B. Banks et al. / Journal of Fluorine Chemistry 131 (2010) 627–634
633
(15 mL). 4-Pentylphenol (0.59 g, 3.6 mmol) was dissolved in dry
THF (15 mL) and carefully added, with stirring, to the sodium
hydride and THF mixture. After the evolution of hydrogen gas
had stopped, 1,3-dibromo-2,4,5,6-tetrafluorobenzene (0.53 g,
1.7 mmol) was added and the reaction heated to reflux for 4
days, cooled, poured on to water (100 mL) and extracted with
dichloromethane (3ꢃ 50 mL). The combined extracts were washed
with water (100 mL), dried (MgSO4), filtered and solvent evapo-
rated. Column chromatography of the residue on silica gel with
hexane:DCM (10:1) as the eluent afforded 4,40-(4,6-dibromo-2,5-
difluoro-1,3-phenylene)bis(oxy)bis(pentylbenzene) 13 (0.72 g, 70%)
H, 2.6. C15H11OBr2F3 requires: C, 42.5; H, 2.6%);
d
H 0.95 (3H, t, 3JHH
7.3, CH3), 1.63 (2H, tt, 3JHH 7.5, 3JHH 7.3, CH2), 2.56 (2H, t, 3JHH 7.5,
ArCH2), 6.80 (2H, AX, 3JAX 8.5, Hortho), 7.12 (2H, AX, 3JAX 8.5, Hmeta);
d
C 14.0 (s, CH3), 24.9 (s, CH2), 37.4 (s, ArCH2), 99.5 (dd, 2JCF 22.8, 2JCF
22.8, C-4), 107.2 (d, 2JCF 20.7, C-1), 115.3 (s, Cortho), 129.9 (s, Cmeta),
138.3 (ddd, 2JCF 16.1, 3JCF 5.8, 4JCF 2.9, C-6), 138.9 (s, C–CH2), 145.7
(ddd, 1JCF 248, 2JCF 14.7, 3JCF 4.5, C-3), 146.1 (ddd, 1JCF 249, 2JCF 13.5,
4JCF 2.9, C-2), 150.2 (ddd, 1JCF 251, 3JCF 3.4, 4JCF 3.4, C-5), 155.1 (s, C–
O); dF ꢁ122.0 (dd, 4JFF 3.2, 5JFF 10.7, F-5), ꢁ130.0 (dd, 3JFF 20.7, 4JFF
3
5
3.2, F-3), ꢁ130.5 (dd, JFF 20.7, JFF 10.7, F-2); m/z (EI+) 426 ([M]+,
28), 424 ([M]+, 44), 422 ([M]+, 23), 395 (100); and, 4,4’-(2,5-
dibromo-3,6-difluoro-1,4-phenylene)bis(oxy)bis(propylbenzene 15b
(0.29 g, 10%) as a white solid; m.p. 117–119 8C (Found C, 53.3;
as
28H30O2Br2F2 requires: C, 56.4; H, 5.05%); vmax 2921, 2851,
1590, 1501, 1455, 1425, 1206, 1165, 1072 cmꢁ1 H 0.86 (6H, t, 3JHH
7.1, CH3), 1.23–1.34 (8H, m, CH2), 1.56 (4H, m, CH2), 2.53 (4H, t, 3JHH
a white solid; m.p. 99–101 8C (Found C, 56.4; H, 5.1.
C
;
d
H, 4.1. C24H22O2Br2F2 requires: C, 53.4; H, 4.1%);
7.3, CH3), 1.64 (2H, m, CH2), 2.58 (2H, t, 3JHH 7.7, ArCH2), 6.85 (2H,
m, Hortho), 7.15 (2H, m, Hmeta); C 14.0 (s, CH3), 24.9 (s, CH2), 37.5 (s,
ArCH2), 107.0 (dd, 2JCF 15.5, 3JCF 7.3, C-2), 115.4 (s, Cortho), 129.9 (s,
d
H 0.96 (3H, t, 3JHH
3
3
7.8, ArCH2), 6.78 (4H, AX, JAX 8.6, Hortho), 7.07 (4H, AX, JAX 8.6,
Hmeta); dC 14.2 (s, CH3), 22.7 (s, CH2), 31.4 (s, CH2), 31.7 (s, CH2),
d
2
35.3 (s, CH2), 103.2 (d, JCF 24.9, C-4), 115.3 (s, Cortho), 129.7 (s,
C
meta), 138.5 (s, C–CH2), 139.2 (dd, 2JCF 13.9, 3JCF 4.6, C-1), 150.7 (dd,
Cpara), 138.3 (s, Cmeta), 142.0 (dd, 2JCF 13.3, 3JCF 3.7, C-1), 147.1 (dd,
1JCF 251, 4JCF 4.4, C-3), 155.3 (s, C–O); dF ꢁ120.8 (s); m/z (EI+) 542
1JCF 256, JCF 3.9, C-2), 153.6 (dd, JCF 245, JCF 4.1, C-5), 155.0 (s,
([M]+, 24), 540 ([M]+, 48), 538 ([M]+, 51), 90 (100).
