An efficient synthesis of novel spiro[[8H]indeno[2,1-b]-thiophene-8,9′-fluorene] building block for blue light-emitting materials

Article abstract of DOI:10.1016/j.tetlet.2006.06.143

We have developed efficient synthetic routes to obtain a novel building block spiro[[8H]indeno[2,1-b]thiophene-8,9′-fluorene] (SITF), a monothiophene-containing spirobifluorene analogue, and constructed blue light-emitting materials, including 2′,7′-bis([

Full text of DOI:10.1016/j.tetlet.2006.06.143

Tetrahedron Letters 47 (2006) 6421–6424
An efficient synthesis of novel
spiro[[8H]indeno[2,1-b]-thiophene-8,90-fluorene]
building block for blue light-emitting materials
Ling-Hai Xie,a Ting Fu,a Xiao-Ya Hou,a Chao Tang,a Yu-Ran Hua,a Rui-Jie Wang,a
Qu-Li Fan,a Bo Peng,a Wei Weia and Wei Huanga,b,
*
aInstitute of Advanced Materials (IAM), Fudan University, 220 Handan Road, Shanghai 200433, People’s Republic of China
bFaculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Republic of Singapore
Received 17 March 2006; revised 23 June 2006; accepted 26 June 2006
Abstract—We have developed efficient synthetic routes to obtain a novel building block spiro[[8H]indeno[2,1-b]thiophene-8,90-
fluorene] (SITF), a monothiophene-containing spirobifluorene analogue, and constructed blue light-emitting materials, including
20,70-bis([1,10-biphenyl]-4-yl)-spiro[indeno[2,1-b]thiophene-8,90-fluorene] (BBP–SITF) and 20,70-bis(9,90-spirobifluoren-2-yl)spiro-
[[8H]indeno[2,1-b]-thiophene-8,90-fluorene] (BSBF–SITF). BSBF–SITF has shown to be a stable blue light-emitting material with
high PL quantum efficiency (89%) and unique regioselective feature at the C2 of thiophene, which indicate that BSBF–SITF will
be useful for constructing complicated optoelectronic systems.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Organic p-conjugated materials continue to attract con-
siderable interest because of their potential applications
in various optoelectronic devices, especially in organic
light-emitting diodes (OLEDs).1 Since Tour and co-
workers early introduced spirobifluorene unit into
organic electronics in 1996,2 spirobifluorene-containing
oligomers and polymers are becoming promising candi-
dates for electroluminescent materials due to their high
luminescence efficiency, carrier mobility, as well as excel-
lent thermal stability. Salbeck et al. exploited spirobiflu-
orene building blocks to construct various oligomers.3
Fully spiro-configured terfluorenes, monodisperse
spirobifluorene trimmers and spirobifluorene-linked
anthracene have also been synthesized and used as blue
light-emitting materials with high thermal stability.4
Carrier-transporting materials of spirobifluorene with
high Tg temperature show excellent nondispersive hole
transporting and ambipolar carrier transporting proper-
ties.5 Our group firstly introduced the spirobifluorene
unit into p-conjugated polymers to enhance the
morphological stability in film states and to demonstrate
the increase of thermally spectral stability.6 In addition,
spirobifluorene derivatives have also been applied to
solar cells, organic phototransistors, NLO and laser
materials.7 However, the disadvantage of this kind of
oligomers is the difficulty to tune the electronic structure
and incorporate other functional groups, which greatly
limits their applications in the field of organic electronics
and construction of complicated optoelectronic systems.
Incorporating heteroaryl groups, for example, thio-
phene, pyridine, carbazole, into spiro compounds will
be a useful strategy to expand the application of spiro
compounds. However, so far, spiro compounds with
heteroaryl groups have seldom been reported.8 To ex-
plore the complicated light-emitting system and gain
better insight into the effect of spiro-substituted moieties
on the electronic structures, in this contribution, we
present the design and synthesis of a novel thiophene-
containing ter(9,90-spirobifluorene)s analogue with reg-
ioselective features, and the investigation of absorption
and emission spectra as well as electrochemical proper-
ties as blue light-emitting materials.
