A new synthesis of acenaphthobenzoporphyrin and fluoranthobenzoporphyrin

Article abstract of DOI:10.3987/COM-05-S(T)23

Benzoporphyrins fused with acenaphthylene or fluoranthene (3) and (4) were prepared by the condensation of bicyclo[2.2.2]octadiene(BCOD)-fused tripyrrane (5) with appropriate pyrrole dialdehydes (13) or (14) and the subsequent retro Diels-Alder reaction.

Full text of DOI:10.3987/COM-05-S(T)23

HETEROCYCLES, Vol. 67, No. 1, 2006
255
HETEROCYCLES, Vol. 67, No. 1, 2006, pp. 255 - 267. © The Japan Institute of Heterocyclic Chemistry
Received, 1st July, 2005, Accepted, 11th August, 2005, Published online, 12th August, 2005. COM-05-S(T)23
A NEW SYNTHESIS OF ACENAPHTHOBENZOPORPHYRIN AND
FLUORANTHOBENZOPORPHYRIN
Tetsuo Okujima,*a Naoki Komobuchi,a Hidemitsu Uno,b and Noboru Ono*a
a Department of Chemistry, Faculty of Science, Ehime University, Matsuyama,
790-8577, Japan: tetsuo@chem.sci.ehime-u.ac.jp; ononbr@dpc.ehime-u.ac.jp
bIntegrated Centre for Science, Ehime University, Matsuyama, 790-8577, Japan
Dedicated to Professor B. M. Trost on the occasion of his 65th birthday.
Abstract – Benzoporphyrins fused with acenaphthylene or fluoranthene (3) and
(4) were prepared by the condensation of bicyclo[2.2.2]octadiene(BCOD)-fused
tripyrrane (5) with appropriate pyrrole dialdehydes (13) or (14) and the
subsequent retro Diels-Alder reaction. The absorptions of these new porphyrins
were very intense at both Soret and Q bands, which might be useful as organic
dyes for solar cells.
INTRODUCTION
Organic conjugated materials are important as active elements in light emitting displays, thin film
transistor, solar cells, or other opt-electronic applications.1 Conjugated cyclic systems like porphyrins and
phthalocyanines provide suitable materials for such applications. Their UV-VIS characteristic absorption
bands are called Q and B band (or Soret band). The Q band (650-730 nm) of phthalocyanine is intense
compared to the B band (320-340 nm). On the other hand, the B band of porphyrins (390-410 nm) is
more intense than the Q band (500-600 nm). Extensive reviews of synthesis, spectroscopic properties, and
application of porphyrins and phthalocyanines are available.2 When they are used for organic solar cells,
the absorption characteristics of the organic layer should match the solar spectrum as closely as possible.3
They are also useful for non-linear optical materials such as optical limiting, for they have low ground
state absorption over a wide spectral bandwidth and strong excited-state absorption across the same
region.4 As the Q bands are intense in phthalocyanines, phthalocyanines are in principle useful for
applications to solar cells. However, synthetic methods of phthalocyanines are limited, and fine tuning of
their electronic properties is not easy. On the other hand, recent development of porphyrin synthesis

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HETEROCYCLES, Vol. 67, No. 1, 2006
makes possible the fine tuning of their properties.2 For example, porphyrin oligomers connected with
double or triple bonds,5 meso-meso, β-β, β-β triply linked porphyrin arrays,6 and expanded porphyrins
such as sapphyrins or hexaphyrins7 extend their conjugation effectively to show remarkable bathochromic
shift in near IR regions. In the manipulation of large π-conjugated molecules, one serious problem is poor
solubility. In order to resolve such a problem, we employed the retro Diels-Alder strategy. For example,
bicyclo[2.2.2]octadiene (BCOD)-fused porphyrin (1) is soluble in organic solvents and can be purified by
column chromatography. Heating pure 1 affords pure tetrabenzoporphyrin (2) in quantitative yield
without any purification procedures (Scheme 1).8 The conversion from 1 to 2 was applied to fabrication
of organic thin film transistor. Spin coating of 1 gives amorphous thin film of 1, which is converted into
polycrystalline thin film of 2 by heating at 200 °C. The thin film shows good transistor properties.9
NH
N
N
NH
N
N
∆
HN
HN
1
2
Scheme 1.
In this paper we report a synthesis of acenaphthobenzoporphyrin (3) and fluoranthobenzoporphyrin (4),
which are expected to have intense absorptions near IR region (Chart 1). The longest wave length
absorption (S0-S1) of 1 or 2 is weak due to symmetrical structure (forbidden). In contrast, S0-S1 transition
of 3 or 4 is allowed to be intense due to their lower symmetry, which is suitable as dyes for solar cells.
Lash and we have prepared a new class of highly conjugated porphyrin chromophores fused with
polycyclic aromatic rings.10,11 Pyrroles fused with polycyclic aromatics such as acenaphthylene or
fluoranthene are prepared by the reaction of the corresponding nitro aromatics with ethyl
isocyanoacetate.12 However, available pyrroles are limited in this procedure and we need another strategy
for the preparation of 3 and 4. We have used BCOD-fused tripyrrane (5) for the preparation of
core-modified tetrabenzoporphyrins.14 The tripyrrane is now used for the preparation of 3 and 4.

