Behavior of allylamines in the system KOH-DMSO

Article abstract of DOI:10.1023/B:RUJO.0000003177.74897.88

Isomerization of triallylamine in the system KOH-DMSO at 90-100°C leads to formation of tris(1-propenyl)amine in quantitative yield. Under similar conditions, diallyl(ethyl)amine is converted into ethylbis(1-propenyl)amine and 1-ethyl-3-methylcyclohexane. Diallylamine in KOH-DMSO gives rise to a complex mixture of products consisting of bis(1-propenyl)amine, methylbis(1-propenyl) amine, 1-ethyl-3-methylcyclohexane, and 2-ethyl-3,5-dimethylpiperidine. Ways of formation of these products are discussed.

Full text of DOI:10.1023/B:RUJO.0000003177.74897.88

Russian Journal of Organic Chemistry, Vol. 39, No. 7, 2003, pp. 915 918. Translated from Zhurnal Organicheskoi Khimii, Vol. 39, No. 7, 2003,
pp. 976 979.
Original Russian Text Copyright
2003 by Musorin.
Behavior of Allylamines in the System KOH DMSO
G. K. Musorin
Favorskii Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences,
ul. Favorskogo 1, Irkutsk, 664033 Russia
Received May 8, 2002
Abstract Isomerization of triallylamine in the system KOH DMSO at 90 100 C leads to formation of tris-
(1-propenyl)amine in quantitative yield. Under similar conditions, diallyl(ethyl)amine is converted into ethyl-
bis(1-propenyl)amine and 1-ethyl-3-methylcyclohexane. Diallylamine in KOH DMSO gives rise to a complex
mixture of products consisting of bis(1-propenyl)amine, methylbis(1-propenyl)amine, 1-ethyl-3-methylcyclo-
hexane, and 2-ethyl-3,5-dimethylpiperidine. Ways of formation of these products are discussed.
Strongly basic systems consisting of an alkali metal
hydroxide and a dipolar aprotic solvent are known to
be effective media for prototropic isomerization of
an allyl group into 1-propenyl [1 4]. Transformations
of heteroelement-containing allyl derivatives in the
system KOH DMSO are determined by both the reac-
tion conditions and the nature of heteroelement. Di-
allyl ether (80 C, 15 h) and diallyl sulfide (50 C, 3 h)
in KOH DMSO undergo isomerization into bis-
(1-propenyl) ether and bis(1-propenyl) sulfide, respec-
tively, in up to 90% yield, while diallyl selenide and
telluride in the same system are converted into 1,3,5-
hexatriene [1, 2]. Unsymmetrical alkyl allyl selenides
and tellurides in KOH DMSO are readily transformed
into the corresponding alkyl 1-propenyl selenides and
tellurides [3 5].
moreover, Balu et al. [9] found conditions for selec-
tive formation of the latter product. The isomerization
of I in the system KOH DMSO in the presence of
hydroquinone is characterized by considerably lower
efficiency. Taking into account that small amounts of
dimsylsodium in DMSO are known to initiate radical
ion reaction [10, 11] and that dimethyl sulfoxide
anions can be generated in the KOH DMSO system
[12], the transformation of compound I into II may
be represented by Scheme 2. Insofar as the process
cannot be suppressed completely by addition of
a radical inhibitor, both radical anion and ionic paths
are possible.
Compound II is formed as a mixture of cis,cis,cis,
cis,cis,trans, cis,trans,trans, and trans,trans,trans
isomers. The isomer ratio strongly depends on the
reaction temperature and the amount of potassium
hydroxide. Elevated temperature, as well as increased
concentration of KOH, favors formation of the trans
isomers of II. According to the data of [10], radical
ions with alkali metal cations in dissociating solvents
give rise to coordination compounds which favor
formation of the cis isomers. Therefore, we presume
that raising the temperature or KOH concentration
leads to decomposition of such complexes. As
a result, the predominant radical ion isomer is trans
rather than cis. The cis trans isomerization is likely
to occur in the radical anions, for a definite isomer
of II almost does not change in the system KOH
DMSO at 90 C. No transformation of I into II was
observed when KOH was replaced by LiOH; in the
presence of sodium hydroxide, the conversion of I
was as low as 15%. The efficiency of the isomeriza-
tion in KOH DMSO decreases on addition of water.
It was found that triallylamine (I) in the system
KOH DMSO at 90 C (6 h) readily undergoes iso-
merization into tris(1-propenyl)amine (II) in up to
88% yield (Scheme 1).
Scheme 1.
Prior to these studies, the isomerization of I was
carried out in KNH2 Al C5H12 N2 [6] and K(Na)
Al2O3 Ar [7, 8]. In these cases, the reaction was
often accompanied by cyclization of I to 3-methyl-
N-(trans-1-propenyl)-1,2,3,4-tetrahydropyridine;
1070-4280/03/3907-0915$25.00 2003 MAIK Nauka/Interperiodica

