Alkoxymethylamines and secondary amine aminals as precursors for aminomethylation of acetylenes

Full text of DOI:10.1134/S1070363208030274

ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 3, pp. 504–505. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.A. Gevorkyan, A.A. Movsisyan, Zh.L. Dzhandzhulyan, A.S. Arakelyan, K.A. Petrosyan, 2008, published in Zhurnal Obshchei
Khimii, 2008, Vol. 78, No. 3, pp. 519–520.
LETTERS
TO THE EDITOR
Alkoxymethylamines and Secondary Amine Aminals
as Precursors for Aminomethylation of Acetylenes
A. A. Gevorkyan, A. A. Movsisyan, Zh. L. Dzhandzhulyan,
A. S. Arakelyan, and K. A. Petrosyan
Institute of Organic Chemistry, National Academy of Sciences of the Republic of Armenia,
ul. Zakariya Sarkavagi 167A, Erevan, 375091 Armenia
e-mail: agevork@sci.am
Received August 31, 2007
DOI: 10.1134/S1070363208030274
Analysis of published data on the Mannich reaction
[1–5] shows that the problem whether well known
precursors used in this reaction are suitable for
acetylenes I is still unsolved [1–5]. Until now there is
no direct experimental evidence showing whether
no longer evolve. The aminomethylation products are
distilled at reduced pressure. Reactions with 0.1 mol
of acetylene are complete within 20–40 min. With
larger amount of catalysts, much more vigorous tarring
is observed.
dialkylaminomethanols R'NCH2OH (II) are the only
2
The above procedure was used to synthesize a
series of acetylene amines [in parentheses are the
yields obtained with the corresponding formal IV).
feasible reactants or the same role can be played by
esters III or formals IV. This controversy as to the
structure of precursors for acetylene aminomethylation
arises from the fact that the involvement of such
compounds in acetylene aminomethylation has still
been considered on the basis of indirect evidence or
speculations [6, 7]. However, in cases where
unequivocal experimental evidence is available, it
relates to reactions of compounds like butoxy-
methylamines with Iotsich reagents, rather than ace-
tylenes themselves [3, 8].
CuJ
RC≡CH + R' NCH2OR'' —→ RC≡CCH2OR2"
2
I
II, III
CuJ
←— RC≡CH + R' NCH2OR' .
2
2
I
IV
1-Diethylamino-3-phenylprop-2-yne. Yield from
diethyl(methomethyl)-, (ethoxymethyl)diethyl-, and
(butoxymethyl)diethylamine 62, 68, 72–74 % (70–
75%), respectively; bp 133–135°С (11 mm Hg) [9].
We found out that both esters III and aminals IV
derived from dialkylaminomethanols can be involved
in acetylene aminomethylation. These reactions are
performed by mixing equimolar amounts of ace-
tylenes, esters III (or aminals IV), and trace amount of
a catalyst (3–7 mg of copper iodide per 0.1 mol of
acetylene) and heating the reaction mixture for some
hours. The best yields (40–75%) in the reactions per-
formed in a distillation flack with a Vigreux column 10 –
15 cm long under slow heating at temperatures 15 –40°С
above the boiling point of the alcohol corresponding to
ester III or the secondary amine corresponding to
aminal IV, until volatiles (alcohol or secondary amine)
3-Phenyl-1-piperidylaminoprop-2-yne. Yield from
(butoxymethyl)piperidine 60% (66%), bp 164°С
(11 mm Hg) [9].
1-Morpholino-3-phenylprop-2-yne. Yield from
(ethoxymethyl)morpholine 72% (69%), bp 168°С
(11 mm Hg) [9].
4-Benzyloxy-1-diethylaminopropo-2-yne. Yield from
(butoxymethyl)diethylamine 45% (34.6%), bp 170°С
(11 mm Hg) [9].
504

ALKOXYMETHYLAMINES AND SECONDARY AMINE AMINALS
505
2. Fisher, L.B., Usp. Khim., 1958, vol. 27, no. 5, p. 589.
3. Tramontini, M., Synthesis, 1973, p. 703.
4. Heaney, H., Papageorgiou, G., and Wilkins, R.F.,
Tetrahedron, 1997, vol. 53, no. 8, p. 2941.
5. Heaney, H., Papageorgiou, G., and Wilkins, R.F.,
Tetrahedron, 1997, vol. 53, no. 39, p. 13361.
1-Diethylamino-4-methylpent-2-yn-4-ol. Yield from
(butoxymethyl)diethylamine 56.8% (68.6%), bp 81–
82°С (2 mm Hg), n2D0 1.4651. The compounds have cor-
rect elemental analyses. 1Н NMR spectra, δH (300 MHz):
1.05 t [6H, J 9.6, N(CH2CH3)2, 1.39 s (6H, Me2COH),
2.42 q [4H, J 9.6, N(CH2CH3)2], 3.30 s (2H, ≡CCH2),
4.63 s (1H, OH).
6. Chukhadzhyan, E.O., Gevorkyan, A.R., Chukha-
dzhyan, El.O., and Shahatuni, K.G., Zh. Org. Khim.,
2000, vol. 36, no. 9, p. 1304.
1
The Н NMR spectra were measured on a Varian
Mercury-300 spectrometer at 300 MHz in DMSO-d6/
CCl4 (1:3), internal reference TMS.
7. Chukhadzhyan, E.O., Gevorkyan, A.R., and Nalban-
dyan, M.K., Zh. Org. Khim., 2000, vol. 36. no. 9,
p. 1304.
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Dzhandzhulyan, Zh.L., and Petrosyan, K.A., Zh.
Obshch. Khim., 2006, vol. 76, no. 7, p. 1223.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 3 2008