HETEROCYCLES, Vol. 67, No. 1, 2006
257
N
M
N
N
NH
NH
HN
CO2t-Bu
N
Zn
N
N
N
N
CO2t-Bu
5
3a: M= H2
3b: M = Zn
4
Chart 1.
RESULTS AND DISCUSSION
Synthesis of BCOD-fused pyrroles (7) and their conversion into acetoxymethylpyrrole (10) or pyrrole
dialdehyde ( 13) ar e summar ized i n Sc heme 2. The Di els- Al der re acti on of
trans-1,2-bis(phenylsulfonyl)ethylene14 with 1,3-cyclohexadiene, followed by the treatment with ethyl
isocyanoacetate or tert-butyl isocyanoacetate gave pyrrole (7a) (R = CO2Et) or (7b) (R = CO2t-Bu),
respectively. In previous papers the pyrroles (7) were prepared via the Diels-Alder reaction of
β-phenylsulfonylnitroethylene with 1,3-cyclohexadienes.8 As trans-1,2-bis(phenylsulfonyl)ethylene is
more readily prepared than β-sulfonylnitroethylene (it is also commercially available), the present method
is more convenient than the original one. Acetoxymethylpyrrole (10) was prepared by the formylation of
7b with POCl3 and DMF, followed by reduction with NaBH4 and acetylation. De-ethoxycarbonylation by
heating 7a with KOH in ethylene glycol at 170 °C gave α-free pyrrole (7c). Tripyrranes are generally
prepared by the reaction of α-free pyrrole with α-acetoxymethylpyrrole under acidic conditions using
p-TsOH or AcOH in EtOH, CH2Cl2, or MeCN. However, BCOD-fused tripyrrane (5) could not be
survived under these conditions. Tripyrrane (5) was obtained with mild conditions using Montmorillonite
K-10 in dry CH2Cl2 at room temperature. Tripyrrane (5) was used without purification for 3 + 1 porphyrin
synthesis, as it was decomposed during purification by column chromatography with silica gel. The 3 + 1
porphyrin synthesis was first used in 1994 by Momenteau,15 then this strategy have been extensively used
for the preparation of various kinds of porphyrins and related compounds. 1 6
Fluoranthoisoindole-1,3-dicarbaldehyde (13) and acenaphtho[1,2-c]pyrrole-2,9-dicarbaldehyde (14) were
used as pyrrole dialdehydes. Cyclopenta-fused polycyclic compounds are key compounds in C60 structure,
and they provide interesting π-conjugation.17 Therefore, porphyrins (3) and (4) may be useful as new dyes
for opt-electronic materials. Dialdehyde (13) was prepared by the Diels-Alder reaction of
7,9-diphenyl-8H-cyclopenta[l]acenaphthylen-8-one (12)18 with isoindole-1,3-dicalbaldehyde (11),8

