Phosphorous Oxychloride Research Articles

Microwave Assisted Synthesis and 3D QSAR Analysis of Analgesic Oxadiazoles

In present work we report design, synthesis and evaluation of the analgesic activity of new 2, 5-disubstituted1, 3, 4-oxadiazoles. An ecofriendly method for the conversion of substituted benzoic acid hydrazides to 2, 5-disubstituted1, 3, 4-oxadiazoles in the presence of phosphorous oxychloride under the influence of microwave irradiation and conventional route has been described. The structures of oxadiazoles formed were confirmed by elemental and spectral analysis. In comparison with conventional microwave assisted method is simple, rapid and efficient. The title compounds were tested for analgesic activity by tail flick method and the series of 20 compounds was subjected for 3D QSAR analysis using V life MDS 3.5 software. The compounds were divided into training and test set. Best QSAR model was selected on the basis of various statistical parameters like square correlation coefficient (r2), cross validated square correlation coefficient (q2), standard error of estimation (SE) and sequential Fischer test (F). 3D QSAR study reveals that electronegative and bulk substitution at second and fifth position of 1, 3, 4-oxadiazole improves the analgesic activity.

An Efficient Metal-Free Methodology for the Synthesis of Hydrazo-Linked 5-(4-aryl)-1H-1,2,4-Triazoles

Hydrazo compounds have displayed significant roles in both biological and physical aspects, such as spinamycin as a potent growth inhibitor against fungi and rat sarcoma cells, hydrazo tocopherol as a component of vitamin E, and electron-rich hydrazo-linked triazines as energetic materials. In this study, a metal-free approach was proposed for the synthesis of hydrazo-linked 5-(4- aryl)-1H-1,2,4-triazoles. The methods for the synthesis of 5-(4-aryl)-1H-1,2,4-triazoles initiated by the reaction of aldehyde with semicarbazide. The resulted compound, 5-(4-aryl)-1H-1,2,4-triazol-3- ol, upon reaction with phosphorous oxychloride yielded 3-chloro-5-(4-aryl)-1H-1,2,4-triazoles. These synthesized compounds upon fusión with various aryl and hetero aryl substituted hydrazines provided desired hydrazo moieties. Synthesized hydrazo compounds were characterized by spectroscopic techniques, viz. 1H-NMR, FT-IR and mass spectrometry. In this study, a series of novel hydrazo- linked 5-(4-aryl)-1H-1,2,4-triazoles were synthesized. The methodology proposed in this study eliminates the use of complicated procedures and heavy metals.

Synthesis, in vitro α‐Glucosidase Inhibition, DFT Calculations, and Molecular Docking Studies of Some New Substituted 2,5‐Bis(pyrazolyl)‐1,3,4‐oxadiazoles

AbstractA pivotal feature of present research study is the synthesis of some new 2,5‐bis(pyrazolyl)‐1,3,4‐oxadiazoles as promising α‐glucosidase inhibitors. In this regard, a facile reaction scheme was designed to afford 1,3,4‐oxadiazole ring. In search of the most favourable reaction condition, a model reaction was first carried out between 1,3‐diphenyl‐1H‐pyrazole‐4‐carbohydrazide (3) and 1,3‐diphenyl‐1H‐pyrazole‐4‐carboxylic acid (4 a) using phosphorous oxychloride (POCl3). The results emanated from this model reaction were utilized to prepare other derivatives to highlight the scope of current synthetic approach and the structures of the prepared molecules were characterized from spectroscopic techniques. These derivatives were further investigated for their α‐glucosidase inhibitory potentials. 2,5‐Bis(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)‐1,3,4‐oxadiazole (5 a) and 2‐(3‐(4‐bromophenyl)‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐5‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)‐1,3,4‐oxadiazole (5 c) displayed strong in vitro inhibitory activities with IC50 73.1±1.13 μM and IC50 87.3±1.12 μM respectively with least toxicity profiles. Molecular docking and computational studies including geometry optimization of synthesized molecular systems, calculations of their orbital energies, and molecular electrostatic potential (MEP) surface maps further helped to establish structural and electronic properties contributing towards their bioactivity. The electrophilicity index significantly quantifies the biological activity. The experimental and computational data altogether facilitated in understanding the therapeutic attributes of these versatile scaffolds in relation to their α‐glucosidase inhibition.

