2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: I. Synthesis of 2-[5-amino-2-aryl-2-chloro-4-cyanofuran-3(2H)-ylidene]-propanedinitriles by reaction of potassium 2-aroyl-1,1,3,3-tetracyanopropenides with concentrated hydrochloric acid

Article abstract of DOI:10.1134/S1070428011030134

Potassium 2-aroyl-1,1,3,3-tetracyanopropenides reacted with concentrated hydrochloric acid to give the corresponding 2-[5-amino-2-aryl-2-chloro-4- cyanofuran-3(2H)-ylidene]propanedinitriles.

Full text of DOI:10.1134/S1070428011030134

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 3, pp. 405–407. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © S.V. Karpov, Ya.S. Kayukov, I.N. Bardasov, O.V. Kayukova, O.V. Ershov, O.E. Nasakin, 2011, published in Zhurnal Organicheskoi
Khimii, 2011, Vol. 47, No. 3, pp. 412–414.
2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides: I. Synthesis
of 2-[5-Amino-2-aryl-2-chloro-4-cyanofuran-3(2H)-ylidene]-
propanedinitriles by Reaction of Potassium 2-Aroyl-1,1,3,3-tetra-
cyanopropenides with Concentrated Hydrochloric Acid
S. V. Karpov, Ya. S. Kayukov, I. N. Bardasov, O. V. Kayukova,
O. V. Ershov, and O. E. Nasakin
I.N. Ul’yanov Chuvash State University, Moskovskii pr. 15, Cheboksary, 428015 Russia
e-mail: serg31.chem@mail.ru
Received January 26, 2010
Abstract—Potassium 2-aroyl-1,1,3,3-tetracyanopropenides reacted with concentrated hydrochloric acid to give
the corresponding 2-[5-amino-2-aryl-2-chloro-4-cyanofuran-3(2H)-ylidene]propanedinitriles.
DOI: 10.1134/S1070428011030134
Polycyano-substituted propenides are known as
precursors of six-membered heterocycles [1–4]. A con-
venient procedure for the synthesis of polycyanopro-
penides is based on opening of the three-membered
ring in polycyanocyclopropanes [5]. We previously
described the synthesis of 2-aroyl-1,1,3,3-tetracyano-
propenides II via reaction of tetracyanocyclopropyl
ketones I with bases. Compounds II attract interest
taking into account that the presence of an aroyl group
in the 2-position makes it possible to convert them into
five-membered heterocycles [5]. We have improved
the procedures for the synthesis, isolation, and puri-
fication of potassium 2-aroyl-1,1,3,3-tetracyanopro-
penides II, so that the latter have become accessible
reagents for further studies.
The present communication opens a series of pub-
lications on reactions of propenides II with nucleo-
philes under various conditions. Here, we report on the
reaction of propenides IIa–IId with hydrochloric acid
as acid catalyst and source of nucleophilic chloride
ions. Propenides II may be regarded as conjugate
anions of strong acids; therefore, their protonation is
possible only by the action of strong mineral acids.
Proton addition to anions II having delocalized nega-
tive charge could give rise to tautomeric structures,
nitrile and ketene imine, where nucleophilic attack is
Scheme 1.
CN
O
CN
OH
CN
CN
NC
CN
CN
CN
H+
NC
Cl
AcOK
HCl
R
CN
R
CN
R
K+
–AcOH
CN
NH2
NC
CN
NC
O
O
R
Ia–Id
IIa–IId
A
IIIa–IIId
R
O
O
CN
O
CN
CN
H+
HCl
NC
CN
Cl
R
CN
R
·
IIa–IId
NH
NC
CN
NC
H2N
N
IV
R = Ph (a), 4-BrC6H4 (b), 4-MeOC6H4 (c), 3-O2NC6H4 (d).
405

