Synthesis and absorption spectra of some novel hetaryltetrakisazocalix[4] arene derivatives

Article abstract of DOI:10.1016/j.dyepig.2012.08.015

In this study, a convenient method for the synthesis of thirteen novel tetrakisazo dyes containing 25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4] arene have been described. 5,11,17,23-Tetra-tert-butyl-25,26,27,28- tetrahydroxycalix[4]arene, 25,26,27,28-tetrahydroxycalix[4]arene and 25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]arene were synthesized. 2-arylhydrazone-3-ketiminobutyronitriles 1(a-m) were synthesized and reacted with hydrazine hydrate to afford the corresponding 5-amino-4-arylazo-3-methyl-1- H-pyrazoles 2(a-m). Thirteen novel hetaryltetrakisazocalix[4]arene derivatives 6(a-m) were achieved by diazotisation of 5-amino-4-arylazo-3-methyl-1-H- pyrazoles using nitrosylsulphuric acid, coupling with 25,27-bis-(4- nitrobenzyloxy)-26,28-dihydroxycalix[4]arene. The obtained hetaryltetrakisazocalix[4]arene dyes 6(a-m) were characterized based on FT-IR, ¹H NMR and Mass spectroscopic techniques as well as Elemental Analysis. The solvatochromic behaviour of these dyes in various solvents was examined. Acid-base effect on the visible absorption maxima of the dyes were also reported.

Full text of DOI:10.1016/j.dyepig.2012.08.015

Dyes and Pigments 96 (2013) 256e263
Contents lists available at SciVerse ScienceDirect
Dyes and Pigments
journal homepage: www.elsevier.com/locate/dyepig
Synthesis and absorption spectra of some novel hetaryltetrakisazocalix[4]arene
derivatives
_
*
Izzet S¸ ener , Nesrin S¸ ener, Selinay Eris¸ kin
Department of Chemistry, Faculty of Science-Arts, Pamukkale University, 20017 Denizli, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history:
Inthisstudy, aconvenientmethodforthesynthesisof thirteennoveltetrakisazodyescontaining25,27-bis-(4-
nitrobenzyloxy)-26,28-dihydroxycalix[4]arene have been described. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-
tetrahydroxycalix[4]arene, 25,26,27,28-tetrahydroxycalix[4]arene and 25,27-bis-(4-nitrobenzyloxy)-26,28-
dihydroxycalix[4]arene were synthesized. 2-arylhydrazone-3-ketiminobutyronitriles 1(aem) were synthe-
sized and reacted with hydrazine hydrate to afford the corresponding 5-amino-4-arylazo-3-methyl-1-H-
pyrazoles 2(aem). Thirteen novel hetaryltetrakisazocalix[4]arene derivatives 6(aem) were achieved by
diazotisation of 5-amino-4-arylazo-3-methyl-1-H-pyrazoles using nitrosylsulphuric acid, coupling with
25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]arene. The obtained hetaryltetrakisazocalix[4]arene
dyes 6(aem) were characterized based on FT-IR, 1H NMR and Mass spectroscopic techniques as well as
Elemental Analysis. The solvatochromic behaviour of these dyes in various solvents was examined. Acid-base
effect on the visible absorption maxima of the dyes were also reported.
Received 2 July 2012
Received in revised form
6 August 2012
Accepted 14 August 2012
Available online 24 August 2012
Keywords:
Azocalix[4]arenes
Diazotization
Disazo dyes
Pyrazole
Diazo-coupling reaction
Solvaatochromism
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
plastics, biomedical studies, and advanced applications in organic
synthesis. Moreover, azo groups bring to calixarenes a chromogenic
The developing field of supramolecular chemistry was launched
by the discovery of an important class of macrocyclic compounds
called calixarene. Calixarenes have received considerable attention
in the past decade in hosteguest or supramolecular chemistry [1].
Calixarenes are cyclic oligomers made of several phenolic units
bounded with methylene bridges. It can exist in the conformations
cone, partial cone, 1,2-alternate and 1,3-alternate [2,3].
Calixarenes and their derivatives can be used as synthetic
receptors to selectively bind a wide variety of guest molecules/ions
forming hosteguest complexes or supramolecular species, and
have been applied successfully to various areas of science and
technology. It is also noted that the calixarene platform can be
selectively functionalized both at the phenolic OH groups (lower
rim) [4] and at the para positions of the phenol rings (upper rim),
which provides unique possibilities to organize several binding
sites appropriately for complexation of potential guests [5].
Azo compounds are the most widely used class of dyes due to
their versatile application in various fields such as the dyeing of
textile fibre and the colouring of differing materials, and for
activity [6,7].
Substances that change colour or change fluorescence in
response to a change in their environment are an integral part of
nature and have been put to human use since antiquity, a modern
example of long standing being the application of indicator
compounds to measure acidity and basicity. In recent years
increasing attention has been paid to such chromogenic molecules,
and a number of calixarene based systems have been studied [2].
Aminopyrazoles are very important class of heterocycles
because of their biological and pharmacological activities. For
example, pyrazolopyrimidines and related fused heterocycles are of
interest as potential bioactive molecules. Some azopyrazole deriv-
atives can also be used in dyes, biological and pharmacological
studies and complexes [8e13]. These compounds can be obtained
by the reaction of nitriles with hydrazine hydrate [14e22].
Despite of the fact that dyeing properties and synthesis of
monoazo dyes based on heterocyclic diazo component [23e27],
and chromogenic calixarenes [28e35], previously have been re-
ported, any investigation involved in hetaryltetrakisazo derivatives
based on 25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]
arene have not been found. As an extension of our previous work in
this area [36e41], in this study we report the synthesis of a series of
new hetaryltetrakisazo dyes based on calix[4]arene 6(aem).
* Corresponding author. Tel.: þ90 258 2963603; fax: þ90 258 2963723.
_
E-mail addresses: isener@pamukkale.edu.tr, isener@pau.edu.tr (I. S¸ ener).
0143-7208/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.dyepig.2012.08.015

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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
257
2. Experimental
nitrosylsulphuric acid at between 0 and 5 ꢂC was poured in portions
over 30 min into this solution. The reaction mixture was stirred for
2 h at this temperature. The resulting diazonium solution was
added in portions over 30 min to a vigorously stirred solution of
25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]arene
0.694 g (1.0 mmol) in DMF/MeOH mixture (26 mL, 8:5, v/v). The
progress of the reaction was followed by thin layer chromatography
(TLC) using an ethylacetate:n-hexane mixture (1:1 by volume) as
developing solvent and silica gel TLC plates as the stationary phase.
