Design, synthesis and radical scavenging performance of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl) diphenol

Abstract

Heterogeneous catalytic synthesis of a pyrazoline derivative, 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol from the reaction between (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one and hydrazine hydrate has been done using sodium impregnated on the activated chicken eggshells (Na-ACE). The agreement of the product structure was confirmed using FTIR, UV-Vis, and LC-ESI-MS instruments. This pyrazoline derivative has a significant activity to scavenge free radical of DPPH model in ethanol solution.

Full text

Design, synthesis and radical scavenging performance of 2,2’-(4,5-dihydro-1H-
pyrazol-3,5-dyl) diphenol
B. Ardiansah, L. Mardiana, R. Bakri, N. P. Aziza, and T. A. Baramanda
Citation: AIP Conference Proceedings 2023, 020086 (2018); doi: 10.1063/1.5064083
View online: https://doi.org/10.1063/1.5064083
View Table of Contents: http://aip.scitation.org/toc/apc/2023/1
Published by the American Institute of Physics
Articles you may be interested in
Magnetically recoverable Fe3O4@SiO2@Sm: Preparation and application in one-pot, three-component
assembly of bis(phenyl-1H-pyrazol-5-ol) derivatives
AIP Conference Proceedings 2023, 020069 (2018); 10.1063/1.5064066
Nano CuFe2O4: A reusable magnetic catalyst for the synthesis of 2-amino-5,10-dioxo-4-styryl-5,10-dihydro-4H-
benzo[g]chromene-3-carbonitrile via a one-pot multicomponent reaction
AIP Conference Proceedings 2023, 020075 (2018); 10.1063/1.5064072
Plants extract mediated synthesis of copper (II) oxide nanoparticles using Oldenlandia corymbosa L. leaf
AIP Conference Proceedings 2023, 020097 (2018); 10.1063/1.5064094
Fe3O4 nanoparticles: An efficient and recyclable catalyst for benzimidazoles synthesis
AIP Conference Proceedings 2023, 020061 (2018); 10.1063/1.5064058

Design, Synthesis and Radical Scavenging Performance of
2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol
B. Ardiansah, L. Mardiana , R. Bakri a), N. P. Aziza, and T. A. Baramanda
Department of Chemistry, Faculty of Mathematics and Natural Sciences (FMIPA),
Universitas Indonesia, Depok 16424, Indonesia
a) Corresponding author: bakri@ui.ac.id
Abstract. Heterogeneous catalytic synthesis of a pyrazoline derivative, 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol
from the reaction between (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one and hydrazine hydrate has been done using
sodium impregnated on the activated chicken eggshells (Na-ACE). The agreement of the product structure was confirmed
using FTIR, UV-Vis, and LC-ESI-MS instruments. This pyrazoline derivative has a significant activity to scavenge free
radical of DPPH model in ethanol solution.
Keywords: activated chicken eggshells, heterogeneous catalyst, chalcone, pyrazoline, antioxidant.
INTRODUCTION
The formation of Reactive Oxygen Species (ROS) occurs as an unavoidable effect of the metabolic activities in
aerobic organism [1]. Compared to the non-radical species, ROS is generally stronger and highly reactive, such as
hydroxyl (OH•), superoxide, alkoxy (RO•), and peroxyl radicals [2]. These radicals disrupt and destroy the
biological role of numerous biomolecules, like lipoprotein, DNA, and other small cellular molecules [2]. The ROS
overproduction in human body, called as oxidative stress, leads to several diseases, such as rheumatoid arthritis,
cancer, and inflammatory disorders [2-4].
The perilous pretence of the ROS can be blocked by radical scavenger (popularly known as antioxidant) which
can act as an electron or hydrogen atom donor. The commercially available free radical scavengers (TBHQ, BHA,
BHT, and etc.) have been linked with their carcinogenic activity in animals and have high toxicity [5]. Therefore, it
is crucial to explore the novel free radical scavenger with the benefits of highly active, non-toxic, non-carcinogenic,
and low-cost.
Pyrazoline is considered to be nitrogen-containing heterocyclic derivative [6]. The extensive number of its
biological and pharmacological activities has been found, such as anti-angiogenic [7], anti-inflammatory [8], and
antioxidant [8, 9] activities. Due to the wide range of biological advantages, the synthetic methods of pyrazoline
and/or pyrazole have attracted more and more attention of many researchers [6-9]. Conventionally, pyrazoline was
synthesized from chalcone using sodium hydroxide as homogeneous base catalyst [8]. Kumar et al synthesized the
pyrazole chalcone via simple grinding method using barium hydroxide C-200 [10]. Recently, Shabalala et al have
prepared the pyrazoles under an ultrasonic irradiation in aqueous medium [11]. However, several of the reported
methods have some limitations and need a tedious work-up [11]. Hence, the environment-friendly and efficient
methods or catalyst is urgently necessary. Herein, we reported the catalytic activity of sodium impregnated on the
activated chicken eggshells (Na-ACE) as green catalyst for the synthesis of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)
-diphenol (reaction scheme shown in Figure 1). The Na-ACE material has been prepared in our previous work
[12-14], and used in this research without further instrumental characterization.
Proceedings of the 3rd International Symposium on Current Progress in Mathematics and Sciences 2017 (ISCPMS2017)
AIP Conf. Proc. 2023, 020086-1–020086-6; https://doi.org/10.1063/1.5064083
Published by AIP Publishing. 978-0-7354-1741-0/$30.00
020086-1

