meso-Quinolyl-substituted tetrabenzoporphins. Synthesis and properties

Article abstract of DOI:10.1007/s11178-005-0161-7

Prolonged heating of phthalimide with 2-methylquinoline in the presence of zinc oxide afforded zink complexes of meso-tri-, di- and monoquinolyltetrabenzoporphins. Alternative preparation methods were developed for some among these compounds. The correspo

Full text of DOI:10.1007/s11178-005-0161-7

Russian Journal of Organic Chemistry, Vol. 41, No. 2, 2005, pp. 298-303. Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 2, 2005,
pp. 306-311.
Original Russian Text Copyright Ó 2005 by Galanin, Kudrik, Lebedev, Aleksandriiskii, Shaposhnikov.
meso-Quinolyl-substituted Tetrabenzoporphins.
Synthesis and Properties
N.E. Galanin, E.V. Kudrik, M.E. Lebedev, V.V.Aleksandriiskii, and G.P. Shaposhnikov
Ivanovo State Chemical Engineering University, Ivanovo, 153460 Russia
e-mail: ttoc@isuct.ru
Received April 15, 2004
Abstract—Prolonged heating of phthalimide with 2-methylquinoline in the presence of zinc oxide afforded zink
complexes of meso-tri-, di- and monoquinolyltetrabenzoporphins.Alternative preparation methods were developed
for some among these compounds. The corresponding porphins were prepared by treating complexes with
hydrochloric acid. The spectral characteristics of compounds synthesized were investigated.
meso-Aryl-substituted tetrabenzoporphins are
prepared by reaction of phthalimide with arylacetic acids
in the presence of a template agent (zinc or cadmium
com-pounds) under stringent conditions: at the
temperature up to 380°C [1–5].
complex in air resulted in mass loss in the sample
corresponding to the successive elimination of the meso-
phenyl substituents. Thus the formation of compounds
II–IV follows Scheme 1.
Therewith due to sterical hindrances the formation of
zinc meso-trans-di(2-quinolyl)tetrabenzoporphinate (III)
is more probable than of its cis-isomer. For instance,
quantum-chemical calculations by the semiempiricalAM1
procedure show that the enthalpy of formation DHf for
We developed a preparation method for zinc meso-
tetra(2-quinolyl)tetrabenzoporphinate (I) by reaction of
phthalimide with 2-methylquinoline in the presence of zinc
oxide [6]. Heating the mixture at boiling point (248°C)
for 12 h afforded compound I in a yield of about 15%.
-
1
-1
compound III is 1837.32 kJ mol , by 37.46 kJ mol less
than for zinc meso-cis-di(2-quinolyl)tetrabenzoporphinate.
It was presumable that a longer heating would lead to
a better yield of complex I. However the boiling of the
reagents mixture for 36 h did not provide the desired result
On the contrary, the yeld of compound I reduced to 2.8%,
and from the reaction mixture were isolated by column
chromatography alongside compound I also zinc
complexes of meso-tri(2-quinolyl)tetrabenzoporphin (II),
meso-di(2-quinolyl)tetrabenzoporphin (III), and meso-
Complexes II–IV were isolated from the reaction
mixture by column chromatography on alumina. It should
be pointed out that the preparative separation of a mixture
of four porphyrins I–IV is a difficulr problem. Therefore
we developed selective preparation methods for tetra-
benzoporphyrins III and IV.
One synthetic method for products of incomplete meso-
aryl substitution in the tetrabenzoporphin is building up
of a macroring from dimeric isoindologen with a fixed
position of the methine group. It is known [4] that in the
selective synthesis of zinc meso-diphenyltetrabenzo-
porphinate a dimeric product can be used prepared by
phthalimide condensation with acetic or malonic acid,
(2-quinolyl)tetrabenzoporphin (IV).
