Dehydrohalogenation of haloalkylarenes in the synthesis of alkenylaromatic hydrocarbons

Full text of DOI:10.1134/S1070428012020212

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 2, pp. 293−295. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.M. Magerramov, M.N. Magerramov, I.A. Aliev, A.M. Mustafaev, U.F. Askerova, 2012, published in Zhurnal Organicheskoi Khimii,
2
012, Vol. 48, No. 2, pp. 300−302.
SHORT
COMMUNICATIONS
Dehydrohalogenation of Haloalkylarenes in the Synthesis
of Alkenylaromatic Hydrocarbons
a
a
a
A. M. Magerramov , M. N. Magerramov , I. A. Aliev ,
b
a
A. M. Mustafaev , and U. F. Askerova
aBaku State University, Baku, 5004 Azerbaijan
Institute of Polymer Materials, National Academy of Sciences of Azerbaijan
Sumgaiyt, Az-5004 Azerbaijan
b
e-mail: agamustafayev@mail.ru
Received June 22, 2009
DOI: 10.1134/S1070428012020212
The alkylation of aromatic hydrocarbons with haloal-
The dehydrohalogenation of 1,4-dimethyl-2-[2-
chloro(bromo)propan-1-yl]benzenes furnished the
1,4-dimethyl-2-[(1Е)-prop-1-en-1-yl]benzene in a nearly
quantitative yield.
kenes in the presence of acid catalysts makes it possible
to obtain haloalkylaromatic compounds with a halogen
atom in a strictly defined position in the side chain [1–3].
The products of this reaction are promising raw material
for the preparation of diverse difficultly available organic
substances. In this connection in extension of study [4] we
investigated the dehydrohalogenation of haloalkylarenes
with KOH solution in ethylene glycol in order to evalu-
ate the opportunity of preparation of alkenylaromatic
hydrocarbons of a definite structure.
For the dehydrohalogenation of the other haloalkylar-
enes we used the mixtures of the alkylation products of
methyl-, ethyl-, and isopropylbenzenes with allyl chloride
and bromide in the presence of Lewis acids. These prod-
ucts were mixtures of o-, m-, and p-(2-halopropan-1-yl)
derivatives of alkylarenes.
Dehydrohalogenation procedure. To a solution of
0.12 mol of KОН in 25 ml of di(ethylene glycol) was
added 0.1 mol of haloalkylarene, and the mixture was
boiled for 1.5 h. The reaction products were extracted into
benzene. The extract was washed with water, benzene was
distilled off, the residue was subjected to rectification.
The dehydrohalogenation of [2-chloro(bromo)propan-
-yl]benzene afforded allylbenzene, (1Z)- and (1Е)-prop-
-en-1-ylbenzenes in the ratio 1 : 6 : 93.
1
1
The dehydrochlorination of (1-chloropropan-2-yl)
benzene led to the formation of a chromatographically pure
prop-1-en-2-ylbenzene, and at the dehydrohalogenation
of (1-bromo- and 1-iodopropan-2-yl)benzenes along-
side the prop-1-en-2-ylbenzene the (1Е)-prop-1-en-1-
ylbenzene was obtained (Scheme 1).
From (1-chloropropan-2-yl)benzene we obtained
2
0
11.4 g (97%) of a mixture of bp 193–196°С, d 0.9068,
4
2
0
n
1.5498. (1Е)-Prop-1-en-1-ylbenzene was isolated
D
of bp 73.5°С (20 mm Hg), d4 0.9083, n D2 0 1.5470.
МR 41.20, calc. 39.69. IR spectrum, ν, cm : 965 s
2
0
–
1
Expectedly the (2-methyl-1-chloropropan-2-yl)
benzene did not suffer the dehydrochlorination. Un-
expectedly dehydroiodination also failed with the
-(1-iodopropan-2-yl)naphthalene. We succeeded to
obtain the 1-(1-prop-1-en-2-yl)naphthalene from the
-(1-iodopropan-2-yl)naphthalene only by pyrolysis of the
-(1-acetoxypropan-2-yl)naphthalene that was the prod-
uct of iodine substitution by an acetoxy group (Scheme 2).
D
(trans-С=С), 770, 730 s (monosubstitution in benzene).
The physicochemical constants were consistent with the
published data [5].
1
The dehydrohalogenation of the mixture of
(
2-chloropropan-1-yl)toluenes gave 12.8 g (97%) of
a mixture of 1-methyl-2-[(1Е)-prop-1-en-1-yl]benzene
43–47%) and 1-methyl-3- and 1-methyl-4-[(1Е)-prop-1-
1
1
(
2
93

294
MAGERRAMOV et al.
Scheme 1.
