Multicomponent synthesis of 2-alkylthio-6-amino-3,5-dicyano-1,4- dihydropyridine-4-spirocycloalkanes. Molecular and crystal structure of 6-amino-2-(2-methylbenzylthio)-3,5-dicyano-1,4-dihydropyridine-4- spirocyclopentane

Article abstract of DOI:10.1134/S1070363211040232

2-Alkylthio-6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocycloalkanes were synthesized via the reaction of cycloalkylidene malononitriles with cyanothioacetamide and alkyl halides. The structure of 6-amino-2-(2- methylbenzylthio)-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane was determined by the X-ray diffraction analysis.

Full text of DOI:10.1134/S1070363211040232

ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 4, pp. 751–755. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © V.D. Dyachenko, V.N. Nesterov, I.V. Dyachenko, 2011, published in Zhurnal Obshchei Khimii, 2011, Vol. 81, No. 4, pp. 661–665.
Multicomponent Synthesis of 2-Alkylthio-6-amino-3,5-dicyano-
1,4-dihydropyridine-4-spirocycloalkanes.
Molecular and Crystal Structure
of 6-Amino-2-(2-methylbenzylthio)-3,5-dicyano-1,4-
dihydropyridine-4-spirocyclopentane
V. D. Dyachenko, V. N. Nesterov, and I. V. Dyachenko
Taras Shevchenko Lugansk National University, ul. Oboronnaya 2, Lugansk, 91011 Ukraine
е-mail: dvd_lug@online.lg.ua
Received April 27, 2010
Abstract—2-Alkylthio-6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocycloalkanes were synthesized via the
reaction of cycloalkylidene malononitriles with cyanothioacetamide and alkyl halides. The structure of 6-
amino-2-(2-methylbenzylthio)-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane was determined by the X-
ray diffraction analysis.
DOI: 10.1134/S1070363211040232
Spiro-substituted nitrogen-containing heterocycles
can be used to treat certain pathologies of the central
nervous system [1–3], rheumatoid arthritis, and
atherosclerosis [4]. We have previously developed
methods for the synthesis of functionally substituted
1,4-dihydropyridine-4-spirocycloalkanes based on the
reaction of cycloalkylidene(cyano)thioacetamide with
malononitrile [5] or cyanothioacetamide [6], the
condensation of cyclohexylidene(cyano)thioacetamide
with 1-morpholino-1-cyclopentene [7], and the
reaction of cyclohexylidene(cyano)thioacetamide with
Meldrum’s acid [8].
with cycloalkylidene malononitriles I by Stork method
[9] to afford adducts VI, followed by the intra-
molecular cyclization to give iminopyridines VII,
which are stabilized as the corresponding amino
derivatives IVa–IVe.
The unambiguous structure of compound IVa was
established by the X-ray diffraction analysis. Figure 1
shows a general view of the molecule, the bond lengths
and angles are given in Tables 1 and 2.
In the investigated molecule the conformation of
the hydrogenated heterocyclic ring can be described as
flattened boat. The atoms N1 and C4 are displaced out
of the ring plane (the plane involves the other four
atoms with an accuracy of 0.003 Å) by –0.138 and
–0.339 Å, respectively. The heterocycle has the same
conformation in the substituted 1,4-dihydropyridine
molecules [5, 10, 11], which contain bulky substituents
or spirocyclohexane ring in the position 4. The
cyclopentane substituent has an envelope conforma-
tion: the C9 atom is displaced out of the plane of the
other atoms by 0.599 Å. The dihedral angle between
the plane and the boat bottom of the heterocycle is
94.3º. Such mutual arrangement of the rings leads to a
minimum non-valence intramolecular steric contacts
between the hydrogen atoms in cyclopentane moiety
and cyano groups. Indeed, there is only one non-valence
In this work we developed a new method of
synthesis of these compounds via a multicomponent
condensation of cycloalkylidene malononitriles I with
cyanothioacetamide II and alkyl halides III in DMF in
the presence of equimolar amount of N-methylmor-
pholine. The reaction products are 2-alkylthio-6-
amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclo-
alkanes IVa–IVe identical to those obtained previously
by the alkylation of N-methylmorpholinium 6-amino-
3,5-dicyano-1,4-dihydropyridine-4-spirocycloalkane-
2-thiolate with alkyl halides [5, 6].