Keywords: Spiro compounds; Spiroindenothiophenefluorene; Blue
light-emitting materials; BF3ÆEt2O.
*
Corresponding author. Tel.: +86 21 5566 4188/4198; fax: +86 21
6565 5123; e-mail addresses: wei-huang@fudan.edu.cn; chehw@nus.
edu.sg
To successfully synthesize spiroindenothiophenefluorene
(SITF), it is necessary to concurrently consider three
0040-4039/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2006.06.143

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L.-H. Xie et al. / Tetrahedron Letters 47 (2006) 6421–6424
S
S
Pd(dba)2,
CsF,
PPh3/DME
Mg/THF,
Br
n
-BuLi/THF,
S
Fluorenone,
Reflux,
S
HCl/HOAc,
Reflux
B(OMe)3, HCl/H2O,
pinacol/CH2Cl2
OH
B
Route (I)
Br
S
1
O
O
NH4Cl (aq)
I
SITF
3b
5d
Br
Scheme 1.
S
S
Mg/THF,
1-Bromobenzene,
Mg/diethyl ether,
Ni(dppp)Cl2
S
Br
Fluorenone,
Reflux,
Br
HCl/HOAc,
Reflux
S
S
OH
NBS/DMF
S
Route (II)
+
NH4Cl (aq)
S
1
3a
2
5c
SITF
BPTF
Scheme 2.
O
Route (III)
R1
4a, R1=H, R2=Br
4-Phenyl phenyl
boronic acid,
or 9,9-spirobifluoren-2-yl
boronic acid,
R1
R2
*
S
R =
R2
S
S
BBP-SITF
Br
OH
S
S
R1
+
BF3.Et2O,
CH2Cl2
R2
4b, R1=Br, R2=Br
4c, R1=H, R2=H
Pd(PPh3
toluene
R2
)4, K2CO3,
R =
R1
R1
S
R2
Mg/THF,
3a Reflux,
NH4Cl (aq)
6a, R1=H, R2=Br
6b, R1=Br, R2=Br
*
R
R
5a, R1=H, R2=Br
5b, R1=Br, R2=Br
5c, R1=H, R2=H
7a, R1=H, R2=Br
7b, R1=Br, R2=Br
PT-SITFF, R1=H, R2=H
SITF, R1=H, R2=H
BSBF-SITF
Scheme 3.
important factors, that is, synthesis of o-halobiaryls,
their reactivity in the preparation of Grignard reagent,
and the Friedel–Crafts reactivity in the dehydration
cyclization. We have attempted three routes to prepare
and obtain the SITF, as summarized in Schemes 1–3.
We examined the effect of o-halobiaryls, for example,
2-bromo-3-phenylthiophene (3a) and 3-(2-bromophen-
yl)thiophene (3b), and conditions of dehydration cycli-
zation, for example, HCl/AcOH and BF3ÆEt2O/CH2Cl2
on the dehydration cyclization.
First of all, 3b was selected as o-halobiaryls and pre-
pared by Suzuki coupling reaction between thienyl bor-
onate ester and o-iodobromobenzene.9 Grignard reagent
from 3b was treated with 4c to obtain tertiary alcohol
5d, followed by dehydration cyclization with a total
yield of nearly 80%. However, Suzuki reaction for 3b
is very expensive. Compound 3a was selected as o-halo-
biaryls, which was easily prepared by the bromination of
3-phenylthiophene. However, the dehydration cycliza-
tion of 5c was not efficient under the condition of
HCl/HOAc and gave SITF in a low yield (35.7%). SITF
and byproduct BPTF were separated and confirmed by
single crystal X-ray diffraction (Fig. 1).10 BPTF was
probably formed in the electrophilic substitution
reaction between 3-phenylthiophene, a decomposition
product of 5c at 110 ꢁC, and 5c. Fortunately, we found
that yield of SITF was effectively improved to 50.2%
under BF3ÆEt2O condition in dilute CH2Cl2 (5c in
CH2Cl2, 4.8 · 10ꢀ3 M) at room temperature.11
Figure 1. The single-crystal X-ray structures of SITF and BPTF.
