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The atmospheric degradation mechanism kinetics of chlorotrifluoroethylene (CTFE), which is initiated by OH˙ and results in a variety of chemical oxidation products, were investigated using density functional theory (DFT) with the aug-cc-pVTZ basis set.

Aim and Objective: Microwave-assisted condensation of acetophenone 1 and aromatic aldehydes 2 gave chalcone analogs 3, which were cyclized to pyrazole derivatives 6a-f via the reaction with hydrazine hydrate and oxalic acid in the presence of the catalytic amount of acetic acid in ethanol. Materials and Methods: The structural features of the synthesized compounds were characterized by melting point, FT-IR, 1H, 13C NMR and elemental analysis. Results: The antibacterial activities of the synthesized pyrazoles were evaluated against three gram-positive bacteria, such as Enterococcus durans, Staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. Conclusion: All the synthesized pyrazoles showed relatively high antibacterial activity against S. aureus strain and none of them demonstrated antibacterial activity against E. coli.

A series of novel 2-(5-aryl-4H-1,2,4-triazol-3-yl)-1H-isoindole-1,3(2H)-diones were synthesized in three steps. In the first step, treatment of substituted benzoyl chlorides with ammonium thiocyanate gave the corresponding benzoyl isothiocyanates which reacted with phthalimide (isoindoline-1,3-dione) to produce a series of novel benzoyl thioureas. Condensation of the latter with hydrazine hydrate in anhydrous ethanol afforded 2-(5-aryl-4H-1,2,4-triazol-3-yl)-1H-isoindole-1,3(2H)-diones. The structure of intermediate thiourea derivatives and final products was confirmed by spectral data (FT-IR, 1H and 13C NMR) and elemental analyses.

Three-component reaction of substituted benzoyl chlorides, ammonium thiocyanate, and isatin in anhydrous acetone gave a series of novel N-(2,3-dioxo-2,3-dihydro-1H-indole-1-carbothioyl)benzamides, and condensation of the latter with hydrazine hydrate in anhydrous ethanol under reflux afforded 1-(5-(aryl)-4H-1,2,4-triazol-3-yl)-2,3-dihydro-1H-indole-2,3-dione derivatives. The structure of the synthesized compounds was confirmed by elemental analyses and FT-IR and 1H and 13C NMR data.

We have developed herein a new approach to the diverse synthesis of novel derivatives of 3-aryl benzo[d]thiazole-2(3H)-imines (3a–g), by a two-component reaction between diazonium salt (2) and various synthesized N-acyl-N’-aryl thioureas (1a–g), in the presence of sodium tert-butoxide as strong base. Finally, it resulted in the production of the desired products with a moderate yield. The chemical structures of these synthesized compounds were confirmed by various physico-chemical methods viz. FT-IR, 1H-NMR, 13C-NMR, and elemental analysis.

Natural bond orbital analysis, salvation, and substituent effects of electron-releasing (–CH3, –OH) and electron-withdrawing (–Cl, –NO2, –CF3) groups at para positions on the molecular structure of synthesized 3-phenylbenzo[ d]thiazole-2(3 H)-imine and its derivatives in selected solvents (acetone, toluene, and ethanol) and in the gas phase by employing the polarizable continuum method model are studied using the M06-2x method and 6-311++G(d,p) basis set. The relative stability of the studied compounds is influenced by the possibility of intramolecular interactions between substituents and the electron donor–acceptor centers of the thiazole ring. Furthermore, atomic charges, electron density, chemical thermodynamics, energetic properties, dipole moments, and nucleus-independent chemical shifts of the studied compounds and their relative stability are considered. The dipole moment values and the highest occupied molecular orbital–lowest unoccupied molecular orbital energy gaps reveal different charge-transfer possibilities within the considered molecules. Finally, natural bond orbital analysis is carried out to picture the charge transfer between the localized bonds and lone pairs.

