Microwave-assisted synthesis of substituted phenanthrenes, anthracenes, acenaphthenes, and fluorenes

Article abstract of DOI:10.1016/j.tet.2009.01.029

Rapid coupling reactions of polycyclic aromatic halides with various N-, S-, and Se-nucleophiles under focused microwave irradiation are described. Using this method, the desired products are obtained with good to excellent yields in a short reaction time. Crown Copyright

Full text of DOI:10.1016/j.tet.2009.01.029

Tetrahedron 65 (2009) 1977–1981
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Microwave-assisted synthesis of substituted phenanthrenes, anthracenes,
acenaphthenes, and fluorenes
*
Shiuh-Chuan Chan, Jing-Pei Jang, Yie-Jia Cherng
Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 40605, Taiwan
a r t i c l e i n f o
a b s t r a c t
Article history:
Rapid coupling reactions of polycyclic aromatic halides with various N-, S-, and Se-nucleophiles under
focused microwave irradiation are described. Using this method, the desired products are obtained with
good to excellent yields in a short reaction time.
Received 2 December 2008
Received in revised form 5 January 2009
Accepted 6 January 2009
Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved.
Available online 14 January 2009
Keywords:
Coupling reaction
9-Halophenanthrene
9-Haloanthracene
2-Chloroanthracene
5-Bromoacenaphthene
2-Bromofluorene
Focused microwave irradiation
1. Introduction
2. Results and discussion
The construction of an aryl–heteroatom bond is an important
study, in particular, the formations of the carbon–nitrogen,1 car-
bon–sulfur,2 and carbon–selenium3 have received much attention
due to the occurrence of these bonds in many molecules, which are
of biological, pharmaceutical, and material interests, such as that in
a series of piperazinylquinoxalines.4 In recognition of their impor-
tance, many good synthetic methods for the formation of aryl–
heteroatom bond have been developed, however, most methods
still need long reaction time, and may require high loading of
transition metal catalysts that will generate hazardous waste. In
comparison, the methods for the construction of polycyclic aro-
matic structures are rarely explored. Taking the beneficial effect of
microwave applications in preparation of pharmaceuticals and
other interesting compounds, the microwave-assisted coupling
reaction would be one of the convenient methods for the con-
struction of polycyclic carbon–heteroatom bonds.5 We demon-
strate herein a novel and efficient synthesis of a series of
phenanthrene, anthracene, acenaphthene, and fluorene derivatives
by the microwave-assisted coupling reactions.
First, we evaluated the feasibility of the direct cross-coupling of
9-bromophenanthrene and N-phenylpiperazine in N-methyl-
pyrrolidone (NMP) or DMSO using t-BuOK or CsOH as the bases.
The reaction mixture was heated at 180 ꢀC under microwave irra-
diation for 25–35 min to afford 9-N-phenylpiperazinylphenan-
threne in 73% and 53% yields, respectively, in NMP and DMSO
(entries 1 and 2, Table 1). The microwave-assisted coupling re-
actions of 9-bromophenanthrene with 4-benzylpiperidine was also
realized in the presence of t-BuOK to afford 54% yield of the desired
product (entry 3, Table 1). Using CsOH as the base in DMSO, the
coupling reaction proceeded smoothly at a lower temperature
(150 ꢀC) to afford the desired amination product in an improved yield
(65%, see entry 4 of Table 1). The coupling reaction of 9-bromo-
phenanthrene with thiomorpholine occurred in a similar fashion to
afford a 61% yield of 9-thiomorpholylphenanthrene (entry 6, Table
1). In comparison of entry 3 versus 4 and entry 5 versus 6, the
coupling reactions were more effective by using CsOH as the base in
DMSO than using t-BuOK in NMP. Thus, the coupling reaction of 9-
bromophenanthrene with acyclic secondary amine, e.g., N-methyl-
benzylamine (5 equiv), was successfully carried out by using CsOH as
a base, to give 9-(N-methylbenzylamino)phenanthrene in good
yield (80%) under microwave irradiation at 150 ꢀC for 40 min (entry
7, Table 1). It was noted that the above-mentioned coupling re-
actions with N-nucleophiles also produced small amounts of
* Corresponding author. Tel.: þ886 4 22391647x6500; fax: þ886 4 22395199.
E-mail address: yjcherng@ctust.edu.tw (Y.-J. Cherng).
