Abstract
A green and highly regioselective approach for the synthesis of poly‐substituted new pyridine derivatives via the Knoevenagel condensation followed by the Michael addition. The reaction ...involves intramolecular cyclization of easily obtainable reactants under environmentally and economically benign mortar pestle grinding technique. This method clearly proves that spatially hindered aldehydes also actively contribute to the construction of the desired pyridine derivatives with good yield (85%–96%) in about 30–40 min. This new avenue offers a number of benefits over earlier reaction approaches such as lengthy work‐up‐processes, operational difficulties and lower yields. This mortar pestle grinding technique is familiar for environmental and economical benign protocols. The druggability properties of synthesized compounds assessed using in silico studies.
A highly efficient and environmentally friendly method for the synthesis of 2‐amino‐4H‐chromene‐3‐carbonitrile (ACC) derivatives has been successfully established. This innovative, solvent‐free ...approach involves a tandem three‐component and one‐pot reaction utilizing arylaldehyde, dicyanomethane, and dimedone/cyclohexane‐1,3‐dione, catalyzed by 2‐aminopyrazine under the mortar‐pestle grinding technique. Key attributes of this synthetic strategy include its simplicity, high efficiency, cost‐effectiveness, absence of column chromatography, shorter reaction times (18–40 min), and consistently high yields (89%–96%). Furthermore, computational studies have been conducted against the 4RHT protein using the synthesized compounds.
Eco‐friendly morter‐pestle method for the construction of 2‐amino‐4H‐chromene‐3‐carbonitrile.
A new and operationally modest one-step C-C and C-O bond construction reaction is developed under sonochemical method. The reaction is achieved with easily accessible 8-hydroxy quinoline as starting ...material in the presence of sulfated tin oxide (SO
4
−2
/SnO
2
) catalyst. The ultrasonic irradiation with heterogeneous catalyst has been established to be a useful technique for the multicomponent synthesis of target compounds.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
An efficient and promising synthetic approach to assemble skeletons of multifunctionalized pyridine derivatives in presence of recyclable heterogeneous sulfated tin oxide (STO) catalyst has been ...evolved. The STO catalyst was used as a promoter for the cyclocondensation process in ethanol at 70°C. Overall performance of this catalyst was attributed to the cooperative contribution of its Lewis and Brønsted‐Lowry acidic sites. Nanosized STO catalyst was synthesized by using sol‐gel process and characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), 1H‐NMR, and scanning electron microscopy (SEM). This catalyst tolerates most of the substrates, and protocol shows precious capabilities consist of high yields, operational simplicity, less reaction time, and eco‐friendly conditions. The newly synthesized heterogeneous catalyst was easily separated and reused. All the reactions are carried out for subsequent cycles without significant loss of catalytic activity and with good proficiency.
Skeletal materials belonging to the defect pyrochlore family have been the subject of considerable interest due to their remarkable properties. In this work, a highly efficient, stable and visible ...light active composite photocatalytic system consisting of defect pyrochlore of composition KMn0·33Te1·67O6 (KMnTeO) and g-C3N4 (g-CN) has been successfully prepared by simple physical mixing of pre-prepared KMnTeO and g-CN components synthesized in solid state and thermal treatment of low-cost melamine, respectively. Structural, morphological and optical properties of as-prepared catalysts were deduced from powder X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), Raman, Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (FESEM-EDX), Transmission Electron Microscopy-High Resolution Transmission Electron Microscopy (TEM-HRTEM), Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS), X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence (PL) measurements. The lattice parameter “a” of parent KMnTeO was obtained from Rietveld refinement of its powder XRD pattern. The FT-IR and Raman spectra of KMnTeO gave characteristic bands belonging to the defect pyrochlore structure. The photocatalytic activities of KMnTeO and composite KMnTeO-g-CN were evaluated by the degradation of methylene blue (MB). Scavenger experiments were carried out to identify the reactive species responsible for the degradation of MB. Furthermore, the reusability and stability of the photocatalysts were explored. The probable photocatalytic mechanism for MB degradation over the composite KMnTeO-g-CN was surmised according to the scavenger experiments. The work provides a new approach for the development of novel defect pyrochlore based composite photocatalysts to treat industrial wastewater containing organic pollutants.
A novel and potential composite KMnTeO-g-CN photocatalyst was prepared by a simple mixing methodology. The optimized composite KMnTeO-g-CN shows enhanced photocatalytic MB degradation of 90.5% (in 30 min) as compared to parent KMnTeO (94.5% in 180 min) under visible light irradiation. Display omitted
•Novel composite KMnTeO-g-CN photocatalyst was prepared for the first time.•The interfacial intercation between KMnTeO and g-CN was revealed by HRTEM.•Composite KMnTeO-g-CN degraded MB faster than parent KMnTeO.•Hydroxyl radicals were the dominant active species in the MB degradation.
