A. Wiehe et al. / Tetrahedron 61 (2005) 5535–5564
5553
CH2CH2CH2CH2CH2CH3), 1.81 (m, 8H, CH2CH2CH2CH2-
CH2CH3), 2.51 (m, 8H, CH2CH2CH2CH2CH2CH3), 4.90 (t,
JZ8 Hz, 8H, CH2CH2CH2CH2CH2CH3), 9.44 ppm (s, 8H,
b-pyrrole-H); 13C NMR (60 MHz, CDCl3): dZ14.14,
22.76, 30.29, 31.70, 31.95, 32.89, 35.55, 38.66, 118.38,
128.08, w145 ppm; UV/vis (CH2Cl2): lmax (log 3)Z303
(4.04), 349 (4.18), 367 (4.27), 400 (4.86), 418 (5.46), 485
(3.44), 520 (4.14), 555 (3.96), 601 (3.55), 660 nm (3.80);
MS (EI, 80 eV, 260 8C): m/z (%): 646 (100) [MC], 575 (27)
[MCK71 (C5H11)], 323 (9) [M2C]; HRMS (EI)
[C44H62N4]: calcd 646.49745, found 646.44920;
[C44H62N4, 647.01 g molK1]. Anal. Calcd C 81.68, H
9.66, N 8.66, found C 81.41, H 9.59, N 8.70.
24 h, the precipitated crystals were removed by suction
filtration through a D3 frit and dried in vacuo to yield
270 mg (0.37 mmol; 10%) of purple crystals: mp 203–
205 8C; RfZ0.23 (CH2Cl2/C6H14, 3:1, v/v), 0.56 (CH2Cl2);
1H NMR (250 MHz, CDCl3): dZK2.76 (s, 2H, NH), 0.89
(t, JZ7 Hz, 3H, 57-CH3), 1.30–1.39 (m, 4H, 56-CH2 and 55-
CH2), 1.51 (m, 2H, 54-CH2), 1.80 (m, 2H, 53-CH2), 2.54 (m,
2H, 52-CH2), 3.96 (s, 3H, 15-OCH3), 3.98 (s, 6H, 10-OCH3
and 20-OCH3), 5.00 (t, JZ8 Hz, 2H, 51-CH2), 7.28–7.35
(m, 3H, phenyl-H), 7.59–7.67 (m, 3H, phenyl-H), 7.75–7.82
(m, 6H, phenyl-H), 8.83 (s, 4H, b-pyrrole-H), 8.95 (d, JZ
5 Hz, 2H, b-pyrrole-H), 9.47 ppm (d, JZ5 Hz, 2H,
b-pyrrole-H); 13C NMR (60 MHz, CDCl3): dZ14.08,
22.69, 29.37, 30.56, 31.89, 35.56, 38.90, 55.49, 113.52,
118.97, 119.24, 120.42, 120.80, 127.39, 127.49, 127.62,
127.88, 130.68, 131.18, 143.40, 143.75, 145.94, 157.91,
157.99 ppm; UV/vis (CH2Cl2): lmax (log 3)Z304 (4.17),
373 (4.35), 401 (4.86), 418 (5.59), 485 (3.45), 516 (4.24),
550 (3.84), 592 (3.67), 648 nm (3.56); MS (EI, 80 eV,
250 8C), m/z (%): 726 (100) [MC], 641 (36) [MCKC6H13],
363 (17) [M2C]; HRMS (EI) [C48H46N4O3]: calcd
4.6.4. 5,10,15-Trihexyl-20-(3-methoxyphenyl)porphyrin
(53). Dry dichloromethane (1500 mL) was placed in a three-
necked-flask equipped with magnetic stirrer, gas inlet
(argon) and a reflux condenser. Heptanal (1.57 mL,
11.25 mmol),
3-methoxybenzaldehyde
(0.46 mL,
3.75 mmol), and pyrrole (1.04 mL, 15 mmol) were added.
Further conditions and workup as described in Section 4.6.1
followed by column chromatography on silica (3!60 cm)
using dichloromethane/n-hexane (1:1, v/v) as eluent. The
desired 5,10,15-trihexyl-20-(3-methoxyphenyl)porphyrin
53 was obtained as the second fraction, preceded by
5,10,15,20-tetrahexylporphyrin 52 (130 mg, 0.2 mmol,
5%). Efforts to recrystallize the 5,10,15-trihexyl-20-(3-
methoxyphenyl)porphyrin were unsuccessful; yield:
200 mg (0.3 mmol; 8%) of a purple amorphous solid: mp
91 8C; RfZ0.48 (CH2Cl2/C6H14, 1:1, v/v); 1H NMR
(250 MHz, CDCl3): dZK2.61 (s, 2H, NH), 1.05 (m, 9H,
56-, 106-, and 156-CH3), 1.29–1.63 (m, 12H, 55-, 105-, and
155-CH2, 54-, 104-, and 154-CH2), 1.85 (m, 6H, 53-, 103-,
and 153-CH2), 2.56 (m, 6H, 52-, 102-, and 152-CH2), 4.02 (s,
3H, OCH3), 4.91 (m, 6H, 51-, 101-, and 151-CH2), 7.40 (m,
1H, phenyl-H), 7.70 (m, 1H, phenyl-H), 7.87 (m, 2H,
phenyl-H), 8.95 (d, JZ5 Hz, 2H, b-pyrrole-H), 9.42 (d, JZ
5 Hz, 2H, b-pyrrole-H), 9.47 ppm (m [AB-spectrum], 4H,
b-pyrrole-H); 13C NMR (60 MHz, CDCl3): dZ14.18,
22.75, 30.23, 30.28, 31.93, 35.35, 35.72, 38.65, 38.82,
55.44, 113.35, 117.70, 119.06, 119.39, 120.47, 127.36,
127.62, 131.19, 144.08, 145.53, 158.00 ppm; UV/vis
(CH2Cl2): lmax (log 3)Z349 (4.23), 367 (4.30), 398
(4.79), 418 (5.55), 485 (3.39), 519 (4.15), 553 (3.88), 597
(3.64), 655 nm (3.70); MS (EI, 80 eV, 240 8C), m/z (%): 668
(100) [MC], 597 (36) [MCKC5H11], 334 (4) [M2C];
HRMS (EI) [C45H56N4O]: calcd 668.44541, found
668.44287.