FIGURE 1. Reaction scheme of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol synthesis
MATERIALS AND METHODS
General and Instrumentation
Hydrazine hydrate, DPPH radical and all solvents were in analytical grade. Chalcone compound,
(E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one (99% purity, checked by GC) as the starting material and Na-ACE
catalyst were prepared in our previous work [14]. TLC analyses were carried out on Merck silica gel 60 F254
aluminum plates. Melting point of the compound was measured in apparatus of Electrothermal-9100 and was
uncorrected. The chemical identity of the compound was recorded on FTIR Shimadz u Prestige-21
spectrophotometer in KBr pellets. Maximum wavelength of product was obtained using UV-Vis Shimadzu 2450
spectrophotometer. Chromatogram and molecular mass of the synthesized compound were recorded on LC-ESI-MS
Mariner spectrometer.
Synthesis of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol
The compound (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one (0.25 mmol), hydrazine hydrate (1 mmol), various
amount of Na-ACE (10, 15, 20 and 25% wt.), and 5 mL of ethanol were mixed in 50 mL round-bottom flask
connected with reflux condenser. Beside the amount of catalyst, to get an optimum protocol of this synthesis, the
reaction time and temperature were also varied. After the specified time (based on optimization) the reaction was
stopped and the product was separated from the mixture by crystallization. To obtain a pure pyrazoline,
recrystallization from hot ethanol was performed. The characterization of the compound gave the following results,
yellow crystal; mp. 136-138oC; FTIR (KBr, cm-1): 3300-3500 (overlap –OH and –NH), 3051 (C-H sp2 aromatic),
2922 and 2847 (C-H sp3), 1592 (C=N), 1193 (C-N); UV-Vis (nm): 357; LC (min): 1.47; ESI-MS (m/z): 255.30
([M+H]+).
Free Radical Scavenging Activity
The in vitro free radical scavenging activity of (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one and
2,2’-(4,5-dihydro-1H-pyrazol-3-dyl)diphenol were screened using DPPH method according to our previous work
[13, 15]. Briefly, a stock solution of the compounds (various concentrations) were blended with ethanolic solution of
DPPH (0.5 mL, 0.01 mM) in 5 mL of final mixture and allowed to react at room temperature. Absorbance values
were recorded at 517 nm every 10 min for 30 min and converted to % inhibition.
% inhibition = [(absorbance of control – absorbance of sample) / absorbance of control] ×100%
RESULTS AND DISCUSSION
Characterization of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol
A pyrazoline derivative compound, 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol was firstly characterized
using FTIR (Fig. 2). It was possible to confirm the presence of imino group (C=N) in the region of 1592 cm-1. The
broadband between 3300-3500 cm-1 was corresponded to the hydroxyl (-OH) stretching vibration, together with the
region of the amine (N-H). Peaks at 2922 and 2847 cm-1 signified the asymmetric and symmetric stretching of C-H
sp3 from methylene and methine group in heterocyclic ring. It agrees with previous research [10, 11].
020086-2