0040-4020/$ – see front matter Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2009.01.029

1978
S.-C. Chan et al. / Tetrahedron 65 (2009) 1977–1981
Table 1
Reactions of 9-halophenanthrene with nucleophiles
X
R
Nucleophile, solvent
Microwave
Entry
–X
Nucleophile
Solvent
Molar proportions
of nucleophile
Temp (ꢀC)
Time (min)
Product, R¼
Yield (%)
1
2
3
4
5
6
7
8
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Cl
Cl
Cl
Cl
N-Phenylpiperazine/t-BuOK
N-Phenylpiperazine/CsOH
4-Benzylpiperidine/t-BuOK
4-Benzylpiperidine/CsOH
Thiomorpholine/t-BuOK
Thiomorpholine/CsOH
NH(CH3)CH2Ph/CsOH
PhSNa
PhSNa
PhSNa
PhSeH/t-BuOK
N-Phenylpiperazine
4-Benzylpiperidine
PhSNa
NMP
DMSO
NMP
DMSO
NMP
DMSO
DMSO
NMP
NMP
NMP
NMP
NMP
NMP
NMP
NMP
5
5
5
3
180
180
190
150
180
150
150
160
170
180
170
200
210
200
210
25
35
40
40
25
40
40
30
30
30
30
60
60
50
60
N-Phenylpiperazinyl
N-Phenylpiperazinyl
4-Benzylpiperidyl
4-Benzylpiperidyl
Thiomorpholyl
Thiomorpholyl
N(CH3)CH2Ph
SPh
73
53
54
65
30
61
80
69
91
95
93
25
20
65
64
5
3.5
3.5
4
4
4
4
5
5
4
9
SPh
SPh
SePh
10
11
12
13
14
15
N-Phenylpiperazinyl
4-Benzylpiperidyl
SPh
PhSeH/t-BuOK
4
SePh
phenanthrene as the side product, indicating a single electron
transfer (SET) process might involve.6
CsOH) to provide 2-phenylselenylanthracene in 61–90% yields
(entries 5–7, Table 3).
The coupling reactions of 9-bromophenanthrene with S- and Se-
nucleophiles, e.g., PhSNa and PhSeH, also proceeded smoothly to
give the corresponding 9-substituted phenanthrene in high yields
(entries 8–11, Table 1). No side product of phenanthrene was ob-
served by TLC analysis. Thus, the coupling reactions favor a direct
nucleophilic substitution as PhSNa and PhSeH are more powerful
nucleophiles than N-nucleophiles.
Having established a practical reaction protocol, we investigated
further the scope of using a less reactive substrate of 9-chloro-
phenanthrene. The coupling reactions of 9-chlorophenanthrene
with secondary amines, only resulted in modest yields (20–25% in
entries 12 and 13 of Table 1), whereas the coupling reactions with
PhSNa and PhSeH, still gave good yields (64–65%) of the desired
products (entries 14 and 15, Table 1).
We attempted the coupling reactions of 9-bromoanthracene
and 9-chloroanthracene with secondary amines, including N-phe-
nylpiperazine, 4-benzylpiperidine, and thiomorpholine, by micro-
wave irradiation. However, no deserved products could be isolated
even in strenuous reaction conditions, presumably due to the steric
hindrance of the bulky 9-haloanthracene. On the other hand,
a significant amount of anthracene was obtained under the reaction
conditions. A SET process was attributed to the formation of an-
thracene by dehalogenation.6 In
a sharp contrast, 9-bromo-
anthracene and 9-chloroanthracene reacted with the nucleophiles
of PhSNa and PhSeH under microwave irradiation to afford good to
excellent yield (64–95%) of the 9-substituted anthracene (entries
8–13, Table 3). An enhancement of yield was realized in the case
using CuI as a catalyst (comparing entry 8 with entry 9, Table 3).
Intrigued by our above-described results, various electron-rich
polycyclic aryl bromides, e.g., 5-bromoacenaphthene and 2-bromo-
fluorene, were chosen to probe whether the coupling reactions
could be achieved with S- and Se-nucleophiles. The results for the
coupling reactions of 5-bromoacenaphthene were summarized in
Table 5. The coupling reaction of 5-bromoacenaphthene with
PhSeH proceeded well in the presence of a base to afford 76–91%
yields of the substitution product (entries 6 and 7, Table 4). How-
ever, the best yield (96%) in the coupling reaction with PhSNa was
obtained by using CuI (3.5 equiv) as the catalyst in NMP solution
(entry 4, Table 4).
By using the same protocol, we were able to carry out the
coupling reactions of 2-halonaphthalene with N-, O-, and S-nucleo-
philes. The results are summarized in Table 2.
