Alkylation of bromoarenes with 4-methylbicyclo[2.2.2]octan-1-ol and 8-methyltricyclo[4.4.0.03,8]decan-1-ol in methanesulfonic acid

Article abstract of DOI:10.1007/s11172-011-0264-y

Alkylation of bromoarenes with 4-methylbicyclo[2.2.2]octan-1-ol or 8-methyltricyclo-[4.4.0.0^3,8]decan-1-ol (twistanol) in methanesulfonic acid gives the corresponding bromine-containing 1-aryl-4-methylbicyclo[2.2.2]octanes and 1-aryl-8-methyltr

Full text of DOI:10.1007/s11172-011-0264-y

Russian Chemical Bulletin, International Edition, Vol. 60, No. 8, pp. 1774—1775, August, 2011
1774
Alkylation of bromoarenes with 4ꢀmethylbicyclo[2.2.2]octanꢀ1ꢀol
and 8ꢀmethyltricyclo[4.4.0.03,8]decanꢀ1ꢀol in methanesulfonic acid
V. V. Mezhnev and R. Kh. Geivandov
Research Company for Fine Organic Synthesis and Organic Functional Materials INCORFINANCES,
27 ul. Burakova, 105118 Moscow, Russian Federation.
Eꢀmail: r.ch.geivandov@gmail.com
Alkylation of bromoarenes with 4ꢀmethylbicyclo[2.2.2]octanꢀ1ꢀol or 8ꢀmethyltricycloꢀ
[4.4.0.03,8]decanꢀ1ꢀol (twistanol) in methanesulfonic acid gives the corresponding bromineꢀ
containing 1ꢀarylꢀ4ꢀmethylbicyclo[2.2.2]octanes and 1ꢀarylꢀ8ꢀmethyltricyclo[4.4.0.03,8]ꢀ
decanes.
Key words: bicyclo[2.2.2]octanes, tricyclo[4.4.0.03,8]decanes (twistanes), the Friedel—Crafts
reaction, liquid crystals, alkylation, bromoarenes.
Disubstituted bicyclo[2.2.2]octanes and twistanes are
The procedure we developed is of preparative value
and can be used for the synthesis of other arenes containꢀ
ing bicyclo[2.2.2]octane and twistane substituents.
of interest as elements of liquidꢀcrystal structures.1,2
Earlier,3,4 we have found that 4ꢀalkylbicyclo[2.2.2]octanꢀ
1ꢀols and 8ꢀalkyltwistanꢀ1ꢀols can alkylate benzene and
bromobenzene at the paraꢀposition in conc. H2SO4 acꢀ
cording to the Friedel—Crafts reaction pattern, the yields
of the alkylation products being >90%. However, this
method is of limited application to other benzene, naphꢀ
thalene, and biphenyl derivatives liable to sulfonation.
In the present work, we demonstrated that the use
of methanesulfonic acid instead of sulfuric acid allows
rapid, highꢀyielding, and highly selective alkylation of
bromobenzene, bromobiphenyl, and 2ꢀbromonaphthalene
with 4ꢀmethylbicyclo[2.2.2]octanꢀ1ꢀol and 8ꢀmethyltwistꢀ
anꢀ1ꢀol (Scheme 1).
Experimental
The starting 4ꢀmethylbicyclo[2.2.2]octanꢀ1ꢀol (1a) and
8ꢀmethyltricyclo[4.4.0.03,8]decanꢀ1ꢀol (1b) were prepared acꢀ
cording to known procedures.5,6
The course of all reactions was monitored by TLC on silica
gel (Merck, Kieselgel 60, and F254). Spots were visualized unꢀ
der UV light (λ = 254 nm). The melting points of the starting
compounds and the reaction products were determined on
a MettlerꢀFPꢀ90 instrument fitted with an Olympus BHꢀ2 poꢀ
larizing microscope. 1H NMR spectra were recorded on Bruker
AMꢀ300 and Bruker Avance II 300 spectrometers. Chemical
Scheme 1
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1746—1747, August, 2011.
1066ꢀ5285/11/6008ꢀ1774 © 2011 Springer Science+Business Media, Inc.

