Spiro-azoles thiazolidinone in the synthesis of polymethine cyanine dyes

Article abstract of DOI:10.1080/10426500307791

A series of some spiro azoles (pyrazolone, oxazolone, and/or imidazolone) inconjucton with heterocyclic thiazolidinone derivatives were prepared as starting materials in the synthesis of polymethine cyanine dyes. Reaction of spiro 2-formyl (oxime) azoles thiazolidinone derivatives with equi- and/or molar ratios of 2(4)-methyl substituted heterocyclic quaternary salts afforded the corresponding compound pentamethine, aza-mero cyanine, and azapentamethine cyanine dyes respectively. Elemental analyses, IR, ¹H-NMR, and mass-spectra identified the new spiro heterocyclic compounds and polymethine cyanine dyes. The visible absorption spectra of all new polymethine cyanine dyes were investigated.

Full text of DOI:10.1080/10426500307791

This article was downloaded by: [University of Connecticut]
On: 29 October 2014, At: 09:20
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Phosphorus, Sulfur, and Silicon and the Related
Elements
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/gpss20
Spiro-Azoles Thiazolidinone in the Synthesis of
Polymethine Cyanine Dyes
Reda Mahmoud Abd El-Aal a
a South Valley University , Aswan, Egypt
Published online: 27 Oct 2010.
To cite this article: Reda Mahmoud Abd El-Aal (2003) Spiro-Azoles Thiazolidinone in the Synthesis of Polymethine Cyanine
Dyes, Phosphorus, Sulfur, and Silicon and the Related Elements, 178:4, 681-692, DOI: 10.1080/10426500307791
To link to this article: http://dx.doi.org/10.1080/10426500307791
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the
Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for
any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever
or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of
the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

Phosphorus, Sulfur and Silicon, 2003, Vol. 178:681–692
C
Copyright 2003 Taylor & Francis
1042-6507/03 $12.00 + .00
DOI: 10.1080/10426500390197896
SPIRO-AZOLES THIAZOLIDINONE IN THE
SYNTHESIS OF POLYMETHINE CYANINE DYES
Reda Mahmoud Abd El-Aal
South Valley University, Aswan, Egypt
(Received November 30, 2001; accepted June 4, 2002)
A series of some spiro azoles (pyrazolone, oxazolone, and/or imida-
zolone) inconjucton with heterocyclic thiazolidinone derivatives were
prepared as starting materials in the synthesis of polymethine cya-
nine dyes. Reaction of spiro 2-formyl (oxime) azoles thiazolidinone
derivatives with equi- and/or molar ratios of 2(4)-methyl substituted
heterocyclic quaternary salts afforded the corresponding compound
pentamethine, aza-mero cyanine, and azapentamethine cyanine dyes
respectively. Elemental analyses, IR, 1H-NMR, and mass-spectra iden-
tified the new spiro heterocyclic compounds and polymethine cyanine
dyes. The visible absorption spectra of all new polymethine cyanine dyes
were investigated.
Keywords: Electronic absorption spectra; photodynamic therapy; qua-
ternary salts; sensitizer in photographic
Much work has been carried out on the synthesis of assembled hetero-
cyclic systems to prepare and study the properties of different types of
cyanine dyes.1–5 Little attention has been focused on the use of spiro het-
erocycles in the synthesis of polymethine cyanine dyes. Thiazolidinone
compounds have been subjects of extensive efforts in the recent past of
Divers biological activities,6,7 such as bactericidal, fungicidal, insecti-
cide, tuberoculostic, that are associated with thiazolidinone derivatives.
Cyanine dyes are used as spectral sensitizer in photographic emulsions8
and as potentail sensitizer for photodynamic therapy.9 In recent years,
some patents have reported that pentamethine cyanine dyes showing
good sensitivity and reflection to 680 nm wavelength laser.10–12
Address correspondence to Reda Mahmoud Abd El-Aal, Chemistry Department, Fac-
ulty of Science, South Valley University, Aswan, 81528, Egypt. E-mail: abdelaal2001@
yahoo.com
681

