Synthesis of N3S, N3O, N2S2, N2O2, N2SO and N2OS Porphyrins
FULL PAPER
for 1 h, DDQ (240 mg, 1.07 mmol) was added and the reaction av. mass 614.8, obsd. m/z ϭ 615.1 [M]ϩ (100%). C41H30N2S2: calcd.
mixture was stirred at room temperature in air for an additional C 80.10, H 4.92, N 4.56, S 10.43; found C 80.03, H 4.98, N 4.51,
hour. The solvent was removed on a rotary evaporator under low
pressure and analysis of the crude compound showed the formation
of four porphyrins. This mixture was separated by silica gel column
chromatography using CH2Cl2 as eluent to afford 1 as a purple
solid (48 mg, 6%). M.p. Ͼ 300 °C. IR (KBr, cmϪ1): ν˜ ϭ 3410, 2928,
S 10.55.
10,15,20-Tris(p-tolyl)-21,23-dioxaporphyrin (4): Condensation of
the diol 8 (268 mg, 1.23 mmol) with 5,10-di(p-tolyl)-15,17-dihydro-
16-oxatripyrrin 12 (500 mg, 1.23 mmol) in propionic acid (125 mL)
under similar reaction conditions as mentioned for 3 gave a green
solid identified as porphyrin 4 in 2% yield (15 mg). M.p. Ͼ 300 °C.
IR (KBr, cmϪ1): ν˜ ϭ 2931, 2868, 1452, 961, 820. 1H NMR
(CDCl3): δ ϭ 2.71 (s, 9 H, CH3), 7.70 (d, J ϭ 7.2 Hz, 6 H, m-tolyl),
8.18 (d, J ϭ 7.2 Hz, 6 H, o-tolyl), 8.70 (s, 2 H, β-pyrrole), 8.89(d,
J ϭ 4.2 Hz, 1 H, β-pyrrole), 8.95 (d, J ϭ 4.2 Hz, 1 H, β-pyrrole),
9.64 (d, J ϭ 4.6 Hz, 2 H, β-furan), 9.70 (d, J ϭ 4.6 Hz, 1 H, β-
furan), 9.82 (d, J ϭ 4.6 Hz, 1 H, β-furan), 10.16 (s, 1 H, meso)
ppm. ESMS: C41H30N2O2 calcd. av. mass 582.7, obsd. m/z ϭ 583.1
[M]ϩ (100%). C41H30N2O2: calcd. C 84.51, H 5.19, N 4.81; found
C 84.66, H 5.23, N 4.88.
1
2860, 1472, 967, 820. H NMR (CDCl3): δ ϭ Ϫ2.91 (s, 1 H, NH)
2.71 (s, 9 H, CH3), 7.55Ϫ7.65 (m, 6 H, m-tolyl), 8.17Ϫ8.25 (m, 6
H, o-tolyl), 8.65 (m, 4 H, β-pyrrole), 9.04 (m, 2 H, β-pyrrole), 9.95
(s, 1 H, β-thiophene), 10.00 (s, 1 H, β-thiophene), 10.68 (s, 1 H,
meso) ppm. 13C NMR (CDCl3): δ ϭ 21.6, 116.1, 123.6, 124.6,
127.3, 128.5, 129.3, 131.4, 132.9, 133.4, 134.1, 135.6, 137.6, 138.1,
138.8, 139.5, 146.6, 148.4, 154.1, 154.9, 156.9, 157.6 ppm. ESMS:
C41H31N3S calcd. av. mass 597.8, obsd. m/z ϭ 598.2 [M]ϩ (100%).
C41H31N3S: calcd. C 82.38, H 5.23, N 7.03, S 5.36; found C 82.63,
H 5.35, N 6.88, S 5.57.
