Unusual interaction of N-phenacyl-2-chloropyridinium ylide with nitriles of the trans-1,3-butadiene series

Full text of DOI:10.1007/s10593-008-0004-x

Chemistry of Heterocyclic Compounds, Vol. 44, No. 1, 2008
UNUSUAL INTERACTION
OF N-PHENACYL-2-CHLORO-
PYRIDINIUM YLIDE WITH NITRILES
OF THE trans-1,3-BUTADIENE SERIES
G. E. Khoroshilov and I. V. Demchak
Keywords: trans-1,3-butadiene, 2,3-dihydroindolizines, N-phenacyl-2-chloropyridinium ylide.
The reaction of N-aroylmethylpyridinium ylides, with electron-acceptor groups (CN, COOEt) in position
3, with unsaturated nitriles of the trans-1,3-butadiene series 2a,b occurs as 1,3-dipolar cycloaddition to give
substituted tetrahydroindolizines [1, 2]. In the absence of electron-acceptor substituents at position 3 pyridinium
ylides react with activated alkenes under typical conditions to form Michael adducts which are stereoselectively
transformed into trans-1,1-dicyanocyclopropanes with elimination of pyridine [3].
We have established that when N-phenacyl-2-chloropyridinium ylide reacts with trans-1,3-butadienes
2a,b the corresponding 2,3-dihydroindolizines 3a,b are formed.
N-Phenacyl-2-chloropyridinium ylide was not isolated but was generated in situ from N-phenacyl-
2-chloropyridinium bromide 1.
1
Clearly expressed signals for the H-2 and H-3 protons are observed in the H NMR spectra of
compounds 3a,b. The 3J coupling constants of these protons indicate that they are in the cis position.
The elemental analyses of compounds 3a,b also indicate formation of 2,3-dihydroindolizines.
1H NMR spectra of CDCl3 solutions with TMS as internal standard were recorded on a Varian VRX-200
(200 MHz) instrument, and IR spectra of nujol mulls on an IKS-40 spectrometer.
Me
N
N
N
Ph
2
Ph
N
O
+
N
Cl
Br
N
+
Ph
Ph
N
O
O
R
R
1
3a,b
2a,b
a R = H, b R = Cl
__________________________________________________________________________________________
Taras Shevchenko Lugansk National Pedagogical University, Lugansk 91011, Ukraine; e-mail:
demchak@mail.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, 130-131, January, 2008.
Original article submitted July 23, 2007.
0009-3122/08/4401-0109©2008 Springer Science+Business Media, Inc.
109

Butadienes 2a,b were made by a known method [2].
Preparation of Compounds 3 (General Method). N-methylmorpholine (5.0 mmol) was added with
stirring to a suspension of salt 1 (2.5 mmol) and the corresponding butadiene 2 (2.5 mmol) in methanol (10 ml).
The mixture was stirred for 3 h. The precipitate formed was filtered off, washed with cold methanol and dried
with hexane, and crystallized from acetonitrile.
3-Benzoyl-1-(2,2-dicyano-1-phenylvinyl)-2-phenyl-2,3-dihydroindolizine (3a). Yield 43%; mp 264°C
(dec.). IR spectrum, ν, cm-1: 2290 (CN), 2164 (CN), 1696 (C=O). 1H NMR spectrum, δ, ppm (J, Hz): 7.91 (2H,
d, J = 8.3, Harom); 7.72 (1H, t, J = 7.2, Harom); 7.64-7.31 (10 H, m, Harom); 7.26 (1H, s, Harom); 7.10 (3H, m, Harom);
6.50 (1H, t, J = 6.8, H-7); 5.76 (1H, d, J = 2.6 , H-3); 5.46 (1H, d, J = 9.2, H-8); 5.16 (1H, d, J = 2.6, H-2).
Found, %: C 86.51; H 4.63; N 9.42. C31H21N3O. Calculated, %: C 86.46; H 4.69; N 9.31.
3-Benzoyl-2-(4-chlorophenyl)-1-(2,2-dicyano-1-phenylvinyl)-2,3-dihydroindolizine (3b). Yield 41%;
1
mp 242-244°C. IR spectrum, ν, cm-1: 2292 (CN), 2164 (CN), 1694 (C=O). H NMR spectrum, δ, ppm (J, Hz):
7.88 (2H, d, J = 7.4, Harom); 7.74 (1H, t, J = 7.6, Harom); 7.64-7.32 (9H, m, Harom); 7.26 (1H, s, Harom); 7.20-7.00
(3H, m, Harom); 6.52 (1H, t, J = 6.81, Harom); 5.72 (1H, d, J = 2.6 , H-2); 5.47 (1H, d, J = 9.5, H-8); 5.14 (1H, d,
J = 2.6, H-3). Found, %: C 76.60; H 4.19; N 8.71. C31H20ClN3O. Calculated, %: C 76.62; H 4.15; N 8.65.
REFERENCES
1.
2.
A. M. Shestopalov, V. P. Litvinov, Yu. A. Sharanin, and G. E. Khoroshilov, Dokl. Akad. Nauk., 312,
1156 (1990).
A. M. Shestopalov, Yu. A. Sharanin, V. N. Nesterov, G. E. Khoroshilov, V. E. Shklover,
Yu. T. Struchkov, and V. P. Litvinov, Khim. Geterotsikl. Soedin., 1354 (1991). [Chem. Heterocycl.
Comp., 27, 1084 (1991)].
3.
V. P Litvinov. Zh. Org. Khim., 31, 1441 (1995).
110