Products of incomplete meso-aryl substitution in the
tetrabenzoporphin form at the use as the template agent
of metal acetates; therewith the acetate ion serves as a
source of a methylene group [7]. The application of zinc
oxide or hydroxide results in formation of solely zinc
meso-tetraaryltetrabenzoporphinate [1]. The presence in
the reaction mixture of compounds II–IV in our case is
an uncommon fact that may be due to the thermal
degradation of complex I for the prolonged heating results
in decrease in its amount. Asimilar pattern was formerly
observed at the study of oxidative degradation at heating
of metal complexes of meso-tetraphenyltetrabenzoporphin
3-(3-oxo-2,3-dihydro-1H-1-isoindolylidenemethyl)-1H-1-
isoindolone (V). We used this compound for preparation
of zinc complex III. The reaction of dimer V with excess
2-methylquinoline in the presence of zinc oxide at 280°C
within 30 min afforded compound III in an approximately
12% yield.
Porphyrin III was isolated from the reaction mixture
[
8]. It was established that the heating of the metal
by column chromatography. Besides a small amount of
1070-4280/05/4102-0298Ó2005 Pleiades Publishing, Inc.

meso-QUINOLYL-SUBSTITUTED TETRABENZOPORPHINS.
299
Scheme 1.
2
1+
1
&+
2
1
1
1
1
1
1
1
ꢁꢂꢃ &ꢀꢄꢆꢇꢄK
=
Q2ꢀ ꢁꢂꢃ &ꢀꢄꢅꢁꢄK
1
=Q
1
1
1
=Q
1
1
1
1
,
,,
1
1
1
1
1
=Q
1
1
1
=Q
1
1
1
,,,
,9
Scheme 2.
complex IV was isolated arising apparently due to
elimination of one meso-substituent from molecule III.
It was shown formerly [7], that in the synthesis of
meso-phenyl-substituted zinc tetrabenzoporphinates
3
-benzylidenephthalimidine could be used.
2
1
By boiling equimolar quantities of phthalimide and
-methylquinoline in trichlorobenzene for 5 h we prepared
2
1+
its quinolyl-substituted analog, 3-(2-quinolylmethylidene)-
1
&+
phthalimidine (VI) (Scheme 3).
2
9
On completion of the reaction trichlorobenzene and
un-reacted 2-methylquinoline were distilled off in a
vacuum. Compound VI was isolated from the reaction
mixture by column chromatography; its composition and
structure were proved by elemental analysis, H and C
NMR spectroscopy.
=Q2
,,,ꢀꢁꢂꢃꢄ
1
In the H NMR spectrum of compound VI the most
downfield signal appearing as broadened singlet at 11.36
ppm belonged to the imino group; a singlet from CH group
proton is observed in the strongest field, at 6.95 ppm.
1
13
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 2 2005

300
GALANIN et al.
Scheme 3.
by field desorption mass spectrometry. It should be noted
2
1
that here the CHN-elemental analysis provided few
information: the percent content of carbon, hydrogen, and
nitrogen in going from tri- to (2-quinolyl)-substituted
tetrabenzoporphins varied insignificantly (from 1 to 0.1%),
therefore the most reliable for proving the structure of
compounds II–IV were the mass spectra.
+
1
1
&+
2
+
&
The electron absorption spectra of meso-heteryl-
substituted zinc tetrabenzoporphinates II–IV (Fig. 1) have
the same pattern as the respective spectra of meso-
phenyl-substituted complexes: They contain a strong Soret
band in the region 449–435 nm and a less strong Q-band
in the region 643–630 nm. The comparison of spectral
data obtained with those of meso-phenyl-substituted zinc
tetrabenzoporphinates [3–5] shows that replacement of
three phenyl substituent in the molecule of zinc meso-
triphenyltetrabenzoporphinate by a 2-quinolyl groups
caused simultaneous red shift of the absorption bands by
1
+
2
9
,
The doublet in the region 8.40–8.35 ppm corresponds to
the proton of the quinolyl substituent in the para-position
with respect to nitrogen, and the doublet at 7.66–
7
.62 ppm originates from the proton in meta-position.