By simultaneous addition of sodium acetate, the pH of the reaction
mixture was maintained at 7.0e8.0 and the mixture was stirred for
2 h at between 0 and 5 ꢂC. The resulting solid was filtered, washed
with cold water and dried. The obtained product was crystallized
from DMFeH2O mixture (2:3 by volume). The structure of
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrahydroxycalix[4]arene
(3), 25,26,27,28-tetrahydroxycalix[4]arene (4), and 25,27-bis-(4-
nitrobenzyloxy)-26,28-dihydroxycalix[4]arene (5) and the general
route for the synthesis of hetaryltetrakisazocalix[4]arene deriva-
tives 6(aem) is outlined in Fig. 2.
2.1. Materials
The chemicals used for the synthesis of the compounds were
obtained from Aldrich (USA) and Merck Chemical Company
(Germany) without further purification. Solvents were of spectro-
scopic grade. Melting points of the synthesis dyes were determined
using Stuart smp 30 melting point apparatus (UK). Nuclear
magnetic resonance (1H NMR) spectra were recorded on a Bruker
(Germany) Spectrospin Avance DPX 400 Ultra-Shield 400 MHz
spectrometer at room temperature in deuterated dimethylsulph-
oxide (DMSO-d6) using tetramethylsilane (TMS) as the internal
standard. Chemical shifts were (d) given in ppm. FT-IR spectra were
recorded on a Mattson (USA) 1000 FT-IR spectrometer as KBr
pellets. LCeESI-MS analyses were recorded on an Agilent
(Germany) 1100 MSD. Elemental analyses were done on a Leco
CHNS-932 analyser. UVevisible absorption spectra were recorded
on an ATI (UK) Unicam UV-100 spectrophotometer over the range
of
l between 300 and 700 nm. The wavelength of maximum
absorption (lmax) was investigated in a various solvents such as,
dimethylsulphoxide (DMSO), dimethylformamide (DMF), acetoni-
trile, methanol, acetic acid and chloroform at various concentra-
tions (1 ꢀ10ꢁ6e1 ꢀ10ꢁ8 M). Change of (lmax) was also investigated
when 0.1 mL of base (potassium hydroxide, 0.1 M) or 0.1 mL of acid
(hydrochloric acid, 0.1 M) was added to 1 mL of the dye solution in
methanol.
2.2.2.1. 25,27-bis-[(4-nitrobenzyloxy)-26,28-dihydroxy-5,17-bis-[30-
methyl-40-phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6a). Light green solid, yield 0.69 g (62%), m.p: 145 ꢂC. Anal. Cal. for
C62H50N14O8; C: 66.55%; H: 4.47%; N: 14.53%; Found: C: 66.65%;
H:4.52%; N: 14.58%. IR (KBr)
y
(cmꢁ1): 3520 cmꢁ1 (eOH), 3015e
3027 cmꢁ1 (Aromatic CeH), 2945e2960 cmꢁ1 (Aliphatic CeH),
1575 cmꢁ1 (N]N), 1090 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
d
(ppm): 2.85, 3.10 (6H, s, pyrazoleeCH3), 3.51 and 4.27 (8H, d,
J ¼ 13.2 Hz, AreCH2eAr), 5.16 (4H, s, CH2), 7.25 and 7.65 (2H, s, OH),
7.35e8.10 (28H, m, AreH), 9.50 (1H, broad, NH), 10.55 (1H, broad,
NH). MS m/z (Mþ): 1118.
2.2. Synthesis
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrahydroxycalix[4]arene
(3) [42], 25,26,27,28-tetrahydroxycalix[4]arene (4) [43] and 25,27-
bis-(4-nitrobenzyloxy)-26,28-dihydroxy calix[4]arene (5) were
synthesized as described by a previously reported method [44].
2.2.2.2. 25,27-bis[(4-nitrobenzyloxy-26,28-hydroxy-5,17-bis-[30-
methyl-40(200-nitro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6b). Light brown solid, yield 0.90 g (75%), m.p: 220 ꢂC. Anal. Cal.
for C62H48N16O12; C: 61.59%; H: 3.97%; N: 18.54%; Found: C: 61.63%;
2.2.1. Synthesis of 2-arylhydrazone-3-ketiminobutyronitriles and 5-
amino-4-arylazo-3-methyl-1-H-pyrazoles
H: 4.01%; N: 18.58%. IR (KBr)
y
(cmꢁ1): 3525 cmꢁ1 (eOH), 3016e
3029 cmꢁ1 (Aromatic CeH), 2942e2958 cmꢁ1 (Aliphatic CeH),
1576 cmꢁ1 (N]N), 1521 cmꢁ1 (NO2), 1096 cmꢁ1 (CeO). 1H NMR
2-Arylhydrazone-3-ketiminobutyronitriles 1(aem) and 5-
amino-4-arylazo-3-methyl-1-H-pyrazoles 2(aem) were prepared
according to the procedures given in literature [14e22]. The
structure of 2-arylhydrazone-3-ketiminobutyronitriles and 5-
amino-4-arylazo-3-methyl-1-H-pyrazoles is outlined in Fig. 1.
(DMSO-d6, 25 ꢂC)
d (ppm): 2.91, 3.20 (6H, s, pyrazoleeCH3), 3.51
and 4.26 (8H, d, J ¼ 13.2 Hz, AreCH2eAr), 5.20 (4H, s, CH2), 7.20 and
7.65 (2H, s, OH), 7.25e8.20 (26H, m, AreH), 9.75 (1H, broad, NH),
11.20 (1H, broad, NH). MS m/z (Mþ): 1208.
2.2.2. General synthesis of hetaryltetrakisazocalix[4]arene
derivatives 6(aem)
2.2.2.3. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-bis-[30-
methyl-40(200-methoxy
phenylazo-10-H-pyrazole-50-ylazo]calix[4]
Nitrosylsulphuric acid was prepared by dissolving sodium
nitrite 0.138 g (2.0 mmol) in concentrated sulphuric acid (4.0 mL) at
70 ꢂC and was cooled down to ꢁ5 ꢂC. 5-amino-3-methyl-4-arylazo-
1-H-pyrazole 2(aem) (2.0 mmol) was dissolved in hot glacial acetic
acid (4 mL) and rapidly cooled in ice bath to ꢁ5 ꢂC. The
arene (6c). Yellow mustard solid, yield 0.82 g (70%), m.p: 130 ꢂC.