To obtain a diaryl sulfide, 2-chloroanthracene was treated with
5 equiv of PhSNa, in NMP at 180 ꢀC by microwave irradiation for
70 min, to give the corresponding 2-thiophenylanthracene in
a moderate yield of 41% (entry 1, Table 3). At an elevated temper-
ature (210 ꢀC) with CuI catalyst, the microwave-assisted coupling
reaction completed in 30 min to give 2-thiophenylanthracene in an
excellent yield (91%, see entry 4 of Table 3). The coupling reaction
with PhSeH was achieved in the presence of a base (t-BuOK or
Table 2
Reactions of 2-halonaphthalene with nucleophiles
Nucleophile, solvent
Microwave
X
R
Entry
–X
Nucleophile
Solvent
Molar
proportions of
nucleophile
Temp (ꢀC)
Time (min)
Product, R¼
Yield (%)
1
2
3
4
5
Br
Br
Br
Br
Cl
N-Phenylpiperazine
N-Phenylpiperazine/CsOH
PhCH2OH/t-BuOK
PhSNa
NMP
DMSO
NMP
NMP
NMP
5
5
5
4
4
180
150
200
180
200
25
40
45
55
60
N-Phenylpiperazinyl
N-Phenylpiperazinyl
OCH2Ph
SPh
SPh
72
51
35
94
61
PhSNa

S.-C. Chan et al. / Tetrahedron 65 (2009) 1977–1981
1979
Table 3
Reactions of haloanthracene with nucleophiles
R
X
Nucleophile, solvent
Microwave
Entry
–X
Nucleophile
Solvent
Molar proportions
of nucleophile
Temp (ꢀC)
Time (min)
Product, R¼
Yield (%)
1
2
3
4
5
6
7
8
2-Cl
2-Cl
2-Cl
2-Cl
2-Cl
2-Cl
2-Cl
9-Br
9-Br
9-Br
9-Br
9-Cl
9-Cl
PhSNa
PhSNa
PhSNa
NMP
NMP
NMP
NMP
NMP
NMP
DMSO
NMP
NMP
NMP
DMSO
NMP
NMP
4
4
4
4
4
4
4
4
4
4
4
4
4
180
200
210
210
180
190
190
180
180
180
180
180
180
70
30
30
30
70
40
40
45
45
30
30
45
30
SPh
SPh
SPh
SPh
SePh
SePh
SePh
SPh
41
50
75
91
68
90
61
88
95
95
88
64
79
PhSNa/CuI (3.5 equiv)
PhSeH/t-BuOK
PhSeH/t-BuOK
PhSeH/t-BuOK
PhSNa
PhSNa/CuI (3.5 equiv)
PhSeH/t-BuOK
PhSeH/CsOH
PhSNa
9
SPh
10
11
12
13
SePh
SePh
SPh
PhSeH/t-BuOK
SePh
Table 4
Reactions of 5-bromoacenaphthene with nucleophiles
Nucleophile, solvent
Microwave
R
Br
Solvent
Entry
Nucleophile
Molar proportions
Temp (ꢀC)
Time (min)
Product, R¼
Yield (%)
of nucleophile
1
2
3
4
5
6
7
PhSNa
NMP
NMP
NMP
NMP
NMP
NMP
NMP
5
5
5
5
5
4
4
200
190
200
200
200
200
210
60
40
40
40
20
60
30
PhS
PhS
PhS
PhS
PhS
SePh
SePh
38
56
83
96
92
76
91
PhSNa/CuI (0.5 equiv)
PhSNa/CuI (2.0 equiv)
PhSNa/CuI (3.5 equiv)
PhSNa/CuI (4.0 equiv)
PhSeH/t-BuOK
PhSeH/t-BuOK
From the results shown in Table 5, the addition of CuI (6 equiv)
enhanced the coupling reaction of 2-bromofluorene with PhSNa
under microwave irradiation, giving the expected product of 2-
thiophenylfluorene in 92% yield (entry 4, Table 5). The cross-cou-
pling reaction between 2-bromofluorene and phenylselenol in the
presence of t-BuOK gave the corresponding product in 78% yield by
microwave irradiation at 210 ꢀC for 20 min (entry 5, Table 5).
