Polyaniline/SiO2 Catalyzed One-pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives

Polyaniline/SiO2 is an efficient catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives from a one-pot, three component, condensation of aldehydes, malononitrile and dimedone at room temperature. This protocol has several advantages such as high yield, a simple work up procedure, low toxicity and easy recovery and reusability of the catalytic material. The catalyst has been readily prepared and characterized by means of thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR).Keywords: Chemical Oxidative Method, Polyaniline/SiO2, Tetrahydrobenzo[b]pyra

El mito de la abundancia: bases para pensar el extractivismo-minero "desde" América Latina

The epistemological bases of the different types of extractivism, especially the mining one, are tracked from the invention of America as a space of looting and extension of Europe, on which the ultimate purpose of domination/conquest was to subordinate and to expropriate the subjectivity and the materiality of the peoples in Abya Yala. The American nature was the depiction on which the myth of abundance was created, which currently remains intact, as a configurator and an organizer of the deep ecological inequality in the modern/colonial world system of nature.Las bases epistemológicas de los diversos extractivismos, en especial el minero, son rastreadas desde la invención de América como espacio de saqueo y extensión de Europa, sobre el cual la dominación/conquista tuvo como final ultimo inferiorizar y expropiar la subjetividad y la materialidad de los pueblos en Abya Yala. La naturaleza americana fue la representación sobre la cual fue creado el mitode la abundancia que permanece en la actualidad de forma intacta, como configurador y ordenador de la profunda desigualdad ecológica en el sistema-mundo moderno/colonial de la naturaleza

Endothermic solvent extraction of copper (II) with furfuryl thioalcohol from sulfate medium

A simple solvent extraction method was developed to extract copper (II) from sulfate solution. The extraction of copper (II) with furfuryl thioalcohol was investigated. The effect of variables such as aqueous phase pH, furfuryl thioalcohol concentration, temperature, stripping reagents, and diluents was investigated. The extraction data revealed that using 15% (v/v) furfuryl thioalcohol with aqueous solution containing 0.5 mol L-1 Na2SO4, equilibrium pH 5.5, and phase ratio organic phase: aqueous phase (O:A) of 1:1 resulted in 98.20 percent extraction of copper (II) without nickel coextraction (II). Extraction isotherm results show that the extraction procedure is endothermic, with ΔH = 28.542 kJ mol-1 and ΔS = 41.740 J K-1 mol-1. Using 2.0 M H2SO4, copper loaded in organic phase was stripped at a rate greater than 99 percent

Modification, Characterization, and Catalytic Application of Mesolite for One Pot Synthesis of 3-Methyl-4-arylmethylene-isoxazol-5(4H)-ones

Natural mesolite type zeolite was collected, modified by sulphuric acid treatment and characterized by using Powder-X ray diffraction, Scanning electron microscopy and Energy dispersive spectroscopy, Fourier transform infrared spectroscopy. Temperature programmed ammonia desorption, Brunauer-Emmer-Teller surface area analysis. Modified dealuminated mesolite shows an efficient catalytic activity for one pot synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones derivatives, via one pot three component condensation of benzaldehyde, ethylacetoacetate and hydroxylamine hydrochloride. Present method offers several advantages over the reported methods like a simple and inexpensive modification of catalyst, mild reaction condition, easy separation of catalyst, simple work-up procedure, nonchromatographic isolation and purification desired product and excellent yield. Furthermore, catalyst could be reused without significant loose in activity. Copyright © 2017 BCREC GROUP. All rights reservedReceived: 25th August 2016; Revised: 10th October 2016; Accepted: 17th October 2016How to Cite: Pawar, G.T., Gadekar, S.P., Arbad, B.R., Lande, M.K. (2017). Modification, Characterization, and Catalytic Application of Mesolite for One Pot Synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1): 32-40 (doi:10.9767/bcrec.12.1.655.32-40)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.655.32-40

Experimental investigations of the effect of oil based mud (OBM) contamination on long-term integrity of API cements

Well construction, well abandonment, and restoration of well integrity are the reasons at a broad level why cementing jobs are performed. During the well construction phase, the primary objective of the cementing job is to replace the drilling mud in the annulus with pure cement. Intermixing of the drilling mud and the cement slurry produces an unpumpable mixture, especially in the case of Oil-Based Mud (OBM). The displacement efficiency of spacers and pre-flushes used to displace the drilling mud is never 100%, thus cement slurries are contaminated with drilling mud. Recently, several research groups have performed studies to understand the strength development phenomenon of OBM contaminated cement slurries. A detailed review of these studies illustrates several shortcomings like variations in sample preparation, focus on the high amount of OBM contamination, lack of documentation of experimental procedures, focus on early curing time, and so on. The primary aim of this study was to develop a standard laboratory experimental procedure for understanding the strength development of OBM contaminated cement slurries and develop a reliable dataset for future references. The study focused on the effect of low OBM contaminations ranging from 0.8% to 6.3% (by volume) on API Class C & H cement samples cured from a minimum of 4 hours to a maximum of 1 year at room temperature (25℃) and elevated temperature of 75℃. Destructive tests to measure the uniaxial compressive strength (UCS) and non-destructive tests to measure the ultrasonic pulse velocity (UPV) were performed on 362 contaminated as well as neat cement samples. Results obtained from these tests showed a detrimental effect on the strength of cement samples even with such low OBM contaminations. Correlations for predicting the long-term strength of OBM contaminated cement slurries were developed using the test results. These correlations developed would help the operators in better estimation of the strength developed by the OBM contaminated cement slurries. In other words, a more accurate prediction of cement wellbore integrity

Preparation of Mg-doped Ce-Zr Solid Catalysts and Their Catalytic Potency for the Synthesis of 5-Arylidene-2,4-Thiazolidinediones via Knoevenagel Condensation

A series of Mg-doped Ce-Zr mixed oxides with different molar ratios were prepared by a simple co-precipitation method. The surface characterization of these materials were investigated by means of XRD, FT-IR, SEM-EDS, CO2-TPD and BET techniques. The catalytic activity of the prepared materials was tested by synthesizing of 5-arylidene-2,4-thiazolidinedione derivatives via a Knoevenagel condensation using aromatic aldehydes and 2,4-thiazolidinedione in ethanol:water medium. The best catalytic activity was obtained with Ce1Mg0.6Zr0.4O2. The particle size or crystallite size was estimated using the Debye-Scherrer equation. Addition of MgO to the Ce-Zr mixed metal oxides affected both particle size and catalytic activity.Keywords: Mg-doped Ce-Zr oxide, surface characterization, co-precipitation, 5-arylidene-2,4-thiazolidinedion

Thermodynamics of Complex Formation Stabilities of Complexes of Copper(II) with Dipeptides in Aqueous Media

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