Diazo reactions with unsaturated compounds: VII. Vinyl p-methylphenyl and vinyl p-nitrophenyl ethers in the Meerwein reaction

Article abstract of DOI:10.1023/B:RUGC.0000015991.28123.8e

Vinyl p-methylphenyl ether in aqueous acetone at pH 3-4 in the presence of catalytic amounts of copper(II) chloride reacts with arenediazonium chlorides to form arylacetaldehydes. Vinyl p-nitrophenyl ether under the same conditions fails to react with are

Full text of DOI:10.1023/B:RUGC.0000015991.28123.8e

Russian Journal of General Chemistry, Vol. 73, No. 9, 2003, pp. 1419 1420. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 9, 2003,
pp. 1501 1502.
Original Russian Text Copyright
2003 by Naidan, Fesak.
Diazo Reactions with Unsaturated Compounds:
VII. Vinyl p-Methylphenyl and Vinyl p-Nitrophenyl Ethers
1
in the Meerwein Reaction
V. M. Naidan and A. Yu. Fesak
Khmel’nitskii Cherkassy State University, Cherkassy, Ukraine
Received October 29, 2001
Abstract Vinyl p-methylphenyl ether in aqueous acetone at pH 3 4 in the presence of catalytic amounts
of copper(II) chloride reacts with arenediazonium chlorides to form arylacetaldehydes. Vinyl p-nitrophenyl
ether under the same conditions fails to react with arenediazonium chlorides.
As we found previously [2], vinyl phenyl ether
reacts with arenediazonium chlorides to form arylation
hydrolysis in a weakly acidic medium is enhanced due
to the fact that the electron density on the ether
products, 1-phenoxy-2-arylethenes and arylacetal- oxygen atom is increased under the effect of the
hydes. It was shown that arenediazonium chlorides,
too, react with vinyl p-methylphenyl ether at 25 30 C
in aqueous acetone in the presence of copper(II)
chloride at pH 3 4, providing arylacetaldehydes Ia If
methylphenyl group. Apparently, for this reason, we
could not isolate unsaturated ethers B from the reac-
tion mixture. It should be noted that the best yields of
aldehydes Ia If can be attained if the reaction pro-
ducts are first subjected to steam distillation and then
distilled in a vacuum.
(
Table 1). The latter reaction probably involves chlo-
rination of vinyl p-methylphenyl ether to form
-chloro-1-(p-methylphenoxy)-2-arylethanes A which,
1
having the highly reactive chlorine atom to the ether
oxygen, can be easily dehydrochlorinated [3], giving
unsaturated ether B, or undergo hydrolysis [3], con-
verting into semiacetals of arylacetaldehydes and p-
cresol. Such semiacetals are known [3] to be unstable
and tend to decompose into corresponding aldehydes p-methylphenyl
and cresol which was isolated from the reaction mix- salts, compared with the vinyl group in vinyl phenyl
ture along with arylacetaldehydes. Probably, this is ether, can be explained by increased electron density
The yields of the reactions of vinyl p-
methylphenyl ether with arenediazonium chlorides
are 15 20% higher than of the reactions of vinyl
phenyl ether with the same arenediazonium chlorides.
The enhanced reactivity of the vinyl group in vinyl
ether
toward
arenediazonium
the reason why we failed to isolate chloroarylation
products A.
on the vinyl group in the former under the effect of
the methyl group of the p-methylphenoxyl radical.
Arylacetaldehydes Ia Ig can also be formed by
hydrolysis of unsaturated ethers B whose tendency for
Arylacetaldehydes Ia If were identified as their
2,4-dinitrophenylhydrazones IIa IIf (Table 2). The
CH =CHOC H CH -p + p-RC H N Cl
p-RC H CH CH(Cl)OC H CH -p,
6 4 2 6 4 3
2
6
4
3
6
4
2
N2
A
HOH
HCl
A
p-RC H CH CH(OH)OC H CH -p
6 4 2 6 4 3
HCl
HOH, H+
p-RC H CH=CHOC H CH -p
p-RC H CH CH=O + HOC H CH -p,
6 4 2 6 4 3
6
4
6
4
3
B
Ia If
R = H (a), CH (b), CH O (c), Cl (d), Br (e), O N (f).
3
3
2
1
For communication VI, see [1].
1
070-3632/03/7309-1419$25.00 2003 MAIK Nauka/Interperiodica