The reaction scheme includes apparently the
alkylation of cyanothioacetamide II with alkyl halides
III to form enaminonitriles V. The latter are alkylated
751

752
DYACHENKO et al.
(–1 + x, 0.5 – y, –0.5 + z) [N1···N2 3.003(6), N1–H1
0.73(4), H1···N2 2.30(4) Å, angle N1–H1···N2 162(2)°]
join the molecules in the crystal into the infinite layers.
Further alkylation of compounds IVb–IVd with
allyl bromide IIIe and benzyl chloride IIIb,
respectively, in DMF in the presence of 10% aqueous
solution of KOH proceeds regioselectively at the
amino group and results in 6-allylamino-2-benzylthio-
3,5-dicyano-1,4-dihydropyridine-4-spirocyclohexane
VIII, 6-benzylamino-2-(4-bromophenylcarbamoyl-
methylthio)-3,5-dicyano-1,4-dihydropyridine-4-spiro-
cyclohexane IX, and 6-benzylamino-2-methylthio-3,5-
dicyano-1,4-dihydropyridine-4-spirocyclohexane
X
(method a). Compounds VIII–X can be obtained in
one-pot procedure by the successive treatment of the
reaction mixture with the corresponding alkyl halide
IIIb–IIIe in an alkaline medium without isolating
thioethers IV (method b).
The acylation of compounds IVb, IVc with
chloroacetyl chloride or acetyl bromide in the boiling
toluene proceeds regioselectively exclusively at the
amino group to form the corresponding N-acyl
derivative XI or XII, respectively.
General view of molecule IVа.
contact H111···C12 (2.37 Å) in the molecule, which is
less than the sum of the van der Waals radii of H and C
atoms [12]. Probably, in the almost planar fragments
N4–C6=C5–C12=N3 of the heterocycle the conjugation
leads to some shortening of the single bonds and
lengthening of the double bonds in compari-son with
the standard values [13] noted earlier [5]. The figure
shows that the planar aryl substituent is located slightly
over the heterocycle plane (torsion angles C3C2S1C13 –
93.2°, C2S1C13C14 –54.3°, and S1C13C14C15 –73.6°.
The structure of the synthesized compounds IVa–
IVe, VIII–X was confirmed by the physicochemical
1
and spectral data. A characteristic feature of the H
NMR spectra of the compounds VIII and IX is the
presence of the signals of nonequivalent protons of
SCH2-group as two doublets at δ 4.08 and 4.41 ppm
(2J 14.0 Hz) (VIII) and at δ 3.81 and 4.18 ppm
(2J 15.5 Hz) (IX). The splitting of the methylene
proton signals indicates the absence of free rotation of
substituents at the sulfur atom.
Intermolecular hydrogen bonds N4–H42···N3 (–1 – x,
1 – y, –z) [N4···N3 3.003(6), N4–H42 0.85(4), H42···N3
2.20(4) Å, angle N4–H42···N3 157(2)º] and N1–H1···N2
Table 1. Some bond lengths (d, Å) in molecule IVа
Table 2. Some bond angles (ω, deg) in molecule IVа
Angle
ω
Angle
ω
Bond
d
Bond
d
C2S1C13
C2N1C6
C3C2N1
C3C2S1
N1C2S1
C2C3C7
C2C3C4
C7C3C4
C3C4C5
C3C4C8
C5C4C8
C3C4C11
99.4(2)
121.0(3)
120.2(3)
123.8(3)
115.9(3)
118.3(3)
122.9(3)
118.7(3)
106.2(3)
109.8(3)
113.7(3)
112.1(3)
C5C4C11
C8C4C11
C6C5C12
C6C5C4
C12C5C4
N4C6C5
N4C6N1
C5C6N1
N2C7C3
N3C12C5
C14C13S1
112.3(3)
102.9(3)
116.5(3)
123.2(3)
120.2(3)
125.6(3)
115.2(3)
119.2(3)
177.1(4)
178.7(5)
113.0(3)
N1–C2
C2–S1
S1–C13
C2–C3
C3–C7
C7–N2
C3–C4
C4–C5
1.373(5)
1.768(4)
1.843(5)
1.352(5)
1.427(5)
1.149(5)
1.516(5)
1.524(5)
C4–C8
C4–C11
C5–C6
C5–C12
C12–N3
C6–N4
C6–N1
1.556(5)
1.557(5)
1.364(5)
1.415(5)
1.139(6)
1.349(5)
1.373(5)
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 4 2011

MULTICOMPONENT SYNTHESIS OF 2-ALKYLTHIO-6-AMINO-3,5-DICYANO-...
