5750
B. Balaganesan et al. / Tetrahedron Letters 44 (2003) 5747–5750
solvent evaporated to dryness to yield 4-t-butylbenz-
(Me); 34.90 (>C<); 121.13 (C-1); 124.51 (C-7); 124.57
(C-6); 124.75 (C-3); 126.59 (C-8); 126.87 (C-5); 127.35
(C-4%); 128.30 (C-4); 128.33 (C-2%); 128.44 (C-1a); 129.54
(C-5a); 129.81 (C-8a); 129.98 (C-4a); 131.30 (C-3%); 136.58
(C-10); 136.85 (C-9); 139.18 (C-1%); 147.17(C-2). Anal.
calcd for C30H26 (386.53): C, 93.22; H, 6.78. Found: C,
93.05; H, 6.99.
eneboronic acid as an off-white solid (32 g, 90%). Method
B: (t-butyl)phenylmagnesium bromide was prepared from
10.4 g of magnesium and 42.6 g of 1-bromo-4-t-butylben-
zene (1, 200 mmol) in THF. Tri-n-butylborate (80 mL,
300 mmol) was added at −78°C and the reaction mixture
was equilibrated to room temperature. Following the
above work-up, 4-t-butylbenzeneboronic acid was
obtained in 70% yield.
9,10-Di-(4-t-butylphenyl)anthracene (4c): pale yellow
1
solid (mp 284°C). H NMR (CDCl3, 300 MHz) l 1.23 (s,
In either case, compound 2 was further purified by wash-
ing off the unreacted starting material with n-hexane. The
authenticity of this sample was in excellent agreement
with the literature.9
General Suzuki–Miyaura coupling towards the synthesis
of 4a–d:
Synthesis of 9,10-di-(4-t-butylphenyl)anthracene (4c):
9,10-dibromoanthracene (13.4 g, 40 mmol), 4-t-butylbenz-
eneboronic acid (2, 17.8 g, 100 mmol), 2 M aq. Na2CO3
solution (40 mL) and toluene (50 mL) were mixed and
degassed with nitrogen. Tetrakistriphenylphosphine-
palladium(0) (0.92 g, 2 mol%) was added and the mixture
refluxed for about 8 h under an inert atmosphere until
complete disappearance of the starting material (moni-
tored by TLC). The reaction mixture was extracted with
ethyl acetate (2×30 mL), the organic layer was washed
with water, dried over anhydrous MgSO4 and evaporated
to dryness to yield 16 g of 9,10-di-(4-t-butylphenyl)-
anthracene (4c, 90%). Further washing with cold ethanol
furnished 4c with 98% purity.
18H); 7.09 (m, 4H); 7.25 (d, J=8.4 Hz, 4H); 7.49 (d,
J=8.4 Hz, 4H); 7.63 (dd, J=8.2, 1.4 Hz, H-1, H-4, H-5,
H-8). 13C NMR (CDCl3, 75 MHz) l 31.36 (Me); 31.61
(>C<); 125.16 (C-3%); 125.30 (C-2); 127.17 (C-1); 128.33
(C-1a); 130.60 (C-9); 134.22 (C-2%); 139.60 (C-1%); 146.10
(C-4%). Anal. calcd for C34H34 (442.64): C, 92.26; H, 7.74.
Found: C, 92.45; H, 7.81.
2-(t-Butyl)-9,10-di-(4-t-butylphenyl)anthracene (4d): pale
1
yellow solid (mp 267°C). H NMR (CDCl3, 300 MHz) l
1.27 (s, 9H); 1.48 (s, 18H); 7.32 (m, 2H); 7.41 (d, J=8.4
Hz, 2H); 7.43 (dd, J=7.8, 2.1 Hz, 3H); 7.59 (d, J=8.4
Hz, 2H); 7.62 (d, J=7.8 Hz, 2H); 7.63 (s, 1H); 7.73 (m,
3H). 13C NMR (CDCl3, 75 MHz) l 30.77, 31.59 (Me);
34.79, 34.96 (>C<); 121.30 (C-1); 124.41 (C-6); 124.48
(C-7); 124.66 (C-3%); 125.14 (C-8); 125.14 (C-5); 126.79
(C-1a, C-5a); 127.11 (C-3); 128.69 (C-4a, C-8a); 129.76
(C-10); 130.07 (C-9); 130.98(C-4); 131.03 (C-2%); 136.10
(C-1%); 147.00 (C-2); 150.15 (C-4%). Anal. calcd for C38H42
(498.75): C, 91.51; H, 8.49. Found: C, 91.29; H, 8.48.
13. Janietz, S.; Bradley, D. D. C.; Grell, M.; Giebeler, C.;
Inbasekaran, M.; Woo, E. P. Appl. Phys. Lett. 1998, 73,
2453–2455.
12. Spectral characteristics:
2-(t-Butyl)-9,10-diphenylanthracene (4b): pale yellow
1
solid (mp 232°C). H NMR (CDCl3, 300 MHz) l 1.24 (s,
14. Mi, B. X.; Go, Z. Q.; Lee, C. S.; Lee, S. T.; Kwong, H.
L.; Wong, N. B. Appl. Phys. Lett. 1999, 75, 4055–4057.
9H); 7.28 (m, 2H); 7.46 (m, 6H); 7.56 (m, 5H); 7.58 (s,
1H); 7.66 (m, 3H). 13C NMR (CDCl3, 75 MHz) d 30.72