ren-2-yl)spiro-[[8H]indeno[2,1-b]thiophene-8,90-fluorene]
(BSBF–SITF) have been prepared by Suzuki coupling
reactions.12 The structures of SITF and its derivatives
were confirmed by 1H NMR, 13C NMR, GC–MS,
MALDI-TOF-MS, and elemental analysis.
The absorption spectra of BBP–SITF and BSBF–SITF
(Fig. 2) exhibit maximum peaks at ca. 345 and
353 nm, respectively, which indicates that the conju-
gated chain length of biphenyl moieties is shorter than
that of fluorene moieties. Their emission spectra show
typical feature of terfluorene derivatives. The quantum
yields of BSBF–SITF in dichloromethane were mea-
sured to be 89% by using 9,10-diphenylanthracene as
standards (Table 1). These results indicate that the intro-
duction of heteroaryl substituents via the spiro center
slightly affects the light emitting character by compari-
son with other manners, such as copolymerization. In
addition, the electroluminescent spectrum has a similar
profile compared with the solid film and no shift was
The desirable blue light-emitting materials 20,70-
bis([1,10-biphenyl]-4-yl)-spiro[indeno[2,1-b]thiophene-8,
90-fluorene] (BBP–SITF) and 20,70-bis(9,90-spirobifluo-

L.-H. Xie et al. / Tetrahedron Letters 47 (2006) 6421–6424
6423
250
300
350
400
450
500
550
600
1.1
150
100
50
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
BBP-SITF
BSBF-SITF
BBP-SITF UV
BSBF-SITF UV
BBP-SITF PL
BSBF-SITF PL
0
-50
-100
-150
-200
250
300
350
400
450
500
550
600
Wavelength (nm)
-3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5
Voltage (V)
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Figure 3. The redox cyclic voltammograms of BBP–SITF and BSBFꢀ–
SITF on Pt electrodes in CH2Cl2/THF supported by nBu4NþPF6
(0.1 M) at a scan rate of 0.1 V/s.
EL
film
solution
with regioselective feature as a blue light-emitting mate-
rial. BSBF–SITF has shown excellent thermal stability
and luminescent properties in the spirobifluorene sys-
tem, which indicate that BSBF–SITF will be promising
for constructing complicated optoelectrical systems.
Acknowledgments
350
400
450
500
550
600
650
700
Wavelength (nm)
This work was financially supported by NNSFC under
Grants 60325412, 90406021, and 50428303, Shanghai
Commission of Science and Technology under Grants
03DZ11016 and 04XD14002, and Shanghai Commis-
sion of Education under Grant 03SG03.
Figure 2. (Top) UV and PL of BBP–SITF and BSBF–SITF in CH2Cl2
solution; (bottom) EL and PL of BSBF–SITF in the solid state.
observed, which illustrates that BSBF–SITF is a stable
blue light-emitting material. Cyclic voltammetry (CV)
was performed to investigate the electrochemical behav-
iors as well as the HOMO and LUMO energy levels of
BBP–SITF and BSBF–SITF (Fig. 3). The oxidation on-
set potential and reduction onset potential of BBP–SITF
References and notes
1. (a) Tang, C. W.; Van Slyke, S. A. Appl. Phys. Lett. 1987,
51, 913; (b) Burroughes, J. H.; Bradley, D. D. C.; Brown,
A. R.; Marks, R. N.; Mackay, K.; Friend, R. H.; Burn, P.
L.; Holmes, A. B. Nature 1990, 347, 539.