Anal. Cal. for C64H54N14O10; C: 65.19%; H: 4.58%; N: 16.63%; Found:
C: 65.17%; H: 4.62%; N: 16.61%. IR (KBr)
y
(cmꢁ1): 3526 cmꢁ1 (eOH),
3012e3025 cmꢁ1 (Aromatic CeH), 2945e2965 cmꢁ1 (Aliphatic Ce
CN
C
NH
N
NH2
NH
N
C
N
X
NH
CH3
X
H3C
N
1 a-m
2 a-m
a; X: H
e; X: o-CH3
f; X: m-NO2
g; X: m-OCH3
h; X: m-Cl
i; X: m-CH3
j; X: p-NO2
k; X: p-OCH3
l; X: p-Cl
m; X: p-CH3
b; X: o-NO2
c; X: o-OCH3
d; X: o-Cl
Fig. 1. The structure of 2-arylhydrazone-3-ketiminobutyronitriles and heterocyclic amine derivatives 2(aem).

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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
OH
OH
O
O
OH
OH
HO
OH
OH
HO
OH
OH
4
3
NO2
X
NO2
5
X
N
N
N
H3C
N
CH3
N
N
N
N
H
NH
OH
OH
N
i
O
O
N
+
2a-m
N
OH
OH
NO2
NO2
O
O
5
NO2
NO2
6a-m
Fig. 2. The structure of (3), (4), (5) and the synthesis of tetrakishetarylazocalix[4]arene derivatives. (i) NaNO2/H2SO4, CH3COOH.
H), 1582 cmꢁ1 (N]N), 1096 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
(ppm): 2.89, 3.21 (6H, s, pyrazoleeCH3), 3.48 and 4.28 (8H, d,
J ¼ 13.2 Hz, AreCH2eAr), 4.10 (6H, s, AreOCH3), 5.18 (4H, s, CH2),
7.30 and 7.60 (2H, s, OH), 7.25e8.17 (26H, m, AreH), 9.72 (1H, broad,
NH), 11.25(1H, broad, NH). MS m/z (Mþ): 1178.
d (ppm): 2.88, 3.19 (6H, s, pyrazoleeCH3), 3.48 and 4.25 (8H, d,
d
J ¼ 13.2 Hz, AreCH2eAr), 4.07 (6H, s, AreCH3), 5.25 (4H, s, CH2),
7.22 and 7.68 (2H, s, OH), 7.26e8.20 (26H, m, AreH), 9.96 (1H,
broad, NH), 11.95 (1H, broad, NH). MS m/z (Mþ): 1146.
2.2.2.6. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(300-nitro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6f). Light yellow, yield 0.94 g (78%), m.p: 225 ꢂC. Anal. Cal. for
C62H48N16O12; C: 61.59%; H: 3.97%; N: 18.54%; Found: C: 61.62%; H:
2.2.2.4. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-bis-[30-
methyl-40(200-chloro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6d). Yellow solid, yield 0.90 g (76%), m.p: 125 ꢂC. Anal. Cal. for
C62H48N14O8Cl2; C: 62.68%; H: 4.04%; N: 16.51%; Found: C: 62.72%;
3.99%; N: 18.57%. IR (KBr)
y
(cmꢁ1): 3529 cmꢁ1 (eOH), 3010e
H: 4.08%; N: 16.55%. IR (KBr)
y
(cmꢁ1): 3528 cmꢁ1 (eOH), 3015e
3032 cmꢁ1 (Aromatic CeH), 2950e2970 cmꢁ1 (Aliphatic CeH),
1578 cmꢁ1 (N]N), 1524 cmꢁ1 (NO2), 1096 cmꢁ1 (CeO). 1H NMR
3036 cmꢁ1 (Aromatic CeH), 2950e2967 cmꢁ1 (Aliphatic CeH),
1576 cmꢁ1 (N]N), 1095 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
(DMSO-d6, 25 ꢂC)
d (ppm): 2.90, 3.18 (6H, s, pyrazole-CH3), 3.51 and
d
(ppm): 2.92, 3.16 (6H, s, pyrazoleeCH3), 3.47 and 4.20 (8H, d,
4.20 (8H, d, J ¼ 13.2 Hz, AreCH2eAr), 5.18 (4H, s, CH2), 7.23 and 7.62
(2H, s, OH), 7.26e8.22 (26H, m, AreH), 10.21 (1H, broad, NH), 12.35
(1H, broad, NH). MS m/z (Mþ): 1208.
J ¼ 13.2 Hz, AreCH2eAr), 5.22 (4H, s, CH2), 7.25 and 7.70 (2H, s, OH),
7.25e8.15 (26H, m, AreH), 9.98 (1H, broad, NH), 11.35 (1H, broad,
NH). MS m/z (Mþ): 1187.
2.2.2.7. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
2.2.2.5. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-bis-[30-
methyl-40(200-methyl phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6e). Orange solid, yield 0.72 g (63%), m.p: 134 ꢂC. Anal. Cal. for
C64H54N14O8; C: 67.01%; H: 4.71%; N: 17.10%; Found: C: 67.04%; H:
methyl-40(300-methoxy
phenylazo-10-H-pyrazole-50-ylazo]calix[4]
arene (6g). Light yellow, yield 0.74 g (63%), m.p: 120 ꢂC. Anal. Cal.
for C64H54N14O10; C: 65.19%; H: 4.58%; N: 16.63%; Found: C: 65.25%;
H: 4.62%; N: 16.69%. IR (KBr)
y
(cmꢁ1): 3525 cmꢁ1 (eOH), 3014e
4.73%; N: 17.12%. IR (KBr)
y
(cmꢁ1): 3528 cmꢁ1 (eOH), 3012e
3026 cmꢁ1 (Aromatic CeH), 2946e2964 cmꢁ1 (Aliphatic CeH),
3025 cmꢁ1 (Aromatic CeH), 2943e2961 cmꢁ1 (Aliphatic CeH),
1578 cmꢁ1 (N]N), 1094 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
1582 cmꢁ1 (N]N), 1095 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
d
(ppm): 2.98, 3.24 (6H, s, pyrazoleeCH3), 3.50 and 4.23 (8H, d,

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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
259
X
X
X
X
H
H
H
H
N
N
N
N
H3C
N
N
H3C
N
CH3
CH3
N
N
N
N
N
N
N
N
N
Kt
N
H
NH
N
N
N
N
N
N
OH
OH
O
O
O
O
O
O
Kt
Kt
NO2
X
NO2
X
NO2
NO2
C
B
N
N
N
H3C
N
CH3
N
N
N
Kt
Kt
N
H
NH
N
N
N
OH
OH
O
O
X
X
X
X
Kt
Kt
N
NO2
N
N
H3C
N
NO2
N
N
H3C
N
CH3
CH3
N
N
N
A
N
H
H
N
N
H
N
H
H
Kt
N
H
NH
NH
N
N
N
N
N
N
N
O
O
O
O
O
O
O
O
NO2
NO2
NO2
NO2
D
E
Fig. 3. The tautomeric form of tetrakishetarylazocalix[4]arene derivatives.