The multiplet in the region 8.20–7.70 ppm corresponds
to four protons of benzene ring attached to the quinolyl
substituent, and to four protons of the isoindole moiety.
The broadening of the signal of the imino group proton
indicates that it is involved into a hydrogen bond with the
nitrogen of the quinoline ring.
9
–11 nm, and the analogous replacement in the zinc meso-
monophenyltetrabenzoporphinate provided a red shift by
–7 nm. The replacement in the zinc meso-diphenyl-tetra-
5
benzoporphinate of the phenyl substituents by 2-quinolyl
ones led to the red shift of the Soret band by 11 nm, and
of Q-band only by 3 nm.
The heating at 300°C of a mixture of compound VI
and excess phthalimide in the presence of zinc acetate
for 20min afforded complex IV in about 10% yield.
This spectral pattern may be due to stronger spatial
distortion of molecules in compounds II–IV compared
to the molecules of the meso-phenyl-sybstituted
porphyrins caused by larger size of the quinoline
fragments than that of benzene rings. Note also that on
the spectra of compounds II–IV bands characterizing
the absorption of the quinoline moieties appear in the
region 314 nm
In the 1H NMR spectra of the zinc complexes II– IV
the most downfield signals in the region 9.80–9.30 ppm
correspond to the methine group protons, and the signal
Although the main reaction product was zinc tetra-
benzoporphinate (VII), the chromatographic isolation of
complex IV was easy due to its high solubility in organic
solvents.
Metal complexes II–IV are dark-green crystalline
substances, well soluble in benzene, chloroform, acetone,
and DMF. Their homogeneity was proved by TLC, the
composition and structure were confirmed by elemental
1
analysis, electronic and H NMR spectroscopy, and also
Scheme 4.
&
+
2
1
2
1
1
=
Qꢀ2$Fꢁ
,
9
1
=Q
1
1
+
1+
2
9,
9,,
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 2 2005

meso-QUINOLYL-SUBSTITUTED TETRABENZOPORPHINS.
301
shifts successively downfield as the number of the meso-
'ꢀ
substituents decreases. This fact is due to the lesser
distortion of the macroring and consequently with growing
deshielding of the methine group protons. The resonance
of protons from the quinolyl moieties ins observed in a
stronger field at 8.70–8.20 ppm, and the multiplets in the
region 8.00–7.40 ppm belong to the protons in the
isoindole fragments.
ꢁ
ꢀ
ꢁ
ꢇꢃ ꢂ
ꢂꢀ
ꢁꢇꢈ
ꢂ
The metal-free porphyrins VIII–X were obtained by
treating the acetone solutions of compounds II–IV by
concn. hydrochloric acid. They were purified by column
chromatography on alumina. The substances are green
crystals well soluble in polar and nonpolar organic solvents.
Their composition and structure were also derived from
ꢁ
ꢇꢁꢂ
ꢂ
ꢀ
ꢁꢁꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢃꢁꢁꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢄꢁꢁꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢅꢁꢁꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢂꢆꢁꢁꢂꢂ
ꢂꢂ
ꢉꢂQP
Fig. 1. Electron absorption spectra in chloroform solution: (1)
compound IV; (2) compound III.
1
elemental analysis, electronic, H NMR, and mass
spectra.
'
The electron absorption spectra of porphyrins VIII–
X (Fig. 2) also resemble the spectra of the corresponding
meso-phenyl-substituted tetrabenzoporphins. In going
from compound VIII to compound X the absorption bands
simultaneously undergo a blue shift by 5–7 nm, and their
splitting is increased.