4
1
4
C
ipso); dF ꢁ100.7 (1F, d, 5JFF 10.0, F-5), ꢁ140.4 (1F, d, 5JFF 10.0, F-2);
m/z (EI+) 598 ([M]+, 29), 596 ([M]+, 54), 594 ([M]+, 27), 483 (100),
4.2.10. 1,4-Dibromo-2,3,5-trifluoro-6-(2-propylphenoxy)benzene 16
Sodium metal (0.3 g, 13 mmol) was added to a solution of 2-
propylphenol (1.43 g, 10.5 mmol) in dry THF (30 mL) under an
inert argon atmosphere which was maintained throughout the
experiment. After all of the sodium had reacted, 1,4-dibromo-
2,3,5,6-tetrafluorobenzene (3.02 g, 9.8 mmol) was added to the
mixture which was heated to reflux for 20 days, cooled, poured on
to water (100 mL) and extracted with dichloromethane (3ꢃ
50 mL). The combined extracts were washed with water
(100 mL), dried (MgSO4), filtered, solvent evaporated and the
resulting solid purified by recrystallisation from ethanol and
water. Column chromatography on silica gel with hexane:DCM
(4:1) as the eluent afforded 1,4-dibromo-2,3,5-trifluoro-6-(2-
propylphenoxy)benzene 16 (0.17 g, 4%) as a white solid; m.p. 56–
58 8C (Found C, 42.3; H, 2.6. C15H11OBr2F3 requires: C, 42.5; H,
297 (44), 77 (16).
4.2.8. 1,4-Dibromo-2,3,5-trifluoro-6-(4-pentylphenoxy)benzene 14
Sodium metal (0.3 g, 13 mmol) was added to a solution of 4-
pentylphenol (1.73 g, 10 mmol) in dry THF (30 mL) under an inert
argon atmosphere which was maintained throughout the experi-
ment. After all of the sodium had reacted, 1,4-dibromo-2,3,5,6-
tetrafluorobenzene (3.08 g, 10.0 mmol) was added and the mixture
heated to reflux for 20 days, cooled, poured on to water (100 mL)
and extracted with dichloromethane (3ꢃ 50 mL). The combined
extracts were washed with water (100 mL), dried (MgSO4), filtered,
solvent evaporated and the resulting solid purified by recrystalli-
sation from ethanol and water. Further column chromatography
on silica gel with hexane:DCM (9:1) as the eluent afforded 1,4-
dibromo-2,3,5-trifluoro-6-(4-pentylphenoxy)benzene 14 (0.20 g, 4%,)
as a white solid; m.p. 69–71 8C (Found C, 45.4; H, 3.4. C17H15OBr2F3
2.6%); d
H 1.01 (3H, t, 3JHH 7.4, CH3), 1.75 (2H, dm, 3JHH 7.4, CH2), 2.79
(2H, t, 3JHH 7.7, ArCH2), 6.38 (1H, d, 3JHH 8.0, ArH), 7.04 (2H, m, ArH),
3
requires: C, 45.2; H, 3.3%);
CH2), 1.60 (2H, tt, JHH 7.9, JHH 7.3, CH2), 2.57 (2H, t, JHH 7.9,
ArCH2), 6.80 (2H, AX, 3JAX 8.6, Hortho), 7.12 (2H, AX, 3JAX 8.6, Hmeta);
d
H 0.90 (3H, t, 3JHH 6.8, CH3), 1.33 (4H, m,
7.25 (1H, d, JHH 6.2, ArH); dC 14.3 (s, CH3), 23.3 (s, CH2), 32.5 (s,
3
3
3
3
ArCH2), 99.6 (ddd, 2JCF 23.8, 2JCF 23.8, JCF 1.9, C-4), 107.2 (dd, 2JCF
19.8, 3JCF 1.8, C-1), 112.6 (s, ArC), 123.5 (s, ArC), 127.1 (s, ArC), 131.2
(s, C–CH2), 131.4 (s, ArC), 138.2 (ddd, 2JCF 11.5, 3JCF 4.1, 4JCF 2.7, C-6),
145.9 (ddd, 1JCF 246, 2JCF 12.3, 3JCF 3.5, C-3), 146.1 (ddd, 1JCF 255, 2JCF
21.3, 4JCF 2.1, C-2), 150.2 (ddd, 1JCF 249, 3JCF 3.5, 4JCF 3.5, C-5), 155.0
