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Background and purpose: 1,2 diarylethylene or stilbenes are hydrocarbon derivatives with two phenyl group bonded to the double bond carbons. There are two isomers of stilbenes that Z-isomer is less stable than E-isomer. However, the Z-isomer is stronger than E-isomer as potent cyclooxygenase-2 (COX-2) inhibitor. E and Z isomers are interconverted through photochemical irradiation. In this research, Z-isomer was converted to E-isomer by irradiation in photoreactor that could be used as COX-2 inhibitor. Materials and methods: The reaction of p-bromothiophenol with dimethyl lsulfate in an aqueous sodium hydroxide solution produced p-bromothioanisole. Mentioned product was reacted with 4-x-styrene via Heck olefination. The olefination was performed with Bu4N+Cl-, LiOAc and LiCl in the presence of Pd (II) as a catalyst in DMF. E-1,2 diarylethylene derivatives were irradiated in photo-reactor and their photochemical products were isolated after irradiating by column chromatography. Results: 1,2–diarylstilbene derivatives were produced and their chemical structure were evaluated by 1H-NMR and IR spectroscopy. UV-vis absorption spectra were measured for all compounds before and after radiation. The photochemical product was isolated and identified Conclusion: E–diarylestilbenes were produced in the presence of Pd (II) and converted to more important Z-isomer by irradiation in photo-reactor

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Background and purpose: Increasing resistance of microbes to antimicrobial drugs necessitates the production of new compounds of more extensive activity together with low toxicity. Compounds containing quinoxaline and pyrazole cycles comprise important group of nitrogen-bearing heterocyclic compounds. These scaffolds possess a wide spectrum of biological effects including antimicrobial and anticancer effects.
Materials and methods: Three steps procedure were designed to prepare the title compound. 3-(glycerol-1-yl)-1-phenyl flavazole was prepared by adding D-glucose, and ortho-phenylenediamine to phenylhydrazine in presence of acetic acid. Then, the desired aldehyde was obtained by adding sodium periodate to the solution. Finally, adding 4-aminoantipyrine gave the target product.
Results: The considered imine compound was synthesized and its structure was confirmed using NMR, IR, and GC- Mass spectroscopy techniques.
Conclusion: In this study, (1-H) pyrazolo [4, 5-b] quinoxaline was prepared using inexpensive and widely available materials. In present research, not only the reaction performance was improved, but also some time and resource savings along with enhanced efficiency were achieved. The method proposed is an efficient, simple, and fast method to synthesize the aforementioned compound with antibacterial potential.