2. Wu, R.; Schumm, J. S.; Pearson, D. L.; Tour, J. M. J. Org.
Chem. 1996, 61, 6906.
3. (a) Salbeck, J.; Yu, N.; Bauer, J.; Weissortel, F.; Bestgen,
H. Synth. Met. 1997, 91, 209; (b) Pudzich, R.; Salbeck, J.
Synth. Met. 2003, 138, 21.
ox
red
were measured to be E
¼ 0:97 and E
¼ ꢀ2:28 V.
onset
onset
Thus, the HOMO and LUMO energy levels were esti-
mated to be ꢀ5.72 and ꢀ2.47 eV, respectively. These
results indicate that incorporation of heteroaryl groups
via the spiro structure slightly affects the electronic
structures of main chains.
4. (a) Katsis, D.; Geng, Y. H.; Ou, J. J.; Culligan, S. W.;
Trajkovska, A.; Chen, S. H.; Rothberg, L. J. Chem.
Mater. 2002, 14, 1332; (b) Wong, K.-T.; Chien, Y.-Y.;
In conclusion, we have successfully designed and synthe-
sized ter(9,90-spirobifluorene)s analogue BSBF–SITF
Table 1. Physical data of spirans SITF, BBP–SITF, and BSBF–SITF
kmax (nm/abs) kmax (nm/PL) Qsol (%)b Td (ꢁC)c Tg (or Tm)
E
(HOMO/eV)d
E
(LUMO/eV)d Bandgap
a
a
ox
onset
red
onset
Compound
SITF
BBP–SITF
BSBF–SITF 309, 353
311, 298
322, 345
333
387, 404
395, 416
—
73%
89%
247
406
429
188
321
>350
1.09
0.97
0.80
ꢀ5.84
ꢀ5.72
ꢀ5.66
—
—
—
3.25
3.14
ꢀ2.28 ꢀ2.47
ꢀ2.23 ꢀ2.52
‘—’ Represents no characteristics.
a Measured in CH2Cl2 solvent.
b 9,10-Diphenylanthracene in cyclohexane solvent as a standard.
c The temperature was recorded corresponding to a 5% weight loss.
d HOMO/LUMO = ꢀ(Eonset ꢀ 0.0468 V) ꢀ 4.8 eV, where the value 0.0468 V is for FOC versus Ag/Ag+.

6424
L.-H. Xie et al. / Tetrahedron Letters 47 (2006) 6421–6424
Chen, R.-T.; Wang, C.-F.; Lin, Y.-T.; Chiang, H.-H.;
(400 MHz, CDCl3): d 7.73 (m, 1H), 7.62 (d, J = 8.0 Hz,
1H), 7.58–7.52 (m, 3H), 7.47–7.41 (m, 3H), 7.37–7.21 (m,
6H), 7.21–7.12 (m, 2H), 6.95–6.88 (m, 3H), 6.81–6.77 (m,
4H), 6.55 (d, J = 7.6 Hz, 1H), 6.29 (d, J = 8.0 Hz, 2H).