To our surprise, the microwave-assisted reaction of 2-bromo-
fluorene with benzyl alcohol gave a 43% yield of 9-benzylfluorene
(Eq. 1), instead of the desired coupling product of 2-benzyloxyl-
fluorene. This result is of interest from the synthetic and
mechanistic points of view. A primary debromination of 2-bromo-
fluorene might proceed with a SET mechanism.6 The intermediate
fluorene was then deprotonated at the C-9 position by a base
(t-BuOK) to give the corresponding carbanion, which would un-
dergo an alkylation reaction with benzyl alcohol to give the ob-
served product of 9-benzylfluorene. In order to verify the proposed
mechanism, we treated fluorene with PhCH2OH under the similar
reaction conditions, i.e., microwave irradiation at 180 ꢀC for 25 min
using t-BuOK as the base in NMP solution. In this case, 9-benzyl-
fluorene was the only isolated product (53%). This experiment thus
supports our proposed mechanism (Scheme 1). In conclusion,
Table 5
Reactions of 2-bromofluorene with nucleophiles
R
Nucleophile, solvent
Microwave
Br
Entry
Nucleophile
Solvent
Molar proportions
of nucleophile
Temp (ꢀC)
Time (min)
Product, R¼
Yield (%)
1
2
3
4
5
PhSNa
NMP
NMP
NMP
NMP
NMP
5
5
5
5
4
180
180
190
190
210
25
25
45
45
20
PhS
PhS
PhS
PhS
SePh
33
75
78
92
78
PhSNa/CuI (2.5 equiv)
PhSNa/CuI (5 equiv)
PhSNa/CuI (6 equiv)
PhSeH/t-BuOK

1980
S.-C. Chan et al. / Tetrahedron 65 (2009) 1977–1981
.
_
Br
.
_ Br-
Br
Solvent
PhCH2O-Na+
t-BuO-K+
PhCH2OH
_
Ph
Scheme 1.
our synthetic method using microwave irradiation is definitely
valuable for a rapid access to various substituted polycyclic aro-
matic compound, such as the derivatives of phenanthrene, an-
thracene, acenaphthene, and fluorene. In particular, we have
established a novel and efficient route to prepare 2-substituted
m/e calcd 338.4536, found 338.1786. Anal. Calcd for C24H22N2: C,
85.17; H, 6.55; N, 8.27. Found: C, 84.61; H, 6.14; N, 7.79.
3.1.2. 9-(4-Benzylpiperidinyl)phenanthrene
Pale yellow solid, mp 136–137 ꢀC; IR (
n
, cmꢁ1, KBr) 2933, 1524,
d 8.68–8.66 (m, 1H), 8.60–8.58
1452; 1H NMR (400 MHz, DMSO-d6)
(m, 1H), 8.29–8.26 (m, 1H), 7.78–7.75 (m, 1H), 7.65–7.59 (m, 3H),
7.53–7.51 (m, 2H), 7.34–7.21 (m, 5H), 3.49–3.46 (d, J¼11.6 Hz, 2H),
2.74–2.69 (m, 4H), 1.87–1.66 (m, 5H); 13C NMR (75 MHz, DMSO-d6)
PhCH2OH (5 equiv.), t-BuOK, NMP
Microwave, 180 °C, 25 min; 43%
Br
Ph
d
148.7, 141.0, 132.8, 131.5, 129.7 (2C), 128.9, 128.8 (2C), 128.3, 127.7,
127.6, 127.5, 127.2, 126.5, 125.9, 124.7, 123.9, 123.1, 114.2, 53.8 (2C),
39.1, 32.8, 29.4 (2C); HRMS m/e calcd 351.4928, found 351.1988.
Anal. Calcd for C26H25N: C, 88.85; H, 7.17; N, 3.98. Found: C, 88.57;
H, 7.25; N, 3.49.
(1)
anthracene and fluorene that have not been previously reported.
Our current results also show that the relative aptitude of polycyclic
aromatic substrates for the coupling reactions follows 2-halo-
naphthalenew9-halophenanthrene>9-haloanthracene>2-chloro-
anthracene.
3.1.3. 9-Thiomorpholylphenanthrene
Yellow solid, mp 130–132 ꢀC; IR (
NMR (400 MHz, DMSO-d6)
n
, cmꢁ1, KBr) 2923, 1492; 1H
d 8.82–8.79 (m, 1H), 8.72–8.70 (m, 1H),
8.22–8.20 (m, 1H), 7.90–7.87 (m, 1H), 7.68–7.66 (m, 2H), 7.58–7.55
(m, 2H), 7.43 (s, 1H), 3.29–3.24 (m, 4H), 2.93–2.84 (m, 4H); 13C NMR
(75 MHz, DMSO-d6)
d 149.0, 132.6, 131.6, 128.6, 128.5, 127.9, 127.8,
3. Experimental section
127.6, 127.4, 126.3, 124.5, 123.9, 123.1, 115.4, 55.7 (2C), 28.1 (2C); MS
m/e 279 (MþþH), 178; HRMS m/e calcd 279.4048, found 279.1089.