In this work, to determine natural bond orbital (NBO) analysis, solvation and substituent effects for electron-releasing substituents (CH 3, OH) and electron-withdrawing derivatives (Cl, NO 2 , CF 3 ) in para positions on the molecular structure of the synthesized 3-phenylbenzo[ d ] thiazole-2(3 H )-imine derivatives 1 -6 [H ( 1 ), CH 3 ( 2 ), Cl ( 3 ), OH ( 4 ), CF3 ( 5 ), NO 2 ( 6 )] in the selected solvents (acetone, toluene, and ethanol) and gas-phase employing polarizable continuum method (PCM) model were studied at the M06-2x/6-311++G(d,p) level of theory. The relative stability of the studied compounds was affected by the possibility of intramolecular interactions between substituents and the electron donor/acceptor centers of the thiazole ring. Furthermore, atomic charges electron density, chemical thermodynamics, energetic properties, dipole moments, and the nucleus-independent chemical shifts (NICS) of the studied compounds and their relative stability are considered. The dipole moment values and the HOMO-LUMO energy gap reveal the different charge transfer possibilities within the considered molecules. Frontier molecular orbital (FMO) analysis revealed that compound 6 has very small HOMO-LUMO energy gaps in the considered phases, and is thus kinetically less stable. The obtained HOMO-LUMO energy gap corresponds to intramolecular hyperconjugative interactions p→p * . Finally, NBO analysis is carried out to demonstrate the charge transfer between localized bonds and lone pairs.

4-Amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione was synthesized in three steps from carbon disulfide, hydrazine hydrate, and acetic acid. Its reaction with benzoyl isothiocyanates prepared from substituted benzoyl chlorides and ammonium thiocyanate afforded the corresponding N-benzoyl-N′-triazolyl-thioureas. The obtained compounds were screened for antibacterial activity against Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853). Their antibacterial activity against gram-positive bacteria was higher than against gram-negative bacteria, and derivatives containing electron-withdrawing groups were more active than those with electron-donating substituents.

A series of new N-benzoyl-N'-triazine thiourea derivatives have been synthesized via the reaction of 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one with benzoyl chloride derivatives and ammonium thiocyanate in acetone under reflux conditions. 4-Amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one was prepared from the reaction of two equivalents of hydrazine hydrate with carbon disulfide and sodium pyruvate. The chemical structure of thioureas was confirmed using FT-IR, 1H NMR, 13C NMR, and high-resolution mass spectrometry, and elemental analysis. The synthesized thioureas were assayed for their antibacterial activity against both gram-positive (Micrococcusluteus and Bacilluscereus) and gram-negative (Pseudomonasaeruginosa and Escherichiacoli) bacteria using the agar well diffusion method.

The isomerization reactions of the 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione have been studied theoretically using density functional theory (DFT) along with various exchange-correlation functionals (B3LYP and M06-2x) as well as the benchmark CBS-QB3 quantum chemical approach. The calculated energy profile has been supplemented with calculations of kinetic rate constants by means of transition state theory (TST). Based on the optimized isomers geometries using the CBS-QB3 method, a natural bond orbital analysis reveals that the electronic delocalization from non-bonding lone-pair orbitals [LP(e)S7] to the neighboring σ*N2-C3 antibonding orbital increase from isomer 1 to isomer 2. Also, the LP(e)S7→σ*N2-C3 delocalizations could fairly explain the increase of occupancies of LP(e) non-bonding orbitals in the ring of isomers 1 and 2 (2 > 1). The electronic delocalization from LP(e)S7 non-bonding to σ*N2-C3 antibonding orbitals increase the ground state structure stability, Therefore, the increase of LP(e)S7→σ*N2-C3 delocalizations could fairly explain the kinetics of the isomerization reactions 1 and 2 (k2 > k1). NBO results also suggest that the kinetics of these processes are controlled by LP→σ* resonance energies.

