Synthesis of hybrid photochromes containing fulgimide and salicylidenaniline fragments and study of their properties

Article abstract of DOI:10.1007/s11172-011-0135-6

Fulgimide salicylidenaniline derivatives were synthesized and studied in solutions and solid-phase films. It was found that the compounds obtained exhibit photochromic properties in different aggregate states. Comparative studies showed that the nature of substituents in the aldehyde moiety of the fulgimide azomethine fragments has little effect on the photochromic properties of the compounds obtained.

Full text of DOI:10.1007/s11172-011-0135-6

Russian Chemical Bulletin, International Edition, Vol. 60, No. 5, pp. 861—866, May, 2011
861
Synthesis of hybrid photochromes containing fulgimide and salicylidenaniline
fragments and study of their properties*
S. I. Luyksaar,a I. V. Platonova,a M. M. Krayushkin,a V. A. Barachevskii,b and S. P. Molchanovb
aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Eꢀmail: luyksaar@gmail.com
bCenter of Photochemistry, Russian Academy of Sciences,
7a ul. Novatorov, 119421 Moscow, Russian Federation.
Eꢀmail: barva@photonics.ru
Fulgimide salicylidenaniline derivatives were synthesized and studied in solutions and solꢀ
idꢀphase films. It was found that the compounds obtained exhibit photochromic properties in
different aggregate states. Comparative studies showed that the nature of substituents in the
aldehyde moiety of the fulgimide azomethine fragments has little effect on the photochromic
properties of the compounds obtained.
Key words: fulgides, fulgimides, salicylidenanilines, photochromic properties, photoꢀ
coloring, photobleaching, photodegradation, spectral and kinetic studies, solidꢀphase layers.
Scheme 1
Fulgimides belong to the thermally irreversible photoꢀ
chromic compounds, which are of interest for the develꢀ
opment of photochromic registration media for the threeꢀ
dimensional (3D) optical memory and molecular switchꢀ
es as a basis for the new generation of computational techꢀ
nique for recording, maintaining, and processing large
massifs of information.1 Their both forms possess high
thermal stability and high fatigue resistance of photochroꢀ
mic transformations, can be easily transformed to derivaꢀ
tives of related structures, that allows one to extend the
range of their functional possibilities.
Upon exposure to the light, fulgimides undergo reversꢀ
ible photoinduced valent isomerization between the open
(Eꢀisomer) and cyclic (Cꢀisomer) isomers, complicated in
some cases by E—Zꢀphotoisomerization (Scheme 1).2
Synthetic potential of fulgimides is rather limited.3—5
We assumed that development of fulgimide "hybrids" with
salicylidenanilines would allow us to broaden their synꢀ
thetic potential, in particular, due to the chelating properꢀ
ties of the latter.6 One of the processes interesting from the
practical point of view, which is accompanied by the
change in magnetic properties, is the ligandꢀdriven lightꢀ
induced spin change (LDꢀLISC) in coordination comꢀ
pounds.7 It consists in the fact that photoirradiation of the
transition metal complex leads to considerable stereoꢀ
chemical rearrangements of the ligand, which destabilize
different spin states of the metal. The LDꢀLISC has the
advantage that it can occur at room temperature on the level
of separate molecules. The absence of necessity of cooperꢀ
ative interactions makes possible its exhibiting in solutions,
different types of films, and, potentially, in the solid state.
In this connection, in the present work in continuation
of our earlier studies8 we synthesized a number of hybrid
photochromic products containing two fragments in one
molecule: the photochromic fulgimide and capable of
complexation salicylidenaniline ones, as well as studied their
photochromic properties in solutions and solidꢀphase films.
Results and Discussion
Synthesis of photochromic compounds. The synthesis
of hybrid photochromes was performed by the reaction of
* Dedicated to Academician V. N. Charushin on the occasion of
his 60th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 841—846, May, 2011.
1066ꢀ5285/11/6005ꢀ861 © 2011 Springer Science+Business Media, Inc.