An efficient asymmetric synthetic route for the synthesis of anti-glaucoma agent, (15R)-latanoprost using Corey lactone diol as chiral substrate under Swern oxidation, allylic reduction and Wittig ...reaction conditions has been developed. In this method, reduction of keto and alkene functional groups has been achieved in a single step using low cost catalyst NiCl
2
/NaBH
4
in methanol. This new synthetic protocol is a good alternative for the synthesis of latanoprost with high stereo selectivity and improved yield.
Graphical Abstract
A simple, convenient and convergent approach for the synthesis of (15R) latanoprost is reported with high stereo selectivity and improved yield from chiral precursor Corey lactone diol using Swern oxidation, allylic reduction and Wittig reaction conditions.
A fast, reliable and sensitive high-performance liquid chromatographic / tandem mass spectrometric assay (LC-MS/MS) was developed to quantify fulvestrant in human plasma using fulvestrant-D3 as an ...internal standard (IS). The analyte was extracted from human plasma by liquid-liquid extraction (LLE) using methyl tertiary butyl ether (MTBE) as an extracting solvent. Chromatographic separation was achieved in a run time of less than 3.0 min on chromolith RP-18e, (100 × 4.6 mm, Ea) column. Analytes quantitation was performed by turbo-ion spray tandem mass spectrometry (TIS-MS/MS). The method involves simple isocratic chromatographic conditions at a flow rate of 1.0 mLmin-1 with approximately 50% flow splitting. Mobile phase was a mixture of 0.5% acetic acid and acetonitrile (20:80, v/v, respectively). Detection by mass spectrometry was achieved in the MRM mode by monitoring the transition pairs of m/z 605.2 to m/z 427.4 ion for fulvestrant and m/z 608.6 to m/z 430.4 for the IS, using the M - H¯ ions for the IS. A fully validated LC-MS/MS method was developed as per ICH guidelines. The developed liquid-liquid extraction (LLE), (LC-MS/MS) assay method demonstrated sufficient ability to track the concentrations of fulvestrant in human plasma at a level of accuracy and sensitivity suitable for pharmacokinetic studies. Calibration plots were linear (r2>0.99) over the concentration range of 0.100 to 25.0 ng. mL-1 for fulvestrant. The overall recovery was 79.29%. Precision expressed as %RSD was ≤ 3.1% and ≤ 2.97 % for intra-day and inter-day data respectively.
A rapid stability‐indicating reversed phase‐ultrapure liquid chromatography (RP‐UPLC) was developed and validated for the estimation of metformin (MET), linagliptin (LIN), and empagliflozin (EMP) ...combination in bulk and tablet dosage form using Kromasil C18 column (2.1 × 50 mm, 1.8 μm) as a stationary phase and a mixture solution of 40% phosphate buffer (pH = 3) and 60% acetonitrile as mobile phase at a flow rate of 0.6 mL/min. The detection was performed at 248 nm using a photodiode array detector. The linearity, sensitivity, selectivity, robustness, specificity, precision, and accuracy were determined. The peak area response–concentration curve was rectilinear over the range of 50–150 (MET), 5–15 (LIN), and 10–30 μg/mL (EMP) with quantitation limits of 0.042 (MET), 0.023 (LIN), and 0.059 μg/mL (EMP). The proposed method was successfully validated for the determination of MET, LIN, and EMP simultaneously in combined tablet dosage form. The performance of the proposed method was compared with reported RP‐UPLC methods and found to be rapid and economical. The developed and validated stability‐indicating RP‐UPLC method was appropriate for the quality control and drug analysis.
A reversed‐phase high‐performance liquid chromatography (RP‐HPLC) method was developed and validated for the identification and quantification of moxifloxacin hydrochloride–related substances in ...finished dosage forms. Chromatographic separation was achieved on an Agilent C18 column (150 × 4.6 mm, 5 μm) with the mobile phase (0.01 M potassium dihydrogen orthophosphate as buffer and methanol in the ratio of 70:30) eluted in isocratic mode. The HPLC flow rate was 1.0 mL min−1, and peaks were monitored at 230 nm using a photodiode array (PDA) detector. The column temperature was kept constant at 30°C, and the injection volume was 10 μL. The run time of the method was 16 min. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Linearity was recorded at various concentrations ranging from 0.25 to 1.5 μg mL−1 for all the moxifloxacin impurities. Linearity, regression value, recovery, %relative standard deviation (RSD) of method precision values were found within the acceptance limits. The method for related substances (RS) in moxifloxacin was found to be specific, linear, accurate, precise, rugged, and robust. The validated method was suitable for the quantification of the RSs in moxifloxacin drug products. The method was applied in quality control lab for the analysis of moxifloxacin impurities in stability analysis.
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