10,15,20-Tris(p-tolyl)-21-oxaporphyrin (2): Diol
8
(500 mg,
10,15,20-Tris(p-tolyl)-21-oxa-23-thiaporphyrin (5): Samples of the
diol 7 (288 mg, 1.23 mmol) and the 16-oxatripyrrin 12 (500 mg,
1.23 mmol) were dissolved in 125 mL of propionic acid and the
reaction mixture was refluxed for 3 h. The excess propionic acid
was removed under vacuum and the crude mixture was purified by
silica gel column chromatography with CH2Cl2 as eluent. The de-
sired porphyrin 5 was obtained as a purple solid (37 mg, 5%). The
same porphyrin was also obtained by the condensation of the diol
16 (185 mg, 0.602 mmol) with the 16-thiatripyrrin 13 (200 mg,
0.602 mmol) under the same experimental conditions as mentioned
above, but in lower yield (10 mg, 2.7%). M.p. Ͼ 300 °C. IR (KBr,
cmϪ1): ν˜ ϭ 2928, 2864, 1443, 962, 814. 1H NMR (CDCl3): δ ϭ
2.72 (s, 9 H, CH3), 7.61Ϫ7.67 (m, 6 H, m-tolyl), 8.07Ϫ8.13 (m, 6
H, o-tolyl), 8.47 (d, J ϭ 4.4 Hz, 1 H, β-pyrrole), 8.60 (d, J ϭ 4.8 Hz,
1 H, β-pyrrole), 8.74 (d, J ϭ 4.8 Hz, 1 H, β-pyrrole), 9.01 (d, J ϭ
4.4 Hz, 1 H, β-pyrrole), 9.36 (d, J ϭ 4.8 Hz, 1 H, β-furan), 9.70 (d,
J ϭ 4.8 Hz, 1 H, β-furan), 9.73 (d, J ϭ 4.8 Hz, 1 H, β-thiophene),
9.97 (d, J ϭ 4.8 Hz, 1 H, β-thiophene), 10.62 (s, 1 H, meso) ppm.
ESMS: C41H30N2OS calcd. av. mass 598.8, obsd. 599.2 [M]ϩ
(100%). C41H30N2OS: calcd. C 82.24, H 5.05, N 4.68, S 5.36; found
C 82.39, H 5.11, N 4.77, S 5.39.
2.29 mmol), pyrrole (500 µL, 7.31 mmol) and p-tolualdehyde (590
µL, 5.06 mmol) were dissolved in 200 mL of CH2Cl2 in a 250 mL
round-bottomed flask under N2. After stirring for 15 min,
BF3·OEt2 (100 µL of 2.5 stock solution) was added as an acid
catalyst to initiate the reaction. The reaction mixture was stirred
for 1 h under a N2 atmosphere. DDQ (520 mg, 2.32 mmol) was
then added and the reaction mixture was stirred for another 1 h in
air. The absorption spectrum and TLC analysis of the crude mix-
ture showed the formation of N4 porphyrin (H2TTP) along with
the desired N3O porphyrin 2. The solvent was removed and the
crude compound was purified by basic alumina column chromatog-
raphy with CH2Cl2 as eluent. The desired porphyrin 2 was isolated
as a fluorescent green solid (93 mg, 7%). M.p Ͼ 250 °C. IR (KBr,
1
cmϪ1): ν˜ ϭ 3422, 2929, 2851, 1469, 956, 813. H NMR (CDCl3):
δ ϭ Ϫ2.82 (s, 1 H, NH), 2.70 (s, 9 H, CH3), 7.52Ϫ7.58 (m, 6 H,
m-tolyl), 8.03Ϫ8.09 (m, 6 H, o-tolyl), 8.61 (d, J ϭ 3.2 Hz, 1 H, β-
pyrrole), 8.65 (d, J ϭ 4.8 Hz, 1 H, β-pyrrole), 8.85 (d, J ϭ 3.2 Hz,
1 H, β-pyrrole), 8.92 (d-d, J ϭ 4.8 Hz, 4.6 Hz, 2 H, β-pyrrole), 9.12
(d, J ϭ 4.6 Hz, 1 H, β-pyrrole), 9.37 (d, J ϭ 4.8 Hz, 1 H, β-furan),
9.70 (d, J ϭ 4.8 Hz, 1 H, β-furan), 10.14 (s, 1 H, meso) ppm. 13C
NMR (CDCl3): δ ϭ 21.1, 117.5, 117.9, 123.0, 124.3, 125.8, 127.3,
127.7, 128.7, 129.1, 134.3, 134.5, 134.6, 135.0, 137.4, 137.5, 137.8,
138.4, 138.7, 139.1, 141.9, 153.8, 154.2 ppm. ESMS: C41H31N3O
calcd. av. mass 581.7, obsd. m/z ϭ 582.2 [M]ϩ (100%). C41H31N3O:
calcd. C 84.66, H 5.37, N 7.22; found C 84.72, H 5.45, N 7.30.
