Mono- and Disubstituted Porphyrins
FULL PAPER
>3008C; 1H NMR (270 MHz, CDCl3, 258C, TMS): d=10.31 (s, 2H;
10,20-Hmeso), 9.38 (AB, 3J(H,H)=5 Hz, 4H; 2,8,12,18-Hb), 9.11 (AB, 3J-
(H,H)=5 Hz, 4H; 3,7,13,17-Hb), 7.84 (m, 4H; Ho-Ph), 7.67 (m, 2H; Hm-
Ph), 7.35 (m, 2H; Hp-Ph), 4.01 (s, 6H; OCH3), ꢁ3.16 ppm (brs, 2H; NH);
13C NMR (60 MHz, CDCl3, 258C): d=158.29, 153.64, 147.10, 145.30,
142.75, 131.58, 131.05, 127.92, 127.78, 120.82, 113.55, 105.26, 55.57 ppm;
UV/Vis (CH2Cl2): lmax (loge)=410 (5.57), 474 (3.77), 536 (3.88), 575
(3.84), 628 nm (3.56); MS (80 eV, EI): m/z (%): 522 (100) [M +], 507 (2)
[M +ꢁCH3], 491 (3) [M +ꢁOCH3], 261 (7) [M2+]; HRMS: m/z calcd for
C34H26N4O2: 522.20558; found: 522.20642.
9.45 (AB, 3J(H,H)=4 Hz, 4H; 2,8,12,18-Hb), 9.13 (m, 2H; 26,32-Pho-H),
8.98 (AB, 3J(H,H)=4 Hz, 4H; 3,7,13,17-Hb), 8.70 (m, 2H; Php-H), 8.59
(m, 2H; Pho-H), 8.00 (m, 2H; Phm-H), ꢁ3.19 ppm (brs, 2H; NH); UV/Vis
(CH2Cl2): lmax (loge)=408 (4.40), 501 (3.21), 535 (2.75), 574 (2.80),
628 nm (2.45); MS (80 eV, EI): m/z (%): 552 (16) [M +], 431 (5) [M +
ꢁC6H4NO2+H]; HRMS: m/z calcd for C32H20N6O4: 552.15460; found
552.15655.
5-(4-Nitrophenyl)porphyrin (26a)
Procedure A: The porphyrin was purified by column chromatography on
silica gel (CH2Cl2/n-hexane 2:1). After recrystallization from CH2Cl2/
CH3OH, the porphyrin was obtained as purple crystals (17 mg,
0.04 mmol, 2%). Rf =0.36 (CH2Cl2/n-hexane 2:1); m.p. >3308C; com-
pound too insoluble for NMR; UV/Vis (CH2Cl2): lmax (loge)=401 (4.95),
496 (4.14), 530 (3.54), 568 (3.67), 624 nm (3.06); MS (80 eV, EI): m/z
(%): 431 (100) [M +], 385 (19) [M +ꢁNO2], 215 (3) [M2+], 192 (3) [M2+
ꢁNO2]; HRMS: m/z calcd for C26H17N5O2: 431.13822; found: 431.13644.
5,10-Bis(3-methoxyphenyl)porphyrin (23c)
Procedure C: The porphyrin was purified by column chromatography on
silica gel (CH2Cl2/n-hexane 2:1). The first fraction contained the mono-
substituted porphyrin 23a and the second fraction the disubstituted por-
phyrin 23c. After recrystallization from CH2Cl2/CH3OH, the product was
obtained as purple crystals (79 mg, 0.15 mmol, 7%). Rf =0.30 (CH2Cl2/n-
hexane 2:1); m.p. 3048C; 1H NMR (270 MHz, CDCl3, 258C, TMS): d=
10.17 (s, 2H; 15,20-Hmeso), 9.38 (s, 2H; 17,18-Hb), 9.32 (AB, 3J(H,H)=
5 Hz, 2H; 2,13-Hb), 9.10 (AB, 3J(H,H)=5 Hz, 2H; 3,12-Hb), 9.02 (s, 2H;
7,8-Hb), 7.85 (m, 4H; Ho-Ph), 7.68 (m, 2H; Hm-Ph), 7.37 (m, 2H; Hp-Ph),
3.99 (s, 6H; OCH3), ꢁ3.35 ppm (brs, 2H; NH); 13C NMR (126 MHz,
CDCl3, 258C): d=158.26, 147.09, 145.28, 131.60, 131.06, 127.91, 127.78,
120.79, 113.51, 105.27, 55.54 ppm; UV/Vis (CH2Cl2): lmax (loge)=406
(5.12), 502 (3.84), 536 (3.31), 575 (3.38), 628 nm (2.95); MS (80 eV, EI):
m/z (%): 522 (100) [M +], 416 (3) [M +ꢁC7H7O]; HRMS: m/z calcd for
C34H26N4O2: 522.20558; found: 522.20560.