753
n
CN
S
n
CN
S
NC
CN
S
O
NCH3
I
Hlg
Z
C
N
H2N
H2N
Z
H2N
Z
NC
CN
Iа, Ib
II
IIIа_IIIe
V
VI
H3C
O
N
NCH3
O
N
H
XIII
n
NC
HN
CN
H3C
HN
CN
H3C
CN
N
H
S
Z
N
O
NH2
N
C
OH
N
N
VII
XIV
XV
O
n
CH3C
NC
HN
CN
SCH3
NC
CN
S
Br
IIIb
NC
HN
CN
H2N
N
H
Z
N
H
N
H
SCH3
H3C
O
IVa−IVe
Ph
IIIb
XII
X
Cl
IIIe
Cl
O
NC
HN
CN
S
NC
HN
CN
NC
HN
CN
S
H
N
N
H
Ph
N
H
S
Ph
N
H
Cl
O
O
Br
Ph
VIII
XI
IX
I, n = 1 (a), n = 2 (b); III, IV, Hgl = Br, Z = 2-CH3C6H4, n = 1 (a), Hgl = Cl, Z = Ph, n = 2 (b), Hgl = I, Z = H, n = 2 (c),
Hlg = Cl, Z = 4-BrC6H4NHCO, n = 2 (d), Hgl = Br, Z = CH=CH2, n = 1 (e).
1
Introduction of 3-methylpyrazol-5-one XIII into
the reaction with cyclohexylidene malononitrile Ib in
ethanol in the presence of N-methylmorpholine led
to the formation of a previously unknown 6'-amino-3'-
methyl-2'H-spiro[cyclohexane-1,4'-pyran[2,3-c]pyrazolo]-
5'-carbonitrile XIV as a result of the Michael’s
reaction, which proceeds with the cyclization of
the corresponding adduct XV. Note that in the H
NMR spectrum of compound XIV the assignment
of the NH-proton signal of pyrazole ring as belonging
to the 2H-isomer, but not to the 1H-isomer, was
carried out taking into account the X-ray diffraction
data for 4-alkyl-substituted 2H-pyrazolo[2,3-c]pyrans
[14].
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 4 2011

754
DYACHENKO et al.
solution of 3.4 g (10 mmol) of substituted 1,4-dihydro-
EXPERIMENTAL
pyridine-4-spirocyclohexane IVb in 15 ml of DMF
was added in succession 5.6 ml (10 mmol) of 10%
aqueous KOH solution and 0.85 ml (10 mmol) of allyl
bromide IIIe. The mixture was stirred for 1 h and kept
for 24 h. Then the reaction mixture was diluted with an
equal volume of water. The precipitate formed was
filtered off and washed with water, ethanol, and
hexane. Yield 2.7 g (71%), colorless needles, mp 144–
146°С (АсОН). IR spectrum, ν, cm–1: 3316 (NH),
Crystals of the compound IVa are monoclinic, at
–120°C: a 8.344(4), b 18.220(7), c 11.282 (4) Å, β
90.90(3)°, V 1715(1) Ǻ3 , dcalc 1.303 g cm–3, Z 4, space
group P21/n. Cell parameters and intensities of 3184
independent reflections were measured on a four-circle
automatic diffractometer Syntex P21 (λMoKα, graphite
monochromator, θ/2θ-scanning, θmax 26°). The struc-
ture was solved by the direct method, which revealed
all non-hydrogen atoms, and was refined in full-matrix
anisotropic approximation for the non-hydrogen atoms
using 2473 reflections with I > 3σ. All hydrogen atoms
were identified by the difference Fourier synthesis and
refined isotropically. The final values of the diver-
gence factors: R 0.076, RW 0.2139 (S 1.08). All calcula-
tions were performed by the program SHELXTL
PLUS [15] (version PC).