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HETEROCYCLES, Vol. 67, No. 1, 2006
followed by oxidation with DDQ. Dialdehyde (14) was prepared from acenaphtho[1,2-c]pyrrole
according to the literature.19
R
SO2Ph
PhO S
SO Ph
2
CNCH CO R, t-BuOK
2 2
2
NH
toluene, reflux, 20 h
THF, rt, 24 h
SO Ph
2
7a: R = CO Et 94%
KOH
6
2
7b: R = CO t-Bu 96%
7c: R = H
(CH OH)
170 °C
97%
2
2
2
83%
CO t-Bu
CO t-Bu
CO2t-Bu
NH
2
2
1. POCl3, DMF
2. AcONa, H2O
NaBH4
THF, MeOH
Ac O, DMAP
2
7b
NH
NH
CHCl
3
CH OH
CH OAc
2
CHO
2
8
9
10
92%
98%
98%
Ph
Ph
O
Ph
Ph
CHO
CHO
1.
TFA, CH(OMe)
3
12
7c
NH
NH
2. DDQ
CHO
CHO
11
70%
13
30%
Scheme 2.
The 3 + 1 porphyrin synthesis is shown in Scheme 3. A mixture of crude tripyrrane (5) and 14 in CHCl3
containing TFA was stirred at room temperature for 11 h followed by oxidation with DDQ to give
porphyrin (15a) in 14 % yield. Porphyrin (15a) was purified by column chromatography on silica gel and
converted into the zinc complex (15b) on treatment with Zn(OAc)2. The similar reaction of 5 with 13
yielded the corresponding porphyrin. However, the reaction mixture could not be purified to separate the
porphyrin and unreacted 13 and then treated with Zn(OAc)2 to give Zn-porphyrin (16) in 24% yield.
Heating 15a at 230 °C for 3 h in vacuo resulted in clean retro Diels-Alder reaction to give
acenaphthotribenzoporphyrin (3a) in quantitative yield. Zinc complex (15b) was also converted into 3b,
which proceeded slightly at lower temperature (200 °C) for 3 h. The retro Diels-Alder reaction of 16
proceeded stepwise at 170 and 270 °C by TG analyses. At first, three ethylene units were eliminated from
BCOD rings and then another ethylene unit was eliminated by heating. When 16 was heated at 270 °C for
3 h, the color of the crystals was changed from red to deep green to give zinc complex (4) in quantitative
yield without purification.

HETEROCYCLES, Vol. 67, No. 1, 2006
259
OHC
HN
N
1. TFA
2. Et N, DDQ
∆
5
+
M
N
N
N
3
3
OHC
14
15a: R = H
2
Zn(OAc)
2
15b: R = Zn
N
Zn
N
1. TFA
∆
5
+
13
4
N
N
2. Et N
3
3. Zn(OAc)
2
16
Scheme 3.
The absorption data of porphyrins (3), (4), (15), and (16) are summarized in Table 1. Some typical spectra
are shown in Figure 1. While porphyrins fused with BCOD such as 15a, 15b and 16 were soluble in
CH2Cl2, benzoporphyrins (3a), (3b), and (4) were insoluble in CH2Cl2. The absorption spectra of
BCOD-fused porphyrins were similar to those of typical β-substituted porphyrins like octaethylporphyrin.
Spectra of them were dramatically changed by the retro Diels-Alder reaction as shown in Figure 1. Such
dramatic changes are induced just by heating. They may be useful for color sensor of temperature.
Porphyrins (3) and (4) have some important features in absorption spectra. As expected, the Q bands of 3
and 4 were highly red shifted and very intense compared to those of symmetrical benzoporphyrin (e.g.
Zn-2: λmax 425, 622 nm). For example, zinc complexes (3b) and (4) showed strong absorptions at 669
(log ε 5.04) and 651 (5.45) nm for S0-S1 transition, respectively. The Soret bands of them were also very
intense with large molar absorptivity over 105 M-1cm-1. Thus, 3 and 4 have strong absorptions over wide
range of visible region, which may be useful as dyes for solar cells or other optics. Such dyes are quite
rare. For example, absorptions of porphyrins are strong near 400 (log ε ca. 5) nm, weak near 500-600 (ca.
3-4) nm. Intensity of absorptions of phthalocyanines is reverse, strong absorption near 700 (log ε ca. 5)
nm and weak absorption near 350 (ca. 3-4) nm. Tetraacenaphthoporphyrins are known to show long
wavelength electronic absorption.10b,11 Absorptions of zinc complex of tetraacenaphthoporphyrin with