ꢀꢁ
ꢀ
ꢁꢂꢃ
ꢂꢁ
ꢀꢁꢄꢃ
1
In the H NMR spectra of porphyrins VIII–X the
ꢃꢁ
most upfield signal in the region–0.99...–1.80 ppm belongs
to the protons of the endocyclic imino groups, and with
decrease in the number of the meso-substituents a
successive upfield shift is observed due to flattening of
the macroring
ꢀ
ꢁꢅꢃ
ꢁꢀꢃ
ꢀ
ꢆꢇꢀꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢄꢇꢀꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢇꢇꢀꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢃꢂꢇꢀ
ꢃꢃ
In the course of chromatography of porphyrins VIII–
X and their metal complexes II–IV we observed their
abnormal mobility in the column packed with alumina. It
turned out that in contrast to the meso-phenyl-substituted
tetrabenzoporphins the highest mobility corresponded to
meso-mono(2-quinolyl)-substituted compounds IV and X,
and the lowest to meso-tri(2-quinolyl)-substituted II and
VIII. This phenomenon is apparently caused by coordina-
tion of the pyridine nitrogens in the meso-substituents to
the aluminum atoms. Therefore with growing number of
ꢈꢃQP
Fig. 2. Electron absorption spectra in chloroform solution:
1) compound X; (2) compound IX; (3) compound VIII.
(
3
-(3-Oxo-2,3-dihydro-1H-1-isoindolylidenemethyl)-
H-1-isoindolone (V) was prepared and pyrified as
1
described in [4].
meso-(2-Quinolyl)-substituted zinc tetrabenzo-
porphinates II–IV. a. A mixture of 1 g of phthalimide
I), 0.3 g of zinc oxide, and 10 ml of 2-methylquinoline
(
(
the meso-substituents the R value of the corresponding
f
V) was boiled for 36 h. The reaction mixture was cooled
poephyrines decreases.
and subjected to chromatography on a column packed
with aluminum oxide of II grade activity. By elution with
a mixture benzene–hexane, 1:10 by volume, was
separated excess 2-methylquinoline, then with a mixture
chloroform–acetone, 10:1 by volume, was separated the
green zone. On removing the solvent the residue was
dissolved in chloroform and subjected to chromatography
on a column packed with aluminum oxide of II grade
activity, eluent chloroform–hexane, 1:1 by volume. The
separation occurred into 4 green zones containing
EXPERIMENTAL
Electron absorption spectra of compounds obtained
were measured on a spectrophotometer Hitachi UV-2000,
H NMR spectra (200 MHz, internal reference HMDS)
and C NMR spectra (75 MHz) were registered on
spectrometer Bruker AM-200 from solutions in
DMSO-d . Field desorption mass spectra were obtained
1
1
3
6
on JEOL JMS 700 instrument.
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 2 2005

302
GALANIN et al.
respectively compounds I–IV which were dark green
substances well soluble in benzene, acetone, and chloro-
form, insoluble in water. On removing the solvent com-
pounds II–IV were isolated.
absorption spectrum (CHCl ), lmax, nm (D/Dmax): 628
3
(0.37), 583 (0.08), 430 (1.00), 404 (0.23), 314 (0.26).
1
H NMR spectrum, d, ppm: 9.78 s (3H), 8.70–8.55 m
(6H), 8.00–7.75 m (16H). Mass spectrum, m/z: 700 [M +
+
+
H] , 1400 [2M + H] . Found, %: C 78.01; H 3.80; N
b. A mixture of 0.5 g (2 mmol) of compound V, 1.5 g
1
1
0.15. C H N Zn. Calculated, %: C 77.24; H 3.60; N
0.01.
3-(2-Quinolylmethylidene)phthalimidine (VI).
(
10 mmol) of 2-methylquinoline, and 0.2 g of zinc oxide
45 25 5
was heated at 280°C for 30 min. The melt was cooled,
crushed into powder, and the product was extracted by
chloroform in a Soxhlet apparatus. The extract was
evaporated to dryness, the dark-green powder obtained
was dissolved in dichloromethane and subjected to
chromatography on a column packed with aluminum
oxide, eluent dichloromethane–benzene, 1:1 by volume.
The main green zone was collected, and the solvent was
evaporated to furnish 0.01 g (12%) of compound III
whose properties were identical to the sample obtained
by procedure a.