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Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
Luyksaar et al.
the fulgimide amino derivatives with different salicylaldeꢀ
hydes. 3ꢀ[αꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀisoꢀ
propylidenetetrahydrofuranꢀ2,5ꢀdione (1) was the startꢀ
ing compound for the synthesis of the fulgimide, which
was obtained according to the known procedure9 in 12%
total yield (Scheme 2).
nals are found in the region δ 1.9—2.5. At the same time,
the 1,3,5ꢀhexatriеne fragment of Еꢀforms of the fulgide
molecule is not placed in the plane of the aromatic ring
because of steric factors, as a result, the ЕꢀMe group of the
isopropylidene fragment is either over or below its plane
and thus is shielded due to the induced magnetic field,
giving the signal in the region δ 1.3—1.4.12,13 The 1H NMR
spectra of compounds 6a—j exhibit signals for the Me
groups of the fulgide fragment as singlets in the region
δ 1.94—2.49, that indicates the Zꢀconfiguration of these
fragments.
Scheme 2
Spectral and kinetic studies. The results of the spectral
and kinetic studies of the synthesized hybrid compounds
6a—j in toluene are given in Table 1. Analysis of the data
obtained shows that all of them exhibit photochromic
properties intrinsic of fulgimides. The absorption spectra
of the open form are structured in most cases (Fig. 1)
except compound 6e, which has the only characteristic
absorption band, whose maximum is bathochromically
shifted as compared to the absorption maxima of the open
forms of other compounds.
Positions of the absorption bands for the cyclic form is
virtually independent on the nature of substituents in the
hydroxyꢀsubstituted phenyl fragment. Nonetheless, from
the data in Table 1 it follows that introduction of strong
electronꢀwithdrawing groups (compounds 6d,f) leads to a
bathochromic displacement of the absorption band for the
cyclic form by 2—3 nm. For compounds with less strong
electronꢀwithdrawing substituents (6j) or with substituꢀ
ents of different nature (6g,i), virtually no changes in the
position of the absorption maximum for the cyclic form
are observed (see Table 1). Conversely, in the case of strong
electronꢀreleasing substituents (6b,c,e,h), a hypsochromic
spectral shift by 2—8 nm is observed.
For all the fulgimides studied, only insignificant photoꢀ
induced changes of optical density in the absorption band
maximum for the cyclic form in the photostationary state
were found, which are apparently due to the efficiently
proceeding reverse reaction of photobleaching (Table 1).
It is seen from Fig. 2 that introduction of electronꢀ
withdrawing substituents causes an increase in the effiꢀ
i. 1) ButOK; 2) KOH, H2O—EtOH; 3) AcCl.
Reflux of fulgide 1 with pꢀ(tertꢀbutoxycarbonylamino)ꢀ
aniline (2) in benzene with subsequent cyclization in the
presence of N,N´ꢀcarbonyldiimidazole (CDI) and removal
of the Boc protecting group in the formed urethane 3
upon the action of the HCl solution in ethanol afforded
Nꢀ(aminophenyl)fulgimide 4 (see Refs 10 and 11 and
Scheme 3).
The reaction of fulgimide 4 with salicylic aldehydes
5a—j in DMF at room temperature for 5 h furnished the
hybrid photochromes 6a—j (Scheme 4).
The structures of compounds 6a—j were confirmed by
1H NMR spectroscopy, mass spectrometry, and elemenꢀ
tal analysis. It is know that Zꢀ or Eꢀconfigurations of
fulgides and fulgimides can be inferred from the chemical
shifts for the methyl groups of the isopropylidene fragꢀ
ment: for Zꢀisomers of fulgides and fulgimides these sigꢀ
Scheme 3
i. 1) CDI; ii. 1) HCl, EtOH; 2) NH3, MeOH.

Hybrid photochromes
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
863
Scheme 4
ciency of the photodegradation process. Electronꢀreleasꢀ
ing substituents in a number of cases significantly increase
stability of fulgimides to irreversible phototransformations
(6b,c,e).
The experimental data obtained allows us to draw
a conclusion that the changes in the nature of substituents
in the aldehyde moiety of the fulgimide azomethine fragꢀ
ments has insignificant effect on the photochromic propꢀ
erties in solutions.
state is low and independent on the structure of comꢀ
pounds under study (Table 2, Fig. 4).
Table 1. Spectral and kinetic characteristics of the syntheꢀ
sized fulgimides 6a—j in toluene
max
max
max
ph
Comꢀ
pound
λ
λ
AA
ΔAB
A
B
nm
In addition, photochromic properties of the fulgimꢀ
ides synthesized were studied in the thin (400 90 nm)
solidꢀphase films. The study of the structure of the
obtained solidꢀstate films showed that the compounds
in the thin solid films are in the amorphous state
(Fig. 3).aaa
Table 2 contains the results of the study of photochroꢀ
mic properties of the synthesized compounds in the thin
amorphous layers.