d
C 14.3 (s, CH3), 22.8 (s, CH2), 31.5 (s, C-12), 31.7 (s, CH2), 35.3 (s,
ArCH2), 99.5 (dd, 2JCF 23.6, 2JCF 23.6, C-4), 107.2 (d, JCF 21.3, C-1),
115.3 (s, Cortho), 129.8 (s, Cmeta), 138.3 (m, C-6), 138.4 (s, C–CH2),
145.7 (ddd, 1JCF 245, 2JCF 14.7, 3JCF 4.4, C-3), 146.5 (ddd, 1JCF 247, 2JCF
13.9, 4JCF 2.9, C-2), 150.3 (ddd, 1JCF 252, 3JCF 4.0, 4JCF 4.0, C-5), 155.1
(s, C–O); dF ꢁ122.0 (dd, 4JFF 2.3, 5JFF 11.6, F-5), ꢁ130.0 (dd, 3JFF 20.6,
2
4
3
(s, C–O); dF ꢁ122.2 (d, JFF 9.5, F-5), ꢁ130.1 (d, JFF 23.2, F-3),
3
5
ꢁ130.4 (dd, JFF 23.6, JFF 9.5, F-2); m/z (EI+) 426 ([M]+, 28), 424
([M]+, 46), 422 ([M]+, 24), 395 (20), 315 (100).
4JFF 2.3, F-3), ꢁ130.5 (dd, JFF 22.7, JFF 11.6, F-2); m/z (EI+) 454
3
5
([M]+, 28), 452 ([M]+, 55), 450 ([M]+, 28), 395 (100).
4.2.11. 1,2-Dibromo-3,6-difluoro-4-(4-pentylphenoxy)-5-
phenoxybenzene 17
4.2.9. 1,4-Dibromo-2,3,5-trifluoro-6-(4-propylphenoxy)benzene 15a
and 4,40-(2,5-dibromo-3,6-difluoro-1,4-
Sodium hydride (0.025 g, 0.63 mmol, 60% (w=w) in mineral oil)
was washed three times with dry hexane (10 mL) under an
atmosphere of dry argon which was maintained throughout the
experiment. The hexane/oil solution was removed and replaced
with dry THF (15 mL). 4-Pentylphenol (0.10 g, 0.63 mmol) was
dissolved in dry THF (10 mL) and carefully added, with stirring, to
the sodium hydride and THF mixture. After the evolution of
hydrogen gas had stopped, a solution of 1,2-dibromo-3,4,6-
trifluoro-5-phenoxybenzene (0.22 g, 0.57 mmol) in dry THF
(15 mL) was added and the reaction mixture heated to reflux for
7 days, cooled, poured on to water (100 mL) and extracted with
dichloromethane (3ꢃ 50 mL). The combined extracts were washed
with water (100 mL), dried (MgSO4), filtered and solvent evapo-
rated. Column chromatography on silica gel with hexane:DCM
(5:1) as the eluent afforded 1,2-dibromo-3,6-difluoro-4-(4-pentyl-
phenoxy)-5-phenoxybenzene 17 (0.25 g, 83%) as a colourless oil;
phenylene)bis(oxy)bis(propylbenzene) 15b
Sodium metal (0.3 g, 13 mmol) was added to a solution of 4-n-
propylphenol (1.43 g, 10.5 mmol) in dry THF (30 mL) under an
inert argon atmosphere which was maintained throughout the
experiment. After all of the sodium had reacted, 1,4-dibromo-
2,3,5,6-tetrafluorobenzene (3.10 g, 10.1 mmol) was added and the
reaction mixture was heated to reflux for 20 days, cooled, poured
on to water (100 mL) and extracted with dichloromethane (3ꢃ
50 mL). The combined extracts were washed with water (100 mL),
dried (MgSO4), filtered, solvent evaporated and the resulting solid
purified by recrystallisation from ethanol and water. Column
chromatography on silica gel with hexane:DCM (9:1) as the eluent
afforded 1,4-dibromo-2,3,5-trifluoro-6-(4-propylphenoxy)benzene
15a (0.26 g, 6%,) as a white solid; m.p. 58–60 8C (Found C, 42.5;