Synthesis and alkylation of triethylammonium 3,5,5-tricyano-4,6-di(2- thienyl)-1,4,5,6-tetrahydro-pyridine-2-selenolate

Full text of DOI:10.1007/s10593-011-0853-6

Chemistry of Heterocyclic Compounds, Vol. 47, No. 7, October 2011 (Russian original Vol. 47, No. 7, July, 2011)
SYNTHESIS AND ALKYLATION OF TRIETHYLAMMONIUM
3,5,5-TRICYANO-4,6-DI(2-THIENYL)-1,4,5,6-TETRAHYDRO-
PYRIDINE-2-SELENOLATE
K. A. Frolov1* and S. G. Krivokolysko1
Keywords: 1,4,5,6-tetrahydropyridine-2-selenolate, (2-thienyl)methylidene-2-malononitrile, 2-cyano-
(2-thienyl)methylideneselenoacetamide.
Partially hydrogenated pyridines with selenium substituents form a small class of organic compounds
[1, 2]. In the course of our study of cyanoselenoacetamide derivatives [3–5], we have developed a method for
the synthesis of a new selenium heterocyclic system, namely, triethylammonium 3,5,5-tri-cyano-4,6-di(2-thien-
yl)-1,4,5,6-tetrahydropyridine-2-selenolate (1). 2-Cyano-2-(2-thienyl)methylideneselenoacetamide (2) [6, 7] was
found to react with (2-thienyl)methylidenemalononitrile (3) in the presence of excess triethylamine to give
1,4,5,6-tetrahydropyridine-2-selenolate 1 in 71% yield. This selenolate obtained is readily alkylated by
bromide 4 at the selenium atom to give 2-aroylmethylselanyl-1,4,5,6-tetrahydropyridine 5 in 62% yield.
Me
S
S
S
Br
S
Et3N,
Me2CO
NC
NC
4
CN
Se
NC
NC
O
CN
Se
CN
CN
+
Me
3–4°C
EtOH, 
N
H
CN
N
H
NH2
Se
S
+
S
Et3NH
2
3
1
5
O
1
The IR spectra were obtained on an IKS-29 spectrophotometer for samples in vaseline mull. The H NMR
spectra were taken on a Bruker Avance II 400 spectrometer at 400 MHz in DMSO-d6 with TMS as internal
standard. The elemental analysis was carried out on a Perkin-Elmer C,H,N-analyzer. The purity of the
compounds obtained was monitored by thin-layer chromatography on Silufol UV-254 plates with 1:1 acetone–
hexane as the eluent with development by iodine vapor and a UV detector. The melting points were determined
on a Koffler block and not corrected.
_______
*To whom correspondence should be addressed, e-mail: ka.frolov@inbox.ru.
1ChemEx Laboratory, Volodymyr Dahl East Ukrainian National University, 20a, build. 7, Molodezhnyi Qr,
Lugansk 91034 , Ukraine.
__________________________________________________________________________________________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1104–1106, July, 2011. Original
article submitted June 1, 2011.
0009-3122/11/4707-0909©2011 Springer Science+Business Media, Inc.
909

Triethylammonium 3,5,5-Tricyano-4,6-di(2-thienyl)-1,4,5,6-tetrahydropyridine-2-selenolate (1). A
mixture of 2-cyano-2-(2-thienyl)methylideneselenoacetamide 2 (0.68 g, 2.8 mmol), (2-thienyl)methyl-
idenemalononitrile 3 (0.45 g, 2.8 mmol), and excess triethylamine (0.58 ml, 4.2 mmol) in acetone (3 ml) was
stirred with cooling (3–4°C) under argon until the starting reagents dissolved (about 2–3 min) and left for 24 h at
this temperature in an argon atmosphere. The precipitate formed was filtered off and washed with ethanol,
acetone, and hexane to give selenolate 1 in 71% yield; mp 139–141°C. IR spectrum, , cm–1: 2235, 2175 (C≡N),
1
3
3460, 3312, 3257 (NH). H NMR spectrum, , ppm (J, Hz): 1.14 (9H, t, J = 6.4, N(CH2CH3)3); 2.79 (6H, q,
3J = 6.4, N(CH2CH3)3); 5.20 (1H, s, H-4); 5.56 (1H, br. s, H-6); 7.10–7.12 (2H, m, 2H-3 thienyl); 7.30 (1H, m,
H-4 thienyl); 7.39 (1H, m, H-5 thienyl); 7.51 (1H, m, H-4 thienyl); 7.57 (1H, m H-5 thienyl); 8.10 (1H, br. s,
NH). Found, %: C 52.23; H 5.04; N 14.08. C16H9N4S2Se·C6H16N. Calculated, %: C 52.58; H 5.01; N 13.94.
3,5,5-Tricyano-2-{[2-(4-methylphenyl)-2-oxoethyl]selanyl}-4,6-di(2-thienyl)-1,4,5,6-tetrahydro-
pyridine (5). A mixture of 1,4,5,6-tetrahydropyridine-2-selenolate 1 (0.4 g, 0.8 mmol) and bromide 4 (0.17 g,
0.8 mmol) in 70% aqueous ethanol (20 ml) was heated at reflux under argon until the starting compounds
dissolved (~2–3 min), rapidly filtered through a paper filter, and left for 24 h at room temperature in an argon
atmosphere. The precipitate formed was filtered off and washed with ethanol and hexane to give 0.26 g
(62%) tetrahydropyridine 5; mp >358°C (dec.) (1:1 ethanol–acetic acid). IR spectrum, , cm–1: 1638 (C=O),
1
2208, 2248 (C≡N), 3422, 3310, 3242 (NH). H NMR spectrum, , ppm (J, Hz): 2.43 (3H, s, 4-CH3C6H4); 4.65
(2H, br. s, SeCH2); 5.07 (1H, s, H-4); 5.44 (1H, d, 3J = 1.9, H-6); 6.53 (1H, m) and 6.48 (1H, m, 2H-3 thienyl);
6.79 (1H, m) and 6.58 (1H, m, 2H-4 thienyl); 7.28 (2H, d, 3J = 8.1, H Ar); 7.62 (1H, m, H-5 thienyl); 7.71 (1H,
3
m, H-5 thienyl); 7.80 (2H, d, J = 8.1, H Ar); 8.17 (1H, br. s, NH). Found, %: C 55.92; H 3.42; N 10.57.
C25H18N4OS2Se. Calculated, %: C 56.28; H 3.40; N 10.50.
REFERENCES
1.
2.
3.
V. P. Litvinov and V. D. Dyachenko, Usp. Khim., 66, 1025 (1997).
V. P. Litvinov, Izv. Akad. Nauk, Ser. Khim., 2123 (1998).
K. A. Frolov, V. V. Dotsenko, S. G. Krivokolysko, and V. P. Litvinov, Khim. Geterotsikl. Soedin., 1413
(2010) [Chem. Heterocycl. Comp., 46, 1142 (2010)].
4.
K. A. Frolov, V. V. Dotsenko, S. G. Krivokolysko, and V. P. Litvinov, Khim. Geterotsikl. Soedin., 313
(2009). [Chem. Heterocycl. Comp., 45, 255 (2009)].
5.
6.
7.
V. D. Dyachenko, S. G. Krivokolysko, and V. P. Litvinov, Zh. Org. Khim., 34, 927 (1998).
V. P. Litvinov and V. D. Dyachenko, Dokl. Akad. Nauk, 352, 636 (1997).
V. P. Litvinov and V. D. Dyachenko, Zh. Org. Khim., 35, 1406 (1999).
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