Arylbicyclo[2.2.2]octanes
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 8, August, 2011
1775
shifts δ are referenced to Me4Si. Mass spectra were recorded on
a Kratos MSꢀ30 instrument (ionizing energy 70 eV; mass numꢀ
bers are cited for the 79Br isotope).
[4ꢀ(4ꢀBromophenyl)phenyl]ꢀ4ꢀmethylbicyclo[2.2.2]octane
(4a). Yield 90%, m.p. 205—207 °C (MeOH) (cf. Ref. 1: m.p.
207—208 °C (HOCH2CH2OCH3)).
Synthesis of 1ꢀbromoarylꢀ4ꢀmethylbicyclo[2.2.2]octanes
(2a—4a) and 8ꢀbromoarylꢀ1ꢀmethyltwistanes (2b—4b) (general
procedure). Compound 1a or 1b (1 mmol) was added to a vigorꢀ
ously stirred mixture of a bromoarene (1 mmol) and methaneꢀ
sulfonic acid (0.5 mL). The reaction mixture was stirred at
20—25 °C for 10 h and poured onto ice. The product was exꢀ
tracted with ether. The combined extracts were washed with
water, dried over Na2SO4, and concentrated. The residue was
recrystallized from appropriate solvents.
[4ꢀ(4ꢀBromophenyl)phenyl]ꢀ8ꢀmethyltricyclo[4.4.0.03,8]ꢀ
decane (4b). Yield 93%, m.p. 166—168 °C (MeOH). 1H NMR
(CDCl3), δ: 7.57—7.40 (m, 8 H); 2.14—2.04 (m, 2 H); 1.88—1.78
(m, 1 H); 1.77—1.43 (m, 8 H); 1.41—1.27 (m, 2 H); 1.20—1.12
(m, 1 H); 0.93 (s, 3 H, Me). MS, m/z (Irel (%)): 380 [M]+ (69),
365 [M – Me]+ (12), 284 [M – C7H12 + (100), 284 [M – C7H12
] –
– Br]+ (61), 230 [M – MeTW]+ (19). Found (%): C, 72.62;
H, 6.59. C23H25Br. Calculated (%): C, 72.44; H, 6.61.
1ꢀ(4ꢀBromophenyl)ꢀ4ꢀmethylbicyclo[2.2.2]octane (2a). Yield
95%, m.p. 86—87 °C (MeOH) (cf. Ref. 1: m.p. 85—86 °C
(EtOH)).
References
1ꢀ(4ꢀBromophenyl)ꢀ8ꢀmethyltricyclo[4.4.0.03,8]decane (2b).
Yield 92%, m.p. 81—82 °C (MeOH) (cf. Ref. 6: m.p. 82—83 °C
(EtOH)).
1. G. W. Gray, S. M. Kelly, J. Chem. Soc., Perkin Trans. 2, 1981,
2, 26.
2. R. Ch. Geivandov, I. V. Goncharova, V. V. Titov, Mol. Cryst.
Liq. Cryst., 1989, 166, 101.
3. R. Kh. Geivandov, Inventor´s Certificate 1150916 USSR;
Byull. Izobret. [Bulletin of Inventions], 1984, 61 (in Russian).
4. M. I. Barnik, R. Ch. Geivandov, I. I. Gorina, N. M. Shtykov,
Mol. Mater., 1998, 9, 251.
5. N. B. Chapman, S. Sotheeswaran, K. J. Toyne, J. Org. Chem.,
1970, 35, 917.
1ꢀ(6ꢀBromonaphthalenꢀ2ꢀyl)ꢀ4ꢀmethylbicyclo[2.2.2]octane
(3a). Yield 96%, m.p. 166—168 °C (MeOH). 1H NMR (CDCl3),
δ: 7.90 (s, 1 H); 7.71—7.62 (m, 3 H); 7.55 (d, 1 H, J = 13.7 Hz);
7.51 (d, 1 H, J = 13.7 Hz); 1.95—1.86 (m, 6 H, CH2); 1.59—1.51
(m, 6 H, CH2); 0.88 (s, 3 H, Me). MS, m/z (Irel (%)): 328 [M]+
+
(42), 258 [M – C5H10
]
(36), 179 [M – C5H10 – Br]+ (100).
Found (%): C, 69.42; H, 6.41. C19H21Br. Calculated (%):
C, 69.30; H, 6.43.
1ꢀ(6ꢀBromonaphthalenꢀ2ꢀyl)ꢀ8ꢀmethyltricyclo[4.4.0.03,8]ꢀ
decane (3b). Yield 94%, m.p. 152—154 °C (MeOH). 1H NMR
(CDCl3), δ: 7.96 (s, 1 H); 7.72—7.65 (m, 3 H); 7.57—7.48 (m, 2 H);
6. R. Kh. Geivandov, D. Sc. (Chem.) Thesis, State Scientific
Center of the Russian Federation "NIOPIK", Moscow, 1998,
110 pp. (in Russian).
2.18—2.09 (m, 2 H); 1.93—1.84 (m, 1 H); 1.82—1.14 (m, 11 H);
+
0.94 (s, 3 H, Me). MS, m/z (Irel (%)): 354 [M]+, 258 [M – C7H12
]
(54), 179 [M – C7H12 – Br]+ (100). Found (%): C, 71.28;
H, 6.50. C21H23Br. Calculated (%): C, 70.99; H, 6.52.
Received December 27, 2010;
in revised form April 14, 2011