5-p-Tolylporphyrin (29a)
Procedure C: Obtained during the synthesis of 29c. After recrystalliza-
tion from CH2Cl2/CH3OH, the product was obtained as purple crystals
(25 mg, 0.06 mmol, 3%). Rf =0.40 (CH2Cl2/n-hexane 2:1); m.p. 2808C;
1H NMR (270 MHz, CDCl3, 258C, TMS): d=10.28 (s, 2H; 10,20-Hmeso),
10.19 (s, 1H; 15-Hmeso), 9.43 (AB, 3J(H,H)=4 Hz, 4H; 12,13,17,18-Hb),
9.38 (AB, 3J(H,H)=4 Hz, 2H; 2,8-Hb), 9.12 (AB, 3J(H,H)=4 Hz, 2H;
3,7-Hb), 8.14 (d, 2H; 3J(H,H)=8 Hz, Ho-Ph), 7.59 (d, 3J(H,H)=8 Hz, 2H;
H
m-Ph), 2.74 (s, 3H; CH3), ꢁ3.63 ppm (brs, 2H; NH); UV/Vis (CH2Cl2):
lmax (loge)=404 (5.26), 499 (4.11), 531 (3.32), 574 (3.60), 629 nm (2.81);
MS (80 eV, EI): m/z (%): 400 (100) [M +], 384 (7) [M +ꢁCH2]; HRMS:
m/z calcd for C27H20N4: 400.16880; found: 400.21536.
5-(3,5-Dimethoxyphenyl)porphyrin (24a)
Procedure A: The porphyrin was purified by column chromatography on
silica gel by using neat dichloromethane eluent. The first fraction was the
desired porphyrin 24a, followed by traces of 5,15-bis(3,5-dimethoxyphe-
nyl)porphyrin 24b.[48a,c] After recrystallization from CH2Cl2/CH3OH, the
porphyrin was obtained as purple crystals (50 mg, 0.11 mmol, 6%).
5,10-Di(p-tolyl)porphyrin (29c)
Procedure C: The porphyrins were purified by column chromatography
on silica gel (CH2Cl2/n-hexane 1:2). The first fraction contained the mon-
osubstituted porphyrin 29a and the second fraction the disubstituted por-
phyrin 29c. After recrystallization from CH2Cl2/CH3OH, the product was
obtained as purple crystals (111 mg, 0.23 mmol, 11%). Rf =0.60 (CH2Cl2/
Procedure B: The yield of the title compound was 22% (0.44 mmol,
22%). Rf =0.37 (CH2Cl2/n-hexane 3:1); m.p. >3408C, subl. >3158C;
HPLC: (Nucleosil 50, 5m, eluent: CH2Cl2, flow: 1 mLminꢁ1, detection at
420 nm) tR: 5.17 min (99%), (same conditions but detection at 254 nm)
tR: 5.24 min (100.0%); 1H NMR (270 MHz, CDCl3, 258C, TMS): d=
10.31 (s, 2H; 10,20-Hmeso), 10.27 (s, 1H; 15-Hmeso), 9.48 (m, 4H;
12,13,17,18-Hb), 9.40 (AB, 3J(H,H)=5 Hz, 2H; 2,8-Hb), 9.17 (d, 3J-
(H,H)=5 Hz, 2H; 3,7-Hb), 7.43 (m, 2H; Ho-Ph), 6.91 (m, 1H; Hp-Ph), 3.98
(s, 6H; OCH3), ꢁ3.62 ppm (brs, 2H; NH); UV/Vis (CH2Cl2): lmax
(loge)=400 (5.49), 495 (4.22), 526 (3.40), 568 (3.73), 622 nm (2.85); MS
(80 eV, EI): m/z (%):446 (100) [M +], 431 (3) [M +ꢁCH3], 416 (4) [M +
ꢁ2CH3], 223 (10) [M2+]; HRMS: m/z calcd for C28H22N4O2: 446.174276;
found: 446.17633.
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n-hexane 1:1); m.p. 2708C; H NMR (270 MHz, CDCl3, 258C, TMS): d=
10.19 (s, 2H; 15,20-Hmeso), 9.41 (s, 2H; 17,18-Hb), 9.32 (AB, 3J(H,H)=
5 Hz, 2H; 2,13-Hb), 9.05 (AB, 3J(H,H)=5 Hz, 2H; 3,12-Hb), 8.95 (s, 2H;
7,8-Hb), 8.13 (d, 4H; 3J(H,H)=8 Hz, Ho-Ph), 7.78 (d, 3J(H,H)=8 Hz, 4H;
H
m-Ph), 2.72 (s, 6H; CH3), ꢁ3.35 ppm (brs, 2H; NH); 13C NMR
(126 MHz, CDCl3, 258C): d=139.20, 137.37, 134.56, 131.04, 127.39,
120.19, 103.98, 21.50 ppm; UV/Vis (CH2Cl2): lmax (loge)=405 (5.48), 502
(4.33), 531 (3.66), 575 (3.84), 625 nm (3.32); MS (80 eV, EI): m/z (%):
490 (15) [M +], 400 (25) [M +ꢁC6H5]; HRMS: m/z calcd for C34H26N4:
490.21575; found: 490.21537.