6a
6b
6c
6d
328 sh
346
331
348
342
370 sh
308
342
381
325
337
356
328
342 sh
365 sh
320
332
352
530
528
522
533
0.70
0.77
0.93
0.91
1.73
1.29
1.09
1.10
1.82
0.63
0.67
0.61
0.78
0.72
0.48
0.68
0.69
0.63
0.67
0.45
0.98
0.99
0.79
0.06
0.08
0.09
0.07
6e
6f
525
532
0.04
0.06
Irradiation of the solidꢀphase samples of fulgimides
causes their coloring, whose extent in the photoequilibrium
6g
6h
530
528
0.06
0.06
A (rel. units)
1
0.8
0.6
0.4
0.2
0
6i
6j
328
358 sh
327
340
360 sh
529
530
0.05
0.08
max
max
Note. Here and in Table 2: λ
lengths of absorption maxima of the open and cyclic forms,
respectively; AA
maxima of the open form; ΔABph is the maximum photoinꢀ
duced change in the optical density of the solution in the
absorption maximum of the cyclic form in photostationary
state.
and λ
are the waveꢀ
A
B
2
max
is the optical density in the absorption
350 400 450 500 550 600 λ/nm
Fig. 1. Absorption spectra of compound 6a in toluene before (1)
and after exposure (2) to the UV light.

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Luyksaar et al.
A/Amax
1.0
Table 2. Spectral and kinetic characteristics of the amorꢀ
phous films of fulgimides synthesized
5
max
max
max
ph
Comꢀ
pound
λ
λ
AA
ΔAB
A
B
0.8
0.6
0.4
0.2
nm
2
3
6a
6b
276
346
536
535
0.70
0.66
0.03
8
1
10
7
278
330
352
1.63
1.49
1.39
0.05
0.05
6
4
9
6c
236
283
338
528
1.98
1.62
2.15
300
600
900 t/°C
Fig. 2. Normalized kinetic curves of photodecomposition of
fulgimides in toluene upon the action of nonfiltered irradiation:
6a (1), 6b (2), 6c (3), 6d (4), 6e (5), 6f (6), 6g (7), 6h (8), 6i (9),
and 6j (10).
6d
6e
340
442
432
542
0.87
0.06
0.06
0.03
248
272
388
524
0.52
0.47
0.60
0.02
6f
230
276
335
360
465
476
528
0.55
0.43
0.40
0.37
0.02
0.01
0.01
From the data in Table 2, it follows that, similarly to
the case of solutions, introduction of a strong electronꢀ
withdrawing substituent (6d) leads to a bathochromic shift
of the absorption band maximum of the cyclic form.
Fulgimides with electronꢀreleasing substituents exhibit
hypsochromic shifts of the absorption maxima of the cyꢀ
clic form, which, however, was less pronounced (see
Table 2). The fulgimide with the strongest electronꢀreꢀ
leasing substituent (6e) was an exception. Its hypsochroꢀ
mic shift reached 12 nm (see Table 2).
For the most fulgimides studied, stability in the solid
films to irreversible photochemical transformation is highꢀ
er than in solutions (cf. Figs 2 and 5), excluding comꢀ
pounds 6j, 6e, and 6d. Compounds 6c and 6f exhibit
a unique stability to irreversible phototransformations.
6g
6h
234
282
326
494
534
1.00
0.67
0.66
0.02
0.02
280
318
330
352
492
1.20
1.09
1.08
0.98
0.06
6i
6j
228 sh
284
328
533
0.51
0.37
0.39
0.02
0.02
237
284 sh
328
342
366
466
530 sh
1.06
0.66
0.66
0.65
0.53
μm
nm
20
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
However, unlike in solutions, the efficiency of the photoꢀ
degradation process is independent on the electronꢀwithꢀ
drawing and electronꢀreleasing properties of substituents,
rather, it is probably determined by the molecular packing
in the amorphous layer.
In conclusion, the fulgimides synthesized exhibit
photochromic properties not only in solutions, but also
in the solidꢀphase films, which seems important for
the planned studies of the LDꢀLISCꢀeffect in the
complexes derived from these compounds. It was found
that the solidꢀphase films have amorphous structure
and that the nature of substituents in the hydroxyꢀsubstiꢀ
tuted phenyl fragment affects spectroscopic characterꢀ
istics of the isomeric forms and the photodegradation
processes.