10,15,20-Tris(p-tolyl)-23-oxa-21-thiaporphyrin (6): Condensation of
the diol 8 (258 mg, 1.18 mmol) with the 16-thiatripyrrin 11
(500 mg, 1.18 mmol) in propionic acid (125 mL) under similar reac-
tion conditions as mentioned for 5 gave the desired porphyrin 6 as
a purple solid (50 mg, 7%). The same product was also synthesised
by the condensation of the diol 15 (205 mg, 0.633 mmol) with the
16-oxatripyrrin 14 (200 mg, 0.633 mmol). This method gave por-
phyrin 6 in lower yield (11 mg, 3%). M.p. Ͼ 300 °C. IR (KBr,
cmϪ1): ν˜ ϭ 2930, 2860, 1441, 960, 816. 1H NMR (CDCl3): δ ϭ
2.71 (s, 9 H, CH3), 7.59Ϫ7.67 (m, 6 H, m-tolyl), 8.07Ϫ8.15 (m, 6
H, o-tolyl), 8.46 (d, J ϭ 4.4 Hz, 1 H, β-pyrrole), 8.60 (d, J ϭ 4.8 Hz,
1 H, β-pyrrole), 8.77 (d, J ϭ 4.8 Hz, 1 H, β-pyrrole), 9.04 (d, J ϭ
4.4 Hz, 1 H, β-pyrrole), 9.37 (d, J ϭ 4.8 Hz, 1 H, β-furan), 9.72 (d,
J ϭ 4.8 Hz, 1 H, β-furan), 9.74 (d, J ϭ 5.2 Hz, 1 H, β-thiophene),
9.77 (d, J ϭ 5.2 Hz, 1 H, β-thiophene), 10.12 (s, 1 H, meso) ppm.
ESMS: C41H30N2OS calcd av. mass 598.8, obsd. 599.1 [M]ϩ
(100%). C41H30N2OS: calcd. C 82.24, H 5.05, N 4.68, S 5.36; found
C 82.31, H 5.10, N 4.71, S 5.40.
10,15,20-Tris(p-tolyl)-21,23-dithiaporphyrin (3): A solution of diol
7 (277 mg, 1.18 mmol) and 5,10-di(p-tolyl)-15,17-dihydro-16-thia-
tripyrrin 11 (500 mg, 1.18 mmol) in 125 mL of propionic acid was
refluxed for 3 h. The progress of the reaction was checked by ab-
sorption spectroscopy, which showed bands characteristic of the
desired porphyrin 3. The excess propionic acid was removed under
vacuum and thorough washing with warm water gave the crude
mixture. The crude product was purified by silica gel column chro-
matography with petroleum ether/dichloromethane (60:40) as elu-
ent to afford the desired porphyrin as a purple solid (102 mg, 14%).
M.p. Ͼ 300 °C. IR (KBr, cmϪ1): ν˜ ϭ 2929, 2864, 1456, 956, 810.
1H NMR (CDCl3): δ ϭ 2.71 (s, 9 H, CH3), 7.60Ϫ7.64 (m, 6 H, m-
tolyl), 8.10Ϫ8.15 (m, 6 H, o-tolyl), 8.71 (s, 2 H, β-pyrrole), 8.81 (d,
J ϭ 3.6 Hz, 1 H, β-pyrrole), 9.07 (d, J ϭ 3.6 Hz, 1 H, β-pyrrole),
9.72 (d, J ϭ 3.6 Hz, 2 H, β-thiophene), 9.82 (d, J ϭ 3.6 Hz, 1 H, 5-Bromo-10,15,20-tris(p-tolyl)-21-oxaporphyrin (17): A solution of
β-thiophene), 9.99 (d, J ϭ 3.6 Hz, 1 H, β-thiophene), 10.74 (s, 1
the oxaporphyrin 2 (20 mg, 0.0344 mmol) in chloroform (15 mL)
in a 50 mL round-bottomed flask was treated with N-bromosuc-
H, meso) ppm. 13C NMR (CDCl3): δ ϭ 21.7, 118.5, 123.0, 124.3,
127.3, 128.3, 128.5, 134.4, 134.8, 134.9, 135.0, 135.7, 135.9, 137.9, cinimide (9.16 mg, 0.0413 mmol) at room temperature for 15 min.
141.9, 147.2, 148.4, 156.8, 157.2 ppm. ESMS: C41H30N2S2 calcd. The progress of the reaction was monitored by TLC and absorption
Eur. J. Org. Chem. 2004, 2223Ϫ2230
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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