726.35699,
found
726.35633;
[C48H46N4O3,
726.92 g molK1]. Anal. Calcd C 79.31, H 6.38, N 7.71,
found C 79.12, H 6.18, N 7.62.
4.6.6. 5,10,15,20-Tetraheptylporphyrin (57). Obtained as
purple needles (5%, 140 mg, 0.2 mmol) during the synthesis
of
5,10,15-triheptyl-20-(3-methoxyphenyl)porphyrin
(Section 4.6.7, 58): mp 103 8C; RfZ0.58 (SiO2, CH2Cl2/
1
C6H14, 1:1, v/v); H NMR (250 MHz, CDCl3): dZK2.66
(s, 2H, NH), 0.90 (t, JZ7 Hz, 12H, CH2CH2CH2CH2CH2-
CH2CH3), 1.35 (m, 16H, CH2CH2CH2CH2CH2CH2CH3 and
CH2CH2CH2CH2CH2CH2CH3), 1.52 (m, 8H, CH2CH2CH2-
CH2CH2CH2CH3), 1.79 (m, 8H, CH2CH2CH2CH2CH2CH2-
CH3), 2.50 (m, 8H, CH2CH2CH2CH2CH2CH2CH3), 4.91 (t,
JZ8 Hz, 2H, CH2CH2CH2CH2CH2CH2CH3), 9.44 ppm (s,
8H, b-pyrrole-H); 13C NMR (60 MHz, CDCl3): dZ14.12,
22.72, 29.41, 30.60, 31.96, 35.56, 38.73, 118.40 ppm; UV/
vis (CH2Cl2): lmax (log 3)Z350 (4.18), 366 (4.27), 400
(4.87), 418 (5.60), 489 (3.40), 520 (4.13), 555 (3.96), 601
(3.54), 660 nm (3.78); MS (EI, 80 eV, 320 8C), m/z (%): 702
(100) [MC], 617 (22) [MCK85 (C6H13)], 351 (5) [M2C];
HRMS (EI) [C48H70N4]: calcd 702.56005, found
702.56445; [C48H70N4, 703.11 g molK1]. Anal. Calcd C
82.00, H 10.03, N 7.97, found C 81.95, H 9.95, N 7.69.
4.6.7. 5,10,15-Triheptyl-20-(3-methoxyphenyl)porphyrin
(58). Preparation, observations, chromatography and
workup as described in Section 4.6.4 using octanal
(1.76 mL, 11.25 mmol). Yield of 5,10,15-triheptyl-20-(3-
methoxyphenyl)porphyrin 58: 170 mg (recrystallization
unsuccessful, 0.24 mmol; 6%) as a purple amorphous
solid; yield of 5,10,15,20-tetraheptylporphyrin 57: 140 mg
(0.2 mmol; 5%) as purple needles. Analytical data for the
title compound: mp 144 8C; RfZ0.52 (CH2Cl2/C6H14, 1:1,
v/v): 0.52; 1H NMR (250 MHz, CDCl3): dZK2.67 (s, 2H,
NH), 0.92 (m, 9H, 57-, 107-, and 157-CH3), 1.30–1.41 (m,
12H, 56-, 106-, and 156-CH2, 55-, 105-, and 155-CH2), 1.53
(m, 6H, 54-, 104-, and 154-CH2), 1.79 (m, 6H, 53-, 103-, and
153-CH2), 2.51 (m, 6H, 52-, 102-, and 152-CH2), 3.98 (s, 3H,
OCH3), 4.93 (m, 6H, 51-, 101-, and 151-CH2), 7.33 (m, 1H,
phenyl-H), 7.63 (m, 1H, phenyl-H), 7.75 (m, 2H, phenyl-H),
8.86 (d, JZ5 Hz, 2H, b-pyrrole-H), 9.37 (d, JZ5 Hz, 2H,
4.6.5. 5-Heptyl-10,15,20-tris(3-methoxyphenyl)porphyrin
(56). Preparation and workup as described in Section 4.6.1
using octanal (0.59 mL, 3.75 mmol). Column chromato-
graphy gave the desired 5-heptyl-10,15,20-tris(3-methoxy-
phenyl)porphyrin 56 as the fourth fraction, preceded by
5,10,15,20-tetraheptylporphyrin 57 (traces), 5,10,15-tri-
heptyl-20-(3-methoxyphenyl)porphyrin 58 (!20 mg) and
the (non-separable) isomeric mixture of 5,10-diheptyl-
15,20-bis(3-methoxyphenyl)porphyrin 59 and 5,15-di-
heptyl-10,20-bis(3-methoxyphenyl)porphyrin 60. The fifth
fraction was 5,10,15,20-tetrakis(3-methoxyphenyl)-
porphyrin 50 (160 mg, 0.22 mmol, 6%). The target fraction
was again dissolved in as little dichloromethane as possible
and then layered with a 2–3-fold excess of methanol. After