15
10
5
0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 μm
Fig. 3. The typical picture of the amorphous film surface of
compound 6h obtained using a scanning sound microscope (the
field of scanning was 5×5 μm, the overfall of heights was 25 nm).

Hybrid photochromes
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
865
A (rel. units)
The films thickness was measured on a Linnik MIIꢀ4 microꢀ
interferometer (Russia).
The structure of the solidꢀphase films was studied using
a SOLVER BIO scanning sound microscope from NTꢀMDT
(Russia).
Irradiation was produced using an LC4 100ꢀ240Vꢀ300VA
mercuryꢀxenon lamp (50—60 Hz) on a HAMAMATSU lightꢀ
ning cure™ (Japan) and UFSꢀ1 and ZhSꢀ11 color optical filters
for photocoloring and photobleaching, respectively.
1H NMR spectra were recorded on Bruker WMꢀ250 (250 MHz)
and Bruker AMꢀ300 (300 MHz) spectrometers in CDCl3 and
DMSOꢀd6. Melting points were determined on a Boеtius microꢀ
scope stage. Reaction progress and purity of compounds obꢀ
tained were monitored by TLC on Merck 60 F254 plates. Merck
60 silica gel (0.040—0.063 mm) was used for flashꢀchromatography.
We used in the work commercially available salicylic aldeꢀ
hydes 5a—j, 3ꢀacetylꢀ2,5ꢀdimethylthiophene, potassium tertꢀbutꢀ
oxide, and N,N´ꢀcarbonyldiimidazole (Acros). Diethyl isoproꢀ
pylidenesuccinate was obtained according to the known proceꢀ
dure14 by condensation of diethyl succinate and acetone in the
presence of potassium tertꢀbutoxide; paraꢀNꢀBocꢀphenylenediꢀ
amine was obtained according to the known procedure.15
Synthesis of Schiff bases 6a—j (general procedure). Fulgimide
4 (0.1 g, 0.0003 mol) and aldehyde 5a—j (0.0003 mol) were
dissolved in DMF (3 mL) with stirring. The reaction mixture
was kept at room temperature for 5 h. The crystals that formed
were filtered off, washed with ethanol on the filter, and recrysꢀ
tallized.
A (rel. units)
0.08
1
3
7
2
6
0.06
0.04
0.02
5
4
3
1.0
0.5
2
1
495
579
λ/nm
2
300
400
500
600
λ/nm
Fig. 4. Absorption spectra of the thin film of compound 6h beꢀ
fore (1), after exposure to the UV light through a UFSꢀ1 light
filter (2) and to the visible light through a ZhSꢀ11 light filter (3).
In the insertion: an increase in intensity of the absorption band
of the cyclic form before (1) and after exposure to the UV light
through a UFSꢀ1 light filter for 1 (2), 2 (3), 4 (4), 8 (5), 15 (6),
and 30 s (7).
Experimental
Spectrophotometric measurements (photostationary specꢀ
tra), as well as kinetics of the photocoloring, photobleaching,
and photodegradation processes of photochromic compounds in
solution in toluene were performed on a Cary 50 Bio spectroꢀ
photometer (Varian, Australia). The concentration of solutions
C = 2•10–4 mol L–1 was chosen as a working one. Cuvettes
10 mm thick were used for spectroscopic studies, whereas for
kinetic measurements, 2 mm thick.
Amorphous thin films were obtained by the pouring method, i.e.
by the even distribution of a given amount of solution of fulgimide
in toluene with the working concentration C = 5•10–3 mol L–1
over a quartz glass with subsequent evaporation of the solvent.
(3Z)ꢀ3ꢀ[1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ{4ꢀ[(2ꢀ
hydroxybenzylidene)amino]phenyl}ꢀ4ꢀ(1ꢀmethylethylidene)pyrrolꢀ
idineꢀ2,5ꢀdione (6a). The yield was 94%. Colorless crystals, m.p.
1
207—208 °C (EtOH). H NMR (CDCl3), δ: 2.05 (s, 3 H, Me);
2.13 (s, 3 H, Me); 2.35 (s, 3 H, Me); 2.41 (s, 3 H, Me); 2.49
(s, 3 H, Me); 6.56 (s, 1 H, Hthioph); 6.92—7.04 (m, 2 H, Harom);
7.27—7.43 (m, 6 H, Harom); 8.59 (s, 1 H, CH=N); 13.09 (s, 1 H,
OH). Found (%): C, 71.41; H, 5.54; N, 5.87. C28H26N2O3S.