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four phenyl groups at the meso-positions appear at 558 (log ε 5.35) and 672 (4.39) nm.10b,11b The red
shifted Soret band of this porphyrin is remarkable, but the Q bands are weak and not so red shifted. On
the other hand, 3b showed intense absorptions at 415 (log ε 5.00), 440 (5.05), 461 (5.11), and 669 (5.04)
nm. The Q band of 4 (651 nm, log ε 5.45) was strong and sharp. Thus, benzoporphyrins with another
fused aromatic ring are expected to afford useful dyes with strong absorption at 650-670 nm.
In conclusion, BCOD-fused acenaphtho- and fluoranthoporphyrins (15) and (16) were synthesized by 3 +
1 porphyrin synthesis of BCOD-fused tripyrrane (5) with dialdehydes. These porphyrins were cleanly
converted into unsymmetrical π-expanded porphyrins (3) and (4) by retro Diels-Alder reaction. Both of
Soret and Q bands of them exhibited strong absorptions with a bathochromic shift compared with those of
BCOD-fused ones. Application of these dyes for solar cells is under investigation in our group.
Table 1. Absorption Maxima of Porphyrins (3), (4), (15), and (16)
sample
solvent
λ
, nm (log ε)
max
15a
15b
16
CH Cl
385 (4.83), 430 (5.07)
419 (4.95), 441 (5.20)
401 (5.51)
523 (4.07), 564 (4.45), 584 (4.17), 650 (3.93)
555 (4.06), 605 (4.71)
2
2
CH Cl
2
2
CH Cl
526 (4.28), 561 (4.23)
2
2
3a
DMF
421 (4.69), 438 (4.85), 461 (4.74)
415 (5.00), 440 (5.05), 461 (5.11)
433 (5.31), 465 (4.93)
540 (4.00), 572 (4.33), 633 (3.62), 691(4.58)
556 (3.96), 599 (4.48), 613 (4.26), 669 (5.04)
599 (4.40), 623 (4.31), 651 (5.45)
3b
4
DMF
DMF
Figure 1. UV-VIS spectra of (a) 15b (solid line) in CH2Cl2, 3b (bold line) in DMF, (b) 16 (solid line) in
CH2Cl2, and 4 (bold line) in DMF.
EXPERIMENTAL
General. Melting points were determined on a Yanaco micro melting point apparatus MP500D and are
uncorrected. DI-EI and FAB mass spectra were measured on a JEOL JMS-700. MALDI-TOF mass
spectra were measured on Voyager DE Pro (Applied Biosystems). IR spectra were taken on a Horiba

HETEROCYCLES, Vol. 67, No. 1, 2006
261
FT-720 Infrared Spectrophotometer. UV-VIS spectra were measured on a JASCO V-570
1
spectrophotometer and a Hitachi U-2810 spectrophotometer. H NMR spectra (13C NMR spectra) were
recorded on a JEOL AL-400 at 400 MHz (100 MHz). Gel permeation chromatography (GPC) was
performed on a JAIGEL 2.5-H. Elemental analyses were performed at Integrated Center for Sciences,
Ehime University.
Pyrroles (7a) and (7b) were prepared by the modified procedure of the original method,8 and
4,7-dihydro-4,7-ethano-2H-isoindole (7c) and 4,7-dihydro-4,7-ethano-2H-isoindole-1,3-dicarbaldehyde
(11) were prepared according to the reported procedures.8
2,3-Bis(phenylsulfonyl)bicyclo[2.2.2]oct-5-ene (6)20
A solution of trans-1,2-bis(phenylsulfonyl)ethylene (37.1 g, 120 mmol) and 1,3-cyclohexadiene (18 mL,
180 mmol) in toluene (150 mL) was refluxed for 20 h. The solvent was removed under reduced pressure,
and the product was washed with ether to give 6 (45.2 g, 97%) as white powder.
Ethyl 4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate (7a)
To a stirred solution of 6 (15.5 g, 40.0 mmol) and ethyl isocyanoacetate (5.6 mL, 52.0 mmol) in THF
(170 mL) was added a 1 M solution of potassium tert-butoxide in THF (120 mL) at 0 °C under an Ar
atmosphere. The resulting mixture was stirred at rt for 15 h. The reaction mixture was poured into 1 M
HCl and extracted with CHCl3. The organic layer was washed with sat. aqueous NaHCO3, water, brine,
and dried with Na2SO4. After removing the solvent in vacuo, the residue was purified by column
chromatography on silica gel with CHCl3, followed by recrystallization from CHCl3/hexane to give 7a
(8.16 g, 94%) as white crystals (mp 129-130 °C).
tert-Butyl 4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate (7b)
To a stirred solution of 6 (9.70 g, 25.0 mmol) and tert-butyl isocyanoacetate (5.5 mL, 37.5 mmol) in THF
(350 mL) was added a 1 M solution of potassium tert-butoxide in THF (75 mL) at 0 °C under an Ar
atmosphere. The resulting mixture was stirred at rt for 15 h. The reaction mixture was poured into 1 M
HCl and extracted with CHCl3. The organic layer was washed with sat. aqueous NaHCO3, water, brine,
and dried with Na2SO4. After removing the solvent in vacuo, the residue was purified by column
chromatography on silica gel with CHCl3, followed by recrystallization from CHCl3/hexane to give 7b
(5.86 g, 96%) as white crystals (mp 181.5-183.1 °C).
tert-Butyl 4,7-dihydro-4,7-ethano-3-formyl-2H-isoindole-1-carboxylate (8)

