Asian Journal of Green Chemistry

Abstract Mechanism of decarboxylation reaction includes, metal catalyst with Ag⁺, a radical path and oxidative decarboxylation have been investigated. The calculations have been done in two different B3LYP/LANL2DZ, and WB97XD/DGDZVP/ DEF2DTZV levels. Four structures have been proposed for oxidized benzoic acid. Among four possible oxidative structures only one structure with 62.99 kcal.mol^-1 activation energy could lead to the decarboxylative product. Silver catalyzed decarboxylation leads to products in one step. The activation energy for this path have been determined to be 43.31 kcal.mol^­-1. The radical path for decarboxylation needs 16.93 kcal.mol^-1 although for radical creation it needs at least 100.12 kcal.mol^-1 energy.

Abstract In this research study, a nano-CuO-CeO₂ catalyzed environmentally benign strategy for the preparation of bis(indolyl)methane derivatives via the three-component reaction between indoles and aldehyde in aqueous media under reflux conditions in excellent yields was established. The structure of the prepared compounds was confirmed using IR, ¹H-NMR. The elemental analysis and morphology of the catalyst was characterized using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results revealed that this synthetic reaction is very simple and bis(indolyl)methane derivatives produced with good yields compared to other articles. The advantages of this method include catalyst recovery, high efficiency, and easy operation method. The highest efficiency (96%) in a short time (15 min) was obtained, which is very important compared to other previous methods presented.

Abstract In this work, we utilized various iron salts {Fe(NO₃)₃, FeSO₄ and FeCl₃} at the presence of aqueous solutions of NiCl₂ and NaOH, respectively, to prepare NiFe₂O₄/NaCl nanocomposites using wet chemical co-precipitation. The dark-brown products were afterwards calcined for 3 h at 600 °C. All products were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD results confirmed formation of the NiFe₂O₄/NaCl nanocomposites. The TEM results revealed that the particles are relatively similar in cube-like shape; however, the size was distinct.

Abstract Vegetable oils such as linseed oil (LO), castor oil (CO), olive oil (OLO), soybean oil (SBO) and sunflower oil (SFO) were epoxidized and characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analysis. Reaction of epoxidized linseed oil with 2-ethylhexanol, dodecanol, n-octanol, 1-decanol and isodecanol in the presence of a catalytic amount of sulfuric acid provided ring-opened products. These ring–opened products of linseed oil exhibited better low temperature flow i.e. better pour point (PP) and high viscosity index (VI). Ring opened products with isodecanol and 2 ethyl hexanol showed better result compared to others. CO, OLO, SBO, SFO epoxide rings were also opened through the same procedure using isodecanol and the products exhibited high viscosity index and excellent low temperature flow as well. Ring opened products displayed better thermal stability when passed through thermogravimetric analysis (TGA) compared to mineral base oil. Better pour point, high viscosity index value, thermos-oxidative stability and better antiwear (AW) property make these products as an environmentally benign alternative to mineral lubricating oil.

Abstract Dihydropyridine derivatives have been identified as calcium channel blockers and are predominantly utilized in cosmetics and pharmaceuticals. These compounds are often used as intermediates for producing biologically active products, including drugs, herbicides, insecticides, and fungicides. The applications of pyridines and their benzo derivatives have been described over the past decade along with natural products containing the pyridine ring system. These applications are classified into three categories: biological, chemical and functional. Functional applications based on the physical properties of pyridines and their benzo-derived compounds describe colors, flavors, and ionic liquids. Chemical applications, based on the chemical properties of pyridines and benzo derivatives, describe reagents in analytical chemistry as well as catalysts and reagents in organic synthesis. Biological applications based on the environmental activity of pyridine compounds in pharmaceutical, agrochemical and veterinary products have been presented in this study. In this research study, the synthesis of 1,4-Dihydropyridine derivatives was investigated through a three-component one-pot reaction using nano-cerium oxide catalyst.

Abstract In this research, zirconium fixed on the Arabic Gum (ZrCl₄@Arabi Gum) was used as a heterogeneous and recyclable Lewis acid catalyst for the one-pot synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives from the reaction of 2-naphthol, and various aldehydes under solvent-free conditions and at 70 ᵒC. The present method has many advantages such as catalyst reusability, high yields, non-toxic, easy of operation, short reaction time, environmentally friendly and high efficiency.

Abstract In this work, a highly accurate and sensitive method with low cost analyzer NAG/ADF/(300-2) homemade instrument coupled under continuous flow injection (CFIA) analysis was used to determine  promethazine hydrochloride in pure and pharmaceutical drug tablets. This method is dependent on the reaction between promethazine hydrochloride and phosphomolybdic acid (PMA) in the presence of ammonium chloride to form a brownish-yellowish ion-pair complex as precipitate. The turbidity of the formed complex has measured at an angle of 0-180° through the attenuation of incident light by precipitating. The chemical and physical parameters have been studied and optimized to enhance the sensitivity for the developed method of the promethazine hydrochloride-PMA-NH₄Cl system. The calibration curve of the proposed method was linear over the range 0.5-30 mmole.L^-1 for both cells (Cell no.1 and Cell no.2), the detection limit for cell A = 2.1659 µg/sample and for cell B = 0.4332 µg/sample from the visual evaluation of the lowest concentration at which the analyte can be reliably detected with the correlation coefficient (r) = 0.9984, 0.9997 for cell A and cell B, respectively. For promethazine-HCl concentrations (5 and 10 mmole.L^-1) for both cells (n=8), the relative standard deviation percent (RSD%) was lower than 0.5%. The method has been successfully applied for the promethazine HCl determination in two pharmaceutical medicines. A comparison was made using the standard addition curve between the newly proposed method (NAG-ADF-300-2 analyzer) and the reference methods, mainly British Pharmacopoeia (B.P), turbidimetry, and UV- spectrophotometry (λ_max =249 nm) using paired t-test. It was noticed that there was no significant difference between the methods at 95% confidence level. The statistical procedures have shown that a homemade NAG/ADF/(300-2) analyzer which contains two identical detections units ( cell A and cell B) is the best choice with an excellent prolonged detection, widespread application and extra sensitive.

Abstract In this research study we synthesized new tetrazoline from a reaction of 2-N-arylidene amino creatinine with sodium azide and 2-N-azido acetamido creatinine. The prepared compound was characterized using the FT-IR, and ¹H NMR. All the physical properties and studied biological activity of synthesized compounds. The compounds 8b and 13c were given more active against gram positive, gram negative bacteria and fungi.