KARPOV et al.
406
Scheme 2.
NH
OH
CN
CN
CN
B
O
H+
HCl
Cl–
R
R
IIa–IId
A
IIIa–IIId
CN
Cl
–KCl
Cl
NC
NC
CN
C
likely to be directed at the cyano groups with sub-
sequent closure of pyridine ring (structure IV). Alter-
native protonation at the carbonyl oxygen atom should
yield zwitterionic species A which should undergo nu-
cleophilic attack at the carbonyl carbon atom, favoring
formation of five-membered heteroring (Scheme 1).
nitrile by reaction of oxalyl chloride with N-methyl-
N-phenylcyanoacetamide.
Thus we have proposed a novel synthetic approach
to functionally substituted furan derivatives on the
basis of the reaction of potassium 2-aroyl-1,1,3,3-tetra-
cyanopropenides II with concentrated hydrochloric
acid; the proposed procedure is advantageous due to
accessibility of the initial reactants and high yield.
We found that treatment of compounds IIa–IId
with concentrated hydrochloric acid leads to the
formation of 2-[5-amino-2-aryl-2-chloro-4-cyano-
furan-3(2H)-ylidene]propanedinitriles IIIa–IIId in 68–
72% yield (Scheme 1). A probable reaction mechanism
involves initial addition of proton to the carbonyl oxy-
gen atom with formation of zwitterion A which under-
goes nucleophilic attack by chloride ion to give chloro-
hydrin B. Next follows heterocyclization to afford
intermediate furan derivative C, and protonation of the
latter in the presence of concentrated hydrochloric acid
yields final compounds III (Scheme 2).
EXPERIMENTAL
The progress of reactions and the purity of products
were monitored by thin-layer chromatography on
Silufol UV-254 plates; spots were detected by UV
irradiation, treatment with iodine vapor, or thermal
treatment. The IR spectra were recorded from samples
dispersed in mineral oil on an FSM-1202 spectrometer
1
with Fourier transform. The H and 13C NMR spectra
were measured on a Bruker DRX-500 spectrometer at
500.13 (1H) and 126.13 MHz (13C) using DMSO-d6 as
solvent and tetramethylsilane as internal reference. The
mass spectra (electron impact, 70 eV) were obtained
on a Shimadzu GCMS-QP2010S DI instrument.
The structure of compounds IIIa–IIId was deter-
mined on the basis of their 1H and 13C NMR, IR, and
mass spectra. Unlike alternative pyridine structure IV,
1
compounds IIIa–IIId displayed in the H NMR spec-
tra a downfield signal at δ 10.5–11.0 ppm from protons
in the amino group [5]; the corresponding signal of
α-aminopyridines is located at δ 6–8 ppm. According
to the 13C NMR data, molecule IIIa contains three
cyano groups (δC 110.47, 112.44, 113.13 ppm) [6]
rather than two in compounds like IV. In addition,
a signal at δC 70 ppm was present in the 13C NMR
spectrum of IIIa due to the central carbon atom in the
dicyanomethylidene fragment. The IR spectra of IIIa–
IIId did not contradict the assumed structure: the
double carbon–carbon bond gave rise to absorption
band at 1665–1685 cm–1.
Potassium 2-benzoyl-1,1,3,3-tetracyanoprop-2-
en-1-ide (IIa). Substituted cyclopropane Ia, 2.46 g
(0.01 mol), was dissolved in 10 ml of acetonitrile, and
1.0 g (0.01 mol) of potassium acetate and 0.5 ml of
water were added under stirring. The mixture was
stirred for 30 min at room temperature (TLC), the
solvent was distilled off under reduced pressure, the
residue was ground with 20 ml of benzene, and the
precipitate was filtered off, washed with benzene,
dried in air, and recrystallized from 5 ml of a 0.05 M
aqueous solution of KCl. Yield 2.3 g (81%), bright
yellow needles, mp. 228–229°C (decomp.). IR spec-
trum, ν, cm–1: 2205 (C≡N), 1655 (C=O).
Relatively few furan derivatives with analogous
substituents have been reported. At present, substituted
2,2-dichloro-5-aminodihydrofurans are available via
reaction of oxalyl chloride with N,N-dialkyl(aryl)acet-
amides [7], methyl 3-(dimethylamino)propynoate [8],
or N,N-diisopropylcubanecarboxamide [9]. Speziale
et al. [10] described the synthesis of 5,5-dichloro-2-
[methyl(phenyl)amino]-4-oxotetrahydrofuran-3-carbo-
Compounds IIb–IId were synthesized in a similar
way from substituted cyclopropanes Ib–Id.
Potassium 2-(4-bromobenzoyl)-1,1,3,3-tetracy-
anoprop-2-en-1-ide (IIb). Yield 62%, mp 221–222°C
(decomp.). IR spectrum, ν, cm–1: 2205 (C≡N), 1681
(C=O).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 3 2011