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HETEROCYCLES, Vol. 67, No. 1, 2006
To a solution of N,N-dimethylformamide (1.1 mL, 14 mmol) in dry CH2Cl2 (2 mL) was added dropwise a
solution of POCl3 (1.3 mL, 14 mmol) in dry CH2Cl2 (2 mL) at 0 °C under an Ar atmosphere. The
resulting mixture was stirred at rt for 30 min. A solution of 7b (2.45 g, 10.0 mmol) in dry CH2Cl2 (70
mL) was added dropwise at 0 °C to the reaction mixture and stirred at rt for 1.5 h. After an addition of
aqueous sodium acetate to the reaction mixture at 0 °C, the mixture was stirred at rt for 30 min. The
organic layer was washed with sat. aqueous NaHCO3, water, brine, and dried with Na2SO4. After
removing the solvent in vacuo, the residue was purified by column chromatography on silica gel with
CHCl3 to give 8 (2.50 g, 92%).
8; colorless plates; mp 100.5–102.0 °C (hexane); MS (70 eV) m/z (rel intensity) 273 (M+, 25%); IR (KBr
disk) νmax 3317, 2974, 1697, 1670, 1454, 1369, 1269, 1138, and 687cm-1; 1H NMR (400 MHz, CDCl3) δ
9.72 (s, 1H), 9.03 (br s, 1H), 6.48–6.57 (m, 2H), 4.39 (d, 1H, J = 4.9 Hz), 4.27 (d, 1H, J = 4.9 Hz), 1.63
(m, 2H), 1.59 (s, 9H), and 1.49 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 178.14, 160.01, 141.04, 136.14,
135.93, 134.39, 124.53, 120.61, 82.08, 33.31, 32.59, 28.39, 26.51, and 26.09; Anal. Calcd for C16H19NO3:
C, 70.31; H, 7.01; N, 5.12. Found: C, 70.36; H, 7.08; N, 5.12.
tert-Butyl 4,7-dihydro-4,7-ethano-3-hydroxymethyl-2H-isoindole-1-carboxylate (9)
To a solution of 8 (2.50 g, 9.15 mmol) in THF/methanol (40 mL/20 mL) was added sodium borohydride
(1.04 g, 27.5 mmol) at 0 °C. The resulting mixture was stirred at same temperature for 1 h. After an
addition of water, the mixture was extracted with ethyl acetate. The organic layer was washed with water,
brine, dried with Na2SO4, and concentrated under reduced pressure. The residue was purified by
recrystallization from hexane to give 9 (2.47 g, 98%).
9; white crystals; mp 144.0–146.6 °C (hexane); MS (70 eV) m/z (rel intensity) 275 (M+, 12%); IR (KBr
disk) νmax 3425, 3267, 1670, 1647, 1369, 1269, 1142, and 1092 cm-1; 1H NMR (400 MHz, CDCl3) δ 8.61
(br s, 1H), 6.48 (m, 2H), 4.63 (m, 2H), 4.31 (m, 1H), 3.86 (m, 1H), 1.97 (m, 1H), 1.57 (s, 9H), 1.48 (m,
13
2H), and 1.41 (m, 2H); C NMR (100 MHz, CDCl3) δ 161.05, 136.12, 135.77, 135.50, 128.69, 124.93,
114.82, 80.44, 56.38, 33.71, 32.39, 28.58, 27.09, and 26.35; Anal. Calcd for C16H21NO3: C, 69.79; H,
7.69; N, 5.09. Found: C, 69.73; H, 7.69; 5.06.
tert-Butyl 3-acetoxymethyl-4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate (10)
To a solution of 9 (2.47 g, 8.97 mmol) in CHCl3 (40 mL) were added acetic anhydride (1.1 mL, 11 mmol)
and catalytic amounts of 4-dimethylaminopyridine at rt. After the resulting mixture was stirred at same
temperature for 2 h, the reaction mixture was poured into sat. aqueous NaHCO3. The organic layer was
washed with water, brine, dried with Na2SO4, and concentrated under reduced pressure. The residue was
washed with ether and hexane to give 10 (2.78 g, 98%).