Anal. Calcd for C18H17NS: C, 77.37; H, 6.13; N, 5.01. Found: C, 76.98;
H, 6.02; N, 4.93.
1H NMR spectra were measured in DMSO-d6 or CDCl3 solutions
on a Bruker 400 spectrometer. Reactions were monitored by ana-
lytical thin-layer chromatography using silica gel 60 F254 (0.2 mm
layer thickness). Flash chromatography was carried out by utilizing
silica gel 60 (70–230 mesh ASTM).
3.1.4. 9-Benzylmethylaminophenanthrene
Pale yellow solid, mp 89–90 ꢀC; IR (
n
, cmꢁ1, KBr) 2952, 1492,
d 8.72–8.70 (m, 1H), 8.62–8.61
1446; 1H NMR (400 MHz, DMSO-d6)
3.1. General procedure for the microwave-assisted coupling
reactions of polycyclic aryl halides with nucleophiles
(m, 1H), 8.55–8.46 (m, 1H), 7.79–7.77 (m, 1H), 7.65–7.61 (m, 2H),
7.54–7.52 (m, 2H), 7.48–7.46 (m, 2H), 7.37–7.35 (m, 2H), 7.32–7.27
(m, 2H), 4.33 (s, 2H), 2.83 (s, 3H); 13C NMR (75 MHz, DMSO-d6)
In a reaction vessel (12 mL) were placed a nucleophile and an aryl
halide (0.1 mmol) in an appropriate solvent (NMP or DMSO,1 mL). A
base [t-BuOK or CsOH (1.1 equiv vs nucleophile)] or CuI (as indicated
in the text) could be added to enhance the reactivity in appropriate
cases. The reactionvesselwas thenplaced intothe cavityof a focused
monomode microwave reactor (CEM Discover) and irradiated for
the period shown in the tables. The reaction temperature was
maintained by modulating the power level of the reactor. The de-
sired products were purified by silica gel chromatography eluting
with a mixture of hexane, ethyl acetate, and acetone.
d 147.8, 138.9, 132.6, 131.7, 129.2, 129.1 (2C), 128.7 (2C), 128.3, 127.8
(2C),127.6,127.5,127.4,126.1,124.6,124.1,123.1,115.7, 60.4, 42.5; MS
m/e 297 (MþþH), 206, 178, 91; HRMS m/e calcd 297.401, found
297.1519. Anal. Calcd for C22H19N: C, 88.85; H, 6.44; N, 4.71. Found:
C, 88.74; H, 6.32; N, 4.47.
3.1.5. 9-Phenylthiophenanthrene
White solid, mp 153–154 ꢀC (lit. 146 ꢀC);7 1H NMR (400 MHz,
CDCl3)
d
8.76 (d, J¼8.0 Hz, 1H), 8.70 (d, J¼8.0 Hz, 1H), 8.46 (d,
J¼8.0 Hz, 1H), 8.02 (s, 1H), 7.82 (d, J¼8.0 Hz, 1H), 7.71–7.63 (m, 2H),
7.61–7.59 (m, 2H), 7.28–7.17 (m, 5H); MS m/e 286 (Mþ), 252,176, 77;
HRMS m/e calcd 286.3966, found 286.0820.
3.1.1. 9-(N-Phenylpiperazinyl)phenanthrene
Pale white solid, mp 262–264 ꢀC; IR ( , cmꢁ1, KBr) 2954, 1504;
n
1H NMR (400 MHz, DMSO-d6)
d
8.72–8.70 (m, 1H), 8.63–8.61 (m,
3.1.6. 9-Phenylselenylphenanthrene
1H), 8.37–8.34 (m, 1H), 7.83–7.81 (m, 1H), 7.69–7.65 (m, 2H), 7.58–
Colorless crystal, mp 160–161 ꢀC;8 1H NMR (400 MHz, CDCl3)
7.55 (m, 2H), 7.35–6.90 (m, 6H), 3.71–3.06 (m, 8H); 13C NMR
d
8.71 (d, J¼8.0 Hz,1H), 8.68 (d, J¼8.0 Hz,1H), 8.43 (d, J¼8.0 Hz, 1H),
(75 MHz, DMSO-d6)
d
151.4, 147.6, 132.4, 131.6, 129.2 (2C), 128.8,
8.12 (s, 1H), 7.80 (d, J¼8.0 Hz, 1H), 7.70–7.66 (m, 2H), 7.62–7.58 (m,
2H), 756–7.20 (m, 5H); MS m/e 334 (Mþ), 254, 176, 77; HRMS m/e
calcd 334.3326, found 334.0267.
