, CH3), 13.10 s (1H, NH). Mass spec-
trum, m/z (Irel, %): 245 (59.6) [M]+, 228 (40.7), 135
(100), 107 (19.3), 93 (49.8), 79 (31.6), 67 (13.4), 55
(9), 43 (28.5). Found, %: C 67.51; H 7.75; N 5.71.
C14H19N3O. Calculated, %: C 67.47; H 7.63; N 5.62.
M 245.32.
The IR spectra were recorded on a Shimadzu FTIR-
8400S spectrometer from samples pelleted with KBr.
The H NMR spectra were measured on a Bruker AM
1
300 instrument (300 MHz) using DMSO-d6 as solvent
and tetramethylsilane as internal reference. The mass
spectra were obtained on a Finnigan Trace DCQ mass
spectrometer. The elemental compositions were deter-
mined on a TermoFinnigan Flash1112 NCH analyzer.
The purity of the isolated compounds was checked by
TLC on Silufol plates using carbon tetrachloride–
acetone (10:1, by volume) as eluent.
3-(1-Adamantyl)-5-methyl-1H-pyrazol-4-amine
(IV). Hydrazine, 0.16 g (3.2 mmol), was added drop-
wise on cooling to a solution of 0.2 g (0.8 mmol) of
compound II in 5 ml of ethanol, and the mixture was
heated for 3 h under reflux; the mixture turned first
dark green and then became colorless. It was cooled
and diluted with 20 ml of water, and the precipitate
was filtered off, dried, and recrystallized from ethanol.
Yield 0.10 g (54%), colorless crystals, mp 242–245°C.
IR spectrum, ν, cm–1: 3221 (NH, NH2); 2901, 2847
This study was performed under financial support
by the Ministry of Education and Science of the
Russian Federation (federal target program “Scientific
and Scientific–Pedagogical Personnel of Innovation
Russia,” project no. NK-262P/5).
REFERENCES
1. Stetter, H. and Rauscher, E., Chem. Ber., 1960, vol. 93,
1
(C−HAd). H NMR spectrum, δ, ppm: 1.25–2.02 m
p. 2054.
(15H, Ad), 2.10 s (3H, CH3), 11.08 br.s (3H, NH,
NH2). Mass spectrum, m/z (Irel, %): 231 (100) [M]+,
216 (11), 174 (40.3), 157 (11.1), 135 (12.4), 110 (6.5),
93 (9.6), 79 (11), 41 (16.1). Found, %: C 72.50;
H 8.91; N 18.01. C14H21N3. Calculated, %: C 72.73;
H 9.09; N 18.18. M 231.34.
2. Stepanov, F.N., Sidorova, L.I., and Dovgan’, N.A.,
Zh. Org. Khim., 1972, vol. 8, p. 1834.
3. Bormasheva, K.M., Nechaeva, O.V., and Moiseev, I.K.,
Russ. J. Org. Chem., 2008, vol. 44, p. 1760.
4. Kon’kov, S.A. and Moiseev, I.K., Bashkir. Khim. Zh.,
2008, vol. 15, p. 106.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 4 2010