Anal. Calcd for C46H26Br2S2: C, 68.83; H, 3.27; Br, 19.91;
S, 7.99. Found: C, 68.75; H, 3.26; S, 7.95. Compound 7b:
1H NMR (400 MHz, CDCl3): d 6.32 (d, J = 8.0 Hz, 2H),
6.55 (d, J = 5.8 Hz, 1H), 6.84–6.86 (m, 3H), 6.91–6.92 (m,
3H), 6.99 (t, J = 7.6 Hz, 1H), 7.22–7.26 (m, 3H), 7.30 (t,
J = 7.6 Hz, 1H), 7.36 (d, J = 7.6 Hz, 2H), 7.46–7.48 (m,
3H), 7.56 (d, J = 7.2 Hz, 1H), 7.60 (d, J = 8.0 Hz, 1H),
7.62 (d, J = 1.6 Hz, 2H). Anal. Calcd for C46H24Br4S2: C,
57.53; H, 2.52; Br, 33.28; S, 6.68. Found: C, 57.49; H, 2.53;
S, 6.64. SITF: 1H NMR (400 MHz, CDCl3): d 6.61 (d,
J = 7.6 Hz, 1H), 6.82 (d, J = 7.2 Hz, 2H), 6.96 (t, J = 8 Hz,
1H), 7.14 (t, J = 7.6 Hz, 2H), 7.28 (t, J = 7.6 Hz, 1H),
7.34–7.40 (m, 4H), 7.58 (d, J = 7.6 Hz, 1H), 7.82
(d, J = 7.6 Hz, 2H). 13C NMR (400 MHz, ppm): d 64.10,
118.82, 119.51, 120.37, 123.79, 124.09, 125.82, 127.72,
128.19, 128.30, 130.37, 139.17, 141.68, 147.86, 147.92,
149.70, 153.21. Anal. Calcd for C23H14S: C, 85.68; H, 4.38;
S, 9.95. Found: C, 85.71; H, 4.32; S, 9.99. GC–MS (EI-
m/z): 322 (M+). BPTF: 1H NMR (400 MHz, CDCl3): d
6.53 (d, J = 8.0 Hz, 4H), 6.76 (t, J = 7.6 Hz, 2H), 6.80 (d,
J = 4.8 Hz, 2H), 6.87–6.94 (m, 6H), 7.02 (t, J = 8.0 Hz,
2H), 7.11 (t, J = 8.0 Hz, 2H), 7.13 (d, J = 5.2 Hz, 2H),
7.47 (d, J = 7.6 Hz, 2H). 13C NMR (CDCl3, ppm): d
148.99, 144.12, 139.79, 139.73, 137.93, 132.27, 129.16,
127.87, 127.71, 127.40, 126.61, 126.48, 122.13, 119.65,
59.45. Anal. Calcd for C33H22S2: C, 82.12; H, 4.59; S,
13.29. Found: C, 82.11; H, 4.57; S, 13.26. GC–MS (EI-
m/z): 482 (M+). PT-SITFF: 1H NMR (400 MHz, CDCl3):
d 6.24 (d, J = 7.6 Hz, 2H), 6.54 (d, J = 8.0 Hz, 1H), 6.73
(t, J = 7.6 Hz, 2H), 6.77 (d, J = 5.6 Hz, 1H), 6.80 (d, J =
7.6 Hz, 2H), 6.86 (t, J = 7.6 Hz, 1H), 6.92 (t, J = 7.2 Hz,
1H), 7.09–7.17 (m, 5H), 7.20–7.25 (m, 3H), 7.32 (t, J =
6.0 Hz, 2H), 7.40 (d, J = 7.6 Hz, 2H), 7.46 (d, J = 1.6 Hz,
1 H), 7.48 (d, J = 7.6 Hz, 1H), 7.52 (d, J = 7.6 Hz, 2H),
7.76 (d, J = 7.6 Hz, 2H). Anal. Calcd for C46H28S2: C,
85.68; H, 4.38; S, 9.95. Found: C, 85.66; H, 4.36; S, 9.94.
MS (MALDI-TOF): 644.3 (calcd for C46H28S2: 644.2).
