Series 2. From a mixture of 2-hydroxymethyl-3,4-dimethylpyrrole, 3,4-dimethylpyrrole, and 3,5-di-tert-
butylbenzaldehyde we obtained: Octamethylporphyrin 1B, yield 500 mg; 5-(3,5-di-tert-
butylphenyl)octamethylporphyrin 2B, yield 150 mg; 5,15-di(3,5-di-tert-butylphenyl)octamethylporphyrin 3B,
yield 460 mg; 5,10-di(3,5-di-tert-butylphenyl)octamethylporphyrin 4B, yield 200 mg; 5,10,15-tri(3,5-di-tert-
butylphenyl)octamethylporphyrin 5B, yield 1600 mg; 5,10,15,20-tetra(3,5-di-tert-butylphenyl)octamethyl-
porphyrin 6B, yield 1600 mg.
Series 3. From a mixture of 3,4-diethyl-2-hydroxymethylpyrrole, 3,4-diethylpyrrole, and benzaldehyde
we obtained: Octaethylporphyrin 1C, yield 90 mg; 5-phenyloctaethylporphyrin 2C, yield 1200 mg;
5,15-diphenyloctaethylporphyrin 3C, yield 370 mg; 5,10-diphenyloctaethylporphyrin 4C, yield 580 mg;
5,10,15-triphenyloctaethylporphyrin 5C, yield 370 mg; 5,10,15,20-tetraphenyloctaethylporphyrin 6C,
yield 190 mg.
Octaethylporphyrins (1). To a solution of 3,4-dialkyl-2-hydroxymethylpyrrole (8.0 mmol) in methanol
(10 ml) in an inert atmosphere we added concentrated hydrobromic acid (0.3 ml). The mixture was stirred at
~20°C for 2 h. The white precipitate of the porphyrinogen was filtered off, washed with methanol, and dissolved
in THF (15 ml). To the obtained solution we added a solution of p-chloroanil (1.2 g, 5 mmol) in THF (50 ml),
and we stirred the mixture for 5 h at ~20°C. The solvent was distilled under vacuum, and the residue was washed
with a 10% solution of sodium hydroxide and with water and dried to constant weight at room temperature. The
octamethylporphyrin 1A (1B) was purified by reprecipitation from a mixture of chloroform and trifluoroacetic
acid. Yield 520 mg. The octaethylporphyrin 1C was isolated by column chromatography (2.5 × 60 cm) with
aluminum oxide of III activity and with chloroform as eluant. Yield 750 mg.
5-Phenyloctaalkylporphyrins (2). A solution of octaalkylbiladiene-a,c (1.0 mmol), the respective
benzaldehyde (10 mmol), and concentrated hydrobromic acid (1 ml) in ethanol (50 ml) was boiled for 4 h, iodine
(0.26 g, 1 mmol) was then added, and the mixture was boiled for a further 15 min. The mixture was cooled and
neutralized with a concentrated solution of ammonia (2 ml). The precipitate was filtered off, washed with
ethanol, and dried. The porphyrins were dissolved in chloroform (100 ml) and chromatographed on a column
(2.6 × 60 cm) of aluminum oxide of III activity with chloroform as eluent. The eluate was evaporated, the
porphyrin was precipitated with methanol (30 ml), and after filtration it was dried to constant weight at ~20°C.
5-Phenyloctamethylporphyrin 2A, yield 280 mg; 5-(3,5-di-tert-butylphenyl)octamethylporphyrin 2B, yield 230
mg; 5-phenyloctaethylporphyrin 2C, yield 380 mg.
5,15-Diphenyloctaalkylporphyrins (3). To a solution of the respective benzaldehyde (2.5 mmol) and p-
toluenesulfonic acid (0.13 g, 6.0 mmol) in methanol (30 ml) in an inert atmosphere we added a solution of
tetraalkyldipyrrolylmethane (2.5 mmol) in methanol (20 ml). The mixture was stirred at ~20°C for 3 h and kept
overnight with cooling. The precipitated porphyrinogen was then filtered off, washed with methanol, and
dissolved in THF (100 ml). To the obtained solution we added a solution of p-chloroanil (0.9 g, 3.75 mmol) in
THF (50 ml), and we stirred the mixture at ~20°C for 4 h. The solvent was distilled under vacuum, and the
residue was washed with a 10% solution of sodium hydroxide and with water and dried at ~20°C to constant
weight. 5,15-Diphenyloctamethylporphyrin 3A was purified by reprecipitation from a mixture of chloroform and
trifluoroacetic acid. Yield 450 mg. 5,15-Di(3,5-tert-butylphenyl)octamethylporphyrin 3B and
5,15-diphenyloctaethylporphyrin 3C were purified by column chromatography (2.5 × 60 cm) of aluminum oxide
with III activity with chloroform as eluent. Yield 460 mg and 400 mg respectively.
5,10,15,20-Tetraphenyloctaalkylporphyrins (6). To a solution of 3,4-dialkylpyrrole (9.0 mmol) and
benzaldehyde (9.0 mmol) in methanol (50 ml) in an inert atmosphere we added concentrated hydrobromic acid
(2 ml). The mixture was stirred at ~20°C for 4 h, and the white precipitate of the porphyrinogen was filtered off,
washed with methanol, and dissolved in THF (40 ml). To the obtained solution we added a solution of
p-chloroanil (1.9 g, 7.7 mmol) in THF (30 ml), and we stirred the mixture at ~20°C for 5 h. The solvent was
distilled under vacuum, and the residue was washed with a 10% solution of sodium hydroxide and with water
and dried to constant weight at ~20°C. The precipitate was dissolved in chloroform (100 ml) and
chromatographed twice on a column (2.5 × 60 cm) of aluminum oxide of III activity with chloroform as eluent.
1269
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