FIGURE 2. FTIR spectrum (a), chromatogram (b) and mass spectrum (c) of synthesized compound
Analysis using UV-Vis spectrophotometer revealed that the 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol
compound has a maximum absorption at 357 nm, and suitable for its appearance as yellow crystal. Based on the
liquid chromatography analysis, there was only a single peak at retention time of 1.47 min, indicated that this
compound was obtained in high purity. Further characterization using mass spectrometry resulted in a m/z value of
255.30 as [M+H]+ which exist as the most abundant peak. From the data, it was proven that the pyrazoline was
successfully synthesized from chalcone and hydrazine hydrate using sodium impregnated on the activated chicken
eggshells catalyst.
Optimization of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol Synthesis
Chalcone can undergo 1,4 nucleophilic addition with hydrazine to form pyrazoline, as explored by some research
group [16-18]. Recently, we have reported the synthesis of 2-(5-(3-methoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl)
phenol using Na-ACE with very low isolated yield of product [13]. With a continued attention and interest in the
020086-3

development of the green catalytic process for heterocyclic compound production, in this paper we report the use of
Na-ACE catalyst for pyrazoline synthesis of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol. We explored the weight
of catalyst used, reaction time and suitable temperature needed to search the optimum condition. Initially, when the
synthesis was performed in the absence of catalyst at 80 °C for 4h, no changes in the reaction mixture was observed.
Although 5 % wt. of catalyst was added in the same condition, the yield of pyrazoline was obtained in trace only
(2 %).
In the next investigation, we increased the catalyst amount used in the reaction. The Na-ACE was varied from 10
to 25 % wt. and the optimum yield was found to be 64 % in addition of 20 % wt. of it (Table 1 Entry 3). The reaction
was conducted in different contact time of reactants and catalyst in the same condition using the optimum weight of
catalyst which recently found. At prolonged reaction time of 2 to 4h, the yield of pyrazoline was also increased
(Entry 3, 5 and 6). However, when we conducted the reaction for 5h, pyrazoline was isolated in low yield (Entry 7).
It may corresponds to the strong absorption of the reactants on the surface of Na-ACE and could not undergoes
desorption completely. Another reason that can explain this observation is the nature of this reaction as an
equilibrium reaction with the ability of reactants reformation from product. The pyrazoline synthesis was also
carried out in different temperature. At 40 °C, 36 % yield of pyrazoline was observed, and when the reaction
temperature was increased to 60 and 80 °C, the pyrazoline production was increased up to 60 and 64 % yield.
Raising temperature to 100 °C could affect to the solvent equilibrium in liquid-vapour phase, so the yield of
pyrazoline decreased to 52%. From the optimization, we see that the optimum protocol for 2,2’-(4,5-dihydro-
1H-pyrazol-3,5-dyl)diphenol synthesis was obtained when the reaction was conducted using 20 % wt. of Na-ACE at
80 °C for 4h with the highest yield of 64 % (Entry 3).
Free Radical Scavenging Activity
A simple method to measure the free radical scavenging activity of the sample solution is by using
2,2-diphenyl-1-picrylhydrazyl (DPPH) method. DPPH is a stable radical compound, and with an odd number of
electron in nitrogen atom, it gave a strong maximum absorption at 517 nm (appeared as purple solution). The color
changed from purple to yellow when the hydrogen donating compound was added to this solution. As a
consequence, the odd number of electron in DPPH becomes paired (produces DPPH-H) and the absorbance at 517
nm reduced [19]. The decrease in absorbance at 517 nm is directly proportional with the respect to the number of
odd electron scavenged.
Table 1. Optimization of pyrazoline synthesis from chalcone
Entry
Catalyst (% wt.)
Time (h)
T (°C)
Yield (%)
1
10
4
80
40
2
15
4
80
48
3
20
4
80
64
4
25
4
80
56
5
20
2
80
10
6
20
3
80
35
7
20
5
80
24
8
20
4
40
36
9
20
4
60
60
10
20
4
100
52
a Reaction conditions: chalcone (0.25 mmol), hydrazine monohydrate
(1 mmol) in ethanol as solvent under reflux.
Table 2. Percentage of free radical scavenging by (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one
(chalcone) and 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol (pyrazoline)
Chalcone
Pyrazoline
Concentration (ppm)
Scavening (%)
Concentration (ppm)
Scavening (%)
12.5
21.85
12.5
30.20
62.5
26.05
25
30.20
500
31.57
62.5
70.47
1000
41.72
125
84.23
020086-4