1
2194 (C≡N). Н NMR spectrum, δ, ppm: 1.05–1.22 m
(2Н, СН2), 1.38–1.66 m (6Н, 3СН2), 1.83–2.04 m (2Н,
СН2), 2.27–2.43 m (2Н, NCH2), 4.08 d and 4.41 d (1Н,
2
3
SCH2, J 14.0 Hz), 5.47 d (1Н, =СН2, Jtrans 17.0 Hz),
3
4.41 d (1Н, =СН2, Jcis 10.0 Hz), 5.47–5.54 m (1Н,
СН=), 7.19 t (2Н, Ph, J 7.5 Hz), 7.25 t (1Н, Ph, J
8.0 Hz), 7.31 d (2Н, Ph, J 7.5 Hz), 7.94 br.s (1Н,
3
3
3
NH), 8.8 br.s (1H, NH). Mass spectrum (EI, 70 eV),
m/z (Irel, %): 377 (100) [M + 1]+. Found, %: С 70.09;
Н 6.31; N 14.75. C22H24N4S. Calculated, %: С 70.18;
Н 6.43; N 14.88.
1
The H NMR spectra were recorded on a Gemini-
200 (199.975 MHz) (IVa–IVe, XI, XII), Bruker AM-
300 (300.13 MHz) (XIV), and Bruker DR-500 spectro-
meters (500.13 MHz) (VIII–X) in DMSO-d6, internal
reference TMS. The IR spectra were recorded on an
IKS-40 instrument in mineral oil. The GLC spectra were
recorded on instruments Grommass GC/MC-Hewlett-
Packard 5890/5972 (column HP-5 MS, 70 eV) in me-
thylene chloride solution (VIII, IX) and Kratos MS-
890 (70 eV) with the direct injection of the substance
into the ion source (XIV). The melting points were deter-
mined on a Koeffler block. The reaction progress was
monitored by TLC (Silufol UV-254, acetone–hexane,
3:5, detecting with iodine vapor and UV irradiation).
6-Benzylamino-2-(4-bromophenylcarbomoyl-
methylthio)-3,5-dicyano-1,4-dihydropyridine-4-spiro-
cyclohexane (ІХ) was obtained similarly from thio-
ether IVd and benzyl chloride IIIb. Yield 4.17 g
(76%), yellow powder, mp 140–142°С (АсОН). IR
spectrum, ν, cm–1: 3328 (NH), 2184 (C≡N), 1670
1
(СОNН). Н NMR spectrum, δ, ppm: 1.02–1.12 m
(4Н, 2СН2), 1.63–1.84 m (4Н, 2СН2), 2.13–2.25 m
2
(2Н, СН2), 2.91 d and 3.02 d (1Н, NCH2, J 14.1 Hz),
2
3.81 d and 4.18 d (1Н, SCH2, J 13.5 Hz), 7.03 t (2Н,
3
3
Ph, J 7.0 Hz), 7.11 t (1Н, Ph, J 6.5 Hz), 7.19 d (2Н,
Ph, 3J 7.0 Hz), 7.48 d and 7.58 d (2Н, С6Н4, 3J 8.0 Hz),
7.99 br.s (1Н, NH), 8.46 br.s (1H, NH), 10.19 br.s (1Н,
NНСО). Mass spectrum (EI, 70 eV), m/z (Irel, %): 549
(100) [M + 1]+. Found, %: С 58.97; Н 4.68; N 12.71.
C27H26BrN5OS. Calculated, %: С 59.12; Н 4.78;
N 12.77.
General procedure for the synthesis of 2-
alkylthio-6-amino-3,5-dicyano-1,4-dihydropyridine-
4-spirocycloalkanes (IVa–IVe). To a stirred solution
of 1 g (10 mmol) of cyanothioacetamide II in 15 ml of
DMF were added 10 mmol of alkyl halide III and
1.1 ml (10 mmol) of N-methylmorpholine. After
stirring for 5 min, to the reaction mixture was added
10 mmol of cycloalkylidene malononitrile I. The
mixture was stirred for 1 h and then kept for 24 h at
20°C. Then the mixture was diluted with an equal
volume of water. The precipitate formed was filtered
off, washed with water, ethanol, and hexane.
Compounds IVa–IVd were crystallized from EtOH.
6-Benzylamino-2-methylthio-3,5-dicyano-1,4-di-
hydropyridine-4-spirocyclohexane (Х) was obtained
similarly from thioether IVc and benzyl chloride III.