Calculated (%): C, 71.47; H, 5.57; N, 5.95.
(3Z)ꢀ1ꢀ{4ꢀ[(3ꢀAllylꢀ2ꢀhydroxybenzylidene)amino]phenyl}ꢀ3ꢀ
[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀmethylethylidene)ꢀ
pyrrolidineꢀ2,5ꢀdione (6b). The yield was 85%. Light yellow crysꢀ
tals, m.p. 168—170 °C (EtOH). 1H NMR (DMSOꢀd6), δ: 2.00
(s, 3 H, Me); 2.08 (s, 3 H, Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H,
Me); 2.41 (s, 3 H, Me); 3.41 (d, 2 H, CH2—CH=CH2, J = 6.4 Hz);
5.01—5.11 (m, 2 H, CH2—CH=CH2); 5.96—6.05 (m, 1 H,
CH2—CH=CH2); 6.71 (s, 1 H, Hthioph); 6.92—6.97 (m, 1 H,
Harom); 7.28—7.31 (m, 2 H, Harom); 7.35 (d, 2 H, Harom, J = 8.4 Hz);
7.51 (d, 2 H, Harom, J = 11.9 Hz); 8.99 (s, 1 H, CH=N); 13.58
(s, 1 H, OH). Found (%): C, 72.85; H, 5.90; N, 5.41. C31H30N2O3S.
Calculated (%): C, 72.91; H, 5.92; N, 5.49.
A/Amax
6
1.0
0.8
0.6
0.4
0.2
3
8
7
2
1
(3Z)ꢀ3ꢀ[1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ[4ꢀ({2ꢀ
hydroxyꢀ5ꢀ[(Z)ꢀphenyldiazenyl]benzylidene}amino)phenyl]ꢀ4ꢀ(1ꢀ
methylethylidene)pyrrolidineꢀ2,5ꢀdione (6c). The yield was 81%.
Orange crystals, m.p. 181—183 °C (dioxane). 1H NMR
(DMSOꢀd6), δ: 2.00 (s, 3 H, CH3); 2.08 (s, 3 H, Me); 2.25
(s, 3 H, Me); 2.35 (s, 3 H, Me); 2.41 (s, 3 H, Me); 6.71 (s, 1 H,
9
5
4
10
Hthioph); 7.16 (d, 1 H, Harom, J = 8.9 Hz); 7.38 (d, 2 H, Harom
,
400
800
1200 t/°C
J = 8.7 Hz); 7.52—7.61 (m, 5 H, Harom); 7.85—7.88 (m, 2 H,
Harom); 8.00—8.04 (m, 1 H, Harom); 8.32 (d, 1 H, Harom, J = 2.2 Hz);
10.37 (s, 1 H, CH=N); 13.64 (s, 1 H, OH). Found (%): C, 71.00;
H, 5.23; N, 9.68. C34H30N4O3S. Calculated (%): C, 71.06;
H, 5.26; N, 9.75.
Fig. 5. Normalized kinetic curves of photodecomposition of
fulgimides in the solidꢀphase layers upon exposure to the nonꢀ
filtered irradiation: 6a (1), 6b (2), 6c (3), 6d (4), 6e (5), 6f (6),
6g (7), 6h (8), 6i (9), and 6j (10).

866
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Luyksaar et al.
(3Z)ꢀ3ꢀ[1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ{4ꢀ[(2ꢀhydrꢀ
Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H, Me); 2.41 (s, 3 H, Me); 4.08
(q, 2 H, OCH2CH3, J = 6.9 Hz); 6.71 (s, 1 H, Hthioph); 6.87—6.92
(m, 1 H, Harom); 7.12 (dd, 1 H, Harom, J = 4.8 Hz, J = 2.1 Hz);
7.24 (d, 1 H, Harom, J = 16.5 Hz); 7.35 (d, 2 H, Harom, J = 8.4 Hz);
7.47 (d, 2 H, Harom, J = 8.4 Hz); 8.97 (s, 1 H, CH=N); 13.12
(s, 1 H, OH). Found (%): C, 69.95; H, 5.87; N, 5.39. C30H30N2O4S.
