GREEN SYNTHESIS AND CHARACTERIZATION OF CINNAMYLIDENEACETOPHENONE COMPOUND USING Fe3O4 MAGNETIC AS CATALYST

Cinnamaldehyde is a compound found in the skin of cinnamon plants which has various bioactivity. In this study, the compound cinnamaldehyde was modified with the help of Fe3O4 which was synthesized with the help of seaweed extract as a heterogeneous catalyst. Fe3O4-MNPs are synthesized using FeCl3 and Sargassum filipendula extracts as their natural reducing agents. The catalytic ability of Fe3O4 was evaluated in the reaction between cinnamaldehyde and aromatic ketone compounds synthesized by the reflux method. Structure Analysis and elucidation of the synthesized compounds were carried out by measuring the vibrations of the functional groups by FTIR, and the determination of H and C atoms by HNMR and CNMR analysis. The FTIR, proton and carbon NMR analysis have identified that the synthesized product was cinnamylideneacetophenone by the name 1,5diphenylpyenta-2,4-dien-1-one. The optimum conditions were obtained at a catalyst concentration of 10% w/w for five hours with a yield of 36%. The yield of this reaction was better than the reaction without a catalyst.


INTRODUCTION
The reduction in the use of chemicals in green chemistry is of concern to recent researchers.
Various instrument modifications and the use of natural materials are often used as alternatives.
Such as synthesis without the use of chemical solvents, the use of microwaveassisted methods or ultrasonic irradiation instruments, and often also utilize natural polymers and plant extracts (Benelli, 2019;Fierascu et al., 2019;Khalaj et al., 2020;Mahmoud et al., 2015;Rajendaran et al., 2019;Sadjadi et al., 2017). In addition, modification of particle size in the nano-scale provides advantages in surface area that affects the intermolecular interaction and the rate of a reaction (Chng et al., 2013;Liandi et al., 2020;Nasir Baig et al., 2015). In this study, the use of Fe3O4 magnetic nanoparticles was chosen as a catalyst in an organic reaction synthesized with the help of seaweed extract.
The use of Fe3O4-MNPs as heterogeneous catalysts in a reaction is of concern because of its superiority. Modification of cinnamaldehyde which is one of the main components of cinnamon bark is often done to obtain new bioactivity or increase bioactivity (Wang et al., 2016;Yen & Chang, 2008).
Sinamaldehyde is able to act as an antimicrobial used in medicine, food and preservatives. However, there are limitations in applying it because the smell is very pungent and volatile (Jo et al., 2015). In this reseach, cinnamaldehyde was modified by recombining it with a ketone compound by using Fe3O4-MNPs as a catalyst.

Synthesis of Fe3O4 magnetic nanomaterials
The Fe3O4 magnetic synthesis with support of seaweed extracts that have been obtained was carried out by the coprecipitation method. In this synthesis, 1 mmol of FeCl3 and 5 mL of seaweed extract were dissolved in aquademin and stirred until homogeneous. Then, 6 M NaOH was added dropwise until it reached pH 11. The mixture was stirred for 2 hours. Then the mixture was decanted with a magnet from the outside and rinsed with ion free water and ethanol. Hereinafter, the synthesized product was dried at 40 o C using an oven.

Synthesis and characterization of Fe3O4 from Sargassum filipendula
The use of heterogeneous catalysts is of concern nowadays because of its   The surface morphology of the Fe3O4 synthesized by seaweed extract and particle size was studied by scanning electron microscope (SEM). The surface of Fe3O4 is shown in Figure 2a, 2b, and 2c with variations of magnification. The results of this SEM analysis, it appears that Fe3O4 was formed in the form of agglomeration. This is due to the magnetic properties which causes the fusion between particles so that no visible particle shape. The size distribution of the synthesized Fe3O4 particle was below 100 nm.   178 EduChemia,Vol.6, No.2, 2021 Fitria, Cahyana, Liandi e-ISSN 2502-4787  proton at position C-2, C-3, C-4 and C-5 (Table. 2). In α, β-unsaturated ketones, protons next to carbonyl (Hα) will have small δ (shielded) and Hβ will have higher (deshielded). At the C-2, C-3, C-4, and C-5 positions, the most significant chemical shift is at the C-3 (Hβ) position.
This can be explained because there is a resonance in α, β-ketones unsaturated so that the carbon in Hβ (proton at C-3) is relatively more positive than the carbon on Hα (proton at C-2). As a result, the electron density at Hβ is smaller than the electron density at Hα. In addition, there are geometric or spatial effects of carbonyl on C-1, so that C-3 is more deshielded than C-2, C-4, and C-5. The chemical shift at δ 7.99 ppm shows the proton at the position of the C-2' and C-6' atoms with the peak of the doublet, which is the highest peak. This is because in addition to the anisotropic effect, there is also an aromatic effect so that H in the C-2' and C-6' positions is deshielded. In  The 13  showed that the compound obtained was in accordance with the expected target compound, namely 1,5-diphenylpyenta-2,4-dien-1-one ( Figure 6).