CH Hlg
2
Hlg = Cl
KOH
KOH
O(CH CH OH)
+
O(CH CH OH)
2
2
2
2
2
2
Hlg = Br 2.5:97.5
Hlg = I 10:90
Scheme 2.
Me CH OAc
Me
CH2I
Me
CH2
2
AcONa
AcOH
Δ
_
AcOH
en-1-yl]benzenes (45–47%), bp of the mixture 88–90°С
1-Isopropyl-2-[(1Е)-prop-1-en-1-yl]-benzene
15 mm Hg), d 0.9045, n D2 0 1.5450. IR spectrum,
2
0
20
20
(
was isolated, bp 218–219°С, d 0.9041, n 1.5287.
4
4
D
–
1
–1
ν, cm : 960 s (trans-С=С), 744 s (1,2-substitution in
МR 54.53, calc. 53.55. IR spectrum, ν, cm : 965 s
D
benzene), 778 w (1,3-substitution in benzene), 820 s
(trans-С=С), 755 s (1,2-substitution in benzene). Found,
%: С 89.70; Н 9.75. С Н . Calculated, %: С 89.94;
(1,4-substitution in benzene).
1
2
16
Н 10.06.
The dehydrohalogenation of the mixture of [2-chloro-
bromo)propan-1-yl]ethylbenzenes furnished 13.8 g
95%) of a mixture of 2-[(1Е)-prop-1-en-1-yl]- (~50%),
(
(
Similarly 1-isopropyl-4-[(1Е)-prop-1-en-1-yl]
2
0
benzene was isolated, bp 233–234°С, d 0.9034,
4
20
–1
3
-[(1Е)-prop-1-en-1-yl]- (~10%), and 4-[(1Е)-prop-1-en-
-yl]-1-ethylbenzenes (~40%), bp of the mixture93–96°С
n
1.5310. МR 54.80, calc. 53.55. IR spectrum, ν, cm :
D D
1
844 s (1,4-substitution in benzene), 965 s (trans-С=С) [6,
7]. Found, %: С 89.82; Н 9.78. С Н . Calculated, %:
С 89.94; Н 10.06.
2
0
(
12 mm Hg), d 0.9036, n D2 0 1.5290. IR spectrum, ν,
4
12 16
–
1
cm : 960 s (trans-С=С), 749 s (1,2-substitution in
benzene), 787 w (1,3-substitution in benzene), 844 s
The dehydrohalogenation of the mixture of 1,2-di-
methyl-[2-chloro(bromo)propan-1-yl]benzenes afforded
13.6 g (93%) of a mixture of 1,2-dimethyl-3-[(1Е)-prop-
1-en-1-yl]-benzene (39.5%), 1,2-dimethyl-4-[(1Е)-
prop-1-en-1-yl]-benzene (51.6%), and of unidentified
compounds (8.9%), bp of the mixture 106–109°С
(1,4-substitution in benzene).
2
-[(1Е)-Prop-1-en-1-yl]-1-ethylbenzene was iso-
2
0
20
lated, bp 75–76°С (8 mm Hg), d 0.9155, nD 1.5380.
.
4
–
1
МR 49.86, calc. 48.93. IR spectrum, ν, cm : 770 s
D
(
1,2-substitution in benzene), 965 s (trans-С=С) [6,
2
0
20
7
]. Found, %: С 90.30; Н 9.42. С Н . Calculated, %:
(12 mm Hg), d 0.9070, n 1.5450. IR spectrum, ν,
11
14
4
D
–1
С 90.41; Н 9.59.
cm : 960 s (trans-С=С), 726, 752, 777 (1,2,3-substitution
in benzene), 830 s (1,2,4-substitution in benzene).
At the dehydrohalogenation of the mixture of
2-chloro-(bromo)propan-1-yl]isopropylbenzenes we ob-
[
At the dehydrohalogenation of the mixture of
1,3-dimethyl-[2-chloro(bromo)propan-1-yl]benzenes we
obtained 14 g (96%) of a mixture of 1,3-dimethyl-2-[(1Е)-
prop-1-en-1-yl]benzene (32%), 1,3-dimethyl-4-[(1Е)-
prop-1-en-1-yl]benzene (66%), bp of the mixture 97–
tained 15.2 g (95%) of a mixture of 1-isopropyl-2-[(1Е)-
prop-1-en-1-yl]benzene (~39%), 1-isopropyl-3-[(1Е)-
prop-1-en-1-yl]benzene (~14%), 1-isopropyl-4-[(1Е)-
prop-1-en-1-yl]benzene (~43%), bp of the mixture 107–
2
0
20
100°С (12 mm Hg), d 20 0.9061, n 20 1.5390. IR spectrum,
1
10°С (12 mm Hg), d 0.8936, n 1.5310. IR spectrum,
4 D
4
D
–
1
ν, cm–1: 964 s (trans-С=С), 788, 768 (1,2,3-substitution
in benzene), 831 s (1,2,4-substitution in benzene).