HETEROCYCLES, Vol. 67, No. 1, 2006
263
10; white needles; mp 160.4–161.4 °C; MS (70 eV) m/z (rel intensity) 317 (M+, 9%); IR (KBr disk) νmax
1
3325, 2981, 1739, 1678, 1362, 1338, 1288, 1230, 1165, 1142, 1088, 1022 cm-1; H NMR (400 MHz,
CDCl3) δ 8.55 (br s, 1H), 6.49 (m, 2H), 5.01 (m, 2H), 4.31 (m, 1H), 3.91 (m, 1H), 2.06 (s, 3H), 1.57 (s,
13
9H), 1.48 (m, 2H), and 1.40 (m, 2H); C NMR (100 MHz, CDCl3) δ 171.33, 160.71, 135.65, 135.54,
135.42, 131.12, 120.17, 115.57, 80.51, 57.01, 33.66, 32.44, 28.53, 26.98, 26.32, and 21.01; Anal. Calcd
for C18H23NO4: C, 68.12; H, 7.30; N, 4.41. Found: C, 67.83; H, 7.33; N, 4.45.
4,13-Dihydro-5,12-diphenyl-4,13-ethano-2H-fluorantho[8,9-f]isoindole-1,3-dicarbaldehyde (13)
A solution of 11 (523 mg, 2.60 mmol) and 12 (713 mg, 2.00 mmol) in xylene (20 mL) was stirred at
130 °C for 3 days. After an addition of hexane (100 mL), the mixture was cooled in refrigerator overnight.
The precipitate was collected by filtration and the recrystallization from CHCl3/hexane for filtrate gave
crystals.
A mixture of the combined crystals and DDQ (0.45 g) in CHCl3 (100 mL) was stirred at rt for 12 h. The
reaction mixture was poured into water. The organic layer was washed with water, brine, and dried with
Na2SO4. After removing the solvent in vacuo, the residue was purified by column chromatography on
silica gel with CHCl3, GPC with CHCl3, and recrystallization from CHCl3/hexane to give 13 (314 mg,
30%)
13; pale yellow powder; mp 200 °C (decomp); MS (FAB) m/z 528 (M++1); IR (KBr) νmax 3289, 1678,
1
1651, 1215, and 775 cm-1; H NMR (400 MHz, CDCl3) δ 9.69 (s, 2H), 9.21 (br s, 1H), 7.65 (m, 10H),
13
7.40 (m, 2H), 7.27 (m, 2H), 6.67 (d, 2H, J = 7.1 Hz), 4.71 (s, 2H), 1.90 (m, 2H), and 1.74 (m, 2H); C
NMR (100 MHz, CDCl3) δ 179.06, 140.68, 140.10, 138.49, 136.13, 134.93, 133.21, 132.62, 129.25,
129.15, 129.10, 128.94, 128.01, 127.54, 127.26, 126.37, 122.86, 33.39, and 26.72; Anal. Calcd for
C38H25NO2·1/2H2O·1/2CHCl3: C, 77.55; H, 4.48; N, 2.35. Found: C, 77.77; H, 4.55; N, 2.66.
BCOD-fused acenaphthoporphyrin (15a)
Montmorillonite K-10 clay (1.0 g) was added to a degassed solution of 7c (145 mg, 1.00 mmol) and 10
(635 mg, 2.00 mmol) in dry CH2Cl2 (30 mL) in a shaded vessel. The resulting mixture was stirred at
30 °C for 6 h under an Ar atmosphere. After the insoluble material was removed by filtration, the filtrate
was poured into sat. aqueous NaHCO3. The organic layer was washed with water, dried with Na2SO4, and
concentrated under reduced pressure.
A solution of the crude 5 in trifluoroacetic acid (2 mL) was stirred at rt for 10 min under an Ar
atmosphere in a shaded vessel. The mixture was diluted with CHCl3 (100 mL), followed by an addition of
14 (247 mg, 1.00 mmol) and stirred at same temperature for 11 h. The reaction mixture was neutralized
with triethylamine and treated with DDQ (227 mg, 1.00 mmol) for 4.5 h with stirring at rt. The mixture