5-Pentylporphyrin (30a)
5-(3-Nitrophenyl)porphyrin (25a)
Procedure C: Obtained during the synthesis of 30c. After recrystalliza-
tion from CH2Cl2/CH3OH, the product was obtained as purple crystals
(8 mg, 0.02 mmol, 1%). Alternatively, dipyrromethane 13 (0.34 g,
2.3 mmol) and 5-pentyldipyrromethane (0.5 g, 2.3 mmol) were dissolved
in dichloromethane (1.2 L) and degassed for 10 min with argon. Trime-
thylorthoformiate (38 mL, 0.35 mol) was added, followed by dropwise ad-
dition of trichloroacetic acid (17.65 g, 108 mmol). After stirring for 4 h at
RT the mixture was treated with pyridine (31.2 mL, 0.39 mol) and stirring
was continued for 17 h. Subsequently, oxygen was bubbled through the
solution for oxidation, followed by filtration, and chromatographic
workup. Yield 1%; Rf =0.52 (n-hexane/ethyl acetate 4:1); m.p. 2758C;
1H NMR (250 MHz, CDCl3, 258C, TMS): d=10.12 (s, 2H; 10,20-Hmeso),
10.11 (s, 2H; 15-Hmeso), 9.65 (AB, 3J(H,H)=5 Hz, 2H; 3,7-Hb), 9.41 (m,
4H; 2,8,12,18-Hb), 9.37 (AB, 3J(H,H)=5 Hz, 2H; 13,17-Hb), 5.06 (t, 3J-
(H,H)=8 Hz, 2H; CH2(CH2)3CH3), 2.56 (m, 2H; CH2CH2(CH2)2CH3),
1.84 (m, 2H; (CH2)2CH2CH2CH3), 1.74 (m, 2H; (CH2)3CH2CH3), 1.15 (t,
3J(H,H)=7 Hz, 3H; (CH2)4CH3), ꢁ3.57 ppm (brs, 2H; NH); 13C NMR
(126 MHz, CDCl3, 258C): d=131.83, 131.62, 130.83, 128.30, 120.21,
104.21, 102.78, 38.64, 35.13, 31.71, 22.78, 14.14 ppm; UV/Vis (CH2Cl2):
lmax (loge)=400 (5.33), 495 (4.12), 526 (3.25), 569 (3.62), 621 nm (2.53);
MS (80 eV, EI, 2508C): m/z (%): 390 (44) [M +], 323 (100) [M +ꢁC4H9];
HRMS: m/z calcd for C25H24N4: 380.20010; found: 380.20008.
Procedure A: The porphyrins were purified by column chromatography
on silica gel (CH2Cl2/n-hexane 2:1). The first fraction contained the di-
substituted porphyrin 25b and the second fraction the monosubstituted
porphyrin 25a. After recrystallization from CH2Cl2/CH3OH, the porphyr-
in was obtained as purple crystals (27 mg, 0.06 mmol, 3%). Rf =0.23
1
(CH2Cl2/n-hexane 2:1); m.p. >3308C; H NMR (500 MHz, CDCl3, 258C,
TMS): d=10.35 (s, 2H; 10,20-Hmeso), 10.29 (s, 1H; 15-Hmeso), 9.50 (AB, 3J-
(H,H)=4 Hz, 2H; 12,18-Hb), 9.48 (AB, 3J(H,H)=4 Hz, 2H; 13,17-Hb),
3
3
9.43 (AB, J(H,H)=5 Hz, 2H; 2,8-Hb), 9.12 (m, 1H; Pho-H), 8.95 (AB, J-
(H,H)=5 Hz, 2H; 3,7-Hb), 8.70 (m, 1H; Php-H), 8.56 (m, 1H; Pho-H), 7.97
(m, 1H; Phm-H), ꢁ3.67 ppm (brs, 2H; NH); 13C NMR (63 MHz, CDCl3,
258C): d=139.98, 131.96, 131.52, 130.43, 128.49, 127.77, 122.88, 105.08,
104.31 ppm; UV/Vis (CH2Cl2): lmax (loge)=401 (5.15), 495 (3.99), 526
(3.23), 567 (3.50), 622 nm (2.72); MS (80 eV, EI): m/z (%): 431 (100)
[M +], 385 (23) [M +ꢁNO2], 215 (3) [M2+]; HRMS: m/z calcd for
C26H17N5O2: 431.13822; found 431.13577.
5,15-Bis(3-nitrophenyl)porphyrin (25b)[48a,d]
Procedure A: Obtained during the synthesis of 25a. After recrystalliza-
tion from CH2Cl2/CH3OH, the porphyrin was obtained as purple crystals
(33 mg, 0.06 mmol, 6%). Rf =0.33 (CH2Cl2/n-hexane 2:1); m.p. >3308C;
1H NMR (250 MHz, CDCl3, 258C, TMS): d=10.39 (s, 2H; 10,20-Hmeso),
Chem. Eur. J. 2005, 11, 3427 – 3442
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3439