Chemical Methodologies
Volume:2 Issue: 4, Jul-Aug 2018

Synthesized DCU analogous such as benzoyl-N,N’-dicyclo hexyl urea, N,N’-dicyclohexyl-N-3,5-dinitro benzoyl urea and N,N’-dicyclohexyl-N-[(E)-3-phenylacryloyl]urea were found to possess free radical scavenging activity. Benzotriazepines comprise an interesting class heteroaromatic compounds because of their significant biological and pharmaceutical properties such as antibacterial, antiviral, psychotropic and antimalarial properties. In this paper, synthesis of 4-aryl-3-cyclohexyl-4,5-dihydro-1H-benzo[f][1,3,5] triazepin-2(3H)-one and N'',N''''''-1,2-phenylenebis N-cyclohexylurea is reported by condensation reaction of amines with cyclohexylisocyanate and aldehydes using iron (III) phosphate as catalyst under environmentally conditions. Melting points, IR spectra 1HNMR spectra were obtained. Analytical TLC of all reactions was performed on Merck precoated plates (silica gel 60 F-254 on aluminum). GC/Mass spectra were recorded on an Agilent 6890 GC Hp-5 capilary 30m × 530µm × 1.5 µm nominal operating at 70 eV.

In this study, we report an effective electrochemical sensor of single-walled carbon nanotubes (SWCNTs)/Nafion glassy carbon electrode (SWCNTs/Nafion/GCE) for determination of dicapthon in water and agricultural food samples. The electroanalytical performance of SWCNTs/Nafion/GCE toward the reduction of dicapthon was analyzed via cyclic and differential pulse voltammetry. The optimum parameters like the effect of pH, concentration of dicapthon solution, scan rate, accumulation potential and accumulation time were thoroughly optimized. At electrochemical optimum conditions, voltammetric reduction peak exhibited a linear with the concentration of dicapthon from 0.2‒60.0 μgmL−1, with a detection limit of 0.036 μgmL−1. The modified electrochemical sensor showed good stability and reproducibility. The determination of dicapthon was examined with SWCNTs/Nafion/GCE in water and agricultural food samples.

The fluorescence quenching of rhodamine 6G by hydroquinone in methanol, water and dimethylsulphoxide (DMSO) is explored. A combination of solvent parameter could be necessary to explain solvatochromism in rhodamine 6G as the consideration for solvent refractive index alone is insufficient. Stokes’ shifts ranged between 25 and 29 nm. Rhodamine 6G’s fluorescence was effectively quenched by hydroquinone within the quencher’s concentration (0.01 to 0.05 M) which was used in this work, and the quenching data were in conformity with the Stern-Volmer’s model. Stern-Volmer’s constants (KSV) were 47.1, 29.6 and 14.8 M-1 in methanol, water and DMSO respectively. These values, together with the calculated bimolecular rate constants (kD) in the respective solvents, were used in the semi-empirical estimation of the fluorescence lifetimes (tF) of rhodamine 6G in the individual solvents. The tF determined values (3.78, 3.89 and 4.36 ns in methanol, water and DMSO respectively) are comparable with literature values.

An accurate estimate of nutrient release pattern from controlled release fertilizer (CRF) is required both for manufactures as well for farmers because it helps them in understanding fertilizer potency and nutrient planning for the crops. Understanding the release pattern of different types of CRF under laboratory conditions as well as in the crop-field is essential in order to determine the fertilizer utilization efficiency on plant growth. The present work explains a simple experimental approach to understand the nutrient release from Neem coated urea (NCU). The coating of Urea with Neem oil (derived from seeds and leaves) inhibit the process of nitrification and reduce formation of nitrates which in-turn will reduce N2O emissions. It prevents the loss of urea in the soil. It also controls a large number of pests such as caterpillars, beetles, leafhoppers, borer, mites etc. Also Neem coating is biodegradable and so it is environment friendly as compared to many non biodegradable polymers used as coating materials in CRF.UV-Vis spectrometer is employed to determine the amount of nitrogen released. The approach reduced analytical error by preventing sample dilution before measuring. According to laboratory results obtained UV-Vis spectrometer proved to be a handy and efficient equipment for studying the nutrient release behavior from CRF. The release profile presents a sigmoidal shape which is in good agreement from the other works in the area reported in the literature. The experimental results obtained are also in tune with the criteria specified by European Committee for Standardization for CRF.