916
MUSORIN
Scheme 2.
This fact can readily be understood, taking into
account that the presence of even small amounts of
water in DMSO sharply reduces the acidity function
H [13, 14].
Scheme 4.
It seemed obvious that the behavior of ethyldiallyl-
amine (III) in the system KOH DMSO should be
analogous to the behavior of I in the same system.
However, the isomerization of III into ethylbis-
(1-propenyl)amine (IV) was accompanied by forma-
tion of 1-ethyl-3-methylcyclohexane (V) (Scheme 3).
The ratio of products IV and V in the reaction mixture
was 1:1.5 (90 C, 6 h).
Scheme 3.
propenylamine (X). Schiff bases like X are known
[17] to be formed from enamines in the presence of
bases. Compound X in KOH DMSO gives rise to
carbanion XI which attacks the carbon atom at the
Scheme 5.
Even more complex mixture was obtained from
diallylamine (VI) in KOH DMSO; according to the
GLC data, more than 8 compounds were present in
the reaction mixture. By gas chromatography mass
spectrometry we succeeded in identifying the follow-
ing compounds: 1-ethyl-3-methylcyclohexane (V),
bis(1-propenyl)amine (VII), methylbis(1-propenyl)-
amine (VIII), and 2-ethyl-3,5-dimethylpiperidine (IX)
(Scheme 4). The fraction of enamine VII did not
exceed 5%. Compound VIII is formed by methylation
of VII with the system KOH DMSO [15, 16]. The
formation of product IX may be explained as follows.
Prototropic isomerization of VI yields compound
VII which is then converted into N-propylidene-1-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 7 2003

BEHAVIOR OF ALLYLAMINES IN THE SYSTEM KOH DMSO
917
Scheme 6.
double C N bond in X to give intermediate XII.
At 90 100 C, the latter undergoes cyclization with
elimination of 1-propenylamine molecule (XIII),
yielding product IX (Scheme 5). It is also possible
that liberated 1-propenylamine (XIII) reacts with
compound VII according to Scheme 6.
Chromaton N-AW-DMCS. The mass spectrum was
obtained on an LKB-2091 GC MS system. The H
NMR spectra were recorded on a Bruker DPX-400
instrument operating at 400.13 MHz; chloroform-d
was used as solvent, and hexamethyldisiloxane, as
internal reference.
1
Presumably, both ionic and radical ion processes
are responsible for the variety of products obtained
from compound VI in the system KOH DMSO. The
presence of three acceptor groups in molecule I
stabilizes radical anion derived therefrom, so that
elimination of some moiety with unpaired electron is
unfavorable. In going to structures III and VI, the
mobility of unpaired electron increases, and it readily
leaves the parent molecule together with appropriate
departing group (Scheme 7), giving rise to unusual
transformations in the system KOH DMSO.
Isomerization of triallylamine (I). a. A mixture of
2.7 g (0.02 mol) of compound I, 4.5 g (0.008 mol)
of KOH (I-to-KOH ratio 1:4), and 50 ml of DMSO
was heated for 6 h at 90 C. The mixture was diluted
with water and extracted with ether, the ether extracts
were washed with water, dried over CaCl2, and sub-
jected to fractional distillation to isolate 4.2 g (88%)
of compound II (the still residue was a tarry material).
The cis,cis,cis cis,cis,trans cis,trans,trans trans,-
trans,trans ratio was 5:3:1:1.
b. A mixture of 1.2 g (0.009 mol) of compound I,
4.4 g (0.08 mol) of KOH (I-to-KOH ratio 1:9), and
50 ml of DMSO was heated for 6 h at 90 C. After
appropriate treatment, 0.9 g (75%) of compound II
was isolated; cis,cis,cis cis,cis,trans cis,trans,trans
trans,trans,trans ratio 3:2:2:1.
Scheme 7.
c. A mixture of 1 g (0.007 mol) of compound I,
9.2 g (0.16 mol) of KOH (I-to-KOH ratio 1:23), and
50 ml of DMSO was heated for 6 h at 90 C. After
appropriate treatment, 0.6 g (60%) of compound II
was isolated; cis,cis,cis cis,cis,trans cis,trans,trans
trans,trans,trans ratio 1:2:4:6.
d. A mixture of 3.1 g (0.02 mol) of compound I,
6.6 g (0.12 mol) of KOH (I-to-KOH ratio 1:6), and
50 ml of DMSO was heated for 5 h at 110 C. After
appropriate treatment, 1.5 g (48%) of compound II
was isolated; cis,cis,cis cis,cis,trans cis,trans,trans
trans,trans,trans ratio 2:2:3:5.
R = H, Et.
e. A mixture of 1.2 g (0.009 mol) of compound I,
4.4 g (0.08 mol) of KOH (I-to-KOH ratio 1:9), 0.12 g
of hydroquinone (10 wt % with respect to I), and
50 ml of DMSO was heated for 6 h at 90 C. After
appropriate treatment, 0.4 g (35%) of compound II
was isolated; cis,cis,cis cis,cis,trans cis,trans,trans
trans,trans,trans ratio 4:2:2:1.
It was difficult to assign the H NMR signals to
particular isomers; therefore, their quantitative deter-
mination was performed by GLC, taking into account
EXPERIMENTAL
1
The reaction mixtures were analyzed by GLC on
a Khrom-5 chromatograph equipped with a 2000
4-mm column; stationary phase 10% of SE-30 on
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 7 2003