The isomerization reactions of the 4-amino-5-methyl-2,4-dihydro- -3 H -1,2,4-triazole-3-thione were studied using the B3LYP and M06-2 x , as well as the CBS-QB3 theoretical methods. The measured energy profiles were com­plemented with kinetic rate constants using the transition state theory (TST). Based on the isomers geometries optimized using the CBS-QB3 method, a natural bond orbital (NBO) analysis shows that the stabilization energies of non-bonding lone-pair orbitals [LP(e)S7] to the s*N2–C3 antibonding orbital inc­rease from isomers 1 to 2 . Moreover, the LP(e)S7 ® s*N2–C3 delocalizations could fairly explain the increase in the occupancies of LP(e)S7 orbitals for iso­mers 1 and 2 ( 2 > 1 ). The studied stabilization energy increases the stability of the ground state structure, and could fairly explain the kinetics of the isomer­ization reactions 1 and 2 ( k 2 > k 1). NBO results also suggest that the kinetics of these processes are controlled by the LP ® σ* resonance energies.

The development of efficient and novel methods for the synthesis of heterocyclic compounds is a broad and important area of organic chemistry because of their importance as pharmaceuticals.1 Indole...

The tautomerization reactions of the 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one studied by means of M06-2x and CBS-QB3 theoretical methods. The measured energy profiles are complemented with kinetic rate coefficients calculations using transition state theory (TST). In line with the optimized tautomers geometries using the CBS-QB3 method, the natural bond orbital (NBO) analysis reveals that the stabilization energies of non-bonding LP(e)S8 to the σ*N2–C3 antibonding orbitals increase from tautomers 1 to 2. Furthermore, the delocalization energies of LP(e)S8→σ*N2–C3 could explain the increase of LP(e)S8 non-bonding orbitals occupancies in the tautomers 1 and 2 (2 > 1). The increase of LP(e)S8→σ*N2–C3 delocalizations could fairly explicate the kinetics of tautomeric pathways 1 and 2 (k2 > k1). Moreover, the HOMO–LUMO energy gap is increased parallel with the decreasing of activation energy barriers. NBO results also show that the kinetics of these processes controlled using LP→σ* resonance energies. Furthermore, nucleus-independent chemical shift (NICS) indices show the calculated reaction and energy barriers are involved by changes in aromaticity characters as well as electron transfer from LP(e)S8 to σ*N2–C3 orbitals, thus these reactions are controlled from both thermodynamic and kinetic viewpoints by the changes aromaticity characters.

A rapid and efficient solvent-free one-pot synthesis of coumarin derivatives by Pechmann condensation reactions of phenols with ethyl acetoacetate using FeF3 as a catalyst under microwave irradiation is described. This one-pot synthesis on a solid inorganic support provides the products in good yields. The newly synthesized compounds were systematically characterized by IR, 1H-NMR, 13C-NMR, MS and elemental CHN analyses. The proposed solvent-free microwave irradiation method using the environmentally friendly catalyst FeF3 offers the unique advantages of high yields, shorter reaction times, easy and quick isolation of the products, excellent chemoselectivity, and a one-pot, green synthesis. The products were screened for antimicrobial activity, and the results showed that the compounds reacted against all the tested bacteria.

A convenient and efficient protocol for the one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives of aldehydes, and 1,3-dicarbonyl compounds with Bismuth (III) sulfate trihydrate as the catalyst was described. We had the advantages of good performance, simplicity, and short time reaction under solvent-free conditions. The catalyst can be repeatedly reused without loss of its activity.

Protocols with starchsulfuric acid (SSA) as reusable catalyst for the synthesis of aryl-1H-pyrazoles are described. SSA acted as an efficient and environmentally friendly catalyst for the regioselective condensation of BaylisHillman adducts 1 with phenylhydrazine hydrochloride leading to the new 1,5-diaryl-1H-pyrazole 2a–2e in excellent yields (Scheme and Table 1).

This study was designed to investigate the antioxidant activity for Juglans regia leaves. The Methanol extract from Iranian Juglans regia leaves that grow in Karaj and Tonekabon regions was examined. In addition, total amount of DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activities and reductive power of crude extracted its different fractions were determined. The antioxidant activity data by DPPH has been compared in both regions.

The Methanol extract of Iranian Spinacia oleraceae L between Babol and Varamin regions was examined. In addition, total amount of DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activities and reductive power of crude extracted its different fractions were determined. This research has shown Spinach has antioxidant activity.