1420
NAIDAN, FESAK
Table 1. Yields and constants of arylacetaldehydes
Table 2. Melting points and elemental analyses of aryl-
acetaldehyde 2,4-dinitrophenylhydrazones p-RC H CH
a
p-RC H CH CHO (I)
6
4
2
6
4
2
CH=NNHC H (NO ) (II)
6
3
2 2
bp, C (p, mm)
or mp, C (solvent for
crystallization)
Comp. Yield,
2
0
n
D
no.
%
Calcu-
lated
N, %
mp,
C
Found N,
%
R
Formula
Ia
Ib
Ic
Id
Ie
62
78 79 (10)
82 83 (4)
98 99 (3)
1.5260
1.5226
1.5340
44
49
22
28
IIa H
119 120 18.92, 18.83 C H N O
IIb CH3 152 153 18.13, 18.07 C H N O
18.66
17.82
16.96
1
4
12
4
4
4
5
b
87 88 (benzene)
15
14
4
b
96 97 (dioxane ether,
IIc CH O 137 138 17.24, 17.06 C H N O
3 15 14 4
1
: 3)
IId Cl
IIe Br
142 143 17.02, 16.83 C H ClN O 16.74
150 151 14.88, 15.08 C H BrN O 14.78
14 11 4 4
14 11 4 4
b
If
6.1
86 87 (water)
IIf O N 189 190 20.53, 20.18 C H N O
20.28
2
14 11 5 6
a
b
For published data, see [4].
Melting point.
physicochemical characteristics of Ia If and IIa IIf
are consistent with those reported in [4].
gave positive qualitative tests for p-cresol with FeCl3
and reacted with bromine water [6].
Vinyl p-nitrophenyl ether in aqueous acetone in
Aldehydes Ib If were prepared similarly to Ia.
the presence of copper(II) chloride fails to react with Compounds Ib, Ic were purified by vacuum distilla-
arenediazonium chlorides and was recovered from the tion, and compounds Id If, by crystallization.
reaction mixtures. The lower reactivity of the vinyl
Arylacetaldehyde 2,4-dinitrophenylhydrazones
group in this compound toward arenediazonium salts
IIa IIf were obtained by the procedure in [7] and
can be explained by the fact that its electron density
purified by crystallization from alcohol.
is strongly decreased under the effect of the nitro
group of the p-nitrophenoxyl radical. The reduced
REFERENCES
activity of the double bond in vinyl p-nitrophenyl
ether in electrophilic and radical reactions has been
noted in [5].
1
2
. Naidan, V.M. and Smalius, V.V., Zh. Obshch. Khim.,
001, vol. 71, no. 11, p. 1899.
2
EXPERIMENTAL
. Naidan, V.M. and Fesak, A.Yu., Zh. Obshch. Khim.,
000, vol. 70, no. 10, p. 1702.
2
Phenylacetaldehyde (Ia). Acetone, 40 ml, 10.5 ml
of freshly distilled vinyl p-methylphenyl ether [bp
3. Mikhant’ev, B.I., Mikhant’ev, V.B., Lapenko, V.L.,
and Voinova, V.K., Nekotorye vinil’nye monomery
(Certain Vinyl Monomers), Voronezh: Voronezh. Gos.
Univ., 1970, pp. 26, 219, 229.
2
0
7
3.5 C (10 mm), n 1.5152], and 0.1 g of powdered
D
calcium carbonate were mixed. The resulting mixture
was vigorously stirred, and a solution of benzenedi-
azonium chloride, prepared from 4.5 ml of aniline,
4
. Naidan, V.M. and Naidan, G.D., Zh. Org. Khim., 1972,
vol. 8, no. 10, p. 2172; Zh. Org. Khim., 1978, vol. 14,
no. 2, p. 278.
1
3 ml of conc. HCl, and a solution of 3.6 g of sodium
nitrite in 5 ml of water, was added dropwise from a
dropping funnel with a cooling shell. The diazo solu-
tion was preliminarily neutralized with powdered
sodium hydrocarbonate to pH 3 4, and then a solution
of 2.1 g of CuCl 2H O in 5 ml of water was added.
5. Filippova, A.Kh., Dubinskaya, E.I., and Shostakov-
skii, M.F., Zh. Org. Khim., 1968, vol. 4, no. 5, p. 818.
2
2
6
. Dictionary of Organic Compounds, Heilbron, J. and
Bunbury, H.M., Eds., London: Eyre and Spottiswoode,
Gaseous products uniformly evolved (1 2 bubbles per
second) at 25 30 C within 8 h. Every 5 10 min we
measured pH of the reaction mixture and added 0.1 g
of calcium carbonate if the pH was equal to 2. When
gaseous products no longer evolved, the mixture was
treated with ether. The ether extracts were dried with
sodium sulfate, the solvent was distilled off, and the
residue was distilled in a vacuum to obtain 3.7 g
1
953, vol. 1. Translated under the title Slovar’ organi-
cheskikh soedinenii, Moscow: Inostrannaya Literatura,
949, vol. 1, p. 576.
1
7. Shriner, R.L., Fuson, R.C., Curtin, D.Y., and Mor-
rill, T.C., The Systematic Identification of Organic
Compounds. A Laboratory Manual, New York: Wiley,
1978. Translated under the title Identifikatsiya organi-
cheskikh soedinenii, Moscow: Mir, 1983, p. 205.
(
62%) of compound Ia and 1.8 g of a white crystalline
substance, mp 35 C [bp 90 91 C (11 mm)], which
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 9 2003