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HETEROCYCLES, Vol. 67, No. 1, 2006
was washed with water, brine, and dried with Na2SO4. After removing the solvent in vacuo, the residue
was purified by column chromatography on silica gel with CHCl3 and recrystallization from
CHCl3/methanol to give 15a (95 mg, 14%).
15a; red purple crystals; mp 200 °C (decomp); MS (FAB) m/z 669 (M++1); UV-VIS (CH2Cl2) λmax nm
1
(log ε) 385 (4.83), 430 (5.07), 523 (4.07), 564 (4.45), 584 (4.17), and 650 (3.93); H NMR (400 MHz,
CDCl3) δ 10.65 (s, 2H), 10.29 (s, 2H), 8.97 (d, 2H, J = 6.3 Hz), 8.00 (d, 2H, J = 7.8 Hz), 7.92 (t, 2H, J =
7.3 Hz), 7.16 (m, 6H), 5.78 (m, 6H), 1.93-2.27 (m, 12H), and -4.09 (br s, 2H); Anal. Calcd for
C48H36N4·1/2H2O: C, 85.05; H, 5.50; N, 8.27. Found: C, 84.97; H, 5.39; N, 8.14.
BCOD-fused [acenaphthoporphyrinato]zinc(II) (15b)
A mixture of 15a (25 mg, 0.037 mmol) and Zn(OAc)2·2H2O (68 mg, 0.37 mmol) in methanol/CHCl3 (5
mL/20 mL) was stirred at rt for 18 h. After filtration, the filtrate was washed with water, brine, dried with
Na2SO4, and concentrated under reduced pressure. The residue was recrystalized from CHCl3/methanol to
give 15b (26 mg, 95%).
15b; black crystals; mp 200 °C (decomp); MS (FAB) m/z 730 (M+); UV-VIS (CH2Cl2) λmax nm (log ε)
380 (4.71), 419 (4.95), 441 (5.20), 555 (4.06), and 605 (4.71); 1H NMR (400 MHz, pyridine-d5/CDCl3) δ
10.58 (s, 2H) 10.18 (s, 2H), 8.99 (d, 2H, J = 6.6 Hz), 7.99 (d, 2H, J = 8.1 Hz), 7.93 (t, 2H, J = 7.4 Hz),
7.16 (m, 6H), 5.75 (m, 6H), and 1.83-2.19 (m, 12H); 13C NMR (100 MHz, pyridine-d5/CDCl3) δ 150.06,
149.93, 149.56, 146.25, 143.71, 143.69, 143.57, 142.66, 140.88, 136.90, 136.83, 135.22, 130.59, 128.16,
126.72, 123.63, 122.59, 100.09, 97.42, 97.34, 36.70, 36.68, 36.63, 36.55, 28.13, 28.05, and 28.01; Anal.
Calcd for C48H34N4Zn·2H2O: C, 75.04; H, 4.99; N, 7.29. Found: C, 75.30; H, 5.01; N, 7.10.
Acenaphtho[q]tribenzo[b,g,l]porphyrin (3a)
Porphyrin (15a) (10 mg) was heated at 230 °C under reduced pressure in grass tube for 30 min to give 3a.
3a; black crystals; mp >250 °C; MS (MALDI-TOF) m/z 584 (M+); UV-VIS (DMF) λmax nm (log ε) 421
(4.69), 438 (4.85), 461 (4.74), 540 (4.00), 572 (4.33), 633 (3.65), and 691 (4.58); (1% TFA/CH2Cl2) λmax
,
nm (log ε) 449 (5.32), 590 (4.04), 637 (4.40), 682 (4.49), and 699 (4.89); Anal. Calcd for C42H24N4: C,
86.28; H, 4.14; N, 9.58. Found: C, 86.09; H, 4.24; N, 9.39.
[Acenaphtho[q]tribenzo[b,g,l]porphyrinato]zinc(II) (3b)
Porphyrin 15b (10 mg) was heated at 200 °C under reduced pressure in grass tube for 3 h to give 3b.
3b; dark green crystals; mp >250 °C; MS (FAB) m/z 646 (M+); UV-VIS (DMF) λmax nm (log ε) 415
1
(5.00), 440 (5.05), 461 (5.11), 556 (3.96), 599 (4.48), 613 (4.26), and 669 (5.04); H NMR (400 MHz,
pyridine-d5/CDCl3) δ 9.80 (s, 4H), 9.16 (m, 6H), 8.53 (d, 2H, J = 5.9 Hz), 8.15 (m, 6H), 7.95 (d, 2H, J =