918
MUSORIN
that the cis isomer leaves the column before the trans
isomer [18].
3. Musorin, G.K., Amosova, S.V., Kopylova, I.G.,
Shcherbakov, V.V., and Keiko, V.V., Zh. Org.
Khim., 1989, vol. 25, p. 2450.
4. Musorin, G.K. and Amosova, S.V., Zh. Org. Khim.,
1992, vol. 28, p. 681.
5. Musorin, G.K., Russ. J. Gen. Chem., 1997, vol. 67,
Isomerization of diallyl(ethyl)amine (III). A mix-
ture of 6.3 g (0.05 mol) of compound III, 11.2 g
(0.2 mol) of KOH, and 50 ml of DMSO was heated
for 6 h at 90 C. Appropriate treatment gave 4.3 g of
a mixture containing (GLC) 39% of IV, 58% of V,
and 3% of unidentified products. Yield of IV 27%;
p. 1820.
6. Hubert, A.J., J. Chem. Soc. C, 1968, p. 2048.
7. Schmidt, H., Wiss. Z/Techn. Hochsch. Leuna-Merser-
burg, 1977, vol. 19, p. 564.
8. Duschek, Ch., Hobold, W., Naick, R., Scmidt, H.,
and Yen, N.T., J. Prakt. Chem., 1975, vol. 317,
p. 491.
9. Balu, K., Duschek, C., and Schmidt, H., GDR
Patent no. 113226, 1975; Ref. Zh., Khim., 1976,
no. 14O136P.
1
yield of V 39%. H NMR spectrum of IV, , ppm:
cis,cis isomer: 4.71 d.q (2H, CH3CH), 6.45 d.q (2H,
NCH), 1.63 d.d (6H, CH3CH), 1.18 t (3H, CH3CH2),
3
3
3.30 q (2H, CH2); J(CHCH) = 8.5 Hz, J(CH3CH) =
7.0 Hz; cis,trans isomer: 4.72 d.q (1H, CH3CH),
6.51 d.q (1H, NCH), 1.66 d.d (3H, CH3CH), 4.65.
1H NMR spectrum of V, , ppm: 0.76 2.06 m (10H,
CH2), 0.88 0.76 m (3H, CH3CH), 0.91 0.89 m (3H,
CH3CH2), 1.14 1.38 m (2H, CH3CH2). GC MS
analysis of the reaction mixture showed the presence
of compounds IV (m/z 125) and V (m/z 126) and
ethyl(1-propenyl)amine (m/z 85).
10. Todres, Z.V., Ion-radikaly v organicheskom sinteze
(Radical Ions in Organic Synthesis), Moscow:
Khimiya, 1986, p. 238.
11. Kornblum, N. and Osuch, C.E., J. Am. Chem. Soc.,
1982, vol. 46, p. 3353.
Isomerization of diallylamine (VI). A mixture of
6.3 g (0.05 mol) of compound VI, 11.2 g (0.2 mol)
of KOH, and 50 ml of DMSO was heated for 6 h at
90 C. Appropriate treatment gave 4.3 g of a mixture
containing (GLC) 8 compounds. The following prod-
ucts were identified by GC MS: V (m/z 126), VII
(m/z 97), VIII (m/z 111), IX (m/z 141), X (m/z 181).
Also, compounds giving rise to ion peaks with
m/z 133, 160, and 195 were present.
12. Trofimov, B.A. and Amosova, S.V., Divinilsul’fid
i ego proizvodnye (Divinyl Sulfide and Its Deriva-
tives), Novosibirsk: Nauka, 1983, p. 264.
13. Reutov, O.A., Beletskaya, I.P., and Butin, K.P.,
CH-kisloty (CH Acids), Moscow: Nauka, 1980, p. 28.
14. Russel, G.A. and Osuch, C.E., J. Am. Chem. Soc.,
1982, vol. 104, p. 3353.
15. Musorin, G.K., Amosova, S.I., Stankevich, V.K.,
Andrievskaya, E.K., and Trofimov, B.A., Zh. Prikl.
Khim., 1987, p. 2073.
16. Musorin, G.K., Trofimov, B.A., Amosova, S.V.,
Vitkovskii, V.Yu., and Kalabin, G.A., Zh. Obshch.
Khim., 1979, vol. 49, p. 831.
17. Dauphin, G., David, L., Jamilloux, B., Kergomar, A.,
and Veschambre, H., Tetrahedron, 1972, vol. 28,
p. 1055.
18. Musorin, G.K., Vitkovskii, V.Yu., Amosova, S.V.,
and Trofimov, B.A., Zh. Org. Khim., 1985, vol. 21,
p. 1320.
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