ISSN 1070-4280, Russian Journal of Organic Chemistry, 2010, Vol. 46, No. 9, pp. 1423−1424. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © B.F. Kukharev, V.K. Stankevich, G.R. Klimenko, N.A. Lobanova, V.V. Stankevich, G.A. Volkov, 2010, published in Zhurnal Organicheskoi
Khimii, 2010, Vol. 46, No. 9, p. 1419.
SHORT
COMMUNICATIONS
Pyrolysis of Enaminone Derivatives of 1,2-Ethylenediamine
B. F. Kukharev, V. K. Stankevich, G. R. Klimenko, N. A. Lobanova,
V. V. Stankevich, and G. A. Volkov
Faworsky Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences
Irkutsk, 664033 Russia
e-mail: irk_inst_chem@irioch.irk.ru
Received January 8, 2010
DOI: 10.1134/S1070428010090290
Enaminones are applied as synthons in the preparation
of heterocyclic compounds [1, 2]. Their properties depend
essentially on the character of the amine fragment of the
molecule. In this study we showed that the enaminones
obtained from acetylacetone and monosubstituted 1,2-eth-
ylenediamines at 200–250°С suffer a thermal cleavage
to give acetone and N-substituted imidazolines.
δ, ppm: 14.10 (CH3), 49.29 (NCH2CH2O), 49.89 (NCH2),
51.46 (CH2N=), 59.17 (OCH2), 165.10 (C=N). Found,
%: С 56.34; Н 9.53; N 21.71. C6H12N2O. Calculated, %:
С 56.22; Н 9.44; N 21.86.
1-(2-Vinyloxyethyl)-2-methylimidazoline (IIb).
Yield 74%, oily substance, bp 90–92°С (3 mm Hg),
d420 0.9840, nD20 1.4942. IR spectrum, ν, cm–1: 3105, 3030,
2915, 2855, 1620, 1605, 1475, 1410, 1350, 1300, 1250,
1180, 1105, 1065, 995, 950, 920, 805, 685, 575, 475.
1Н NMR spectrum, δ, ppm: 1.89 s (3H, СH3), 3.33 m
(4H, CH2NHCH2), 3.62 m (2H, CH2N=), 3.72 t (2H,
CH2O, 3J 5.4 Hz), 3.99 d.d (1Н, cis-HC=CO, 2Jгеm 2.2,
The reaction apparently proceeds along a mechanism
similar to that of the ester cleavage of β-dicarbonyl
compounds.
Δ
O
HN HN R
Me
N
N R
2
3Jcis 6.7 Hz), 4.14 d.d (1H, trans-HC=CO, Jgem 2.2,
_Me2CO
3
3
3Jtrans 14.3 Hz), 6.41 d.d (1H, ОСН=С, Jcis 6.7, Jtrans
14.3 Hz). 13C NMR spectrum (CDCl3), δ, ppm: 13.97
(CH3), 45.67 (NCH2CH2O), 49.86 (NCH2), 51.87
(CH2N=), 65.37 (OCH2), 86.53 (=CH2), 150.99 (OCH=),
163.37 (C=N). Found, %: С 62.47; Н 9.23; N 18.05.
C8H14N2O. Calculated, %: С 62.31; Н 9.15; N 18.17.
Me
Me
IIа_IIc
Iа_Ic
Enaminones Iа–Ic were heated at 200–250°С and
pressure of 15 mm Hg collecting a wide fraction of the
decomposition products. Imidazolines IIа–IIc were
separated by subsequent distillation.
3-Vinyloxy-1-(2-methylimidazolin-1-yl)-2-pro-
panol (IIc). Yield 69%, oily substance, bp 155–158°С
(2 mm Hg), nD20 1.5117. IR spectrum, ν, cm–1: 3309,
3116, 3080, 2928, 2868, 2745, 2582, 1664, 1613, 1494,
1431, 1376, 1321, 1269, 1201, 1117, 1077, 1021, 1004,
2-(2-Methylimidazolin-1-yl)ethanol (IIа). Yield
65%, bp 166–170°С (10 mm Hg), mp 40–41°С, nD20 1.514
(of supercooled liquid). IR spectrum, ν, cm–1: 3290, 3079,
2958, 2932, 2776, 1667, 1605, 1499, 1454, 1433, 1362,
1316, 1268, 1203, 1177, 1114, 1078, 1054, 1013, 976,
1
975, 943, 819, 746, 704, 647, 595, 554, 470. Н NMR
1
spectrum, δ, ppm: 1.89 s (3H, Me), 3.19–3.44 m (4H,
NCH2CH2N=), 3.60 m (2H, CHCH2N), 3.67 m (2H,
ОCH2), 3.95 m (2H, CHOH), 4.01 d.d (1Н, cis-HC=CO,
940, 866, 814, 679, 602, 590, 512, 418. Н NMR spec-
trum, δ, ppm: 1.84 s (3H, СH3), 3.15 t (2H, NCH2CH2O,
3J 5.4 Hz), 3.30 m (2H, NCH2), 3.56 m (4H, CH2N=,
CH2O), 5.78 br.s (1H, ОН). 13C NMR spectrum (CDCl3),
3
2Jgem 2.1, Jcis 6.7 Hz), 4.17 d.d (1H, trans-HC=CO,
1423