In this study, the synthesis of 4H-chromenes of biological activity via a multicomponent reaction of dimedone, aromatic aldehydes and malononitrile catalyzed by glutamic acid as a catalyst was investigated. The structural features of the synthesized compounds were characterized by melting point, IR and 1H NMR analysis. The catalyst being reported here is cheap, safe to handle and the whole procedure is eco-friendly, Milder conditions, one-pot, excellent yields, operational simplicity and ecofriendly preparation are some advantages of this protocol. The compounds were screened for antimicrobial activity. The results showed that these compounds reacted against all the tested bacteria and fungi.

Zinc chloride (ZnCl 2 ) is used as an efficient catalyst condensation of 4-hydroxycoumarin and with various aromatic aldehydes leading to the formation of biscoumarin derivatives. Easy isolation of the products, short reaction times, excellent yields and reusability of catalyst was theadvantage of thismethod.

Zn(NO 3 ) 2 as an efficient catalyst have been used for the one-pot synthesis of 1,8-Dioxo- octahydroxanthene Derivatives via multi-component reactions between dimedone and various aromatic aldehydes under solvent-free conditions. The presented method is available, environmentally friendly, cheap and highly effective to give the products in good to excellent yields.

A mixture of 2-amino benzamide with aromatic aldehyds in the presence of SSA under solvent-free condition were converted to quinazolinones with good yields.

An efficient,simple and one-pot protocol for synthesis of coumarin derivatives on the basis condensation reaction of phenols with ethyl acetoacetate employing glutamic acid as a novel catalyst is described.

An efficient method for one-pot synthesis of 3,4-Dihydropyrimidin-2-(1H) -one derivatives the Biginelli condensation reaction of aromaticaldehydes, b-ketoesters and urea under solvent-free conditions was described.

A mixture of benzyl, aromatic aldehyde and ammonium acetate in presence of SiO2-NaHSO4 under solvent-free condition were converted to 2,4,5-Triaryl-1H-Imidazoles. The short reaction time, cleaner reaction, and easy workup make this protocol practical and economically attractive.

Series of some new spiro‐1,4‐dihydropyridine derivatives have been synthesized in good yields in a four‐component, solvent‐free process by condensation of isatins, primary amines, ethyl cyanoacetate, and cyclohexanone under microwave irradiation.

A simple, efficient protocol for the one-pot Biginelli condensation reaction of aromaticaldehydes, β-ketoesters and urea employing glutamic acid as a novel catalyst is described.

Chemistry of dihydropyridines in 1882 with Ar thur Hansh reports the β-keto ester, aldehydes and ammonia can be combined to form 1, 4-dihydropyridine was developed. Because of the many benefits of 1, 4-dihydropridine is presented and now as vital medicines to treat angina, high blood pressure and allergies have been introduced. The combination of amlodipine and infedipines as brand name drugs1-5. Another successful treatment of 4-aryl -1, 4-dihydropridine is that they use as calcium channels blockers in the treatment of cardiovascular disease and hypertension. Calcium channel blockers are a class of drugs that control entrance of calcium into cells and exit of calcium from cellular stores. These compounds lower blood pressure by relaxing smooth muscle wall of heart and arteries and reduce ORIENTAL JOURNAL OF CHEMISTRY

1,4-Dihydropyridines oxidizes to pyridine derivatives by hydrogen peroxide in the presence of Copper(II) chloride as catalyst at room temperature.

Three component one-pot reaction for synthesis novel of imidazo(2,1-b)thiazoles with high yield were obtained by the condensation of 4-phenylthiazol-2-amine, aromatic aldehyde and isocyanide.

Series of some new arylpyrazole derivatives have been synthesized in good yields via one-pot condensation reaction using nano-Fe 2 O 3 as heterogeneous catalyst.