682

683

684
R. M. A. El-Aal
The object of this investigation is to report the synthesis and elec-
tronic absorption spectra in ethanolic solution in the hope that we might
discover new photosensitization effects.
Results and Discussion
Reaction of 1 mmol amount ratio of 3-methyl-1-phenylpyrazol-5-one,
2-methyoxazol-5-one and imidazol-2,4-dione 1a–1c13 with 1 mmol
amounts of nitroso compounds such as p-nitrosophenol and a ( )-
nitroso-naphthols in basic catalyst afforded the corresponding of 4-aryl
(naphthyl)-imino-azole derivatives 2a–2e as Shiff base compounds. El-
1
emental analyses, IR, H-NMR, and MS spectral were confirmed the
structures of compounds 2a–2e. Thus, IR showed general absorption
1
1
1
spectra at 1698–1690 cm (C O), 1585 cm (C N), 3340–3360 cm
(OH), 1H-NMR (CDCl3) reveal general signals at 4.5–4.7 (s, 1H, OH),
1.0–1.1 (s, 3H, CH3), 6.9–7.8 (m, 9H, Ar H) for compound 2a and 6.7–
7.7 (m, 11H, Ar H) for compound 2b, Table I. The newly synthesized
Shiff base compounds 2a–2e were considered as structures for the syn-
thesis of new spiro-4-azolo thiazolidinone derivatives. Thus, cycload-
dition reaction of equimolar ratio of thioglycolic acid with the previ-
ously compounds 2a–2e in boiling benzene using water separator for
five days14 afforded the spiro-4-azolo thiazolidinone derivatives 3a–3e.
The structures of these compounds were proved by elemental analyses,
IR, 1H-NMR, and MS spectral data. Thus, IR showed general absorption
1
1
1
spectra at 1698–1690 cm (C O), 1585 cm (C N), 3340–3360 cm
1
(OH), H-NMR (CDCl3) reveal general signals at 4.6–4.9 (s, 1H, OH),
6.8–7.9 (m, 8H, Ar H + het. H), 1.25 (s, 3H, CH3), for compound
3d and 8.7 (s, 2H, NH), for compound 3e, Table I. Compounds 3a–3e
treated with phosphorus oxychloride in dimethylformamide in the room
temperature afforded the corresponding compounds 4-chloro-5-formyl
spiro-4-azolo thiazolidinone derivatives 4a–4e. Reaction of a ratio of
1 mmol amount 4a–4e with 2 mmol amounts of 2(4)-methyl substi-
tuted heterocyclic quaternary salts in the presence of acetic anhydride16
resulted in pentamethine cyanine dyes 5a–5g. The structures of com-
pounds 4a–4e and 5a–5g were confirmed by elemental analyses, IR,
1H-NMR, and MS spectral data, Tables I and II.
Reaction of spiro-4-azolo thiazolidinone derivatives 3a–3e with ni-
trous acid afforded the corresponding compounds 2-oxime-spiro-4-azolo
thiazolidinone derivatives 6a–6e. These newly synthesized oxime com-
pounds 6a–6e were considered as a key intermediate in the synthesis of
aza-mero cyanine dyes 7a–7g and aza-pentamethine cyanine dyes 8a–
8g respectively. Thus, reaction of a ratio of 1 mmol amount of 2-oxime-
spiro-4-azolo thiazolidinone derivatives 6a–6e with 1 or 2 mmol

685

686
R. M. A. El-Aal
amounts of 2(4)-methyl heterocyclic quaternary salts in the presence of
basic catalyst afforded the corresponding spiro-4-azolo thiazolidinone-
4[2(4)] aza-mero cyanine dyes 7a–7g and 4,5[2(4)]-aza-pentamethine
cyanine dyes 8a–8g respectively (Scheme 1). Elemental analyses and
SCHEME 1