_
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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
3.95%; N: 18.57%. IR (KBr)
y
(cmꢁ1): 3526 cmꢁ1 (eOH), 3012e
3037 cmꢁ1 (Aromatic CeH), 2950e2965 cmꢁ1 (Aliphatic CeH),
1578 cmꢁ1 (N]N), 1522 cmꢁ1 (NO2), 1094 cmꢁ1 (CeO). 1H NMR
(DMSO-d6, 25 ꢂC)
d (ppm): 2.92, 3.22 (6H, s, pyrazoleeCH3), 3.45
and 4.25 (8H, d, J ¼ 13.2 Hz, AreCH2eAr), 5.21 (4H, s, CH2), 7.25 and
7.68 (1H, s, OH), 7.21e8.21 (26H, m, AreH), 9.98 (1H, broad, NH),
10.60 (1H, broad, NH). MS m/z (Mþ): 1208.
2.2.2.11. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(400-methoxy
phenylazo-10-H-pyrazole-50-ylazo]calix[4]
arene (6k). Dark brown solid, yield 0.88 g (75%), m.p: 142 ꢂC. Anal.
Cal. for C64H54N14O10; C: 65.19%; H: 4.58%; N: 16.63%; Found: C:
65.24%; H: 4.55%; N: 16.60%. IR (KBr)
y
(cmꢁ1): 3528 cmꢁ1 (eOH),
Fig. 4. IR spectra of dye 6b.
3016e3035 cmꢁ1 (Aromatic CeH), 2951e2970 cmꢁ1 (Aliphatic Ce
H), 1575 cmꢁ1 (N]N), 1097 cmꢁ1 (CeO). 1H NMR (DMSO-d6,
25 ꢂC)
d (ppm): 2.89, 3.21 (6H, s, pyrazoleeCH3), 3.49 and 4.21 (8H,
J ¼ 13.2 Hz, AreCH2eAr), 4.20 (6H, s, AreOCH3), 5.22 (4H, s, CH2),
7.30 and 7.72 (2H, s, OH), 7.26e8.25 (26H, m, AreH), 9.72 (1H,
broad, NH), 10.42 (1H, broad, NH), MS m/z (Mþ): 1178.
d, J ¼ 13.2 Hz, AreCH2eAr), 4.18 (6H, s, AreOCH3), 5.25 (4H, s, CH2),
7.20 and 7.70 (2H, s, OH), 7.10e8.18 (26H, m, AreH), 9.95 (1H, broad,
NH), 10.58(1H, broad, NH). MS m/z (Mþ): 1176.
2.2.2.8. 25,227-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(300-chloro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6h). Golden yellow solid, yield 1.47 g (75%), m.p: 220 ꢂC. Anal. Cal.
for C62H48N14O8Cl2; C: 62.68%; H: 4.04%; N: 16.51%; Found: C:
2.2.2.12. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(400-chloro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6l). Brown solid, yield 0.92 g (78%), m.p: 143 ꢂC. Anal. Cal. for
C62H48N14O8Cl2; C: 62.68%; H: 4.04%; N: 16.51%; Found: C: 62.72%;
y
(cmꢁ1): 3529 cmꢁ1 (eOH),
H: 4.07%; N: 16.55%. IR (KBr)
y
(cmꢁ1): 3528 cmꢁ1 (eOH), 3015e
62.71%; H: 4.08%; N: 16.57%. IR (KBr)
3018e3036 cmꢁ1 (Aromatic CeH), 2940e2963 cmꢁ1 (Aliphatic
CeH), 1578 cmꢁ1 (N]N), 1097 cmꢁ1 (CeO). 1H NMR (DMSO-d6,
3028 cmꢁ1 (Aromatic CeH), 2945e2966 cmꢁ1 (Aliphatic CeH),
1578 cmꢁ1 (N]N), 1096 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
25 ꢂC)
d (ppm): 2.93, 3.23 (6H, s, pyrazoleeCH3), 3.51 and 4.25 (8H,
d
(ppm): 2.86, 3.20 (6H, s, pyrazoleeCH3), 3.48 and 4.22 (8H, d,
d, J ¼ 13.2 Hz, AreCH2eAr), 5.23 (4H, s, CH2), 7.25 and 7.70 (2H, s,
OH), 7.23e8.19 (26H, m, AreH), 10.05 (1H, broad, NH), 11.85 (1H,
broad, NH). MS m/z (Mþ): 1187.
J ¼ 13.2 Hz, AreCH2eAr), 5.26 (4H, s, CH2), 7.24 and 7.67 (2H, s, OH),
7.15e8.20 (26H, m, AreH), 10.11 (1H, broad, NH), 12.25 (1H, broad,
NH). MS m/z (Mþ): 1187.
2.2.2.9. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(300-methyl phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6i). Yellow-brown solid, yield 0.75 g (65%), m.p: 230 ꢂC. Anal. Cal.
for C64H54N14O8; C: 67.01%; H: 4.71%; N: 17.10%; Found: C: 67.06%;
2.2.2.13. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(400-methyl phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6m). Light brown solid, yield 0.85 g (75%), m.p: 123 ꢂC. Anal. Cal.
for C64H54N14O8; C: 67.01%; H: 4.71%; N: 17.10%; Found: C: 67.05%;
y
(cmꢁ1): 3526 cmꢁ1 (eOH), 3015e
H: 4.72%; N: 17.13%. IR (KBr)
y
(cmꢁ1): 3527 cmꢁ1 (eOH), 3016e
H: 4.75%; N: 17.14%. IR (KBr)
3032 cmꢁ1 (Aromatic CeH), 2948e2964 cmꢁ1 (Aliphatic CeH),
3030 cmꢁ1 (Aromatic CeH), 2942e2963 cmꢁ1 (Aliphatic CeH),
1580 cmꢁ1 (N]N), 1093 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
1576 cmꢁ1 (N]N), 1095 cmꢁ1 (CeO). 1H NMR (DMSO-d6, 25 ꢂC)
d
(ppm): 2.87, 3.16 (6H, s, pyrazoleeCH3), 3.50 and 4.28 (8H, d,
d
(ppm): 2.85, 3.24 (6H, s, pyrazoleeCH3), 3.49 and 4.25 (8H, d,
J ¼ 13.2 Hz, AreCH2eAr), 4.05 (6H, s, AreCH3), 5.17 (4H, s, CH2), 7.22
and 7.67 (2H, s, OH), 7.22e8.20 (26H, m, AreH), 9.76 (1H, broad,
NH), 10.65 (1H, broad, NH). MS m/z (Mþ): 1146.