Calculated (%): C, 70.02; H, 5.88; N, 5.44.
(3Z)ꢀ1ꢀ{4ꢀ[(3,5ꢀDiiodoꢀ2ꢀhydroxybenzylidene)amino]phenyl}ꢀ
3ꢀ[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀmethylethylidene)ꢀ
pyrrolidineꢀ2,5ꢀdione (6j). The yield was 76%. Orange crystals,
m.p. 197—199 °C (dioxane). 1H NMR (DMSOꢀd6), δ: 2.01
(s, 3 H, Me); 2.08 (s, 3 H, Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H,
Me); 2.41 (s, 3 H, Me); 6.70 (s, 1 H, Hthioph); 7.38 (d, 2 H,
Harom, J = 8.5 Hz); 7.53 (d, 2 H, Harom, J = 8.5 Hz); 8.01 (s, 1 H,
Harom); 8.14 (s, 1 H, Harom); 8.92 (s, 1 H, CH=N); 14.57 (s, 1 H,
OH); Found (%): C, 46.52; H, 3.34; N, 3.80. C28H24I2N2O3S.
Calculated (%): C, 46.56; H, 3.35; N, 3.88.
oxyꢀ5ꢀnitrobenzylidene)amino]phenyl}ꢀ4ꢀ(1ꢀmethylethylidene)ꢀ
pyrrolidineꢀ2,5ꢀdione (6d). The yield was 88%. Yellow crystals,
m.p. 227—230 °C (dioxane). 1H NMR (DMSOꢀd6), δ: 2.01 (s, 3 H,
Me); 2.08 (s, 3 H, Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H, Me); 2.41
(s, 3 H, Me); 6.71 (s, 1 H, Hthioph); 7.18 (d, 1 H, Harom, J = 9.2 Hz);
7.39 (d, 2 H, Harom, J = 8.5 Hz); 7.51 (d, 2 H, Harom, J = 8.5 Hz);
8.28 (dd, 1 H, Harom, J = 9.2 Hz, J = 2.7 Hz); 8.68 (d, 1 H,
Harom, J = 2.7 Hz); 9.17 (s, 1 H, CH=N); 14.15 (s, 1 H, OH).
Found (%): C, 65.19; H, 4.87; N, 8.10. C28H25N3O5S. Calculatꢀ
ed (%): C, 65.23; H, 4.89; N, 8.15.
(3Z)ꢀ1ꢀ(4ꢀ{[4ꢀ(Diethylamino)ꢀ2ꢀhydroxybenzylidene]amino}ꢀ
phenyl)ꢀ3ꢀ[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀmethylꢀ
ethylidene)pyrrolidineꢀ2,5ꢀdione (6е). The yield was 72%. Yellow
crystals, m.p. 189—191 °C (EtOH). 1H NMR (DMSOꢀd6), δ:
1.10 (t, 6 H, NCH2CH3, J = 7.2 Hz); 2.00 (s, 3 H, CH3); 2.07
(s, 3 H, CH3); 2.25 (s, 3 H, Me); 2.35 (s, 3 H, Me); 2.40 (s, 3 H,
Me); 3.38 (q, 4 H, NCH2CH3, J = 7.2 Hz); 6.07 (s, 1 H, Harom);
6.32 (d, 1 H, Harom, J = 8.7 Hz); 6.70 (s, 1 H, Hthioph); 7.26—7.36
(m, 5 H, Harom); 8.69 (s, 1 H, CH=N); 13.49 (s, 1 H, OH).
Found (%): C, 70.92; H, 6.51; N, 7.72. C32H35N3O3S. Calculatꢀ
ed (%): C, 70.95; H, 6.51; N, 7.76.
References
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M. M. Krayushkin, O. V. Venidiktova, A. M. Gorelik, V. A.
Barachevskii, Izv. Akad. Nauk, Ser. Khim., 2009, 2345 [Rus.
Chem. Bull., Int. Ed., 2009, 58, 2423].
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Oliver, P. J. Strydom, J. Whittall, J. Chem. Soc., Perkin Trans. 1,
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Commun., 2003, 192.
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Strokach, T. M. Valova, Z. O. Golotyuk, V. A. Barachevskii,
Khim. Geterotsikl. Soedin., 2006, 1170 [Chem. Heterocycl.
Compd. (Engl. Transl.), 2006, 42, 1012].
