Adamantylation of arenes
Russ.Chem.Bull., Int.Ed., Vol. 64, No. 1, January, 2015
247
1H NMR, : 1.81 (m, 6 H, H()); 2.11 (m, 3 H, H()); 2.15 (m, 6 H,
H()); 2.18 (s, 3 H, Me(3)); 2.29 (s, 3 H, Me(2)); 4.85 (s, 1 H,
OH); 6.77 (d, 1 H, H(4), J= 7.9 Hz); 7.01 (d, 1 H, H(5), J = 7.9 Hz).
tion is a reversible reaction and the dealkylation for ether
1
d proceeds slower than for resorcinol. It is known that
similar butylation—debutylation is characteristic of 2,4,6ꢀ
tri(tertꢀbutyl)anisole: this ether does not undergo dealkylꢀ
13
C NMR, : 21.4 (Me); 28.9 (C()); 35.8 (C()); 36.7 (C());
3.1 (C()); 122.5 (C(4), C(5)); 127.0 (C(6)); 137.2 (C(2), C(3));
4
1
ation in trifluoroacetic acid, in contrast to the correspondꢀ
51.2 (C(1)). Found (%): C, 84.52; H, 9.48. C H O. Calculatꢀ
ing phenol.10 Heating of known 4ꢀ(1ꢀadamantyl)ꢀ1,3ꢀ
18 24
ed (%): C, 84.36; H, 9.43.
8
dimethoxybenzene in CF COOH at 80 C does not lead
3
5ꢀ(1ꢀAdamantyl)ꢀ2,3ꢀxylenol (1b). A. A mixture of 2,3ꢀxylenol
to its isomerization, which was observed for adamantylatꢀ
(0.122 g, 1 mmol) and 1ꢀAdOH (0.152 g, 1 mmol) in CF COOH
3
ed pyrogallol and 2,3ꢀxylenol.
(2 mL) was allowed to stand at room temperature for 30 days.
5
ꢀ(1ꢀAdamantyl)ꢀ1,3ꢀdimethylbenzene (1e) was obꢀ
The isolation was similar to that for compound 1a, the yield was
0
.194 g (76%), m.p. 126—127 C.
tained by the reaction of mꢀxylene with 1ꢀAdOH in
B. Compound 1a (0.256 g, 1 mmol) in CF COOH (2 mL).
CF COOH. It is known that 2ꢀ(1ꢀadamantyl)toluene was
3
3
was heated at 80 C for 5 h. The acid was evaporated, the reacꢀ
tion mixture was washed with water, the precipitate was filtered
off and dried. The yield was 0.144 g (56%), m.p. 126—127 C.
not detected even in the trace amounts after attempted
adamantylation of toluene with 1ꢀbromoadamantane.
Apparently, this is explained by a considerable sterical
hindrance arising upon introduction of the adamantyl subꢀ
stituent at orthoꢀposition to the methyl group. This also
explains the formation of compound 1e upon reaction of
mꢀxylene with 1ꢀAdOH in CF COOH. The reaction of
mꢀcresol with 1ꢀAdOH in CF COOH leads to 6ꢀ(1ꢀadaꢀ
mantyl)ꢀ3ꢀmethylphenol (1f). Compound 1f, like 6ꢀ(1ꢀ
adamantyl)ꢀ2,3ꢀdichlorophenol (1c) and 4ꢀ(1ꢀadamanꢀ
tyl)ꢀ1,3ꢀdimethoxybenzene, does no isomerize upon heatꢀ
ing in CF COOH at 80 C. Alkylation of 3ꢀchlorophenol
under similar conditions leads to the disubstituted prodꢀ
uct, 4,6ꢀdi(1ꢀadamantyl)ꢀ3ꢀchlorophenol (1g). Physicoꢀ
chemical characteristics of compounds 1d—f correspond
to the literature data,9
characteristics of new compounds 1a—c,g are given in the
Experimental.
1
1
–1
1
IR, /cm : 3267 (OH); 2890, 2847 (CH , Ad). H NMR,
2
: 1.80 (m, 6 H, H()); 1.90 (m, 6 H, H()); 2.11 (m, 3 H, H());
2.16 (s, 3 H, Me(3)); 2.31 (s, 3 H, Me(2)); 4.66 (s, 1 H, OH);
6.68 (d, 1 H, H(2), J = 1.6 Hz); 6.80 (d, 2 H, H(4), H(6), J = 1.6 Hz).
13
C NMR, : 11.2 (Me(3)); 20.45 (Me(2)); 29.0 (C()); 36.9
3
(
(
C()); 37.7 (C()); 43.2 (C()); 109.5 (C(4)); 119.1 (C(6)); 119.4
C(2)); 137.7 (C(3)); 149.9 (C(5)); 155.3 (C(1)). Found (%):
3
C, 84.47; H, 9.51. C H O. Calculated (%): C, 84.36; H, 9.43.