(a)
(b)
FIGURE 3. Absorbance profile of synthesized compound (a) 12.5 ppm and (b) 125 ppm
The percentage of free radical scavenging is tabulated in Table 2. Chalcone compound,
(E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one, as the starting material has a low activity. The solution containing
62.5 ppm of this compound was able to scavenge 26.05 % free radical only. Moreover, the chalcone only inhibit
41.72% free radical when 1000 ppm solution was added to the ethanolic solution of DPPH. It is considered that the
IC50 value for (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one is >1000 ppm. In contrast, 2,2’-(4,5-dihydro-1H-
pyrazol-3,5-dyl)diphenol with N-heterocyclic moiety showed an attractive performance to scavenge free radical in
DPPH model with IC50 of 48.96 ppm. From Fig. 3, it is clearly seen that the scavenged free radical is of a function of
sample concentration and time.
CONCLUSIONS
A pyrazoline compound of 2,2’-(4,5-dihydro-1H-pyrazol-3,5-dyl)diphenol has been successfully synthesized by
using a simple heterogeneous catalyst, sodium impregnated on the activated chicken eggshells (Na-ACE). The best
protocol was found to produce pyrazoline (64% of yield) with the following condition, weight of catalyst: 20% wt.,
time: 4 hours, and temperature 80 °C in ethanol as solvent. The synthesized compound has a high free radical
scavenging activity in DPPH model with IC50 value of 48.96 ppm.
ACKNOWLEDGMENTS
The authors are grateful to Universitas Indonesia through PITTA Grant 2017 with contract No.
676/UN.2.R3.1/HKP.05.00/2017.
REFERENCES
1. A. Detsi, M. Majdalani, C. A. Kontogiorgis, D. Hadjipavlou-Litina and P. Kefalas, Bioorg. Med. Chem. 17,
8073 (2009)
2. A. E. M. R. Afify and H. M. M. Hassan, Asian Pac. J. Trop. Biomed. 6, 771 (2016)
3. L. A. Pham-Huy, H. He and C. Pham-Huyc, International Journal of Biomedical Science (IJBS) 4, 89
(2008).
4. X. H. Yao, Z. B. Zhang, P. Song, J. Y. Hao, and D. Y. Zhang, Ind. Crops Prod. 94, 405 (2016)
5. A. A. M. Botterweck, H. Verhagen, R. A. Goldbohm, J. Kleinjans and P. A. van den Brandt, Food Chem.
Toxicol. 38, 599 (2000)
6. B. Insuasty et al., Bioorg. Med. Chem. 18, 4965 (2010)
7. M. S. Christodoulou, S. Liekens, K. M. Kasiotis, and S. A. Haroutounian, Bioorg. Med. Chem. 18, 4338
(2010)
8. B. P. Bandgar, S. S. Gawande, R. G. Bodade, N. M. Gawande, and C. N. Khobragade, Bioorg. Med. Chem.
17, 8168 (2009)
9. R. Prasath, P. Bhavana, S. Sarveswari, S. W. Ng, and E. R. T. Tiekink, J. Mol. Struct. 1081, 201 (2015).
10. P. Kumar, S. Kumar, K. Husain, and A. Kumar, Chinese Chem. Lett. 22, 37 (2011)
020086-5

11. N. G. Shabalala, R. Pagadala, and S. B. Jonnalagadda, Ultrasonics Sonochem. 27, 423 (2015)
12. L. Mardiana, B. Ardiansah, R. Bakri, and H. Cahyana, AIP Conference Proceedings 1729, 020051 (2016)
13. L. Mardiana, R. Bakri, A. Septiarti, and B. Ardiansah, IOP Conf. Ser. Mater. Sci. Eng. 188, 012022 (2017)
14. L. Mardiana, B. Ardiansah, R. Bakri, A. H. Cahyana, Y. Anita, and N. P. Aziza, Jurnal Teknologi 79, 175
(2017).
15. A. H. Cahyana and B. Ardiansah, AIP Conference Proceedings 1729, 020057 (2016)
16. D. Chinnaraja, R. Rajalakshmi, V. Latha, and H. Manikandan, J. Saudi Chem. Soc. 20, S599 (2016)
17. F. B. Miguel, J. A. Dantas, S. Amorim, G. F. S. Andrade, L. A. S. Costa, and M. R. C. Couri, Spectrochim.
Acta A: Mol. Biomol. Spectrosc. 152, 318 (2016)
18. Z. N. Siddiqui, T. N. M. Musthafa, A. Ahmad, and A. U. Khan, Bioorg. Med. Chem. Lett. 21, 2860 (2011).
19. N. A. Shakil, M. K. Singh, M. Sathiyendiran, J. Kumar, and J. C. Padaria, Eur. J. Med. Chem. 59, 120
(2013).
020086-6