Chemical Methodologies
Volume:5 Issue: 4, Jul-Aug 2021

In this research, several heterocyclic rings (triazole, thiadiazol, thiazol) containing imidazo (1,2-a) pyrimidine moiety have been prepared via a series of reactions. To do this, synthesis of 2-substituted imidazo (1,2-a) pyrimidine was performed by condensation of 2-aminopyrimidine with (4-bromo phenacyl bromide) or (4-phenyl phenacyl bromide). Carbaldehyde group was prepared at position-3 of 2-substituted imidazo/pyrimidine rings by Vilsmeier-Haak reaction. Thiosemicarbazon derivatives (Schiff bases) were synthesized by condensation of 3-carbaldehyde derivatives with thiosemicarbazide. Cyclization of thiosemicarbazone derivatives with Ac2O, 4-bromophenacyl bromide and HCl afforded the corresponding thiadiazole(diacetyl) derivatives, 1,3-thiazole derivatives and 1,2,4-triazole derivatives respectively. Structures of the new derivatives were confirmed via FT-IR spectroscopy, some of which were confirmed via 1H-NMR spectroscopy. Three of these new derivatives were evaluated by their anti-corrosion activity.

There are many reports about the use of medicinal plants in traditional medicine, as well as the application of metal nanoparticles in various biomedical fields. The purpose of the present study is bio synthesize of silver nanoparticles, using the aqueous extract of Alisma Plantago-Aquatica L plant and to achieve optimal conditions for the synthesis of these nanoparticles. For this reason, the effect of different parameters such as pH, extract volume, concentration of silver nitrate solution, temperature and reaction time were studied and their optimal amount was determined. Then, the nanoparticles synthesized in optimum conditions, were evaluated (UV-Vis), X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscope (TEM) and Fourier-Transform Infrared spectroscopy (FTIR). Strong and width peak of the visible UV spectrophotometer, at 438 nm wavelength, showed the formation of silver nanoparticles. The X-ray diffraction pattern confirmed the formation of crystalline silver nanoparticles at a size of about 25 nm. The results of FESEM showed nanoparticle shape in a spherical and monodisperse, with a particle size range of 20 to 58 nm. The TEM analysis also yielded a nanoparticle size of about 20 nm. The results of the Fourier transform infrared spectroscopy (FTIR), indicate the involvement of hydroxyl, amine and carboxyl groups in the plant extract in the synthesis of silver nanoparticles. The results of this study showed that the"Alisma Plantago-Aquatica L." plant extract can be introduced as an appropriate, affordable and safe alternate in terms of green chemistry, instead of toxic and high-risk chemicals.

Natural gas must be dehydratedbefore being sent to the distribution network to control corrosion and prevent the formation of solid hydrates. Membrane technology is a viable alternative to conventional glycol absorbents and adsorbent solids. This study was performed to evaluate the dehydration of crude natural gas by membrane separation process. Various operating conditions such as the effect of silica nanoparticles, pressure and sweeping gas on the removal of water vapor dissolved in natural gas were investigated using PES membrane and its nanocomposite. PES membranes and their nanocomposites with silica was made by solution mixing method in solvent dimethyl formamide. The properties of silica nanoparticles and fabricated nanocomposite membranes were evaluated by Fourier transfer spectroscopy and scanning electron microscopy. The dehydration rate was from natural gas in the pressure range of 2 to 10 bar and temperature of 30 °C in the presence of nitrogen sweeping gas. The addition of silica nanoparticles to the PolyetherSulfonemembrane significantly reduced the moisture content of natural gas. Also, with increasing feed pressure, the amount of water permeation from the membrane improved. The use of nitrogen sweeping gas reduced the amount of water in natural gas in pure Polyether Sulfone membranes by more than 80% and in nanocomposite membranes by more than 100%.

This work aimed to develop and validate a simple, accurate, precise, and reproducible spectroscopic method for simultaneous estimation of rosuvastatin calcium and teneligliptin hydrobromide hydrate by UV-Visible first-order derivative method. According to our present knowledge, no UV method was reported for combination of rosuvastatin and teneligliptin. So, in this work, it was decided to performed the first-order derivative method and it was validated as per ICH(Q2 R1) guideline. Rosuvastatin calcium and teneligliptin hydrobromide hydrate showed absorbance at the working wavelength of 230.03 nm (Zero crossing point of rosuvastatin calcium) and 222.66 nm (Zero crossing point of rosuvastatin calcium), respectively, using methanol as diluent. Linearity was found over the concentration range of 1-42 µg/ml for both drugs and correlation coefficients was 0.9995 and 0.9994, respectively. Accuracy was found between 98.91%-101.13% and 99.38%-100.25% for rosuvastatin calcium and teneligliptin hydrobromide hydrate, respectively. LOD was found to be 0.213µg/ml and 0.120 µg/ml for rosuvastatin calcium and teneligliptin hydrobromide hydrate respectively. LOQ was found to be 0.646 µg/ml and 0.3648 µg/ml for rosuvastatin calcium and teneligliptin hydrobromide hydrate, respectively. The result revealed that the developed method is suitable for analysis of determining rosuvastatin calcium and teneligliptin hydrobromide hydrate in a binery mixture.