18
24
6
ꢀ(1ꢀAdamantyl)ꢀ2,3ꢀdichlorophenol (1c). A mixture of 2,3ꢀdiꢀ
chlorophenol (0.326 g, 2 mmol) and 1ꢀAdOH (0.304 g, 2 mmol)
3
in CF COOH (4 mL) was allowed to stand at room temperature
3
for 7 days, the isolation was similar to that for compound 1a,
–
1
the yield was 0.102 g (17%), m.p. 140—141 C. IR, /cm :
1
3506 (OH); 2904, 2850 (CH , Ad); 801 (Cl). H NMR, : 1.80
2
,12—14
melting points and spectral
(m, 6 H, H()); 2.11 (m, 9 H, H() and H()); 5.64 (s, 1 H, OH);
7
.01 (d, 1 H, H(4), J = 8.4 Hz); 7.09 (d, 1 H, H(5), J = 8.4 Hz).
C NMR, : 11.2 (Me(3)); 20.45 (Me(2)); 29.0 (C());
6.9 (C()); 37.7 (C()); 43.2 (C()); 109.5 (C(4)); 119.1 (C(6));
19.4 (C(2)); 137.7 (C(3)); 149.9 (C(5)); 155.3 (C(1)).
1
3
3
1
In conclusion, we suggested a convenient and selective
method for the synthesis of different adamantylated arenes,
including isomeric adamantylꢀ2,3ꢀxylenols. The reaction
of 1ꢀadamantanol with 1,3ꢀdisubstituted benzenes gives
monoꢀ or diadamantylated products, depending on the
structure of the starting compounds.
Found (%): C, 64.57; H, 6.14. C H Cl O. Calculated (%):
16
18
2
C, 64.59; H, 6.10.
,6ꢀDi(1ꢀadamantyl)ꢀ1,3ꢀdimethoxybenzene (1d). A mixture
4
of 1,3ꢀdimethoxybenzene (0.138 g, 1 mmol) and 1ꢀAdOH (0.304 g,
2 mmol) in CF COOH (2 mL) was allowed to stand at room
3
temperature for 12 h, the isolation was similar to that for comꢀ
pound 1a, the yield was 0.324 g (92%), m.p. 241—242 C
Experimental
1
(
(
cf. Ref. 8: 241—242 C). H NMR, : 1.79 (m, 6 H, H()); 2.07
m, 3 H, H()); 2.11 (m, 6 H, H()); 3.86 (s, 6 H, OMe(1),
13
OMe(3)); 6.48 (s, 1 H, H(2)); 7.09 (s, 1 H, H(5)). C NMR,
: 29.1 (C()); 36.5 (C()); 37.0 (C()); 40.9 (C()); 55.0 (OMe(1),
OMe(3)); 124.5 (C(5)); 129.5 (C(4), C(6)); 157.0 (C(1)).
5ꢀ(1ꢀAdamantyl)ꢀ1,3ꢀdimethylbenzene (1e). A mixture of
mꢀxylene (0.106 g, 1 mmol) and 1ꢀAdOH (0.152 g, 1 mmol) in
IR spectra were recorded on a Bruker Vectorꢀ22 Fourierꢀ
transform IR spectrometer (KBr), 1H and 13C NMR spectra
were recorded on a BrukerꢀAvance III 600 spectrometer (600.13
1
13
(
H) and 150.90 ( C) MHz) in CDCl , elemental analysis was
3
performed on a Flash EA 1112TM Analyzer (Krasnoyarsk Reꢀ
gional Multiꢀuser Center of the Siberian Branch of the Russian
Academy of Sciences). Heteronuclear 2D H— C NMR spectra
CF COOH (2 mL) was allowed to stand for ~24 h at room temꢀ
3
1
13
perature, the isolation was similar to that for compound 1a, the
yield was 0.222 g (86%), m.p. 151—152 C (cf. Ref. 12: 151—152 C).
1
13
(
HSQC and HMBC) were used to assign the H and C signals.
1
H NMR, : 1.80 (m, 6 H, H()); 1.92 (m, 6 H, H()); 2.12 (m, 3 H,
The 2D experiments were carried out using standard parameters
supplied by the spectrometer software. The HMBC experiment
was optimized for the constants JH,C = 8 Hz.
ꢀ(1ꢀAdamantyl)ꢀ2,3ꢀxylenol (1a). A mixture of 2,3ꢀxylenol
0.244 g, 2 mmol) and 1ꢀAdOH (0.152 g, 1 mmol) in CF COOH
H()); 2.35 (s, 6 H, Me(1), Me(3)); 6.86 (s, 1 H, H(2)); 7.02 (s, 2 H,
13
H(4), H(5)). C NMR, : 28.8 (C()); 36.8 (C()); 36.9 (C());
3.3 (C()); 122.5 (C(4), C(6)); 127.5 (C(2)); 137.4 (C(1), C(3));
151.3 (C(5)).
6ꢀ(1ꢀAdamantyl)ꢀ3ꢀmethylphenol (1f). A mixture of mꢀcresol
4
6
(
(
3
2 mL) was stirred for 20 min at 12 C and then was allowed to
stand for ~24 h. A precipitate formed was filtered off, washed
with water, and dried. The yield was 0.205 g (80%), m.p.
(0.108 g, 1 mmol) and 1ꢀAdOH (0.152 g, 1 mmol) in CF COOH
(2 mL) was allowed to stand at room temperature for ~24 h, the
isolation was similar to that for compound 1a, the yield was
3
1
31—132 C. IR, /cm–1: 3586 (OH); 2904, 2848 (CH , Ad).
2