12. BBP–SITF: 1H NMR (400 MHz, CDCl3): d 7.93 (d,
J = 8.0 Hz, 2H), 7.70 (d, J = 8.0 Hz, 2H), 7.63 (d,
J = 7.2 Hz, 1H), 7.59–7.54 (m, 12H), 7.45–7.39 (m, 6H),
7.36 (d, J = 4.8 Hz, 1H), 7.34–7.29 (m, 2H), 7.09 (s, 2H),
7.00 (t, J = 7.6 Hz, 1H), 6.74 (d, J = 7.6 Hz, 1H). 13C
NMR (100 MHz, CDCl3, ppm): d 153.10, 149.51, 148.99,
148.08, 140.86, 140.75, 140.61, 140.31, 139.98, 139.17,
130.53, 129.01, 127.80, 127.65, 127.58, 127.22, 127.54,
127.37, 125.92, 123.99, 122.61, 120.76, 119.58, 118.86,
64.21. Anal. Calcd for C47H30S: C, 90.06; H, 4.82; S, 5.12.
Found: C, 90.04; H, 4.81; S, 5.10. MS (MALDI-TOF):
Hsieh, P.-Y.; Wu, C.-C.; Chou, C. H.; Su, Y. O.; Lee,
G.-H.; Peng, S.-M. J. Am. Chem. Soc. 2002, 124, 11576;
(c) Kim, Y. H.; Shin, D. C.; Kim, S. H.; Ko, C. H.; Yu, H.
S.; Chae, Y. S.; Kwon, S. K. Adv. Mater. 2001, 13, 1690.
5. (a) Bach, U.; De Cloedt, K.; Spreitzer, H.; Gratzel, M.
Adv. Mater. 2000, 12, 1060; (b) Poplavskyy, D.; Nelson, J.
J. Appl. Phys. 2003, 93, 341; (c) Wu, C. C.; Liu, T.-L.; Lin,
Y.-T.; Hung, W.-Y.; Ke, T.-H.; Wong, K. T.; Chao, T.-C.
Appl. Phys. Lett. 2004, 85, 1172.
6. (a) Yu, W.-L.; Pei, J.; Huang, W.; Heeger, A. J. Adv.
Mater. 2000, 12, 828; (b) Zeng, G.; Yu, W.-L.; Chua, S.-J.;
Huang, W. Macromolecules 2002, 35, 6907.
7. Bach, U.; Lupo, D.; Compte, P.; Moser, J. E.; Weisso¨rtel,
F.; Salbeck, J.; Speitzer, H.; Gra¨tzel, M. Nature 1998, 395,
583.
8. (a) Mitschke, U.; Ba¨uerle, P. J. Chem. Soc., Perkin Trans.
1 2001, 740; (b) Wong, K.-T.; Chen, R.-T.; Fang, F.-C.;
Wu, C.-C.; Lin, Y.-T. Org. Lett. 2005, 7, 1979–1982.
9. Campo, M. A.; Larock, R. C. J. Org. Chem. 2002, 67,
5616.
10. Data for X-ray structure analysis were collected at room
temperature on a Bruker SMART 1K CCD area detector
˚
with Mo Ka radiation (k = 0.71073 A). Structures were
solved by direct methods and refined against F2 with the
full-matrix, least-squares methods using SHELXS-97 and
SHELXL-97, respectively. Crystal data for SITF. C23H14S,
M = 322.40, colorless diamond 0.15 · 0.10 · 0.04 mm,
hexagonal, P65, Z = 6, a = 19.158(4), b = 19.158(4),
c = 8.518(4), a = 90ꢁ, b = 90ꢁ, c = 120ꢁ, V = 2707.6(13)
3
A , F(000) = 1008, Dc = 1.186 Mg mꢀ3
,
l
(Mo
˚
Ka) = 0.178 mmꢀ1. Crystal data for BPTF. C33H22S2,
M = 482.63, colorless cuboid 0.35 · 0.30 · 0.25 mm,
monoclinic, P21/c, Z = 4, a = 13.492(3), b = 12.732(3),
c = 15.427(3),
a = 90ꢁ,
b = 112.29(3)ꢁ,
c = 90ꢁ,
V = 2452.0(8) A , F(000) = 1008, Dc = 1.307 Mg mꢀ3, l
(Mo Ka) = 0.238 mmꢀ1. Crystallographic data (excluding
structure factors) for the structures in this paper have been
deposited with the Cambridge Crystallographic Data
centre as supplementary publication numbers CCDC
298219 and 298220. Copies of the data can be obtained,
free of charge, on application to CCDC, 12 Union Road,
Cambridge CB2 IEZ, UK [fax: +44 (0)1223 336033 or
e-mail: deposit@ccdc.cam.ac.uk].
