ISSN 1070-4280, Russian Journal of Organic Chemistry, 2008, Vol. 44, No. 9, pp. 1406–1407. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © K.V. Lipin, A.V. Eremkin, O.V. Ershov, Ya.S. Kayukov, O.E. Nasakin, 2008, published in Zhurnal Organicheskoi Khimii, 2008,
Vol. 44, No. 9, pp. 1423–1424.
SHORT
COMMUNICATIONS
Reaction of 5,5-Dialkyl-2-halo-6-hydroxy-5,6-dihydro-
1H-pyridine-3,4,4-tricarbonitriles with Aldehyde Oximes
K. V. Lipin, A. V. Eremkin, O. V. Ershov, Ya. S. Kayukov, and O. E. Nasakin
I.N. Ul’yanov Chuvash State University, Moskovskii pr. 15, Cheboksary, 428015 Russia
e-mail: oleg.ershov@mail.ru
Received February 11, 2008
DOI: 10.1134/S1070428008090315
Studies on new methods for modification of hydro-
genated pyridines having unusual functional environ-
ment attract much interest from the viewpoint of devel-
opment of the chemistry of heterocyclic compounds. In
the recent time, the number of publications concerning
reactions of polycyano compounds with ketone and
aldehyde oximes has increased considerably [1].
2220 cm–1 was assigned to the conjugated cyano
group, and medium-intensity band at 2260 cm–1, to
the nonconjugated cyano group; stretching vibrations
of the N–H bonds were observed in the region 3200–
3300 cm–1. Compounds IIa–IIc displayed in the
1H NMR spectra a doublet at δ 9.90–9.54 ppm from
the NH proton in the tetrahydropyridine ring, two
singlets in the region δ 7.95–7.72 ppm from the amide
NH2 group, and a quartet at δ 7.04–7.01 ppm (IIa, IIb)
or a singlet at δ 6.70 ppm (IIc) from the N=CH proton;
in addition, signals from alkyl and furyl (IIc) protons
were present.
While studying reactions of 5,5-dialkyl-2-halo-6-
hydroxy-5,6-dihydro-1H-pyridine-3,4,4-tricarbonitriles
Ia–Ic [2] with aldehyde oximes we isolated the corre-
sponding 2-alkylideneaminooxy-3,3-dialkyl-4,5-dicy-
ano-6-halo-1,2,3,4-tetrahydropyridine-4-carboxamides
IIa–IIc in 90–95% yield. The reactions occurred under
mild conditions (room temperature), and no catalyst
was necessary; either anhydrous aldehyde oxime or an-
hydrous acetonitrile can be used as solvent. We believe
that the electrophilic carbon atom in the axial cyano
group on C4 favors replacement of the hydroxy group
according to “push–pull” mechanism; as a result, the
cyano group is converted into carbamoyl.
6-Bromo-4,5-dicyano-2-ethylideneaminooxy-3,3-
dimethyl-1,2,3,4-tetrahydropyridine-4-carboxamide
(IIa). Compound Ib, 0.24 g (1 mmol), was dissolved
in 1 ml of acetaldehyde oxime, the solution was kept
for 36 h, and the precipitate was filtered off and
washed with acetone. Yield 0.31 g (90%), mp 200–
202°C. IR spectrum, ν, cm–1: 3200 (N–H); 2220, 2260
1
(C≡N); 1690 (C=O); 1660 (C=N). H NMR spectrum,
δ, ppm: 9.54 d (1H, 1-H), 7.85 s (1H, CONH2), 7.72 s
(1H, CONH2), 7.01 q (1H, N=CH), 4.82 d (1H, 2-H),
1.85 d (3H, N=CHCH3), 1.35 s and 0.95 s (3H each,
3-Me). Found, %: C 42.31; H 4.18; N 20.53.
C12H14BrN5O2. Calculated, %: C 42.37; H 4.15;
N 20.59.
The structure of compounds IIa–IIc was deter-
mined on the basis of their IR, H NMR, and mass
spectra. The IR spectra of IIa–IIc contained strong
absorption bands in the region 1680–1700 cm–1 due to
stretching vibrations of the carbonyl group and C=N
bond in the oxime fragment; a strong band at
1
6-Bromo-4,5-dicyano-3,3-diethyl-2-ethylidene-
aminooxy-1,2,3,4-tetrahydropyridine-4-carbox-
amide (IIb) was synthesized in a similar way. Yield
0.34 g (92%), mp 197–198°C. IR spectrum, ν, cm–1:
3200 (N–H); 2220, 2260 (C≡N); 1700 (C=O); 1690
NC CN
NC CONH2
CN
R2
R1
R2
R1
CN
Hlg
R2CH=NOH
R2
N
HO
N
H
O
N
Hlg
1
H
(C=N). H NMR spectrum, δ, ppm: 9.61 d (1H, 1-H),
Ia–Ic
IIa–IIc
7.95 s (1H, CONH2), 7.88 s (1H, CONH2), 7.04 q (1H,
N=CH), 4.8 d (1H, 2-H), 1.95 m (2H, CH2CH3), 1.85 d
(3H, N=CHCH3), 1.47 m and 1.35 m (1H each,
Hlg = Br, R1 = R2 = Me (a); Hlg = Br, R1 = Et, R2 = Me (b);
Hlg = Cl, R1 = Et, R2 = 2-furyl (c).
1406
Lipin
