A novel method for the synthesis of dichloroalkenes

Article abstract of DOI:10.1007/s11172-005-0168-9

A novel convenient method for the synthesis of dichloroalkenes was developed. The method involves catalytic olefination of hydrazones of aliphatic carbonyl compounds with bromo(trichloro)methane.

Full text of DOI:10.1007/s11172-005-0168-9

Russian Chemical Bulletin, International Edition, Vol. 53, No. 11, pp. 2647—2649, November, 2004
2647
Brief Communications
A novel method for the synthesis of dichloroalkenes
V. G. Nenajdenko,aꢀ A. V. Shastin,b V. M. Muzalevskii,a and E. S. Balenkovaa
aDepartment of Chemistry, M. V. Lomonosov Moscow State University,
Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (095) 932 8846. Eꢀmail: nen@acylium.chem.msu.ru
bInstitute of Problems of Chemical Physics, Russian Academy of Sciences,
142432 Chernogolovka, Moscow Region, Russian Federation.
Eꢀmail: shastin@icp.ac.ru
A novel convenient method for the synthesis of dichloroalkenes was developed. The method
involves catalytic olefination of hydrazones of aliphatic carbonyl compounds with bromo(triꢀ
chloro)methane.
Key words: olefination, carbonyl compounds, hydrazones, bromotrichloromethane, caꢀ
talysis, copper salts, dichloroolefins.
Construction of new carbonꢀcarbon bonds is a key
problem in modern organic chemistry, while transformaꢀ
tion of carbonyl compounds into olefins is one of the
most general approach to construction of new C=C
bonds.1 Earlier,2 catalytic olefination was discovered as a
novel reaction. It was found that treatment of Nꢀunꢀ
substituted benzaldehyde hydrazones with CCl4 in the
presence of bases and catalytic amounts of cuprous chloꢀ
ride affords β,βꢀdichlorostyrenes.
compounds gave the target dichloroalkenes in low yields.
For instance, in the reaction of octanal hydrazone with
CCl4, the yield of 1,1ꢀdichlorononene (1) was 15%
(Scheme 1).7
Scheme 1
gemꢀDichloroolefins are valuable products of organic
synthesis and are used to obtain chloroacetylenes,3 acetyꢀ
lenes,4 and alkali metal acetylenides.5 In addition, the
gemꢀdichloroolefin fragment is part of the structure of
pyrethroids (e.g., cypermethrin and cyfluthrin) widely used
as pesticides.6
Our preceding attempted syntheses of dichloroolefins
by catalytic dichloromethylenation of aliphatic carbonyl
Later,8 it was demonstrated that bromotriꢀ
chloromethane is a more reactive alkenylating reagent
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2538—2540, November, 2004.
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Nenajdenko et al.
than tetrachloromethane, even in the presence of a cataꢀ
lyst (0.5 mol. % CuCl). In the present work, with the aim
of extending the range of the target products, we carried
out reactions with a wide set of aliphatic aldehydes and
ketones and obtained dichloroalkenes in satisfactory to
good yields (the yield of compound 1 increased to 60%).
The products obtained contain both alkyl substituents and
small rings and have framework and cyclic structures
(Scheme 2, Table 1). To attain the highest possible yields,
a solution of an in situ prepared hydrazone was added to a
solution of bromotrichloromethane, aqueous ammonia,
and cuprous chloride in DMSO (according to the "norꢀ
mal" procedure, polyhaloalkane is added to a solution of
hydrazone, a base, and a catalyst). The reversed order of
mixing the reagents ensures significantly higher concenꢀ
trations of polyhaloalkane and the catalyst with respect to
hydrazone than in the case of normal order of addition; as
shown earlier,2 this should increase the yield of the target
olefin.
For some carbonyl compounds, we used both ways of
mixing the reagents (see Table 1). It turned out that the
reversed order of addition increases the yields of the tarꢀ
get alkenes by 10 to 30% and the yield of the cyclooctanone
derivative increased nearly three times.
According to the data obtained, the yield of the alkene
strongly depends on the spatial environment of the carboꢀ
nyl group. For instance, when passing from phenylꢀ
acetaldehyde and relatively nonꢀhindered heptyl methyl
ketone to noticeably more hindered dibutyl ketone, the
yields of dichloroalkenes 2—4 decrease from 60—70
to 43%. In the series of cyclic ketones, the yields of alkꢀ
enes containing from fiveꢀ to eightꢀmembered rings show
a parallel change with the energy of the ring strain:
5 < 6 > 7 > 8 (see Scheme 2).
Table 1. Dichloroolefins from aliphatic carbonyl compounds
Dichloroalkene
Yield (%)*
(2)
68
Scheme 2
(3)
63
43
(4)
(5)
55 (34)
i. CBrCl3, 0.5 mol.% CuCl
Thus, we developed a novel simple and convenient
method for the synthesis of dichloroalkenes from hydrꢀ
azones of aliphatic carbonyl compounds. The main adꢀ
vantages of the method proposed are easyꢀtoꢀperform
reactions, inexpensive starting reagents, minimum
amounts of a catalyst. The yields of the target alkenes are
comparable with the yields attained via other methods.1
(6)
(7)
42
70 (38)
(8)
60 (36)
44 (15)
Experimental
1
H and 13C NMR spectra were recorded on a Varian
(9)
VXRꢀ400 spectrometer (400 MHz and 100 MHz, respectively)
in CDCl3 with Me4Si as the internal standard. IR spectra were
recorded on a URꢀ20 spectrophotometer (thin film). TLC analyꢀ
sis was carried out on Silufol UVꢀ254 plates; spots were visualꢀ
ized with an acidified solution of KMnO4, the iodine vapor, and
UV light. Column chromatography was carried out on Merck
silica gel (63ꢀ200 mesh).
Synthesis of dichloroalkenes (general procedure). An argonꢀ
prefilled flask was charged with hydrazine hydrate (0.5 mL,
10 mmol) and DMSO (5 mL). A solution of a carbonyl comꢀ
pound (10 mmol) in 5 mL of DMSO was added dropwise with
vigorous stirring. After the reaction was completed (monitoring
by TLC), the solution of the hydrazone obtained was added to a
vigorously stirred mixture of CBrCl3 (5 mL), 25% aqueous
(10)
(11)
27
25
* The yields given in parentheses were attained in the normal
order of addition of CBrCl3 to hydrazone.