A mixture of 6 g (0.04 mol) of phthalimide, 5.7 g
(0.04 mol) of 2-methylquinoline, and 20 ml of trichloro-
benzene was boiled for 8 h, then the trichlorobenzene
and unreacted 2-methylquinoline were distilled off in
a vacuum. The residue was dissolved in chloroform and
subjected to chromatography on a column packed with
aluminum oxide (eluent chloroform) collecting the light-
yellow zone. On removing the solvent 1.2 g (10.9%) of
light-yellow powdery compound VI was obtained well
soluble in benzene, acetone, chloroform, and DMF,
c. A mixture of 0.5 g (2 mmol) of compound VI, 1 g
1
insoluble in water. H NMR spectrum, d, ppm: 11.36 s
(
7 mmol) of phthalimide, and 1 g of zinc acetate was
(
(
1H), 8.40–8.35 d (1H), 8.20–7.70 m (8H), 7.66–7.62 d
1H), 6.95 s (1H). 13C NMR spectrum, d, ppm: 169.25,
heated at 300°C for 20 min. The melt was cooled, crushed
into powder, and the product was extracted by chloro-
form in a Soxhlet apparatus. The extract was evaporated
to dryness, the dark-green powder obtained was dissolved
in dichloromethane and subjected to chromatography on
a column packed with aluminum oxide, eluent dichloro-
methane. The main green zone was collected, and the
solvent was evaporated to furnish 0.12 g (10%) of
compound IV whose properties were identical to the
sample obtained by procedure a.
1
67.87, 155.79, 147.32, 138.60, 137.67, 134.30, 132.61,
1
30.31, 128.58, 127.75, 126.38, 123.26, 121.03, 102.41.
Found, %: C 79.55; H 4.60; N 10.42. C H N O.
18 12
2
Calculated, %: C 79.40; H 4.44; N 10.29.
meso-(2-Quinolyl)-substituted tetrabenzo-
porphins VIII–X. In 5 ml of acetone was dissolved
0.05 g of zinc complex II–IV, 1 ml of concn. HCl was
added, and the mixture was left standing for 1 h at 20°C.
Then 5 ml of concn. NH solution and 20 ml of chloroform
Zinc meso-tri(2-quinolyl)tetrabenzoporphinate
3
was added, and the mixture was stirred for 5 min. The
organic layer was separated, the solvent was evaporated,
the residue was dissolved in chloroform and subjected to
chromatography on a column packed with aluminum oxide
of II grade activity (eluent benzene-chloroform, 1:1 by
volume). Compounds VIII–X were isolated by removing
the solvent.
(
II). Yield 0.07 g (4.8%), R 0.20 (CHCl , Silufol).
f 3
Electron absorption spectrum (CHCl ), lmax, nm
3
(D/Dmax): 643 (0.32), 597 (0.15), 449 (1.00), 418 (0.45),
1
3
8
9
3
16 (0.88). H NMR spectrum, d, ppm: 9.30 s (1H), 8.66–
.25 m (18H), 7.95–7.65 m (16H). Mass spectrum, m/z:
+
+
54 [M + H] , 1907 [2M + H] . Found, %: C 80.25; H
.4.02; N 10.16. C H N Zn. Calculated, %: C 79.31;
6
3
35
7
H 3.70; N 10.28.
meso-Tri(2-quinolyl)tetrabenzoporphin (VIII).
Yield 0.03 g (59%), Rf 0.25 (CHCl3, Silufol). Electron
Zinc meso-di(2-quinolyl)tetrabenzoporphinate
III). Yield 0.10 g (6.7%), R 0.39 (CHCl , Silufol). Elec-
(
absorption spectrum (CHCl ), lmax, nm (D/Dmax): 679
f
3
3
tron absorption spectrum (CHCl ), lmax, nm (D/Dmax):
(0.19), 622 (0.28), 583 (0.16), 444 (1.00), 433 sh, 401
(0.36). H NMR spectrum, d, ppm: 9.28 s (1H), 8.68–
3
1
6
34 (0.36), 589 (0.07), 437 (1.00), 409 (0.38), 314 (0.82).