2-ACYL(AROYL)-1,1,3,3-TETRACYANOPROPENIDES: I.
407
Potassium 1,1,3,3-tetracyano-2-(4-methoxyben-
zoyl)prop-2-en-1-ide (IIc). Yield 55%, mp 223–224°C
(decomp.). IR spectrum, ν, cm–1: 2200 (C≡N), 1664
(C=O).
C 57.65; H 2.93; N 17.88. C15H9ClN4O2. Calculated,
%: C 57.61; H 2.90; N 17.92. M 312.71
2-[5-Amino-2-chloro-4-cyano-2-(3-nitrophenyl)-
furan-3(2H)-ylidene]propanedinitrile (IIId). Yield
68%, mp 146–147°C (decomp.). IR spectrum, ν, cm–1:
3253, 3102 (NH2); 2217 (C≡N); 1691 (C=C). 1H NMR
Potassium 1,1,3,3-tetracyano-2-(3-nitrobenzoyl)-
prop-2-en-1-ide (IId). Yield 72%, mp 213–214°C
(decomp.). IR spectrum, ν, cm–1: 2230 (C≡N), 1656
(C=O).
3
spectrum, δ, ppm: 7.87 t (1H, Harom, J = 8.1 Hz),
3
4
8.18 d.d (1H, Harom, J = 7.8, J = 1.4 Hz), 8.46 d.d
3
4
(1H, Harom, J = 8.1, J = 1.8 Hz), 8.51 t (1H, Harom
,
2-[5-Amino-2-chloro-4-cyano-2-phenylfuran-
3(2H)-ylidene]propanedinitrile (IIIa). A solution of
2.84 g (0.01 mol) of propenide IIa in 10 ml of 30%
hydrochloric acid was stirred for 15 min at 80°C. The
precipitate was filtered off, washed with water, and
recrystallized from isopropyl alcohol–5% sulfuric acid
(1:1). Yield 2.04 g (72%), mp 150–151°C (decomp.).
IR spectrum, ν, cm–1: 3250, 3110 (NH2); 2215 (C≡N);
4J = 2 Hz), 10.89 s (2H, NH2). Mass spectrum, m/z
(Irel, %): 327 (10), 329 (3). Found, %: C 51.37; H 1.92;
N 21.33. C14H6ClN5O3. Calculated, %: C 51.31;
H 1.85; N 21.37. M 327.68.
This study was performed under financial support
by the Federal Special-Purpose Program “Scientific
and Scientific–Pedagogical Staff of Innovation
Russia” (state contract no. 16.740.11.0335).
1
1696 (C=C). H NMR spectrum, δ, ppm: 7.53–7.62 m
3
(3H, Harom), 7.68 d (2H, Harom, J = 6.6 Hz), 10.72 s
(2H, NH2). 13C NMR spectrum, δC, ppm: 55.67 (C4),
69.59 [C(CN)2], 105.34 (C2), 110.47 (CN), 112.94,
113.13 [C(CN)2], 126.87, 128.94, 131.38, 132.46
(Carom), 168.09 (C3), 170.36 (C5). Mass spectrum, m/z
(Irel, %): 282 (55), 283 (10), 284 (15). Found, %:
C 59.75; H 2.52; N 18.83. C14H7ClN4O. Calculated, %:
C 59.48; H 2.50; N 19.82. M 282.68.
REFERENCES
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3. Wieth, S., Gruendmann, E., Jaehnisch, K., Winter, G.,
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lar way.
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2-[5-Amino-2-(4-bromophenyl)-2-chloro-4-
cyanofuran-3(2H)-ylidene]propanedinitrile (IIIb).
Yield 69%, mp 135–136°C (decomp.). IR spectrum, ν,
cm–1: 3253, 3102 (NH2); 2219 (C≡N); 1685 (C=C).
5. Bardasov, I.N., Kayukova, O.V., Kayukov, Ya.S.,
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3
1H NMR spectrum, δ, ppm: 7.66 d (2H, Harom, J =
3
8.7 Hz), 7.76 d (2H, Harom, J = 8.7 Hz), 10.75 s (2H,
NH2). Mass spectrum, m/z (Irel, %): 362 (10), 363 (3),
361 (1). Found, %: C 46.57; H 1.62; N 15.43.
C14H6BrClN4O. Calculated, %: C 46.50; H 1.67;
N 15.49. M 361.58.
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2-[5-Amino-2-chloro-4-cyano-2-(4-methoxy-
phenyl)furan-3(2H)-ylidene]propanedinitrile (IIIc).
Yield 72%, mp 141–142°C (decomp.). IR spectrum, ν,
cm–1: 3255, 3102 (NH2); 2217 (C≡N); 1694 (C=C).
1H NMR spectrum, δ, ppm: 7.05–7.08 m (2H, Harom),
7.58–7.61 m (2H, Harom), 10.70 s (2H, NH2). Mass
spectrum, m/z (Irel, %): 312 (10), 314 (3). Found, %:
vol. 27, p. 4361.
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10. Speziale, A.J., Smith, L.R., and Fedder, J.E., J. Org.
Chem., 1965, vol. 30, p. 4303.
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