Measured densities and viscosities of xylene, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol and their binary mixtures with xylene in the liquid state were reported over the whole composition range at 298.15 K and atmospheric pressure. From the experimental data, excess molar volumes and deviations in viscosity were calculated and interpreted in terms of intermolecular interactions and structural effects. Statistical association fluid theory (SAFT) and perturbed chain statistical association fluid theory (PC-SAFT) were applied to correlate the densities of binary mixtures. These models can predict the density accurately but obtained values by the PC-SAFT are closely matched with the experimental data.

A new LC-MS based method was developed to detect three potential genotoxic impurities namely, N',N'''-(4,6-dichloropyrimidine-2,5-diyl)bis[N,N-dimethyl(imidoformamide)]} (Impurity-I), {N-(2-amino-4-chloro-6-{[(1S,2R)-2-(hydroxymethyl)cyclopent-3-en-1-yl]amino}pyrimidin-5-yl)formamide} (Impurity-II) and {(1R,5S)-5-[(2,5-diamino-6-chloropyrimidin-4-yl)amino]cyclopent-2-en-1-yl}methanol (Impurity-III), at low level in Abacavir sulfate, a nucleoside reverse transcriptase inhibitor. It utilizes Zorbax phenyl hexyl column (150 mm x 4.6 mm, 3.5 μm) with electrospray ionization in selected ion monitoring (SIM) mode for quantitation of these PGIs. The method is able to quantify Impurity-I at 0.74 ppm, Impurity-II and Impurity-III at 0.73 ppm with respect to 5.0 mg/mL of Abacavir sulfate. The method was found to be linear in the range of LOQ to 150% of Toxicological Threshold Concentration level of 2.5 ppm. The correlation coefficients of PGI’s obtained were >0.999 in each case. The method accuracy of these PGI’s is in the range between 88.7-115.0%. The method is sensitive, specific, linear, accurate, precise and meets the criteria of validation as per International Conference on Harmonization.the formula isnot displayed correctly!

The importance of door knockers persuades us to anticipate the atmospheric corrosion through Neural Network (NN) which is validated by data originated from literature. NNs are used in order to anticipate the effective parameter on bronze atmospheric corrosion including the ambient temperature, exposition time, relative humidity, PH, SO2 concentration as an air pollutant and also metal’s precipitations. As these factors are extremely complicated, exact mathematical language of the diverse metals corrosion are not comprehended. The results of this study showed that SO2 concentration as an air pollutant and time of exposition are the fundamental effects on corrosion weight loss of bronze.

A short and efficient protocol for the synthesis of novel α-aminophosphonate esters containing β-lactam moiety is described. Inexpensive and mild catalyst such as fumaric acid was used for the synthesis of α-aminophosphonate esters by reacting N-(4-methoxyphenyl)-2-(substituted) propiolactam-3-carbaldehyde with amine and triethylphosphite in acetonitrile at reflux. α-aminophosphonate esters containing β-lactam hybrids were obtained in good yield and purity.A short and efficient protocol for the synthesis of novel α-aminophosphonate esters containing β-lactam moiety is described. Inexpensive and mild catalyst such as fumaric acid was used for the synthesis of α-aminophosphonate esters by reacting N-(4-methoxyphenyl)-2-(substituted) propiolactam-3-carbaldehyde with amine and triethylphosphite in acetonitrile at reflux. α-aminophosphonate esters containing β-lactam hybrids were obtained in good yield and purity.