Synthesis, characterization and antimicrobial activity of new thioxo tetrahydropyrimidine derivatives

A sequence of thioxotetrahydropyrimidenes derivatives, N-(4-chloro/methoxyphenyl)-3-formyl-6-methyl-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamides (4a-l) were synthesized by the formylation of N-(4-chloro/methoxyphenyl)-6-methyl-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamides (3a-l) by dry dimethyl formamide (DMF) and phosphorous oxychloride at room temperature. Formerly, compounds (3a-l) were synthesized by the condensation of N-(4-chloro/methoxyphenyl)-3-oxobutanamide (1), various aromatic aldehydes (2a-f) and thiourea with catalytic amount of concentrated hydrochloric acid under reflux temperature. The structures of the synthesized various thioxotetrahydropyrimidenes have been characterized by using elemental analysis, Infrared, 1H-NMR, 13C-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was showing that the compounds 4a, 4e, 4g, 4h, 4i and 4l displayed inspirational antibacterial and antifungal activity compared to the used reference standard.

Synthesis and characterizations of some new selenolo[2,3‐b]quinoxaline derivatives

AbstractIn this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2‐chloroquinoxaline‐3‐carbonitrile 1. The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH4 as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3‐cyanoquinoxaline‐2‐selenolate, which was subsequently reacted with α‐halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9. This salt was then refluxed with acetic anhydride to produce oxazinone compound 10. The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo[2,3‐b]quinoxaline derivative 11. Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound.

Synthesis of 2-arylbenzo-1,3-tellurazoles by oxidative cyclization of 2,2′-ditellurobis[N-(arylmethylene)benzenamines

A method has been developed to prepare 2-arylbenzo-1,3-tellurazoles from bis(2-aminophenyl) ditelluride and aromatic aldehydes by oxidative cyclization following an easily implemented one pot procedure. Imines obtained by combining aldehyde and ditelluride were cyclized with phosphorous oxychloride without prior purification, resulting in the formation of benzo-1,3-tellurazoles carrying aryl or heteroaryl substituents in position 2 in yields up to 58 %. Evidence is presented for a radical reaction pathway. This method is set apart from other options by avoiding strongly reducing conditions and minimizing the synthetic effort required to prepare aryl substituted benzo-1,3-tellurazoles. An X-ray crystallographic characterization of 2-(2-quinolinyl)benzo-1,3-tellurazole indicated only weak TeˑˑˑN secondary bonding interactions.

New Bis-1,3,4-Thiadiazoles Based on Fumaric Acid: Preparation, Structure Elucidation, Antibacterial Activities, and Quantum-Chemical Studies

New bis-1,3,4-thiadiazoles 1–7 were obtained by the reaction of fumaric acid and N-(alkyl/aryl/cyclic)thiosemicarbazides in the presence of phosphorous oxychloride. The structures of all compounds were elucidated by FT-IR, 1H NMR, and 13C NMR and elemental analysis. Antibacterial activity of the compounds was studied for eight selected bacteria. Compounds 2–7 exhibited effect on Klebsiella pneumoniae. However, none of the compounds effect on Pseudomonas aeruginosa, Staphylococcus epidermidis, Salmonella enterica serovar Kentucky, Serratia marcescens. Self-consistent reaction force (SCRF) calculations were performed in DMSO medium to examine solvent energies using CPCM and SMD models. 6-31G(d) and 6-311++G(2d,2p) basis sets were used for DFT calculations. Besides electronic parameters such as electronegativity, electrophilicity and spectroscopic examinations of the compounds, QTAIM, local electron affinities, and Fukui analyses were also performed. Theoretical approaches supporting the experimental observations revealed that compounds containing aromatic and cyclic groups exhibit stronger antibacterial behavior than compounds containing aliphatic groups.