J ¼ 13.2 Hz, AreCH2eAr), 4.06 (6H, s, AreCH3), 5.24 (4H, s, CH2),
7.23 and 7.68 (1H, s, OH), 7.20e8.22 (26H, m, AreH), 9.92 (1H,
broad, NH), 10.60 (1H, broad, NH). MS m/z (Mþ): 1146.
2.2.2.10. 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-[30-
methyl-40(400-nitro phenylazo-10-H-pyrazole-50-ylazo]calix[4]arene
(6j). Dark brown solid, yield 0.95 g (79%), m.p: 150 ꢂC. Anal. Cal. for
C62H48N16O12; C: 61.59%; H: 3.97%; N: 18.54%; Found: C: 61.62%; H:
3. Results and discussion
In our earlier studies, carbocyclic and heterocyclic amine
substituted azocalix[4]arenes [36e39] were investigated. In this
Table 1
Influence of solvent on lmax (nm) of dyes 6(aem).
Dye no.
DMSO
DMF
Acetonitrile
Methanol
Acetic acid
Chloroform
6a
6b
6c
6d
6e
6f
6g
6h
6i
388
396
323
327,408s
351s, 418
344,423s
333,401s
340,413
342s,388
324,416s
330,388s
333,410s
336
326,409s
352s, 412
344,427s
333,413s
338,416
340s,393
320,415s
330,404s
331,415s
334,410s
352,425s
346,420s
324,387s
325,409s
351s, 415
346,422s
334,414s
342,418
347,386s
415
330,405s
332,414s
338,422s
386
357s, 521
349,425s
338,410s
344,409s
346,400s
414
334,408s
400
340
356,430, 518
346,426s
336,416s
336,419
344,410
416
333,408s
332,416s
340,566s
376
354s, 410
344, 426
334,406s
338,410
344,393s
406
330,390s
331,405s
332,404s
406
6j
6k
6l
408
338,556s
344
446
340,535s
334
339,561s
364,564s
336,414s
338
340,418s
384
6m
s: shoulder.

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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
261
reaction of p-tert-butylphenol with formaldehyde according to the
method given in reported literature [42]. Secondly, the calix[4]
arene was obtained from treatment of p-tert-butylcalix[4]arene
with aluminium chloride according to the method given in litera-
ture [43]. At the third stage, 25,27-bis-(4-nitrobenzyloxy)-26,28-
dihydroxycalix[4]arene was synthesized according to the proce-
dures given in literature [44]. Afterwards, we synthesized 2-
arylhydrazone-3-ketiminobutyronitriles 1(aem) and 5-amino-4-
arylazo-3-methyl-1-H-pyrazoles 2(aem) according to the proce-
dures given in literature [14e22]. The heterocyclic diazonium salts
were derived from heterocyclic amines 2(aem). Later, 2.0 equiva-
lent heterocyclic diazonium salts 2(aem) reacted with 1.0 equiva-
lent of 25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]arene
in DMF/MeOH mixture to obtain the corresponding hetarylte-
trakisazocalix[4]arene derivatives 6(aem). These general reactions
are shown in Figs. 1 and 2. By the purification of the reaction
mixtures, the thirteen hetaryltetrakisazocalix[4]arene derivatives
have been obtained in 62e79% yield.
DMSO
1.0
0.8
0.6
0.4
0.2
0.0
DMF
Acetonitrile
Methanol
Acetic acid
Chloroform
300
400
500
600
700
Wavelength (nm)
The obtained products from the above mentioned reactions
were characterized using elemental analysis, Mass, FT-IR and 1H
NMR spectral data. The hetaryltetrakisazocalix[4]arene derivatives
6(aem) may exist in five possible tautomeric forms which are
a phenol-azo form, a phenol-hydrazone form, two quinone-
hydrazone forms, and quinone form named A, B, C, D and E,
respectively, as shown in Fig. 3. The infrared spectra of all the
compounds 6(aem) showed a band in the range of 3520e
3529 cmꢁ1 corresponding to nOH and a band located at 3010e
3037 cmꢁ1 assigned to aromatic CeH. The others nmax values at
2940e2970 cmꢁ1 aliphatic CeH, 1521e1424 cmꢁ1 (NO2), 1575e
1582 cmꢁ1 (N]N), 1090e1097 cmꢁ1 (CeO) were also recorded.
Because of the infrared spectra of all compounds showed eOH
bands at 3520e3529 cmꢁ1 and (CeO) bands 1090e1097 cmꢁ1, it
can be suggested that these compounds do not exist as the keto
forms in C, D and E in the solid state.
Fig. 5. Absorption spectra of dye 6b in various solvents.
paper, the synthesis of some tetrakisazocalix[4]arene derivatives
6(aem) have been reported. The compounds of thirteen new
hetaryltetrakisazocalix[4]arenes 6(aem) were prepared by
25,27-bis-(4-nitrobenzyloxy)-26,28-dihydroxycalix[4]
arene with diazotized heterocyclic amines 2(aem) in nitro-
sylsulphuric acid. firstly, p-tert-butylcalix[4]arene was prepared by
coupling
Methanol
Methanol + HCl
Methanol + KOH
1.0
0.8
0.6
0.4
0.2
0.0
The IR spectra of dye 6b is shown in Fig. 4.
The structures of 6(aem) were examined by using high-
resolution NMR. The 1H NMR spectrums were measured in
DMSO-d6 at 25 ꢂC. The 1H NMR spectra of all compounds have
typical AB patterns and showed four doublet peak for methylene
protons (ArCH2Ar) at between 3.45 and 4.28 ppm. The 6a, 6b, 6d, 6f,
6h, 6j, 6l showed two singlet peak for methyl protons (pyrazolee
CH3) at between 2.85e2.98 and 3.10e3.24 ppm. The 6c, 6e, 6g, 6i,
6k, 6m showed two singlet peak for methyl protons (AreOCH3) and
(AreCH3) at between 4.10-4.20 ppm and 4.05e4.07 ppm. All
compounds 6(aem) showed a multiplet peak at between 7.10 and
8.25 ppm for aromatic protons (AreH), a singlet peak at between
7.20 and 7.72 ppm for hydroxyl proton (eOH). The 1H NMR spec-
trums of dyes 6(bef), 6h and 6l showed a broad peak at between
300
400
500
600
700
Wavelength (nm)
Fig. 6. Absorption spectra of dye 6b in acidic and basic solutions.
Table 2
Absorption maxima of dyes 6(aem) in acidic and basic solutions.
Dye no.