Synthesis of Polymethine Cyanine Dyes
687
IR and 1H-NMR spectra confirmed the structures of compounds 7a–7g
and 8a–8g. Thus, IR showed general absorption spectra of compounds
1
7a–7g and 8a–8g 1700–1690 cm 1 (C O), 1590 cm 1 (C N), 3340 cm
(OH), 2980 cm (Mel) and 1H-NMR (CDCl3) reveal general signals at
1
4.6 (s, 1H, OH), 6.5–7.8 (m, 13H, Ar H + CH ), 1.25 (s, 3H, CH3), 1.15
(s, 3H, CH3) for compound 7f and 4.7 (s, 1H, OH), 6.6–7.9 (m, 20H,
Ar H + CH ), 1.2 (s, 3H, CH3), 1.15 (s, 3H, CH3) 3.9 (s, 3H, CH3 N+)
for compound 8f (Table III).
The newly synthesized pentamethine 5a–5g, aza-merocyanine dyes
7a–7g and aza-pentamethine cyanine dyes 8a–8g were highly colored
and fairly soluble in polar organic solvents giving a green fluorescence.
These cyanine dyes were only sparingly soluble in nonpolar solvents
and soluble in conc. H2SO4 liberating iodine vapor on warming.
Effect of Molecular Structure on the Electronic
Absorption Spectra of the Synthesized Cyanine Dyes
The electronic absorption spectral features (max. and
values) of
max.
the newly synthesized cyanine dyes 5a–5g, 7a–7g, and 8a–8g in ethano-
lic solutions are depicted in Table IV.
The visible absorption spectra of pentamethine cyanine dyes 5a–
5g, aza-mero cyanine 7a–7g, and aza-pentamethine cyanine dyes
8a–8g in 95% ethanol undergo bathochromic or hypsochromic shifts
depending on the nature of the quaternary residue A. Thus, substi-
tuting of A = 1-methylpyridin-2-ium salt moiety in compound 5a by
A = 1-methylquinolin-2-ium salt moiety in compound 5b resulted in
bathochromic shifts of 15–195 nm accompanied with the appearance
of one band at 585 nm. This could be attributed to the more extensive
-conjugation in compound 5b. Also, the visible absorption spectra of the
newly synthesized cyanine dyes were influenced by the aryl and naph-
thyl groups. Thus, substituting of R = aryl moiety in compound 7b by
the R = naphthyl moiety in compound 7d causes bathochromic shifts
of 5–45 nm. This is due to increasing the conjugation in compound 7d
(Table IV).
EXPERIMENTAL
Melting points were recorded on a Gallenkamp melting point appara-
tus and are uncorrected. Elemental analyses were carried out at the
Microanalytical Center at Cairo University. Infrared were determined
on a Perkin Elmer Infrared 1650 FT-IR instrument, visible spec-
tra (300–700 nm) were recorded on a Shimadzu-UV-Visible-160 spec-
trophotometer. 1H-NMR spectra were recorded on an EM-390 90 MHz

688

689

690
R. M. A. El-Aal
TABLE IV Visible Absorption Spectraa of the Newly Synthesized
Polymethine Cyanie Dyes
1
1
(nm)/log ε
mol cm
max
max
I Pentamethine cyanine dyes 5a–5g
5a
5b
5c
5d
5e
5f
5g
400 (3.50) 415 (3.66) 420 (3.65)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
525 (3.66)
565 (3.72)
600 (3.70)
700 (2.02)
520 (3.32)
—
590 (3.95)
695 (3.22)
510 (3.78)
555 (3.89)
585 (3.93)
695 (3.45)
585 (3.68)
690 (2.98)
580 (3.91)
695 (2.05)
II Aza-mero cyanine dyes 7a–7g
7a
7b
7c 7d 7e
7f
7g
465 (3.08) sh415 (3.53) 485 (2.95) sh420 (3.37) sh410 (3.33)
—
—
sh410 (3.28)
525 (3.16)
565 (3.29)
610 (3.33)
680 (2.65)
—
—
—
—
485 (3.51)
590 (3.56)
—
—
—
—
—
530 (3.45)
595 (3.46)
—
520 (3.35)
590 (3.46)
—
585 (3.11)
605 (3.15)
680 (2.68)
680 (2.90)
685 (2.85)
680 (2.92)
III Aza-pentamethine cyanine dyes 8a–8g
8a
8b
8c
8d
8e
8f
8g
—
sh410 (3.64)
—
420 (3.53) sh400 (3.51)
—
sh410 (3.81)
575 (4.13)
595 (4.14)
695 (3.32)
480 (3.38) sh520 (3.77) 490 (3.45) 540 (3.57)
540 (3.75) sh520 (3.79)
—
—
595 (3.88)
695 (3.30)
—
—
595 (3.60)
700 (2.88)
585 (3.85)
690 (2.78)
590 (3.80)
690 (2.90)
1
aData shown are
= log
max
(mol cm2) in parentheses; sh = shoulder.
max max
NMR spectrometer and mass spectra were recorded on an HPMs 6988
spectrometer.
Synthesis of 4-Aryl(naphthyl)-imino-azole
Derivatives 2a–2e
A solution of 3-methyl-1-phenylpyrazolone, 2-methyloxazolone, and
imidazolone (0.01 mmol) in ethanol (20 ml) was treated with aro-
matic nitroso compounds (p-nitroso-phenol and ( )-nitroso-naphthol)
(0.01 mmol) in the presence of catalytic amount of piperidine (0.5 ml).
The reaction mixture was refluxed for 7–9 h (monitored TLC). The sol-
vent was then evaporated under reduced pressure and the residue was
treated with ice-water. The solid product was collected and crystallized
from ethanol. The results are listed in Table I.