Novel route to dichloroalkenes
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004 2649
ammonia (3 mL), and CuCl (0.005 g, 0.5 mol. %) for 0.5 h. The
reaction mixture was stirred until the gas ceased to evolve
(5—30 min for different substrates) and then poured into water
(300 mL). The product was extracted with dichloromethane
(3×100 mL) and the combined extract was dried over sodium
sulfate. The solvents were removed in vacuo and the residue was
purified by column chromatography with hexane as the eluent.
The H NMR spectra of compounds 1, 2, and 4—11 are
identical with those previously reported for 1,9 2,10 4,11 5, 8, 9,12
6,13 7, 11,14 and 10.15
4. Z. Wang, S. Campagna, G. Xu, M.E. Pierce, J. M. Fortunak,
and P. N. Confalone, Tetrahedron Lett., 2000, 41, 4007.
5. E. Hajime, N. Tsutomu, I. Masahiko, and N. Masazumi,
Tetrahedron Lett., 1981, 22, 4441.
6. V. K. Promonenkov, T. G. Perlova, L. N. Andreeva, L. M.
Levit, I. K. Kolchin, E. S. Nemets, A. M. Katunskii, E. Yu.
Balashova, I. I. Eliseeva, V. V. Akshentsev, M. Ya. Pushina,
V. A. Kasparov, E. D. Butova, V. V. Krotov, A. A. Fokin,
and P. A. Krasutskii, Piretroidy. Khimikoꢀtekhnologicheskie
aspekty [Pyrethroids. Aspects of Chemical Technology],
Khimiya, Moscow, 1992, 336 pp. (in Russian).
1
1,1ꢀDichloroꢀ2ꢀmethylnonꢀ1ꢀene (3). The yield was 63%,
colorless oil, Rf 0.84 (hexane). Found (%): C, 56.90; H, 8.21.
7. V. N. Korotchenko, Ph.D. (Chem.) Thesis, M. V.
Lomonosov Moscow State University, Moscow, 2003,
198 pp.
C10H18Cl2. Calculated (%): C, 57.42; H, 8.67. IR, ν/cm–1
1620 (C=C). H NMR, δ: 2.23 (t, 2 H, C(3)H2, J = 7.3 Hz);
:
1
1.85 (s, 3 H, CH3—C=C); 1.43 (pent, 2 H, C(4)H2, J = 7.3 Hz);
1.32—1.24 (m, 8 H, C(5)H2, C(6)H2, C(7)H2, C(8)H2); 0.88 (t,
3 H, Me, J = 7.3 Hz). 13C NMR, δ: 135.37 (C(1)); 113.99
(C(2)); 35.41, 31.77, 29.21, 29.10, 26.98, 22.64, 19.80, 14.07.
8. V. G. Nenajdenko, V. N. Korotchenko, A. V. Shastin, D. A.
Tyurin, and E. S. Balenkova, Zh. Org. Khim., 2004, 40, No. 12
[Russ. J. Org. Chem., 2004, 40 (Engl. Transl.)].
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Fr., 1994, 131, 1001.
11. F. Karrenbrock, H. J. Schafer, and I. Langer, Tetrahedron
Lett., 1979, 2915.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 03ꢀ03ꢀ
32052a).
12. A. D. Ketley, A. J. Berlin, E. Gorman, and L. P. Fesher,
J. Org. Chem., 1966, 31, 305.
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Received June 29, 2004;
in revised form August 30, 2004