Novel Bis-1,3,4-Thiadiazoles Derivatives: Synthesis, Spectroscopic Characterization, DFT Calculations and Evaluation of their Antimicrobial and Antioxidant Activities

Two new, bis-1,3,4-thiadiazoles derivatives (I and II), were prepared by cyclization reaction of oxalic acid with N-alkyl/allyl thiosemicarbazides and phosphorous oxychloride (POCl3). Then the newly prepared products screened for their antimicrobial and antioxidant activities. The biological activity results shown that tested compounds exhibited effective antibacterial activity against six different bacteria. However, the compound II demonstrated greater ABTS˙+ scavenging ability. The characterization of the synthesized molecules was done by FT-IR, 1H NMR, 13C NMR spectroscopic methods and elemental analysis. Moreover, the experimental FT-IR and NMR spectra of the molecules were compared with the results calculated at the cc-pvtz, 6-311g(2d,2p), and 6-311++g(2d,2p) levels of theory. The effect of substituted groups on the spectral and electronic properties of the compounds was investigated. NCI and QTAIM analyses were performed to examine the effects of allyl group and intramolecular interactions on σ and π bonds. How the N-H bonds of the substituted groups affect the bond degrees was investigated using Fuzzy, Laplacian and Mayer approaches, and the relationship of the data with the antioxidant properties of the compounds was examined. In addition, the relationship between bond stretching force constant and intrinsic bond strength index, electron density, and delocalization index for some bonds was revealed.

Synthesis a Number of Heterocyclic Compounds and some of chalcones Derived From Levofloxacin

The hydrazide (1) was used as synthone for the following Compound pyridazine-3,6-dione (2) by reaction of hydrazide (1) with maleic anhydride and Compound phthalazine-1,4-dione (3) by the reaction of hydrazide (1) with phthalic anhydride. Substituted thiosemicarbazides (6-7) by hydrazide(1) reaction with substituted isothiocyanates in ethanol. The thiosemicarbazide (5) was, also synthesized by the reaction of hydrazide (1) with ammonium thiocyanate in presence of concentrated hydrochloric acid. 1-Formyl-2-acyl hydrazine (4) was obtained by the reaction hydrazide (1) with formic acid, and Substituted 1,3,4-oxadiazoles (8-12) were obtained by reaction the hydrazide (1) with substituted carboxylic acid. Then, it was cyclized by phosphorous oxy chloride. 1,3,4-Oxadiazole-5-thiol (35) was synthesized by reaction of the hydrazide (1) with carbon disulfide in presence alcoholic potassium hydroxide solution. Then, the compound (35) was used to synthesize: a- 1,3,4-Oxadiazoles (36-39) by reaction with alkyl halide. b-1,3,4-Oxadiazoline thione (40) by reaction with formaldehyde. c- Triazole (41) by reaction with hydrazine hydrate in absolute ethanol. Pyrazolines compounds (23-32) were synthesized from the reaction of the hydrazide (1) with chalcones (13-22) (which were prepared by condensation of substituted Benzaldehyde with substituted acetophenone under basic conditions). Pyrazoline dion (33) and pyrazole (34) were synthesized through the reaction of the hydrazide (1) with diethyl malonate and acetyl acetone respectively.
 These compounds were characterization on bases of spectral (FT-IR)، and (1H-NMR , 13C-NMR)،and physical data .

Design of new hybrids indole/phthalimide/oxadiazole-1,2,3 triazole agents and their anticancer properties

A series of a new hybrid compounds combining 1,2,3-triazole with oxadiazolyl, Phthalimidyl or indolyl moiety has been synthesized. The reaction of our starting compound 5-phenyl-1-(aryl)-1H-1,2,3-triazole-4-carbohydrazides (5) with 5-nitrofuran-2-carboxylic acid (6) in refluxing phosphorous oxychloride afforded 2-nitro-5-(5-phenyl-1-(aryl)-1H-1,2,3-triazol-4-yl)-1,3,4-oxadiazoles 7a-c in good yields. Treatment of 5 with phthalic anhydride (8) in glacial acetic acid afforded N-(1,3-dioxoisoindolin-2-yl)-5-phenyl-1-(aryl)-1H-1,2,3-triazole-4-carboxamide 9a-d, while the reaction of 5 with isatin in slight acidic medium furnished N'-(2-oxoindolin-3-ylidene)-5-phenyl-1-(aryl)-1H-1,2,3-triazole-4-carbohydrazides 11a-d in 88–90% yields. The chemical structures for the novel products were elucidated via NMR spectroscopy and confirmed by single crystal x-ray diffraction studied. Promising antiproliferation activity have been found in some of the synthesized compounds when tested against various human cancer cell lines (HCT-116, HepG2 and MCF-7).