3
˚
11. Compound 6a: 1H NMR (400 MHz, CDCl3): d 7.79 (d,
J = 7.6 Hz, 1H), 7.69 (d, J = 8 Hz, 1H), 7.60 (d, J =
7.6 Hz, 1H), 7.51 (d, J = 8 Hz, 1H), 7.39 (d, J = 7.6 Hz,
1H), 7.33–7.29 (m, 3H), 7.17 (t, J = 7.6 Hz, 1H), 7.00 (t,
J = 7.6 Hz, 1H), 6.97 (d, J = 2 Hz, 1H), 6.83 (d, J = 8 Hz,
1H), 6.63 (d, J = 7.6 Hz, 1H). 13C NMR (CDCl3, ppm): d
152.40, 149.90, 148.70, 148.12, 147.62, 140.67, 140.57,
139.09, 131.48, 130.69, 128.61, 128.50, 128.00, 127.32,
125.96, 124.15, 123.80, 121.78, 121.69, 120.43, 119.68,
118.89, 63.88. Anal. Calcd for C23H13BrS: C, 68.83; H,
3.27; Br, 19.91; S, 7.99. Found: C, 68.80; H, 3.22; S, 7.94.
1
626.3. BSBF-SITF: H NMR (400 MHz, CDCl3): d 7.85
(d, J = 7.6 Hz, 4H), 7.80 (d, J = 7.6 Hz, 2H), 7.76 (d,
J = 8.0 Hz, 2H), 7.66 (d, J = 8.0 Hz, 2H), 7.58 (d,
J = 7.6 Hz, 1H), 7.39–7.31 (m, 12H), 7.26 (t, 1H), 7.12–
7.06 (m, 6H), 6.94–6.88 (m, 5H), 6.74 (t, J = 6.8 Hz, 4H),
6.68 (d, J = 7.6 Hz, 2H), 6.59 (d, J = 7.6 Hz, 1H). 13C
NMR (CDCl3, ppm): d 153.07, 149.51, 149.48, 149.33,
148.89, 148.65, 147.99, 141.41, 141.29, 141.14, 140.99,
140.32, 139.14, 141.99, 130.42, 128.08, 128.01, 127.95,
127.91, 127.68, 127.38, 125.84, 124.39, 124.12, 123.96,
122.81, 122.44, 120.39, 120.28, 120.24, 119.56, 118.87,
66.23, 64.13. Anal. Calcd for C73H42S: C, 92.18; H, 4.45;
S, 3.37. Found: C, 92.16; H, 4.46; S, 3.35. MS (MALDI-
TOF): 950.3.
1
GC–MS (EI-m/z): 400/402 (M+, 100). Compound 6b: H
NMR (400 MHz, CDCl3): d 6.60 (d, J = 7.6 Hz, 1H), 6.92
(s, 2H), 7.01 (t, J = 7.6 Hz, 1H), 7.32 (t, J = 7.6 Hz, 1H),
7.35 (d, J = 4.4 Hz, 1H), 7.43 (d, J = 5.2 Hz, 1H), 7.52 (d,
J = 8 Hz, 2H), 7.59 (d, J = 7.6 Hz, 1H), 7.64 (d, J =
8.0 Hz, 2H); 13C NMR (CDCl3, ppm): d 63.59, 118.98,
119.85, 121.76, 122.24, 123.83, 126.11, 127.38, 128.29,
131.04, 131.71, 139.00, 139.57, 147.71, 148.34, 149.62,
151.61. Anal. Calcd for C23H12Br2S: C, 57.53; H, 2.52; Br,
33.28; S, 6.68. Found: C, 57.49; H, 2.51; S, 6.64. GC–MS
(EI-m/z): 478 (M+), 480, 482. Compound 7a: 1H NMR