Synthesis of Polymethine Cyanine Dyes
691
Synthesis of Spiro-4-azolo Thiazolidinone
Derivatives 3a–3e
A mixture of the imino derivatives 2a–2e and mercaptoacetic acid
(0.01 mmol) in dry benzene was refluxed for 13–15 h. The hot reaction
mixture was filtered, concentrated, and boiling water was added. The
solid product was collected and crystallized from methanol. Relevant
data are listed in Table I.
Synthesis of 3-Chloro-2-formyl-spiro-4-azolo
Thiazolidinone Derivatives 4a–4e
To a solution of 3a–3e (0.02 mmol) in (100 ml) dry dimethylfor-
mamide and phosphorous oxychloride (0.02 mmol) was added under
stirring in an ice-bath. Stirring was continued at room temperature for
15 min. The solution was heated for 30 min, cooled, and then poured
into 400 ml ice-water. The solid product was collected and crystallized
from petroleum ether 60–80 C. Relevant data are listed in Table I.
Synthesis of Spiro-4-azolo Thiazolidinone-2,3[2(4)]-
pentamethine Cyanine Dyes 5a–5g
A mixture of 4a–4e (0.01 mmol) and 2(4)-methyl heterocyclic qua-
ternary salts (0.02 mmol) were dissolved in acetic anhydride (10 ml).
The reaction mixture was refluxed for 5–10 min, and the excess of
acetic anhydride was distilled off. The cooled residue was triturated
with ethanol, then filtered while hot and concentrated. The precipitated
products, after dilution with water, were collected and crystallized from
methanol. The characterization data of compounds 5a–5g are listed in
Table II.
Synthesis of 2-Oxime-spiro-4-azolo Thiazolidinone
Derivatives 6a–6e
To a solution of 3a–3e (0.01 mmol) and sodium nitrite (0.02 mmol)
in aqueous ethanol (20 ml), conc. sulphuric acid (10 ml) was added
drowse while stirring in ice-bath. The stirring was continued at room
temperature for 10 min.
The precipitated products after dilution with water were collected
and crystallized from ethanol. Relevant data are shown in Table II.
Synthesis of Spiro-4-azolo Thiazolidinone-2[2(4)]-
aza-mero Cyanine 7a–7g and 2,3[2(4)]-Aza-pentamethine
Cyanine Dyes 8a–8g
A mixture of 6a–6e (0.01 mmol) and 2(4)-methyl heterocyclic quater-
nary salts (0.01 and 0.02 mmol) were dissolved in ethanol (20 ml) and
piperidine (0.5 ml) was added. The reaction mixture was refluxed for

692
R. M. A. El-Aal
10–12 h, filtered while hot, concentrated, and cooled. The solid products
were separated after dilution with water were collected and crystal-
lized from methanol to give the corresponding compounds 7a–7g and
8a–8g respectively. The characterization data of these dyes are listed in
Table III.
REFERENCES
[1] A. I. M. Koraiem, R. M. Abu El-Hamd, and R. M. Abd El-Aal, Dyes & Pigments, 191,
14 (1990).
[2] R. M. Abd El-Aal, J. Chem. Research (S), 128 (1997).
[3] R. M. Abd El-Aal, Dyes & Pigments, 267, 39 (1998).
[4] Z.-F. Dia and B.-X. Peng, Dyes & Pigments, 169, 36, 2 (1998).
[5] Z.-F. Dia and B.-X. Peng, Dyes & Pigments, 243, 36, 3 (1998).
[6] W. L. Lipschitz and Z. Hadidian, J. Pharmacol. Expt., 81 (1984).
[7] Kh. M. Hassan and Z. H. Khalil, Z. Naturaforsch., 34, 1326 (1979).
[8] S. Watanabe and T. Tani, J. Imaging Sci. Technol., 39(1), (1995).
[9] M. Krieg and P. W. Pedmond, Photochem. Photobiol., 57, 472 (1993).
[10] K. Tatsuno and K. Yasuo, Jpn. Pat. 07-70 453 (1995).
[11] O. Asushi and I. Takayuki, Jpn. Pat. 06-336 086 (1994).
[12] Y. Atsushi and A. Yasushi, Jpn. Pat. 06-199 045 (1994).
[13] A. I. M. Koraiem, M. M. Girgis, Z. H. Khalil, and R. M. Abu El-Hamd, Dyes &
Pigments, 89, 15 (1998).
[14] A. K. Khalaflla, M. E. Hassan, and H. A. Soleman, J. Indian Chem. Soc., 318, 69
(1992).
[15] O. K. Christian and R. Peter, J. Heterocyclic Chem., 26, 55 (1989).
[16] R. M. Abd El-Aal, H. A. Shindy, and A. I. M. Koraiem, Heteroatom Chem., 259, 8(3)
(1997).