Synthesis and biological screening of novel series of 2-(4-hydroxy-3-methoxy-5-nitro-phenyl)-[1,3,4]oxadiazole by conventional and non conventional techniques

Novel acid hydrazide 1 when reacted with a series of different carboxylic acids in presence of phosphorous oxychloride to give novel series of 2-(4-hydroxy-3-methoxy-5-nitro-phenyl)-[1,3,4]oxadiazole 3a-3f. Use of conventional and non-conventional techniques is adapted to study the duration time of reaction. These oxadiazole compounds are studied by using spectral analysis like 1H NMR, FT-IR and mass spectroscopy. Further they are screened for antibacterial and anti-fungal biological activities.

Application of hydroxypropylated crosslinked starch from the grains of Oryza sativa L. as potential disintegrant in compressed solid dosage form

Context: The modification of starch from the grains of NSICRc222 rice variety may provide a new material with enhanced disintegrating functionality in compressed solid dosage forms. Aims: To synthesize hydroxypropylated crosslinked rice starch that may possess characteristics of a good disintegrant. Methods: Starch was isolated by the wet milling method. The crosslinking was performed using trisodium trimetaphosphate as crosslinking agent, and successively hydroxypropylated by using phosphorous oxychloride. The evidences of chemical modifications were determined by FTIR, TGA, and DSC. The application of modified rice starch as a disintegrant was evaluated by determining the dissolution profile, and was compared to the performance of commercially available disintegrants. The compatibility of modified rice starch was employed using FTIR, and the stability of the formulation was subjected to an accelerated stability study. Results: The changes in infrared spectra and thermogram confirmed successful chemical modification of rice starch. Allopurinol and modified starch mixture staged from 0 to 3 months showed no significant changes in the infrared spectra, which suggest compatibility of HCR with allopurinol. The dissolution rate of allopurinol tablets at pH 1.2, pH 4.5, and pH 6.8 with various superdisintegrants were comparable to the dissolution rate that utilized hydroxypropylated crosslinked rice starch as disintegrant. The accelerated stability study showed no significant changes from 0th to 3rd month, and no degradation products were detected in the HPLC analysis. Conclusions: The chemical modification of rice starch through crosslinking and hydroxypropylation yielded a novel material comparable to the commercially available superdisintegrants.

Docking Simulations and Primary Assessment of Newly Synthesized Benzene Sulfonamide Pyrazole Oxadiazole Derivatives as Potential Antimicrobial and Antitubercular Agents

A novel series of benzene sulfonamide pyrazole oxadiazole derivatives have been synthesized by reaction of 4-(5-(3-fluoro-4-methoxyphenyl)-3-(hydrazinecarbonyl)-1H-pyrazol-1-yl) benzene sulfonamide with different substituted benzoic/pyridinyl/indolyl acids in phosphorous oxychloride, characterized by IR, 1H NMR, 13C NMR, MS analytical data and evaluated for their antimicrobial as well as antitubercular activity. Molecular docking studies against Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein synthase A, (Kas-A) was carried out to understand the possible mode of its inhibition and potential of synthesized compounds as antitubercular agents. Antibacterial activity of compounds 5d (3-Cl) and 5f (2,4-diCl) were found good against E. coli, P. aeruginosa, S. aureus and S. pyogenes as compared to standard Ampicillin. Compound 5d was found active antitubercular agents against M. tuberculosis H37Rv.

N′-(3-Bromo-7-oxo-7H-benzo[de]anthracen-9-yl)-N,N-dimethylimidoformamide

We report a synthesis of 3-bromo-9-N′-(N,N-dimethylformamidino)benzanthrone in good yield by a condensation reaction of 3-bromo-9-aminobenzanthrone with dimethylformamide in the presence of phosphorous oxychloride. The structure of the synthesized amidine was characterized by FTIR-ATR, NMR experiments, and elemental analysis. The title compound was analyzed by UV-Vis and fluorescence spectroscopy in various organic solvents.

