Synthesis, Characterization of some new Heterocyclic Compounds Derived from Chalcones Containing Schiff Bases

The present work involves the new chalcones containing Schiff bases, In this study, firstly, reaction of 3-acetylcoumarin with terephthaldehyde to prepared chalcones which contains a free aldehyde group which has been reacted with (4-Aminoantipyrine) to prepare Schiff bases, which was reacted (sodiumazide) as precursor to form (Tetrazole) followed by condensation of these chalcones with some compounds (hydroxylamine, aminophenol, phenylenediamine, hydrazine, semicar-bazide, thiosemicarbazide, urea, thiourea and quanidine) as precursor to form Isoxazole, oxazepane, diazepine, pyrazoles and pyrimidine derivatives in basic medium using classical and ultrasonic technique. The comparison of the classical methods with ultrasonic methods. Was achieved. The compositions of the prepared compounds were confirmed by FT-IR and 1 H NMR spectroscopy.


INTRODUCTION
Coumarin A heterocyclic compound formed by the fusion of a benzene ring with an α-pyrone ring, which is called (Benzo-α-Pyrone) (Jain and Joshi, 2012), One of the most important biological effects of coumarin is anti-tumor and cytotoxic (Peng et al., 2013), and after many studies and knowledge of the process mechanism through clinical chemistry studies, coumarin and its derivatives were recorded as important phytochemicals, mostly in higher plants to treat a variety of types of cancer (Al-shahwany and Omer, 2021). Chalcones are considered as flavonoid compounds which have therapeutic effects in a range of biological activities as anti-cancer (Elkanzi et al., 2022), anti-oxidant (Tiwari et al., 2021), and anti-inflammatory (Salehi et al., 2021). Schiff bases are prepared from the condensation of aldehydes and ketones with primary amines (R-NH2) and were discovered by the German scientist (Schiff), who first attended them in 1864 and named after him (Alfatlawi et al., 2022). The biological efficacy of Schiff bases has been evaluated and demonstrated efficacy, against many cancer diseases, anti-microbial (Venkateswarlu et al., 2022), anti-tuberculosis (Jameel and Sheat, 2013), anti-AIDS (Kar et al., 2022). most of the heterocyclic organic compounds have biological activity (Devi et al., 2022). Some tetrazole compounds have been used as anti-inflammatory and antiviral agents (Myznikov et al., 2022), in addition to being used as herbicides, anti-fungal, and antibacterial. (Dalaf et al., 2022). Green chemistry It is a technique in chemical preparations that aims to reduce the emitted substances resulting from emissions in chemical manufacturing to the least possible extent (Quispe et al., 2022), as it introduces new techniques that can facilitate human life and activities without harming the environment (Chakole et al., 2022), as green chemistry includes the use of modern techniques and chemical methods that reduce substances polluting the environment or prohibiting the use of raw materials (Gangrade et al., 2015), solvents or catalytic auxiliary agents and materials that may disintegrate and which are hazardous to the environment and humans (Liu et al., 2021).

EXPERIMENTAL Instrumentation
Melting points were measured by Electrothermal Gallen Kamp melting points and were uncorrected. Infrared (FT.IR.) spectra was recorded using (KBr) disk was recorded on Bruker FT.IR. spectrophotometer. 1 HNMR spectra were recorded using Inova 500 MHz by using DMSO-d 6 as a solvent, while using TMS as an internal reference in University of Kashan, Iran.

Preparation of (3-AcetylCoumarin) ( 3 )
Compound (1) (3-acetylcoumarin) was prepared by reacting (0.01 mol) of salicylaldehyde with (0.01mol) of methyl acetoacetate with the addition of (1 ml) of piperidine. Piperidine with stirring in the ethanol solvent with continuous stirring for 15 minutes where a dark yellow precipitate is formed and washed with ethanol until the color turns and is recrystallized using hot Methanol , (Table 1) shows the physical data of the synthesized compound. (Al-shahwany and Omer, 2021)

Preparation 4-(3-oxo-3-(Coumarin-3-yl) prop-1-en-1-yl) benzaldehyde ( 2 )
Chalcones are prepared by dissolving (0.01mol) of the 3-acetylcoumarin compound in (25 mL) of ethanol and then adding (0.01 mol) of piperidine while stirring for 15 minutes, then adding to the reaction mixture (0.01 mol) of terephthaldehyde dissolved in (10ml) of ethanol over Form batches with stirring at room temperature for 10 minutes and then the mixture rises for 6 hours. The mixture was cooled, then crushed ice is added to it where a solid precipitate is formed, filtered and washed with cold water until the solution is equalized, dried and recrystallized like (methanol) as in the equation below, The physical properties of the prepared compounds as shown in (Table 1). (Al-Hayali et al., 2018).

Green methods (ultrasonic technique)
The above compounds were prepared using ultrasonic technology and zirconium chloride octahedrate was used as catalyst and irradiated using ultrasonic technology in a water bath at 45-65°C for 40 minutes to give the products shown in (Table 1)

RESULTS AND DISCUSSION
The key of this work is the chalcone intermediate was obtained by Clasian -Schmidt condensation of corresponding 3-acetylcoumarin (1) with aldehyde (terephthaldehyde), in basic condition by addition of piperidine, the structural formula of the compounds (2) was established by physical and spectral data of FT.IR which show two band position of carbonyl groups at (1650 cm -1 and at 1750 cm -1 ), as shown in scheme 1. The prepared chalcone was identified by studying the spectral properties of the compounds (I.R, 1H-NMR) by infrared spectrum and nuclear magnetic resonance spectrum. The infrared spectra of these compounds showed the appearance of absorption bands in the frequency range (1700 cm -1 ). It goes back to the stretching frequency of the carbonyl group (C = O), where the stretching frequency of the carbonyl group in chalcones is less than its natural frequency due to the resonance of the double bond, and it also gave absorption bands in the range of frequencies (υ 1508-1585 cm -1 ) that go back to the frequency of Stretch the double-joint (C=C).

Scheme 1: The synthetic route of compound (2)
The reaction of chalcone (2) with one moles 4-aminoantipyrine and gave Schiff bases compound (3), the scheme (2) showed these reactions, Schiff bases were diagnosed by studying the spectral properties of compounds (FT-IR and 1 H NMR spectroscopy). The infrared spectra of these compounds showed the appearance of absorption bands in the frequency range (1650 υ cm-1) dating to the stretching frequency of the Schiff base group (C=N), also showed in situ absorption bands (1210-1280 υ cm-1) due to the band frequency (C-N).

Scheme 2: the synthetic route of compound (3)
The reaction of compound 3 with one mole sodium azide gave Tetrazol compound (4), the scheme (3) showed these reactions, Schiff bases were diagnosed by studying the spectral properties of compounds (FT-IR and 1 H NMR spectroscopy). The infrared spectra of these compounds showed the appearance of absorption bands in the frequency range (1410-1460 υ cm-1). It refers to the stretching frequency of the Schiff bases group (N=N), and the in-situ absorption bands (1210-1280 υ cm-1) are due to the band stretching frequency (C-N). It also showed in situ absorption bands (3250-3350 υ cm-1) due to the band stretching frequency (H-N),