Methanol
Methanol þ KOH
Methanol þ HCl
Chloroform
Acetic acid
6a
6b
6c
6d
6e
6f
6g
6h
6i
327,408s
351s, 418
344,423s
333,401s
340,413
342s,388
324,416s
330,388s
333,410s
336
375
326,411s
353s, 409
343,433s
333,412s
338,423s
348,417s
320,415s
331,401s
331,415
345,422s
360,430s
340,430s
340
325,409s
351s, 415
346,422s
334,414s
342,418
347,386s
415
330,405s
332,414s
338,422s
386
326,409s
352s, 412
344,427s
333,413s
338,416
340s,393
320,415s
330,404s
331,415s
334,410s
352,425s
346,420s
324,387s
310s, 475,
376,421s
388,304s
373,313s
388,422s
382,422s
387,419s
377,405s
371,540s
364
6j
6k
6l
446
340,535
334
368,522s
369
340,418s
384
6m
s: shoulder.

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I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
9.72 and 10.21 ppm for (eNH) proton and a broad peak at 11.20e
12.35 ppm for tautomeric hydrazo (eNH) proton. The 1H NMR
spectra of dyes 6a, 6g, 6i, 6j, 6k and 6m showed only NH proton, but
did not showed hydrazo NH proton. According to 1H NMR results,
dyes named as 6a, 6g, 6i, 6j, 6k and 6m have a mixture of phenol-
azo (A) and quinone (E) tautomeric forms, but not phenol-
hydrazone (B), quinone-hydrazone (C, D) tautomeric form. The
dyes named as 6(bef), 6h and 6l present as a mixture of B, C and D
three tautomeric forms in DMSO-d6 as showed in Fig. 3.
The effects of the acid and base on the absorption spectrum of
the dyes solutions were investigated and the result were depicted
in Table 2.
The absorption spectra of the dyes in methanol were quite
sensitive to the addition of base (potassium hydroxide, 0.1 M).
Therefore, the lmax of dyes 6(aem) showed a bathochromic shifts
with the addition of base to methanol except for 6f and 6k. For
example; lmax of 6b was recorded at 418 nm in methanol, 475 nm in
methanol þ KOH (Fig. 6).
When hydrochloric acid (0.1 M) was added to the dye solutions
in methanol, hypsochromic shifts were detected, except for 6h, 6j
and 6m. The lmax of 6b was observed at 418 nm in methanol and
409 nm in methanol þ HCl. These results indicate that the tauto-
meric form in methanol changed with another tautomeric form in
acidic and basic solution (Fig. 6).
3.1. UVevisible analysis
In general, tautomeric equilibrium strongly depend on the
nature of the media. Therefore, the behaviour of tetrakisazo dyes
was studied in various solvents. Because of solubility problems, the
absorption spectra of disazo dyes 6(aem) were measured in
As seen in Table 1 accommodation of electron-withdrawing and
electron donating groups into the benzene ring resulted in bath-
ochromically shifts in acetonitrile, methanol and chloroform except
for 6g, acetic acid except for 6g, 6m when compared with dye 2a. In
contrast, introduction of electron-withdrawing and electron
donating groups into the benzene ring gave rise to hypsochromic
shifts in DMSO except for 6b, 6g, 6i, 6k, in DMF except for 6b, 6e, 6f,
6g, 6k when compared with dye 2a. The introduction of nitro
groups into the benzene ring resulted in large bathochromic shift o-
and m-position and small bathochromic shift in p-position in all
various solvents at a concentration of approximately (10ꢁ6
e
10ꢁ8 M). Solvents used for the UV measurements have different
dielectric constants (ε), i.e. DMSO (ε, 46.45), DMF (ε, 36.71), aceto-
nitrile (ε, 35.94), methanol (ε, 32.66), acetic acid (ε, 6.17) and
chloroform (ε, 4.89) [45]. The results obtained from the absorption
measurements are given in Table 1. The visible absorption spectra of
the dyes did not have correlation with the polarity of solvents. Only
plausible explanation for this irregular behaviour may be due to the
supramolecular structure of these dyes with intramolecular
hydrogen bonding, having great potential of interacting with the
solvents molecules through non-covalent or non-conventional
interactions. Alternatively, it can be thought that these types of
supramolecular structures usually bind or encapsulate solvent
molecules into their cavity and thereby prevent to exhibit regular
solvatochromic effect [46]. Similar behaviours have been reported
for azocaliks[4]arene, azocaliks[6]arene, azoresorsinarene and
azoindole and this solvent independent manner of the absorption
maxima had been explained by the stability in molecules
[38,39,45,47]. It is known that, the ground state for nearly all
molecules is less polar than excited state so that a polar solvent will
tend to stabilize in the excited state more than ground state [46]. It
was found that, as the polarity of the solvents was increased with
the increasing dielectric constant of the solvents, the absorption
maxima of the dyes generally indicates small bathochromic shifts.
The dyes generally showed bathochromic shifts in most polar
solvents, such as DMSO and DMF. The spectral shifts of dye 6b in
various solvents are depicted in Figs. 5 and 6, respectively.
There is no significant change in the absorption spectra of the
dyes in methanol, acetic acid and chloroform except for dye 6e, 6f,
6g, 6j, 6k, 6l, 6m.
solvent (For dye 6b Dl: 89 nm, for dye 6f Dl: 61 nm, for dye 6j Dl
:
9 nm relative dye 6a for spectra in methanol). Moreover, the
absorption spectra of methoxy derivatives (dye 6c) gave rise to
bathochromic shift in all solvent except for DMSO and DMF, dye 6g
except for methanol and acetic acid, dye 6k except for DMF.
4. Conclusions
In summary, the synthesis and characterization of thirteen novel
hetaryltetrakisazocalix[4]arene based dyes 6(aem) were studied
by means of FT-IR, 1H NMR and Mass spectroscopic techniques as
well as Elemental Analysis. The heterocyclic diazonium salts were
derived from heterocyclic amines 2(aem) in nitrosylsulphuric acid,
and reacted with 0.5 equivalent of 25,27-bis-(4-nitrobenzyloxy)-
26,28-dihydroxycalix[4]arene in DMF/MeOH mixture (26 mL, 8:5,
v/v) to afford 25,27-bis-[(4-nitrobenzyloxy-26,28-dihydroxy-5,17-
bis-[30-methyl-40-arylylazo-10-H-pyrazole-50-ylazo]calix[4]arene
6(aem). The FT-IR spectra results of hetaryltetrakisazocalix[4]
arene dyes 6(aem) revealed that these compounds exist in forming
phenol-azo and phenol-hydrazone form (A, B) in solid state. The
results of 1H NMR spectra of the dyes for 6a, 6g, 6i, 6j, 6k and 6m
have a mixture of phenol-azo (A) and quinone (E) tautomeric
forms, but not phenol-hydrazone (B), quinone-hydrazone (C, D)
tautomeric form. The dyes 6(bef), 6h and 6l present as a mixture of
B, C and D three tautomeric forms. The 1H NMR spectrum of all
compounds have typical AB patterns and showed four doublet peak
for methylene protons (ArCH2Ar) at between 3.45 and 4.28 ppm.