128.0,127.8,126.8,126.6,126.4,125.3,124.1,123.2,122.4,119.9,116.2
(2C), 114.1, 52.9 (2C), 49.7 (2C); MS m/e 338 (MþþH), 177, 77; HRMS

S.-C. Chan et al. / Tetrahedron 65 (2009) 1977–1981
1981
3.1.7. 2-(N-Phenylpiperazinyl)naphthalene
3.1.16. 9-Benzylfluorene
White solid, mp 132–134 ꢀC (lit. 133–134 ꢀC); 1H NMR
(400 MHz, CDCl3)
White solid, mp 150–152 ꢀC (lit. 163–164 ꢀC);9 1H NMR
(400 MHz, DMSO-d6)
d
7.77–7.70 (m, 3H), 7.48–7.45 (m, 1H), 7.41–
d
7.72 (d, J¼5.2 Hz, 2H), 7.33 (t, J¼5.2 Hz, 2H), 7.29
7.28 (m, 3H), 7.24–7.05 (m, 5H, Ph), 3.47–3.35 (m, 8H).
(t, J¼5.2 Hz, 2H), 7.25–7.18 (m, 5H), 7.14 (d, J¼5.2 Hz, 2H), 4.22 (t,
J¼5.2 Hz, 1H), 3.09 (d, J¼5.2 Hz, 2H); 13C NMR (75 MHz, CDCl3)
3.1.8. 2-Benzyloxynaphthalene
d 146.8 (2C), 140.8 (2C), 139.8, 129.5 (2C), 128.3 (2C), 127.1 (2C),
White solid, mp 92–94 ꢀC (lit. 102–103 ꢀC);10 1H NMR (400 MHz,
126.6 (2C), 126.3, 124.8 (2C),119.8 (2C), 48.7, 40.1; MS m/e 256 (Mþ),
165, 91; HRMS m/e calcd 256.3484, found 256.1258. Anal. Calcd for
C20H16: C, 93.70; H, 6.29. Found: C, 93.45; H, 5.82.
DMSO-d6) d 7.84–7.82 (m, 2H), 7.80–7.78 (m, 1H), 7.52–7.50 (m, 2H),
7.47–7.43 (m, 4H), 7.36–7.32 (m, 2H), 7.24–7.21 (m, 1H), 5.21 (s, 2H).
3.1.9. 2-Phenylthionaphthalene
3.1.17. 2-Phenylthiofluorene
Yellow solid, mp 55–58 ꢀC (lit. 50–55 ꢀC);11 1H NMR (400 MHz,
Pale yellow solid, mp 79–80 ꢀC; IR ( , cmꢁ1, KBr) 2925, 1577,
n
CDCl3)
d
7.93–7.85 (m, 4H), 7.55–7.50 (m, 2H), 7.40–7.29 (m, 6H).
1465; 1H NMR (400 MHz, CDCl3)
d
7.75 (d, J¼5.2 Hz, 1H), 7.71 (d,
J¼5.2 Hz, 1H), 7.54 (s, 1H), 7.51 (d, J¼5.2 Hz, 1H), 7.41–7.39 (m, 1H),
3.1.10. 2-Phenylthioanthracene
7.36 (t, J¼5.2 Hz, 1H), 7.32–7.26 (m, 5H), 7.21–7.19 (m, 1H), 3.86 (s,
Yellow solid, mp 152–154 ꢀC; IR (
n
, cmꢁ1, KBr) 2921, 1575, 1475;
2H); 13C NMR (75 MHz, CDCl3)
d 144.3, 143.2, 141.3, 140.9, 136.9,
1H NMR (400 MHz, CDCl3)
d
8.36 (s, 1H), 8.27 (s, 1H), 7.97–7.94 (m,
133.1, 130.7, 130.1 (2C), 129.1 (2C), 128.6, 127.0, 126.9, 126.6, 125.1,
120.5, 119.9, 36.8; MS m/e 274 (MþþH), 165, 109; HRMS m/e calcd
274.3855, found 274.0811. Anal. Calcd for C19H14S: C, 83.17; H, 5.14.
