Reactions of acetylenic hydrocarbons with various CH acids

Full text of DOI:10.1023/A:1016362932121

Russian Journal of Organic Chemistry, Vol. 38, No. 3, 2002, pp. 452 453. Translated from Zhurnal Organicheskoi Khimii, Vol. 38, No. 3, 2002,
pp. 473 474.
Original Russian Text Copyright
2002 by Dybova, Yurchenko, Gritsai, Buikliskii, Mel’nikova.
SHORT
COMMUNICATIONS
Reactions of Acetylenic Hydrocarbons with Various CH Acids
T. N. Dybova, O. I. Yurchenko, N. V. Gritsai,
V. D. Buikliskii, and E. D. Mel’nikova
Kuban’ State University, ul. Stavropol’skaya 149, Krasnodar, 350040 Russia
Received July 25, 2001
Only a few published data are available on vinyla-
tion of acetylenic compounds with CH acids. Nucleo-
philic addition reactions with formation of a C C
bond were reported mainly for alkynes having elec-
tron-acceptor substitutents [1, 2]. Electrophilic attack
on the triple bond is more difficult to occur, and
special catalysts are to be used [3].
ably through intermediate carbocation and unstable
nitronate [5] (Scheme 2).
Scheme 2.
We have previously studied electrophilic addition
of CH acids, such as benzoylnitromethane, p-nitro-
benzoylnitromethane, m-nitrobenzoylnitromethane,
methyl nitroacetate, nitromethane, and acetylacetone,
to acetylenic systems: acetylene, phenylacetylene,
2-propynyl chloride, and trimethylsilylacetylene in the
presence of a catalytic amount of sulfuric acid and
found that these reactions take various pathways. We
were the first to reveal [4] that acetylene, phenyl-
acetylene, trimethylsilylacetylene, and 2-propynyl
chloride react with benzoylnitromethane, p-nitroben-
zoylnitromethane, and m-nitrobenzoylnitromethane in
the presence of acid catalyst (H2SO4) to give hetero-
cyclic compounds of the isoxazole series. Like -nitro
ketones, methyl nitroacetate ( -nitro ester) reacts with
acetylene derivatives, following the 1,3-dipolar cyclo-
addition pattern (Scheme 1).
No desired results were obtained when 2-propynyl
chloride or 3-trimethylsilyl-2-propynyl chloride was
used as substrate. In all cases, only the initial com-
pounds were isolated from the reaction mixtures
despite wide variation of the conditions. Obviously,
electron-acceptor substituents at the Csp atom hamper
the reaction [6].
Aliphatic -diketone, acetylacetone, reacted with
phenylacetylene in the presence of HgSO4/H2SO4 as
catalyst. The reaction was accompanied by prototropic
rearrangement, and the product was -dicarbonyl
compound III with a longer conjugation chain
(Scheme 3).
Scheme 1.
Scheme 3.
Under similar conditions, nitromethane failed to
react with phenylacetylene, and the initial compounds
were recovered from the reaction mixture. Increase
in the amount of sulfuric acid in the reaction mixture
led to formation of -substituted ketone II, presum-
1070-4280/02/3803-0452$27.00 2002 MAIK Nauka/Interperiodica

REACTIONS OF ACETYLENIC HYDROCARBONS WITH VARIOUS CH ACIDS
453
The structure of compound III was unambiguously
confirmed by the IR and H NMR data and by its
hydrolysis to acetophenone.
ture of 9.80 g (0.098 mol) of acetylacetone, 0.044 g
of HgO, and 0.5 ml of concentrated sulfuric acid.
The mixture was stirred for 3 h at 50 C. Vacuum dis-
tillation gave 4.50 g (23%) of product III, bp 116 C
1
Methyl 5-chloromethylisoxazole-3-carboxylate
(I). Concentrated sulfuric acid, 0.41 g (0.004 mol),
was added to a mixture of 0.3 g (0.004 mol) of
2-propynyl chloride and 0.48 g (0.004 mol) of methyl
nitroacetate in 30 ml of dry benzene. The mixture
was kept for 5 h at 60 C, cooled, and evaporated to
isolate 0.3 g (42%) of methyl 5-chloromethylisoxa-
zole-3-carboxylate (I). mp 61 C (from ethanol).
1H NMR spectrum, , ppm: 3.91 s (3H, CH3), 5.02 s
(2H, CH2Cl), 7.00 s (1H, CH). Found, %: C 40.95;
H 3.39; N 7.75. C6H6ClNO3. Calculated, %: C 41.03;
H 3.42; N 7.98.
1
(2 mm). H NMR spectrum, , ppm: 1.83 s (3H,
CH3), 2.42 s (6H, CH3CO), 7.50 m (5H, C6H5). IR
1
spectrum, , csm : 1685 (C O), 1610 (C C).
Found, %: C 76.91; H 6.91; H 6.81. C13H14O2. Cal-
culated, %: C 77.23; H 6.93.
The IR spectra were recorded on an IKS-29 spec-
1
trometer in chloroform. The H NMR spectra were
obtained on a Tesla BS-587A instrument at 80 MHz
in CDCl3 using TMS as internal reference.
REFERENCES
2-Methyleneaminooxy-1-phenyl-1-ethanone (II).
Concentrated sulfuric acid, 1.00 g (0.10 mol), was
added to 11.38 g (0.187 mol) of nitromethane, cooled
to 20 C. A solution of 1.02 g (0.010 mol) of phenyl-
acetylene in 4.50 g (0.074 mol) of nitromethane was
added with stirring, and the mixture was kept for
25 min at 20 C, treated with a 5% solution of
Na2CO3, and extracted with ether. The extract was
dried over CaCl2 and evaporated, and the residue
was distilled in a vacuum to obtain 0.33 g of product
II (yield 20%), bp 72 C (3 mm), n2D0 = 1.5362.
1H NMR spectrum, , ppm: 4.68 s (2H, COCH2O),
7.27 s (2H, CH2), 7.66 m (5H, C6H5). Found, %:
C 65.87; H 5.28; N 8.21. C9H9NO2. Calculated, %:
C 66.26; H 5.52; N 8.59.
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vol. 66, pp. 394 397.
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Komarov, N.V., Russ. J. Org. Chem., 1998, vol. 64,
no. 5, pp. 642 646.
5. Roitburg, G.V., Smit, V.A., Semenovskii, A.V.,
Kucherov, V.F., and Chizhov, O.S., Izv. Akad. Nauk
SSSR, Ser. Khim., 1972, no. 10, pp. 2225 2229.
6. Voronkov, M.G., Sherstyannikova, L.V., and Shergi-
na, N.I., Abstracts of Papers, VI Vsesoyuznaya kon-
ferentsiya po khimii atsetilena i ego proizvodnykh
(VIth All-Union Conf. on the Chemistry of Acetylene
and Its Derivatives), Baku, 1979, vol. 2, p. 83.
3-Acetyl-4-phenyl-3-penten-2-one (III). Phenyl-
acetylene, 10.00 g (0.098 mol), was added to a mix-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002