In this research, the removal efficiency of an Acid Brown-14 as azo dye was carried out by an adsorbing method using a magnetic-activated carbon adsorbent, through which separation of adsorbent could be performed by a magnet at the end of the process. A second-order reduced polynomial model is used for method and optimization. Based on the model foresight, the process can remove the dye up to 82 % under the optimum situations of the primary pH = 4.6, [Dye] = 20 ppm, and [Ads.] = 791 ppm at room temperature. An experimentally accurate assessment of the model revealed that the model has a good agreement with the model prediction.

In the current study, new derivatives were synthesized by reaction of N-hydroxyphthalimide with chloro acetyl chloride in the presence of Et3N as a base to form 1,3-dioxoisoindolin-2-yl 2-chloroacetate (B1), which in turn enters several reactions with different amines where it interacts with primary amines to give 1,3-dioxoisoindolin-2-yl acetate derivatives (B2-B4) in basic medium, in the same way it interacts with these amines but with adding KNCS to form thiourea derivatives (B5-B7). It also reacts with diamines to give bis(azanediyl) derivatives (compounds B8-B10). The prepared derivatives were diagnosed using infrared FTIR and 1HNMR,13CNMR for some derivatives. Compounds B4, B5 and B9 were measured as corrosion inhibitors the inhibition efficiency varied from 85% to 99% and thermodynamic functions, i.e. Gibbs free energy, activation energy, enthalpy, entropy, were calculated for the derivatives at a concentration of (50 ppm) when mixed with carbon steel as additives and exposing the plate to an acidic medium of hydrochloric acid at a concentration of (1M) in different temperatures. The results revealed that as the temperature increases, the inhibition efficiency decreases.

The short, easy and total synthesis of Murrayanine (1),  Mukonine (2), carbazole alkaloids were elaborated, based on a regioselective buchwald coupling of methyl 4-bromo-3-methoxybenzoate  with aniline and successive transformation into the corrsponding carbazole alkaloids by  oxidative coupling followed by cyclization of the phenyl and aryl rings.

This study dealt with the problem of produced water (PW) at Missan Oil Company (MOC) which results in huge quantities of water annually from different fields of the company and particularly in Alommara oil field .The produced water is discarded to the evaporation ponds outside the field which causes serious problem to the environment. We studied that problem and how to treat the produced water generated from Alammara Degassing Station for reinjection application to increase the secondary oil recovery. A pilot plant (10m3/day) for PW treatment was manufactured based on some bench scale treatment to select the sequence process to treat the targets parameters. Many parameters were selected to be treated based on its effect on water injection specifications .The selected  parameters were  Oil and Grease , Iron ,Turbidity ,TSS, Particle Size , Dissolved Oxygen , PH and Bacteria. Removing oil by using corrugated plate interceptor technique (CPI) is the first stage of treatment. In some circumstances, the presence of iron in the produced water needs a treatment to meet the reinjected specifications of water. A chemical oxidant (Sodium Hypochlorite) was used in the pilot plant to oxidize the iron and removed later. The total suspended solids (TSS) are decreased to the required concentration by using coagulation – Flocculation process and dual sand filter media .The other target parameters to be treated in the pilot plant are bacteria and dissolved oxygen. Chemical agents, Gluteraldehyde and Sodium Sulfite were used to treat bacteria and dissolved oxygen respectively. Caustic Soda solution was used to obtain a suitable PH value. The specifications of treated water by this piot plant were very proper for safely reinjection to increase the recovery of oil.

In this study, silver nanoparticles (AgNPs) were synthesized by using Malva sylvestris flower extract. Different parameters such as, pH, extract volume, silver nitrate concentration, temperature and reaction time were controlled correctly and the effect of them on the synthesis of nanoparticles were investigated. Some of techniques like, UV-Vis, FTIR, SEM, TEM, and XRD were used to analyze the characteristics of AgNPs. According to our results, the shape and size of nanoparticles were spherical and about 20 - 30 nm range, respectively. In addition, the surface plasmon resonance (SPR) of nanoparticles occurred in 445 nm. The effect of catalytic activity AgNPs synthesized on the reaction Sodium Borohydride (NaBH4) with Methylene Blue (MB) and its antibacterial activity on (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Salmonellatyphy murium) as a references bacteria have been studied. Also, the effect of Malva sylvestris flower extract on them was measured and analyzed precisely. The results showed ability of catalytic activity on the reduction of MB. Further, synthesized nanoparticles have significant ability antibacterial activity against gram negative bacteria (Escherichia coli and salmonella typhy murium).