According to these results, it can be said that all compounds have
cone conformation.
It was observed that lmax of the dyes shifted hypsochromically
in acetic acid with respect to the lmax in methanol except for dyes
6b, 6f and 6l. lmax values of dyes in DMSO and DMF were shifted
bathochromically with respect to the lmax in methanol except for
6k and 6l. lmax values of dyes in DMF were shifted bathochromi-
cally with respect to the lmax in methanol except for 6e and 6i. For
example; the absorption maxima of 6b was observed at 412 nm in
acetic acid, 521 nm in DMSO, 518 nm in DMF and 418 nm in
methanol, respectively (Fig. 5).
The lmax of dyes 6c, 6d, 6e, and 6f did not change significantly in
the all solvents used for the absorption measurements. The
absorption spectra of prepared dyes showed a maximum absorp-
tion peak with a shoulder in all solvents except for 6a, 6g, 6i, 6j, 6k
and 6m. The dye 6a in methanol, acetic acid and chloroform, 6g in
methanol and acetic acid, 6j except for methanol and DMSO in all
solvent, 6k in acetic acid, 6m in DMF and acetic acid showed
a maximum absorption peak with a shoulder. It suggest that these
dyes present more than one tautomeric form. Typical examples of
these results are given in Fig. 5.
Acknowledgements
The authors are grateful to the Scientific Research Projects
Council of Pamukkale University (PAU.BAP, 2010FBE003,
2010FBE091).
References
[1] Menon SK, Modi NR, Patel B, Patel MB. Azo calix[4]arene based
neodymium(III)-selective PVC membrane sensor. Talanta 2011;83:1329e34.

_
I. S¸ ener et al. / Dyes and Pigments 96 (2013) 256e263
263
[2] Gutsche CD. In: Stoddart JF, editor. Calixarenes revisited, monographs in
supramolecular chemistry, Ch:6. Cambridge: The Royal Society of Chemistry;
1998.
[3] Ikeda A, Shinkai S. Novel cavity design using calix[n]arene skeletons: toward
molecular recognition and metal binding. Chemical Reviews 1997;97(5):
1713e34.
[4] Collins EM, Mckervey MA, Madigan E, Moran MB, Owens M, Ferguson G, et al.
Chemically modified calix[4]arenes. Regioselective synthesis of 1,3-(distal)
derivatives and related compounds. X-ray crystal structure of a diphenol-
dinitrile. Journal of the Chemical Society, Perkin Transactions 1 1991;(12):
3137e42.
[24] Yen MS, Wang IJ. A facile syntheses and absorption characteristics of some
monoazo dyes in bis-heterocyclic aromatic systems part I: syntheses of pol-
ysubstituted-5-(2-pyrido-5-yl and 5-pyrazolo-4-yl)azo-thiophene deriva-
tives. Dyes and Pigments 2004;62:173e80.
_
[25] Karcı F, Demirçalı A, S¸ ener I, Tilki T. Synthesis of 4-amino-1H-benzo[4,5]
imidazo[1,2-a]pyrimidin-2-one and its disperse azo dyes. Part 1: phenylazo
derivative. Dyes and Pigments 2006;71:90e6.
[26] Karcı F, Demirçalı A. Synthesis of 4-amino-1H-benzo[4,5]imidazo[1,2-a]pyr-
imidin-2-one and its disperse azo dyes. Part 2: hetarylazo derivatives. Dyes
and Pigments 2006;71:97e102.
_
[27] Sener I, Karcı F, Ertan N, Kılıc E. Synthesis and investigations of the absorption
[5] Gutsche CD, Nam KC. Calixarenes. 22. Synthesis, properties, and metal
complexation of aminocalixarenes. Journal of the American Chemical Society
1988;110(18):6153e62.
[6] Peters AT, Chisowa E. Colour-constitution relationships in 2-acylamino-4-N, N-
diethylaminobenzene disperse dyes. Dyes and Pigments 1993;22(4):223e38.
[7] Hartmann H, Schulze M, Guenter R. Nucleophilic substitution in arylazo
phenols e a simple route for preparing chloro-substituted azobenzenes. Dyes
and Pigments 1991;15(4):255e62.
[8] Jaiswal N, Jaiswal R, Barthwal J, Kishor K. Synthesis and biological-activity of
some new 10-[(3,5-diaryl-2-pyrazolin-1-yl)acetyl]phenothiazines. Indian
Journal of Chemistry 1981;20B:252e6.
[9] Küçükgüzel SG, Rollas S, Erdeniz H, Kiraz M, Ekinci AC, Vidin A. Synthesis,
characterization and pharmacological properties of some 4-arylhydrazono-2-
pyrazoline-5-one derivatives obtained from heterocyclic amines. Journal of
Medicinal Chemistry 2000;35:761e71.
spectra of hetarylazo disperse dyes derived from 2,4-quinolinediol. Dyes and
Pigments 2006;70:143e8.
[28] Morita Y, Agawa T, Nomura E, Taniguvhi H. Synthesis and NMR behavior of
calix[4]quinone and calix[4]hydroquinone. Journal of Organic Chemistry
1992;57:3658e62.
[29] Oueslati F, Dumazet-Bonnamour I, Lamartine R. Synthesis of new chromo-
genic 2,20-bithiazolycalix[4]arenes. Tetrahedron Letters 2001;42:8177e80.
[30] Halouani H, Dumazet-Bonnamour I, Lamartine R. Synthesis of novel chro-
mogenic bi-and tri-functionalized calix[4]arenas. Tetrahedron Letters 2002;
43:3785e8.
[31] Lhotak P, Moravek J, Stibor I. Diazo coupling: an alternative method for the
upper rim amination of thiacalix[4]arenas. Tetrahedron Letters 2002;43:
3665e8.
[32] Deligöz H, Ercan N. The synthesis of some new derivatives of calix[4]arene
containing azo groups. Tetrahedron 2002;58:2881e4.
[10] Ertan N. Synthesis of some hetarylazopyrazolone dyes and solvent effects on
their absorption spectra. Dyes and Pigments 1999;44:41e8.
[11] Khalil AK, Hassan MA, Mohamed MM, El-Sayed AM. Metal salt-catalyzed
diazocoupling of 3-substituted-1H-pyrazol-2-in-5-ones in aqueous medium.
Dyes and Pigments 2005;66:241e5.
[12] Emandi A, Serban I, Bandula R. Synthesis of some new solvatochromic 1(4)-
substituted pyrazol-5-one azo derivatives. Dyes and Pigments 1999;41:
63e77.
