PREPARATION OF -METHYL-SUBSTITUTED DIALKYL KETONES
1185
1
0 mmol of ester Ia, b in 1 ml of ethanol. The solu-
6 ml of ethanol. After precipitation of pyrazolone III
the reaction mixture was left standing at room
temperature. The mixture self-heated and foaming
was observed. In several days from the viscous dark-
cherry-colored reaction mixture separated a colorless
precipitate that was filtered off. The precipitate turned
red on filter. It was washed with ice water, dried in
air and recrystallized from ethanol. We obtained
3.5 g (72%) of rubazonic acid IV as dark-red needles,
mp 295 297 C (publ. mp 295 297 C [6]). Mass
tion was left for 24 h at room temperature. The
separated precipitate was filtered off and washed with
ethanol. We obtained 0.95 1.1 g (67 78%) of com-
pound III as orange needles or red powder of small
crystals, subl. > 140 C, mp 180 184 C (in a sealed
1
capillary). IR spectrum, , cm : 3300 br, 1740,
1
1
710, 1610. H NMR spectrum, , ppm: 2.20 s (3H,
Me), 4.35 s (3H, MeON), 8.68 br.s (1H, NH).
Found, %: C 42.44; H 4.95; N 29.84. C H N O .
5
7
3
2
Calculated, %: C 42.55; H 5.00; N 29.77. Under the
other conditions (e.g., at boiling) sometimes formed
up to 30% of another isomer that was detected in
spectrum, m/z (I ): 207 M (100%). Found, %: C
0
rel
45.94; H 4.60; N 33.77. C H N O . Calculated, %:
8
9
5
2
C 46.37; H 4.38; N 33.80.
1
the H NMR spectrum by the signals at 2.30 and
1H NMR spectra were registered on spectrometer
4
.30 ppm.
Bruker AC-200 (200 MHz) in CDCl . IR spectra
3
Dimethyl
2,2 -di(methoxyimino)-3,3 -azinodi-
were recorded on IKS-29 spectrophotometer from
mulls in mineral oil. Mass spectrum was measured
on Kratos MS-30 instrument (ionizing electrons
energy 70 eV).
butanoate (IIa). A mixture of 10 mmol of ester Ia,
mmol of hydrazine hydrate, and 2 ml of ethanol
5
was left at room temperature for 24 h. The separated
precipitate was filtered off and washed with ethanol.
We obtained 0.35 g (25%) of pyrazolinone III. The
filtrate was evaporated, the residue was recrystallized
from hexane. We obtained 0.88 g (56%) of com-
pound IIa as yellow crystals, mp 120 122 C. IR
The authors are grateful to N. A. Klyuev (Sever-
tsov Institute of Environmental and Evolution
Problems, Russian Academy of Sciences) for measur-
ing the mass spectrum.
1
1
spectrum, , cm : 1755, 1615. H NMR spectrum,
ppm: 2.05 s (3H, MeC), 3.85 s (3H, MeOCO),
REFERENCES
,
4
1
.05 s (3H, MeON). Found, %: C 45.91; H 5.70; N
7.64. C H N O . Calculated, %: C 45.86; H 5.77;
1. German Patent 2805590, 1977; Chem. Abstr., 1979,
vol. 90, 6410p.
2. Europe Patent 387499, 1989. Chem. Abstr., 1991,
vol. 114, 163754k.
1
2
18
4
6
N 17.83.
Diethyl 2,2 -di(methoxyimino)-3,3 -azinodi-
butanoate (IIb) was prepared similarly to compound
IIa. Yield 0.82 g (48%), orange flakes, mp 114
3
. Russian Patent 2147021, 1998. Byull. Izobr., 2000,
no. 9.
1
1
4. Zakharychev, V.V., Golubtsova, M.D., and Kovalen-
ko, L.V., Izv. Akad. Nauk, Ser. Khim., 1999, no. 3,
pp. 499 504.
1
14.5 C. IR spectrum, , cm : 1755, 1605. H NMR
spectrum, , ppm: 1.35 t (3H, MeCH ), 2.05 s (3H,
MeC), 4.05 s (3H, MeON), 4.30 q (2H, MeCH ).
Found, %: C 49.20; H 6.47; N 16.49. C H N O .
Calculated, %: C 49.12; H 6.48; N 16.37.
2
2
5
. Zakharychev, V.V. and Kovalenko, L.V., Zh. Org.
Khim., 2000, vol. 36, no. 6, pp. 948 949.
. Metwally, S.A., Youness, M.I., and El-Zohry, M.F.,
Indian J. Chem., Sect. B, 1985, vol. 24B, no. 8,
pp. 870 872.
1
4
22
4
6
6
4-(5-Hydroxy-3-methyl-1H-pyrazol-4-ylimino)-5-
methyl-2,4-dihydropyrazolone (IV). To 0.141 mol
of hydrazine hydrate at stirring and cooling with ice
bath was added dropwise 0.047 mol of ester IIb in
7. Ruccia, M., Ann. Chim. (Rome), 1959, vol. 49.
pp. 720 730; Chem. Abstr., 1961, vol. 53, 21892i.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 37 No. 8 2001