(3Z)ꢀ1ꢀ{4ꢀ[(3,5ꢀDichloroꢀ2ꢀhydroxybenzylidene)amino]ꢀ
phenyl}ꢀ3ꢀ[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀmethylꢀ
ethylidene)pyrrolidineꢀ2,5ꢀdione (6f). The yield was 84%. Orange
1
crystals, m.p. 197—199 °C (dioxane). H NMR (DMSOꢀd6), δ:
2.00 (s, 3 H, Me); 2.08 (s, 3 H, Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H,
Me); 2.41 (s, 3 H, Me); 6.70 (s, 1 H, Hthioph); 7.38 (d, 2 H,
Harom, J = 8.4 Hz); 7.53 (d, 2 H, Harom, J = 8.4 Hz), 7.74 (s, 2 H,
Harom); 9.03 (s, 1 H, CH=N), 14.29 (s, 1 H, OH). Found (%):
C, 62.29; H, 4.46; N, 5.14. C28H24Cl2N2O3S. Calculated (%):
C, 62.34; H, 4.48; N, 5.19.
(3Z)ꢀ1ꢀ{4ꢀ[(5ꢀBromoꢀ2ꢀhydroxyꢀ3ꢀmethoxybenzylidene)ꢀ
amino]phenyl}ꢀ3ꢀ[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀ
methylethylidene)pyrrolidineꢀ2,5ꢀdione (6g). The yield was 84%.
Orange crystals, m.p. 185—187 °C (dioxane). 1H NMR
(DMSOꢀd6), δ: 2.00 (s, 3 H, Me); 2.07 (s, 3 H, Me); 2.25 (s, 3 H,
Me); 2.35 (s, 3 H, Me); 2.40 (s, 3 H, Me); 6.70 (s, 1 H, Hthioph);
7.26 (s, 1 H, Harom); 7.34—7.37 (m, 3 H, Harom); 7.41—7.47
(m, 3 H, Harom); 8.93 (s, 1 H, CH=N); 13.04 (s, 1 H, OH).
Found (%): C, 60.06; H, 4.68; N, 4.79. C29H27BrN2O4S. Calcuꢀ
lated (%): C, 60.11; H, 4.70; N, 4.83.
(3Z)ꢀ1ꢀ{4ꢀ[(3,5ꢀDiꢀtertꢀbutylꢀ2ꢀhydroxybenzylidene)amino]ꢀ
phenyl}ꢀ3ꢀ[1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀ(1ꢀmethylꢀ
ethylidene)pyrrolidineꢀ2,5ꢀdione (6h). The yield was 43%. Pale
yellow crystals, m.p. 131—133 °C (EtOH). 1H NMR (DMSOꢀd6),
δ: 1.30 (s, 9 H, C(Me)3); 1.42 (s, 9 H, C(Me)3); 2.00 (s, 3 H,
Me); 2.08 (s, 3 H, Me); 2.25 (s, 3 H, Me); 2.35 (s, 3 H, Me); 2.41
(s, 3 H, Me); 6.70 (s, 1 H, Hthioph); 7.38—7.51 (m, 6 H, Harom);
9.00 (s, 1 H, CH=N); 13.84 (s, 1 H, OH). Found (%): C, 74.13;
H, 7.24; N, 4.75. C36H42N2O3S. Calculated (%): C, 74.19;
H, 7.26; N, 4.81.
(3Z)ꢀ3ꢀ[1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ{4ꢀ[(3ꢀ
ethoxyꢀ2ꢀhydroxybenzylidene)amino]phenyl}ꢀ4ꢀ(1ꢀmethylethylꢀ
idene)pyrrolidineꢀ2,5ꢀdione (6i). The yield was 32%. Cream crysꢀ
tals, m.p. 164—167 °C (EtOH). 1H NMR (DMSOꢀd6), δ: 1.35
(t, 3 H, OCH2CH3, J = 6.9 Hz); 2.00 (s, 3 H, Me); 2.08 (s, 3 H,
12. V. Deblauwe, G. Smets, Makromol. Chem., 1988, 189, 2503.
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Y. Kurita, Bull. Chem. Soc. Jpn., 1995, 68, 616.
14. C. G. Overberger, C. W. Roberts, J. Am. Chem. Soc., 1949,
71, 3618.
15. G. Aranda, O. Riant, Synth. Commun., 1990, 20, 733.
Received April 11, 2011