1,3-Dimethyl-2-[(1Е)-prop-1-en-1-yl]-benzene was
ν, cm : 962 s (trans-С=С), 755 s (1,2-substitution in
benzene), 788 w (1,3-substitution in benzene), 845 s
(1,4-substitution in benzene).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 2 2012

DEHYDROHALOGENATION OF HALOALKYLARENES
295
isolated, bp 75°С (4 mm Hg), d 42 0 0.9029, n 1.5270.
20
equipped with a katharometer, a column 5 mm × 1.5 m,
stationary phaseApieson-Lon Chromosorb W, ramp 140–
200°С, heating rate 5 deg/min, carrier gases helium and
nitrogen. The identification of the dehydrohalogenation
products was performed by GLC with isolation or con-
centration by rectification on a column of the efficiency
20 theoretical plates, and with the use of IR spectral data.
D
–
1
МR 49.27, calc. 48.93. IR spectrum, ν, cm : 964 s
D
(
trans-С=С), 780 s (1,2,3-substitution in benzene).
Found, %: С 90.32; Н 9.48. С Н . Calculated, %:
11
14
С 90.41; Н 9.59.
Similarly 1,3-dimethyl-4-[(1Е)-prop-1-en-1-yl]
2
0
benzene was isolated, bp 77°С (4 mm Hg), d 0.9091,
4
2
0
–1
n
1.5440. МR 50.69, calc. 48.93. IR spectrum, ν, cm :
D
D
8
25 s (1,2,4-substitution in benzene), 965 s (trans-С=С)
REFERENCES
[6, 7]. Found, %: С 90.35; Н 9.39. С Н . Calculated,
11 14
%
: С 90.41; Н 9.59.
1
. Magerramov, M.N., Farkhadova, S.M., Zokhrabbeko-
va, E.Z., and Usubova, E.N., Izv. Vuzov, Ser. Khim. Khim.
Tekhnol. 1979, vol. 22, p. 275.
From 1,4-dimethyl-2-[2-chloro(bromo)propan-1-
yl]-benzene 13.8 g (95%) of 1,4-dimethyl-2-[(1Е)-
prop-1-en-1-yl]benzene was obtained of bp 96–97°С
2
3
. Magerramov, M.N., Zh. Org. Khim. 1982, 18, 133.
2
0
20
(12 mm Hg), d4 0.9000, n 1.5420. МR 50.54, calc.
D D
. Magerramov M.N., Yusifov Ch.A., and Sadykhov N.S. Izv.
vuzov. Ser. khim. i khim. tekhnol. 1982, 25, 1059.
–
1
4
8.93. IR spectrum, ν, cm : 828 s (1,2,4-substitution in
benzene), 965 s (trans-С=С) [6, 7]. Found, %: С 90.37;
Н 9.35. С Н . Calculated, %: С 90.41; Н 9.59.
4
. Magerramov M.N., Zokhrabbekova E.Z., LyutfalievA.G.,
andAskerova U.F.,Abstracts of Papers, I Mezhdunarodnaia
nauchnaia konferentsiia “Tonkii organicheskii sintez i
kataliz” (1st Int. Sci. Conference on Fine Organic Synthe-
sis), Baku, 1999, p. 74.
11
14
1
-(Prop-1-en-2-yl)naphthalene. By the pyrolysis of
2.8 g (0.1 mol) of 1-(1-acetoxypropan-2-yl)naphthalene
in a quartz tube packed with crushed pyrex glass at
2
5
0
10–520°С and the volume rate of the reagent supply
.3 l h 10.4 g (62%) of 1-(prop-1-en-2-yl)naphthalene
5. Mixer R.Y., Heck R.F., Winstein S., andYounq W.G., J. Am.
Chem. Soc., 1953, vol. 75, p. 4094.
−
1
2
0
was obtained, bp 100–102°С (2 mm Hg), d 1.0115,
4
2
0
–1
6. Bellamy, L.J., The Infra-red Spectra of Complex Molecules,
n
1.6090; МR 57.51, calc. 55.03. IR spectrum, ν, cm :
D
D
London: Methuen, 1958.
8
90 m (=С=СН ). The physicochemical constants were
2
consistent with the published data [8].
7. Nakanishi, K., Infrared Absorption Spectroscopy. Practical,
San Francisco: Holden-Day; Tokyo: Nankodo, 1962.
IR spectra of compounds were recorded on a spec-
trophotometer Varian 3600 FT-IR from thin films. The
chromatograms were taken on an instrument Chrom-2
8
. Hopff, N. and Lussi, N., Makromol. Chem., 1963, vol. 62,
p. 32.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 2 2012