Yield 2.35 g (67%), yellow crystals, mp 227–228°С
(EtОН). IR spectrum, ν, cm–1: 3322 (NH), 2199
1
(C≡N). Н NMR spectrum, δ, ppm: 1.14–1.38 m (3Н,
1
The H NMR spectra, melting points, and chromato-
cyclohexane), 1.51–1.73 m (5Н, cyclohexane), 1.99–
2.17 m (2Н, cyclohexane), 2.45 s (3Н, СН3), 2.84 d
graphic data were identical to those reported pre-
viously [5, 6]. Yields 63 (IVa), 74 (IVb), 69 (IVc), 79
(IVd) and 71% (IVe).
2
and 3.04 d (1Н, NCH2, J 16.0 Hz), 7.12 d (2Н, Ph, 3J
8.0 Hz), 7.29–7.33 m (3Н, Ph), 7.38 br.s (1Н, NH), 8.45
br.s (1H, NH). Found, %: С 68.44; Н 6.29; N 15.80.
C20H22N4S. Calculated, %: С 68.54; Н 6.35; N 15.99.
6-Allylamino-2-benzylthio-3,5-dicyano-1,4-dihyd-
ropyridine-4-spirocyclohexane (VIII). a. To a stirred
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MULTICOMPONENT SYNTHESIS OF 2-ALKYLTHIO-6-AMINO-3,5-DICYANO-...
755
Synthesis of compound VIII. b. To a stirred
solution of 1 g (10 mmol) of cyanothioacetamide II in
15 ml of DMF was added 1.15 ml (10 mmol) of benzyl
chloride ІІІb and 1.1 ml (10 mmol) of N-methylmor-
pholine. The reaction mixture was stirred for 5 min.
Then 1.5 g (10 mmol) of cyclohexylidene malononitrile
Ib was added, and the mixture was stirred for 1 h and
kept for 24 h at 20°C. Then to the stirred mixture was
added 5.6 ml (10 mmol) of 10% aqueous KOH solu-
tion and 0.85 ml (10 mmol) of allyl bromide ІІІe. The reac-
tion mixture was stirred for 1 h and kept for 24 h. Then
the mixture was diluted with an equal volume of water.
The precipitate formed was filtered off and washed
with water, ethanol, and hexane. Yield 2.9 g (77%).
mixture was stirred for 1 h and kept for 24 h. The
precipitate formed was filtered off and washed with
ethanol and hexane. Yield 1.7 g (69%), colorless
crystals, mp 135–137ºС (EtOH). IR spectrum, ν, cm–1:
3280, 3349, 3412 (NH), 2188 (C≡N), 1648 (δNН2). 1Н
NMR spectrum, δ, ppm: 1.15–2.14 m (10Н, 5СН2),
2.31 s (3Н, СН3), 6.34 br.s (2Н, NH2), 11.88 br.s (1H,
NH). Mass spectrum (EI, 70 eV), m/z (Irel, %): 245 (6)
[M + 1]+, 244 (25) [M]+, 215 (9), 201 (100) [M – Н2О –
НСN]+, 188 (29), 146 (11), 123 (8), 111 (15), 91 (9),
78 (13), 66 (14), 55 (24), 39 (40). Found, %: С 63.81;
Н 6.48; N 22.87. C13H16N4O. Calculated, %: С 63.92;
Н 6.60; N 22.93.
REFERENCES
Synthesis of compound IX by the method b is
similar using the appropriate alkyl halides ІІІb and
IIId. Yield 4.6 g (84%).
1. Guillaumet, G., J. Pharm. Belg., 1994, vol. 49, no. 3,
p. 216.
2. European Patent Appl. EP 546.358, 1992, C. A., 1994,
vol. 120, no. 13, 164006d.
3. USA Patent no. 6686361, 2004, Ref. Zh. Khim., 2004,
19О101P.
Synthesis of compound X by the method b is
similar using the appropriate alkyl halides ІІІb and
IIIc. Yield 2.4 g (69%).
4. USA Patent no. 5962462, 1999, Ref. Zh. Khim., 2000,
19О91P.
5. Dyachenko, V.D., Krivokolysko, S.G., Nesterov, V.N.,
Struchkov, Yu.T., and Litvinov, V.P., Izv. Akad. Nauk,
Ser. Khim., 1996, no. 10, p. 2535.