“UV-curing of novel tri-functional melamine-phosphate oligomer: An effect of coating with polyurethane acrylate toward mechanical, thermal, and flame retardant properties”

A novel melamine-phosphate tri-functional acrylate (MPTO) was successfully synthesized via cyclization reaction of hexamethylolmelamine (HMM) with phosphorous oxychloride (POCl3) followed by addition reaction of hydroxyethylmethacrylate (HEMA). The molecular structure of MPTO was identified by FTIR and 1H-NMR, 13C-NMR, and GC-MS spectra. The synthesized MPTO oligomer was impregnated with polyurethane acrylate to make various formulations and UV cured on wood and galvanized steel panels. The results of UV cured films from differential scanning calorimeter (DSC) and thermo-gravimetric analysis (TGA) exhibited increase in thermal stability and highest char yield of 18.4% at 800°C. The diffused diffraction peak appearing around 2ϴ = 16–22° corresponds to an amorphous structure which leads to irregular arrangement with formation of strong cross-linking polymer network. Furthermore, all coating films show prominent flame retardancy with UL-94 V-0 rating and maximum limiting index (LOI) values of 34.8%. The polyurethane acrylate (PU) coatings cured with MPTO that exhibited excellent mechanical properties were estimated using various tests such as adhesion, pencil hardness, solvent resistance, flexibility, and corrosion test. The coating performance revealed that MPTO can improve the mechanical, thermal, and flame retardant properties because of its unique structure identity of melamine-phosphate moiety and long aliphatic segment of an acrylate ester.

Synthesis, Characterization and Evaluation of Antidiabetic Activity of Novel Pyrazoline Fused Indole Derivatives

The primary purpose of this research work is to synthesize, characterize and biological evaluation of novel pyrazoline fused indole derivatives lead to creating a new molecular frame work.
 Methodology: In the present study, the new series of novel pyrazoline fused indole derivatives were synthesized from from indole and substituted acetophenone by the 4 step process. In the first step indole and dimethyl formamide were coupled by using phosphorous oxychloride and NaOH to prepare the compound 1 Indole-3-aldehyde. In the second step compound 1 was condensed with substituted aetophenone to synthesis the compound 2 chalcones (a-h). In the third step chalcones 2(a-h) were coupled with semicarbazide or thiosemicarbazide to synthesis the compound 3(a-p). In the final step compound 3(a-p) were coupled with indole-3-aldehyde to prepare the final product of R-substitutedN-((1H-indol-3-yl)methylene)-5-(1H-indol-3-yl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamide and R-substitutedN-((1H-indol-3-yl)methylene)-5-(1H-indol-3-yl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide 4(a-p).
 Results: The chemical structures of the synthesized compounds were characterized by means of IR, Mass and NMR spectroscopy. The compounds were screened for anti-diabetic activity by In-vitro and In-vivo methods. In In-vivo method 4a, 4m have exhibited moderate anti-diabetic activity as that of standard drug, glibenclamide. In In-vitro method 4a, 4e & 4m have shows moderate anti-diabetic activity as that of reference standard, acarbose.
 Conclusion: The synthesized novel pyrazoline fused indole derivatives have moderate antidiabetic activity as that of standard drug by In-vitro and In-vivo methods. These compounds can be further exploited to get the potent lead compound.

New Bioactive Fused Triazolothiadiazoles as Bcl-2-Targeted Anticancer Agents.

A series of 3-(6-substituted phenyl-[1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazol-3-yl)-1H-indoles (5a–l) were designed, synthesized and evaluated for anti-apoptotic Bcl-2-inhibitory activity. Synthesis of the target compounds was readily accomplished through a reaction of acyl hydrazide (1) with carbon disulfide in the presence of alcoholic potassium hydroxide to afford the corresponding intermediate potassium thiocarbamate salt (2), which underwent cyclization reaction in the presence of excess hydrazine hydrate to the corresponding triazole thiol (3). Further cyclisation reaction with substituted benzoyl chloride derivatives in the presence of phosphorous oxychloride afforded the final 6-phenyl-indol-3-yl [1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazole compounds (5a–l). The novel series showed selective sub-micromolar IC50 growth-inhibitory activity against Bcl-2-expressing human cancer cell lines. The most potent 6-(2,4-dimethoxyphenyl) substituted analogue (5k) showed selective IC50 values of 0.31–0.7 µM against Bcl-2-expressing cell lines without inhibiting the Bcl-2-negative cell line (Jurkat). ELISA binding affinity assay (interruption of Bcl-2-Bim interaction) showed potent binding affinity for (5k) with an IC50 value of 0.32 µM. Moreover, it fulfils drug likeness criteria as a promising drug candidate.