The present study aimed to use a method for the synthesis of some 3, 4-dihydropyrimidin-2-(1H) - ones/thiones. The study tried to answer the question whether this reaction can be performed without solvent and with new catalyst or not. To find answer to the question, we described a novel protocol for the efficient synthesis of 3, 4-dihydropyrimidin-2-(1H)-one derivatives using aromatic aldehyde, ethylacetoacetate, and urea/thiourea under solvent-free conditions by using SiO2-CaCl2as acatalyst. Using this catalyst has some advantages; it's high yields, usable in mild conditions, available, reusable, ecofriendly, cost effective and environmentally friendly. The structural features of the synthesized compounds were characterized by IR, 1H NMR and 13C NMR. The compounds were screened for antimicrobial activity. The results showed these compounds react against all the tested bacteria. We have demonstrated a novel method for the synthesis of substituted dihydropyrimidinones catalyzed by SiO2-CaCl2 under solvent-free conditions.

We report a short and efficient 3-component reaction for synthesis of a series of [1,2-b]pyrrole derivatives from ninhydrin, alkyl propiolates, and simple primary amines under solvent free and microwave irradiation. This method provides a new route to produce pyrrole derivatives in good to excellent yields.

Starch-supported sulfuric acid acts as an efficient and environmentally friendly catalyst for the regioselective synthesis of new pyrazoles (III) via condensation of Baylis—Hillman adducts (I) with phenylhydrazine.

Esmaeil Biazar1, Ali Beitollahi2,S Mehdi Rezayat3, Tahmineh Forati4, Azadeh Asefnejad4, Mehdi Rahimi4, Reza Zeinali4, Mahmoud Ardeshir4, Farhad Hatamjafari1, Ali Sahebalzamani4, Majid Heidari41Chemistry Department, Islamic Azad University, Tonekabon Branch, Mazandaran, Iran; 2Material Department, Iran University of Science and Technology, Tehran, Iran; 3Department of Pharmacology, School of Medicine, Tehran University of Medical sciences, Tehran, Iran; 4Biomedicall Department, Islamic Azad University, Science and Research Branch, Tehran, IranAbstract: The decrease in particle size may offer new properties to drugs. In this study, we investigated the size reduction influence of the acetaminophen (C8H9O2N) particles by mechanical activation using a dry ball mill. The activated samples with the average size of 1 µm were then investigated in different time periods with the infrared (IR), inductively coupled plasma (ICP), atomic force microscopy (AFM), and X-ray diffraction (XRD) methods. The results of the IR and XRD images showed no change in the drug structure after the mechanical activation of all samples. With the peak height at full width at half maximum from XRD and the Scherrer equation, the size of the activated crystallite samples illustrated that the AFM images were in sound agreement with the Scherrer equation. According to the peaks of the AFM images, the average size of the particles in 30 hours of activation was 24 nm with a normal particle distribution. The ICP analysis demonstrated the presence of tungsten carbide particle impurities after activation from the powder sample impacting with the ball and jar. The greatest reduction in size was after milling for 30 hours.Keywords: acetaminophen, mechanical activation, structure investigation, nanoparticles, ball mill

A series of some new spiro-1,4-dihydropyridine derivatives have been synthesized in good yields in a four component, and solvent-free process by condensation of isatins, primary amines, ethyl cyanoacetate and cyclohexanone on solid support montmorillonite K10

A new protocol for the synthesis of a series of tetrahydrodihydroxy-oxoindeno[1,2-b]pyrrole from simple primary amines, alkyl propiolates, and ninhydrin was developed. The key step in the synthesis is an efficient three-component reaction of an amine with an alkyl propiolate to give a 3-amino acrylate derivative, which then reacts with ninhydrin.

Some new spiro derivatives (5a-h, 9a-c and 13a-c) of 11H-indeno(1,2-b)quinoxalin-11-ones 1a-b and 6H-indeno(1,2-b)pyrido(3,2-e)pyrazin-6-one 6 and isatin 10 were synthesized by two different pathways. The chalcones 4a-h, 8a-c and 12a-c were prepared by the reaction of acetophenone and its four derivatives with 1a-b, 6 and 10 via base-catalyzed condensation followed by addition of acid. In the first procedure, the chalcones were isolated and reacted with hydrazine hydrate to give products. In the second procedure, the chalcones were in situ reacted with hydrazine hydrate without isolation to give spiro compounds in improved yields.