HETEROCYCLES, Vol. 67, No. 1, 2006
265
7.5 Hz), and 7.87 (t, 2H, J = 7.2 Hz); Anal. Calcd for C42H22N4Zn·H2O: C, 75.74; H, 3.63; N, 8.41.
Found: C, 75.35; H, 3.96; N, 8.08.
BCOD-fused fluoranthoporphyrin (16)
Tripyrrane (5) was prepared by the reaction of 7c (73 mg, 0.50 mmol) with 10 (318 mg, 1.00 mmol) in
the presence of Montmorillonite K-10 clay (0.5 g). A solution of the crude 5 in trifluoroacetic acid (2 mL)
was stirred at rt for 10 min under an Ar atmosphere in a shaded vessel. The mixture was diluted with
CHCl3 (100 mL), followed by an addition of 13 (264 mg, 0.500 mmol) and stirred at same temperature
for 12 h. The reaction mixture was neutralized with triethylamine, washed with water, brine, and dried
with Na2SO4. After an addition of methanol (20 mL) and Zn(OAc)2·2H2O (276 mg, 1.5 mmol), the
mixture was stirred at rt for 18 h. The reaction mixture was washed with water, dried with Na2SO4, and
concentrated under reduced pressure. The residue was purified by column chromatography on silica gel
with CHCl3 and recrystallization from CHCl3/methanol to give 16 (119 mg, 24%).
16; red crystals; mp 170 °C (decomp); MS (FAB) m/z 1012 (M++2); UV-VIS (CH2Cl2) λmax nm (log ε)
1
401 (5.51), 526 (4.28), and 561 (4.23); H NMR (400 MHz, CD2Cl2) δ 10.40(s, 2H), 10.26 (s, 2H), 7.89
(m, 8H), 7.52-7.68 (m, 4H), 7.16 (m, 8H), 6.74 (m, 2H), 6.08 (m, 2H), 5.70 (m, 6H), and 1.89-2.42 (m,
16H); Anal. Calcd for C70H50N4Zn・1/2H2O・3/4CHCl3 : C, 76.48; H, 4.69; N, 5.04. Found: C, 76.28; H,
4.74; N, 5.24.
[Fluoranthobenzoporphyrinato]zinc(II) (4)
Porphyrin (16) (34 mg) was heated at 270 °C under reduced pressure in grass tube for 3 h to give 4.
4; dark green crystals; mp >250°C; MS (FAB) m/z 898 (M+); UV-VIS (DMF) λmax nm (log ε) 330 (4.74),
433 (5.31), 465 (4.93), 599 (4.40), 623 (4.31), and 651 (5.45); 1H NMR (400 MHz, pyridine-d5/CDCl3) δ
9.72 (s, 2H), 9.67 (s, 2H), 9.58 (s, 2H), 9.14 (m, 4H), 8.99 (m, 2H), 8.17 (m, 6H), 8.08 (m, 10H), 7.79 (d,
2H, J = 7.8 Hz), 7.46 (t, 2H, J = 7.4 Hz), and 6.81 (d, 2H, J = 6.9 Hz); 13C NMR (100 MHz,
pyridine-d5/CDCl3) δ 139.72, 136.97, 136.26, 136.06, 134.59, 131.88, 130.58, 130.23, 129.68, 128.30,
127.91, 125.75, 125.63, 121.98, 120.87, 120.65, and 120.57; Anal. Calcd for C62H34N4Zn: C, 82.71; H,
3.81; N, 6.22. Found: C, 82.56; H, 3.98; N, 6.13.
ACKNOWLEDGEMENTS
The present work was supported by a Grant-in-Aid for Scientific Research (No. 16750037 to T.O.) from
the Ministry of Education, Culture, Sports, Science and Technology, Japan.

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