Synthesis and characterization of some New 2- and 6- substituted of 5- Acetyl - 4- (P- phenyl) Pyrimidine and substituted thieno [2, 3- d] Pyrimidine

The series of new pyrimidines derivatives 2- and 6- Substituted of 5 - Acetyl - 4 - (P- phenyl) Pyrimidine and Substituted thieno [2, 3- d] Pyrimidine are synthesis by the reaction between some substituted of benzaldehydes with ethyl aceto acetate in the present of ethanol as a solvent to give the products(3e-h), when react alkyl halide with (3e-h) in ethanol obtain new Pyrimidine derivatives(4e-h) heating them with phosphorous oxy chloride in dioxane to form (5e-h) which reacts with thiourea in ethanol to produce (6e-h) these compounds reacting with chloro acetic acid to form new Substituted thieno [2,3-d] Pyrimidine (8e-h). All the synthesized compounds of new pyrimidines derivatives are identified by the physical properties by it's melting points, colors and the yields are characterized by the elemental (CHN)analysis, IR, UV Spectrum.

Synthesis of 3‐cyano‐2‐pyridone derivative and its utility in the synthesis of some heterocyclic compounds with expecting antimicrobial activity

AbstractNew 2‐pyridone derivatives bearing p‐methoxyphenyl and p‐bromophenyl substituents at C‐4 and C‐6 were prepared smoothly by the one‐pot reaction in high yield, and in a comparatively short time, it reacted with phosphorous oxychloride to produce the corresponding chloro compound. The latter was reacted with several nitrogen nucleophiles such as sodium azide, hydrazine, acetohydrazide, and benzohydrazide to give tetrazolo, hydrazino, and triazolo derivatives, respectively. The reaction of hydrazino derivative with cyclopentanone, furan‐2‐carbaldehyde afforded the corresponding hydrazone derivatives. Cyclocondensation of the latter compounds with thioglycolic acid afforded the nicotinamide derivatives. 2‐Pyridone reacted with ethyl chloroacetate to afford chloroacetate and ethyl acetate derivatives. Ethyl acetate‐derivative reacted with hydrazine hydrate and gave the acetohydrazide derivative, it was condensed with p‐anisaldehyde and gave the 4‐methoxybenzylidene acetohydrazide derivative. Also, 2‐pyridone reacted with chloroacetic acid and or benzoyl chloride, afforded the benzoate derivative and 2‐((6‐(4‐bromophenyl)‐3‐cyano‐4‐(4‐methoxyphenyl) pyridin‐2‐yl) oxy) acetic acid, respectively. Structures of the products were confirmed using spectroscopic data and elemental analyses. Antibacterial activity of the synthesized compounds was evaluated against Escherichia coli and Staphylococcus aureus.

Benzoik Asit Temelli Yeni 1,3,4-Tiyadiazollerin Sentezi, Karakterizasyonu, ve Antioksidan Aktiviteleri

N-aryl-1,3,4-thiadiazole derivatives were obtained by cyclization reaction of benzoic acid and N-arylthiosemicarbazides in the presence of phosphorous oxychloride (POCl3). FT-IR, 1H-NMR, and 13C-NMR, spectroscopic methods, and elemental analysis were used to elucidate the identification of the synthesized molecules. The in vitro antioxidant activity of the synthesized molecules was analysed with the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical–trapping process. IC50 values of these molecules were measured from 25.17 to 43.55 𝜇M. Among the synthesized compounds, compound II had the best antioxidant activity. Moreover, this work explained the structure-activity relationship of the obtained molecules with different substituents in radical trapping reactions.