Found: C, 82.74; H, 5.56.
2H), 7.93 (s, 1H), 7.90 (d, J¼6 Hz, 1H), 7.45–7.41 (m, 4H), 7.34–7.31
(m, 3H), 7.29 (d, J¼6 Hz, 1H); 13C NMR (75 MHz, CDCl3)
d 135.2,
132.8, 132.1, 131.8, 131.7, 131.3 (2C), 130.3, 129.3 (2C), 129.1 (2C),
128.2, 128.1, 127.8, 127.3, 126.3, 125.8, 125.6, 125.5; MS m/e 286
(Mþ), 176, 77; HRMS m/e calcd 286.3966, found 286.0823. Anal.
Calcd for C20H14S: C, 83.87; H, 4.92. Found: C, 83.42; H, 4.61.
3.1.18. 2-Phenylselenylfluorene
Yellow solid, mp 78–79 ꢀC; IR ( , cmꢁ1, KBr) 2925, 1575, 1475; 1H
n
NMR (400 MHz, CDCl3)
d
7.75 (d, J¼5.2 Hz, 1H), 7.69 (d, J¼5.2 Hz,
3.1.11. 2-Phenylselenylanthracene
1H), 7.67 (s, 1H), 7.51 (d, J¼5.2 Hz, 1H), 745–7.43 (m, 2H), 7.36 (t,
Pale yellow solid, mp 158–159 ꢀC; IR (
n
, cmꢁ1, KBr) 2920, 1621,
8.57 (s, 1H), 8.50 (s, 1H), 8.17 (s,
1H), 8.06–8.02 (m, 3H), 7.54–7.51 (m, 3H), 7.45–7.43 (m, 1H), 7.38–
7.37 (m, 3H); 13C NMR (75 MHz, CDCl3)
133.2 (2C), 132.0, 131.9,
J¼5.2 Hz, 1H), 7.31–7.28 (m, 1H), 7.25–7.23 (m, 3H), 3.85 (s, 2H); 13C
1573; 1H NMR (400 MHz, CDCl3)
d
NMR (75 MHz, CDCl3) d 144.4, 143.1, 141.4, 140.9, 132.3 (2C), 132.2,
132.0, 130.3, 129.3 (2C), 128.6, 127.0 (2C), 126.8, 125.1, 120.6, 119.9,
36.8; MS m/e 322 (Mþ), 242, 165, 77; HRMS m/e calcd 322.3215,
found 322.0264. Anal. Calcd for C19H14Se: C, 70.80; H, 4.88. Found:
C, 70.33; H, 4.37.
d
131.8, 131.5 (2C), 130.4, 129.5, 129.4 (2C), 129.2, 128.9, 128.2, 128.1,
127.5, 126.3, 125.7, 125.6, 125.5; MS m/e 334 (Mþ), 254, 176, 165, 77;
HRMS m/e calcd 334.3326, found 334.0264. Anal. Calcd for
C20H14Se: C, 71.85; H, 4.22. Found: C, 71.56; H, 4.42.
Acknowledgements
3.1.12. 9-Phenylthioanthracene
We thank the financial support of the Central Taiwan University
of Science and Technology and National Science Council.
White solid, mp 98–100 ꢀC (lit. 99–100 ꢀC);12 1H NMR
(400 MHz, CDCl3)
d 8.82–8.80 (m, 2H), 8.61 (s, 1H), 8.07–8.05 (m,
2H), 7.57–7.51 (m, 4H), 7.10–6.91 (m, 5H).
References and notes
3.1.13. 9-Phenylselenylanthracene
1. (a) Chen, Y.-J.; Chen, H.-H. Org. Lett. 2006, 8, 5609; (b) Gujadhur, R.; Ven-
kataraman, D.; Kintigh, J. T. Tetrahedron Lett. 2001, 42, 4791; (c) Lang, F.; Zewge,
D.; Houpis, I. N.; Volante, R. P. Tetrahedron Lett. 2001, 42, 3251; (d) Narayan, S.;
Seelhammer, Y.; Gawley, R. E. Tetrahedron Lett. 2004, 45, 757.
2. Wang, Y.-C.; Jayanth, T. T.; Cheng, C.-H. Org. Lett. 2006, 8, 5613.
3. (a) Bonaterra, M.; Martin, S. E.; Rossi, R. A. Tetrahedron Lett. 2006, 47, 3511; (b)
Gujadhur, R.; Venkataraman, D. Tetrahedron Lett. 2003, 44, 81; (c) Taniguchi, N.;
Onami, T. J. Org. Chem. 2004, 69, 915.