1
H NMR spectrum, d, ppm: 9.45 s (2H), 8.66–8.45 m
8.30 m (18H), 7.90–7.45 m (16H), –0.99 s (2H). Mass
+
+
+
(
12H), 7.90–7.60 m (16H). Mass spectrum, m/z: 826 [M] ,
spectrum, m/z: 891 [M] , 1784 [2M + H] . Found, %:
+
1
653 [2M + H] . Found, %: C 78.20; H 3.50; N 10.45.
C 78.01; H 3.80; N 10.15. C H N . Calculated, %:
6
3
37
7
C H N Zn. Calculated, %: C 78.43; H 3.66; N 10.17.
C 84.82; H 4.18; N 11.00.
5
4
30
6
Zinc meso-(2-quinolyl)tetrabenzoporphinate (IV).
Yield 0.05 g (3.4%), R 0.69 (CHCl , Silufol). Electron
meso-Di(2-quinolyl)tetrabenzoporphin (IX). Yield
0.04 g (72%), R 0.42 (CHCl , Silufol). Electron absorption
f
3
f
3
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 2 2005

meso-QUINOLYL-SUBSTITUTED TETRABENZOPORPHINS.
303
spectrum (CHCl ), lmax, nm (D/Dmax): 671 (0.17), 616
REFERENCES
3
(
0.24), 603 sh, 565 (0.13), 439 (1.00), 425 (0.75) 397
1
. Luk’yanets, E.A., Dashkevich, S.N., and Kobayashi, Nagao.,
Zh. Obshch. Khim., 1993, vol. 63, p. 1411.
1
(0.25). H NMR spectrum, d, ppm: 9.33 s (2H), 8.55–
8
.48 m (12H), 7.8 8–7.62 m (16H), –1.55 s (2H). Mass
2
. Kopranenkov, V.N., Dashkevich, S.N., and Luk’yanets, E.A.,
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+
+
spectrum, m/z: 765 [M + H] , 1529 [2M + H] . Found,
%
C 84.79; H 4.22; N 10.99.
: C 84.01; H 5.10; N 10.38. C H N . Calculated, %:
54 32 6
3
. Galanin, N.E., Kudrik, E.V., and Shaposhnikov, G.P., Zh.
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meso-(2-Quinolyl)tetrabenzoporphin (X). Yield
.03 s (57%), R 0.75 (CHCl , Silufol). Electron absorption
4. Kudrik, E.V., Islyaikin, M.K., and Frantseva, S.V., Zh. Obshch.
Khim., 1997, vol. 67, p. 1202.
0
f
3
spectrum (CHCl ), lmax, nm (D/Dmax): 664 (0.19), 615
5. Galanin, N.E., Kudrik, E.V., and Shaposhnikov, G.P., Zh.
Obshch. Khim., 2002, vol. 72, p. 1198.
3
(
(
(
(
0.24), 608 (0.25), 601 (0.23), 568 (0.12), 432 (1.00), 418
0.79) 389 (0.25). H NMR spectrum, d, ppm: 9.73 s
6
. Galanin, N.E., Kolesnikov, N.A., Kudrik, E.V., and
Shaposhnikov, G.P., Zh. Org. Khim., 2004, vol. 40, p. 297.
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and Fukui, M., Inorg. Chim. Acta, 1991, vol. 186, p. 95.
1
3H), 8.75–8.52 m (6H), 7.88–7.45 m (16H), –1.80 s
7
+
2H). Mass spectrum, m/z: 638 [M + H] , 1277 [2M +
+
H] . Found, %: C 85.35; H 4.75; N 10.66. C H N .
8. Galanin, N.E., Cand. Sci. (Chem.) Dissertation, Ivanovo,
4
5
27
5
Calculated, %: C 84.74; H 4.27; N 10.99.
2002.
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 2 2005