6. Dyachenko, V.D., Krivokolysko, S.G., and Litvinov, V.P.,
Izv. Akad. Nauk, Ser. Khim., 1997, no. 10, p. 1849.
7. Dyachenko, A.D., Desenko, S.M., and Dyachenko, V.D.,
N-(2-Benzylthio-3,5-dicyano-1,4-dihydropyridine-
4-spirocyclohexan-6-yl)-2-chloroacetamide (ХІ). A
mixture of 3.4 g (10 mmol) of compound IVb and
0.8 ml (10 mmol) of chloroacetyl chloride in 20 ml of
toluene was refluxed for 1 h and kept for 24 h. The
formed colorless crystals were filtered off and washed
with hexane. Yield 2.8 g (68%), mp 121–122°С. IR spec-
trum, ν, cm–1: 3312 (NH), 2195 (C≡N), 1671 (СОNН).
1Н NMR spectrum, δ, ppm: 1.12–1.92 m (10Н, 5СН2),
4.19 s (2Н, SСН2), 4.22 s (2Н, ClСН2), 7.14–7.43 m
(5Н, Ph), 10.5 br.s (1Н, NH), 10.56 br.s (1H, NHСО).
Found, %: С 60.95; Н 5.02; N 13.44. C21H21ClN4OS.
Calculated, %: С 61.08; Н 5.13; N 13.57.
Khim. Geterotsikl. Soedin., 2002, no. 6, p. 845.
8. Dyachenko, A.D., Desenko, S.M., and Dyachenko, V.D.,
Vestn. Khar’kovsk. Univ., Khimiya, 2002, no. 549,
no. 8(31), p. 51.
9. Stork, G., Brizzolara, A., Landesman, H., Szmuszko-
vicz, E.J., and Terrel, R., J. Am. Chem. Soc., 1963,
vol. 85, no. 2, p. 207.
10. Nesterov, V.N., Shklover, V.E., Struchkov, Yu.T.,
Sharanin, Yu.A., Sherstopalov, A.M., and Rodinov-
skaya, L.A., Acta Crystallogr. C, 1985, vol. 41, p. 1191.
11. Dyachenko, V.D., Krivokolysko, S.G., Nesterov, V.N.,
and Litvinov, V.P., Khim. Geterotsikl. Soedin., 1996,
p. 1243.
N-(2-Methylthio-3,5-dicyano-1,4-dihydropyridine-
4-spirocyclohexan-6-yl)acetamide (ХІІ) was obtained
similarly from thioether IVc and acetyl bromide. Yield
2.2 g (73%), colorless crystals, mp 159–161ºС. IR
spectrum, ν, cm–1: 3334 (NH), 2288 (C≡N), 1677
1
(СОNН). Н NMR spectrum, δ, ppm: 1.22–1.79 m
(10Н, 5СН2), 2.05 s (3Н, СН3СО), 2.48 s (3Н, SСН3),
10.18 br.s (1Н, NH), 10.34 br.s (1H, NHСО). Found, %:
С 59.42; Н 5.89; N 18.41. C15H18N4OS. Calculated, %:
С 59.58; Н 6.00; N 18.53.
12. Rowland, R.S. and Taylor, R., J. Phys. Chem., 1996,
vol. 100, p. 7384.
13. Allen, F.H., Kennard, O., Watson, D.G., Brammer, L.,
Orpen, A.G., and Taylor, R., J. Chem. Soc., Perkin
Trans. 2, 1987, no. 12, p. S1.
6'-Amino-3'-methylthio-2'Н-spiro[cyclohexane-
1,4'-pyrano[2,3-c]pyrazol]-5'-carbonitrile (XIV). To
a stirred solution of 1.5 g (10 mmol) of cyclo-
hexylidene malononitrile Ib in 15 ml of ethanol was
added 0.98 g (10 mmol) of 3-methylpyrazol-5-one XII
and 3 drops of N-methylmorpholine. The reaction
14. Dyachenko, V.D. and Rusanov, E.B., Khim. Geterotsikl.
Soedin., 2004, no. 2, p. 270.
15. Robinson, W. and Sheldrick, G.M., in Crystallographic
Computing – Techniques and New Technologies,
Oxford: Oxford Univ. Press, 1988, p. 366.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 4 2011