4. (a) Perumal, R. V.; Mahesh, R. Bioorg. Med. Chem. Lett. 2006, 16, 2769; (b)
Monge, A.; Palop, J. A.; Del Castillo, J. C.; Calder’o, J. M.; Roca, J.; Romero, G.; Del
Rio, J.; Lasheras, B. J. Med. Chem. 1993, 36, 2745; (c) Zifa, E.; Fillion, G. Pharmacol.
Rev. 1992, 44, 401; (d) Lumma, W. C., Jr.; Victor, J. L.; Stone, C. A.; Hartman, R. D.;
Saari, W. S.; Engelhardt, E. L. J. Med. Chem. 1981, 24, 93; (e) Lumma, W. C., Jr.;
Hartman, R. D.; Saari, W. S.; Engelhardt, E. L. J. Med. Chem. 1978, 21, 536.
5. (a) Nyffenegger, C.; Pasquinet, E.; Suzenet, F.; Poullain, D.; Jarry, C.; Leger, J.-M.;
Guillaumet, G. Tetrahedron 2008, 64, 9567; (b) Yong, J.-K.; Varma, R. S. Tetra-
hedron Lett. 2004, 45, 7205; (c) Wang, T.; Magnin, D. R.; Hamann, L. G. Org. Lett.
2003, 5, 897.
Pale yellow, mp 112–115 ꢀC (lit. 117 ꢀC);13 1H NMR (400 MHz,
CDCl3)
d 8.89–8.87 (m, 2H), 8.58 (s, 1H), 8.33–8.31 (m, 1H), 8.05–
8.02 (m, 2H), 7.82–7.80 (m, 1H), 7.62–7.60 (m, 2H), 7.08–7.04 (m,
5H).
3.1.14. 5-Phenylthioacenaphthene
White solid, mp 91–92 ꢀC (lit. 92–94 ꢀC);14 1H NMR (400 MHz,
CDCl3)
d
7.84 (d, J¼5.6 Hz, 1H), 7.70 (d, J¼4.8 Hz, 1H), 7.45–7.43 (m,
1H), 7.30 (d, J¼4.8 Hz, 1H), 7.26 (d, J¼4.8 Hz, 1H), 7.16–7.14 (m, 2H),
7.10–7.05 (m, 3H), 3.43–3.39 (m, 4H).
3.1.15. 5-Phenylselenylacenaphthene
Pale yellow solid, mp 105–107 ꢀC; IR ( , cmꢁ1, KBr) 2923, 1475;
n
1H NMR (400 MHz, CDCl3)
1H), 7.52–7.48 (m, 1H), 7.37–7.32 (m, 2H), 7.21–7.11 (m, 5H), 3.38–
3.31 (m, 4H); 13C NMR (75 MHz, CDCl3)
148.3, 146.5, 140.0, 138.2,
d
7.82 (d, J¼6.8 Hz, 1H), 7.70 (d, J¼8.4 Hz,
6. Pastor, S. D. Helv. Chim. Acta 1988, 71, 859.
7. Wong, Y.-C.; Jayanth, T. T.; Cheng, C.-H. Org. Lett. 2006, 24, 5613.
8. Pierini, A. B.; Rod, R. A. J. Org. Chem. 1979, 44, 4667.
d
9. Davis, W.; Ross, W. C. J. Chem. Soc. 1949, 2831.
10. Fuji, K.; Ichikawa, K.; Node, M.; Fujita, E. J. Org. Chem. 1979, 44, 1661.
11. Nakazawa, T.; Hirose, N.; Itabashi, K. Synthesis 1989, 12, 955.
12. Pirkle, W. H.; Finn, J. M. J. Org. Chem. 1983, 48, 2779.
13. Degrand, C. Tetrahedron 1990, 46, 5237.
14. Baliah, A. J. Indian Chem. Soc. 1955, 32, 702.
135.7, 132.8, 128.8 (3C), 127.5 (2C), 125.3, 124.6, 121.0, 119.9, 119.6,
30.6, 30.1; MS m/e 310 (Mþ), 230,152, 77; HRMS m/e calcd 310.3104,
found 310.0268. Anal. Calcd for C18H14Se: C, 69.67; H, 4.55. Found:
C, 69.72; H, 4.70.