[33] Deligöz H. Synthesis and properties of a series of novel calix[6]arene diazo
derivates. Journal of Inclusion Phenomena and Macrocyclic Chemistry 2002;
43(3e4):285e9.
[34] Karakus¸ ÖÖ, Deligöz H. Azocalixarenes. 8: synthesis and investigation of the
absorption spectra of di-substituted azocalix[4]arenas containing chromo-
genic groups. Journal of Inclusion Phenomena and Macrocyclic Chemistry
2008;61:289e96.
[35] Chakrabarti A, Chawla HM, Francis T, Pant N, Upreti S. Synthesis and cation
binding properties of new arylazo-and heteroarylazotetrathiacalix[4]arenes.
Tetrahedron 2006;62:1150e7.
[36] Karcı F, Sener I, Deligoz H. Azocalixarenes. 1: synthesis, characterization and
investigation of the absorption spectra of substituted azocalix[4]arenas. Dyes
and Pigments 2003;59(1):53e61.
[37] Karcı F, Sener I, Deligoz H. Azocalixarenes. 2: synthesis, characterization and
investigation of the absorption spectra of azocalix[6]arenes containing chro-
mogenic groups. Dyes and Pigments 2004;62(2):131e40.
[38] Sener I, Karcı F, Kılıc E, Deligoz H. Azocalixarenes. 3: synthesis and investi-
gation of the absorption spectra of hetarylazo disperse dyes derived from calix
[4]arenes. Dyes and Pigments 2004;62(2):141e8.
[13] Tsai PC, Wang IJ. Synthesis and solvatochromic properties of some disazo dyes
derived from pyrazolo[1,5-a]pyrimidine derivatives. Dyes and Pigments 2005;
64:259e64.
[14] Elnagdi MH, Fahmy SM, Elmoghayar MRH, Elias MAM. Pyrimidine derivatives
and related compounds. I. Synthesis of some 2,3-disubstituted-4,5,6-
tetrahydropyrazole[1,5-a]pyrimidine derivatives. Zeitschrift für natur-
forschung, Teil B: Anorganische Chemie, Organische Chemie 1975;30B(9e10):
778e83.
_
[15] Elnagdi MH, Sallam MMM, Fahmy HM, Ibrahim SAM, Elias MAM. Reactions
with the arylhydrazones of cyanoketones: the structure of 2-arylhydrazone-
3-ketimino-nitriles. Helvetica Chimica Acta 1976;59(2):551e7.
[16] Elnagdi MH, Elmoghaya MRH, Fleita DH, Hafez EAA, Fahmy SM. Pyrimidine
derivatives and related compounds. 4. A route for synthesis of pyrazolo[3,4-
e]-as-triazines, pyrazolo[3,4-d] pyrimidines, and pyrazolo[1,5-c]-as-triazines.
Journal of Organic Chemistry 1976;41(24):3781e4.
[39] Sener I, Karcı F, Kılıc E, Deligoz H. Azocalixarenes. 4: synthesis, characteriza-
tion and investigation of the absorption spectra of hetarylazo-substituted
calix[6]arenes containing heterocyclic groups. Dyes and Pigments 2004;
62(2):149e57.
[17] Ghozlan SAS, Abdelhamid IA, Abdelshaft GH, Elnagdi MH. Studies with
functionally substituted enamines: synthesis of new amino-pyrimidines and
1,2,4-triazines. Journal of Chemical Research 2004;12:789e93.
[18] Karcı F. Synthesis of disazo dyes derived from heterocyclic components.
Coloration Technology 2005;121:275e80.
[19] Ho YW. Synthesis of some new azo pyrazolo[1,5-a]pyrimidine-thieno[2,3-b]
pyridine derivatives and their application as disperse dyes. Dyes and Pigments
2005;64:223e30.
[40] Tilki T, Sener I, Karcı F, Gulce A, Deligoz H. Approach to the synthesis of
chemically modified bisazocalix[4]arenes and their extraction properties.
Tetrahedron 2005;61(40):9624e9.
_
[41] S¸ ener I, Kadifeli F. Synthesis and absorption spectra of some novel hetar-
yldisazocalix[4]arene derivatives. Coloration Technology 2011;127(6):404e10.
[42] Gutsche CD, Iqbal M. p-tert-butylcalix[4]arene. Organic Synthesis 1990;68:
234e7.
[43] Gutsche CD, Iqbal M, Stewart D. Calıxarenes 18. Synthesis procedures for
para-tert-butylcalix[4]arene. Journal of Organic Chemistry 1986;51(5):742e5.
[44] S¸ ahin Ö, Memon S¸ , Yılmaz M. Synthesis of chiral calix[4]arene derivative and
evaluation of its recognition properties. Journal of Macromolecular Science,
Part A. Pure and Applied Chemistry 2010;47(1):20e5.
[20] Zvilichovsky G, Davıd M. The reactıon of phenylmalononıtrıle wıth hydrazıne
e
synthesıs and propertıes of 3,5-dıamıno-4-phenylpyrazole, 2-amıno-3-
phenylpyrazolo[1,5-a]pyrımıdıne, and related-compounds. Journal of the
Chemical Society, Perkin Transactions 1 1983;1:11e6.
[21] Kandeel ZE, Abdelrazek FM, Eldin NEMS, Elnagdi MH. Activated nitriles in
heterocyclic synthesis-novel synthesis of benzo[g]imidazo [1,2-c]pyrimidines
and benzo[g]imidazo [1,2-a]pyridine derivatives. Journal of the Chemical
Society, Perkin Transactions 1 1985:1499e501.
[45] Reichart C, Welton T. Solvent and solvent effect in organic chemistry. 4th ed.
Weinheim: Willey-VCH Verlag & Co.KgaA; 2011.
[46] Jain KJ, Kanaiya PH, Bhojak N. Synthesis, spectral characterization of azo dyes
derived from calix[4]resorcinarene and their application in dyeing of fibers.
Fibers and Polymers 2008;9(6):720e6.
[22] Sing SP, Kumar D. Reınvestgation of the reported synthesis of naphtho[20,10-
4,5]thiazolo[2,3-c][1,2,4]triazepines. Heterocycles 1990;31:855e60.
[23] Song H, ChenK, TianH. Synthesis ofnovel dyes derived from 1-ethyl-3-cyano-6-
hydroxy-4-methyl-5-amino-2-pyridone. Dyes and Pigments 2002;53:257e62.
ꢀ
[47] Seferoglu Z, Aktan E, Ertan N. Spectral characterization and computational
studies of some novel phenylazoindol-2-one dyes. Coloration Technology
2009;125(6):342e51.