One Pot Synthesis Of (+−)/(S)-Atenolol And(+−)/(S)Propranolol By Employing Polymer Supported Reagent

Abstract

(+^?)/(S)-Atenolol and((+^?)/(S)- propranolol were synthesized by using reaction of((+^?)/(S) -epichlorohydrin with polymer supported phenoxide anion followed by reaction with isopropylamine.     

Lipase Ps-C Catalysed Hydrolysis Of Aryl Deesters: A New Route To The Synthesis Of Achiral Half Esters

Pseudomonas cepacia lipase supported on ceramic particles (PS-C) offers a simple alternative route for the synthesis of achiral half esters, with very high yields, easy work up and remarkable substrate selectivity, as it cleaves only phenolic esters having a phenyl group (i.e. C₆H₅-O-CO-C₆H₅).     

Studies on Silver Accumulation and Nanoparticle Synthesis By <Emphasis Type="Italic">Cochliobolus lunatus</Emphasis>

Development of reliable and eco-friendly processes for synthesis of metallic nanoparticles is an important step in the field of application of nanotechnology. Biological systems provide a useful option to achieve this objective. In this study, potent fungal strain was selectively isolated from soil samples on silver supplemented medium, followed by silver tolerance (100–1,000 ppm) test. The isolated fungus was subjected to morphological, 18S rRNA gene sequencing and phylogenic studies and confirmed as Cochliobolus lunatus. The silver accumulation and nanoparticle formation potential of wet cell mass of C. lunatus was investigated. The accumulation and nanoparticle formation by wet fungal cell mass with respect to pH change was also studied. The desorbing assay was used to recover accumulated silver from cell mass. C. lunatus was found to produce optimum biomass (0.94 g%) at 635 ppm of silver. Atomic absorption spectroscopy study showed that at optimum pH (6.5 ± 0.2), cell mass accumulates 55.6% of 100 ppm silver. SEM and FTIR studies revealed that the cell wall of C. lunatus is the site of silver sorption, and certain organic groups such as carbonyl, carboxyl, and secondary amines in the fungal cell wall have an important role in biosorption of silver in nanoform. XRD determined the FCC crystalline nature of silver nanoparticles. TEM analysis established the shape of the silver nanoparticles to be spherical with the presence of very small-sized nanoparticles. Average size of silver nanoparticles (14 nm) was confirmed by particle sizing system. This study reports the synthesis and accumulation of silver nanoparticles through reduction of Ag⁺ ions by the wet cell mass of fungus C. lunatus.     

Studies on Amendment of Different Biopolymers in Sandy Loam and Their Effect on Germination,Seedling Growth of <Emphasis Type="Italic">Gossypium herbaceum</Emphasis> L.

Different biopolymers, agar, cellulose, alginate, psyllium gaur gum, and bacterial exopolysaccharide (EPS) powders were amended to check their efficacy in enhancing maximum water holding capacity (MWHC), permanent wilting point (PWP), and germination and seedling growth of the Gossypium herbaceum in a laboratory scale. The efficacy of all biopolymers for enhancement of MWHC, PWP, and growth was also analyzed by measuring organic carbon, organic matter, total nitrogen, respiration rate, and microflora in amended and control sandy loams. The range of concentrations (0.2–2%) of all biopolymers was incorporated in sandy loam containing pots. The soil without polymer was considered as control. The psyllium (0.6%) and bacterial EPS (1%) amended soil has 242 and 233% increase in MWHC and thus delaying in the permanent wilting point by 108 and 84 h at 37 °C, respectively, as compared to control. All biopolymers found to increase more or less MWHC, organic matter, total nitrogen, microflora, and PWP as compared to control. The psyllium and bacterial EPS show the highest increase organic matter, biomass, and microflora. The highest reduction in MWHC after 12 weeks were observed in cellulose, gaur gum, and alginate; besides, psyllium, bacterial EPS, and agar showed comparatively less reduction MWHC, i.e., 24% and 14.5%, respectively. The toxicity studies of biopolymer were carried out on earthworm (Eisenia foetida). It revealed their nontoxic nature. The biopolymer amendment in sandy loam can be an effective strategy to improved soil texture, fertility, and thereby crop yield.     

Direct Growth of Cobalt Hydroxide Rods on Nickel Foam and Its Application for Energy Storage

The present work reports synthesis of cobalt hydroxide (Co(OH)₂) rods on nickel foam and its supercapacitor application. Hierarchical Co(OH)₂ rods with length of approximately 3.5 μm and diameter of approximately 400 nm were prepared by one‐step, simple, and inexpensive chemical‐bath‐deposition method. The direct growth of Co(OH)₂ rods on the Ni foam gave three dimensional (3D) structure for easy access of electrolyte throughout material surface. Also, well‐adhered interface between Co(OH)₂ rods and Ni‐foam surface gave better conduction channels. Detailed electrochemical study was performed by using cyclic voltammetry and galvanostatic charge/discharge measurements. The results demonstrate that Co(OH)₂ rods on Ni foam are efficient electrodes for supercapacitor application.     

Processable heat resistant polyamides containing tetraphenyl thiophene having pendant phenyl moiety with heterocyclic quinoxaline unit: Synthesis and characterization

A series of new polyamides containing tetraphenyl thiophene having pendant phenyl moiety with heterocyclic quinoxaline unit were synthesized by using the solution polycondensation method of novel diamine monomer V with isopthaloyl chloride (IPC) and terpthaloyl chloride (TPC) in various mole proportions. These novel polymers were characterized by FT-IR, solubility, inherent viscosity, thermal analysis and X-ray diffraction studies. Inherent viscosities of these polymers were in the range 0.66 to 1.44 dL/g indicating moderate to high molecular weight built-up. These polymers exhibited solubility in various solvents such as DMAc, NMP, pyridine, m-cresol etc. X-ray diffraction pattern of polymers showed that introduction of pendant phenyl moiety would disturb the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA and DSC showed excellent thermal stability of polymers. The structure -property correlation among these polyamides were studied, in view of these polymer's potential applications as processable high temperature resistance materials.     

Towards Vaporized Molecular Discrimination: A Quartz Crystal Microbalance (QCM) Sensor System Using Cobalt‐Containing Mesoporous Graphitic Carbon

A recent study on nanoporous carbon based materials (J. Am. Chem. Soc.­ 2012 , 134, 2864) showed that the presence of abundant graphitized sp² carbon species in the frameworks led to higher affinity for aromatic hydrocarbons than their aliphatic analogues. Herein, improved understanding of the sensitive and selective detection of aromatic substances by using mesoporous carbon (MPC)‐based materials, combined with a quartz crystal microbalance (QCM) sensor system, was obtained. MPCs were synthesized by direct carbonization of mesoporous polymers prepared from resol through a soft templating approach with Pluronic F127. The carbon‐based frameworks can be graphitized through the addition of a cobalt source to the precursor solution, according to the catalytic activity of the cobalt nanoparticles formed during the carbonization process. From the Raman data, the degree of the graphitization was clearly increased by increasing the cobalt content and elevating the carbonization temperature. From a QCM study, it was proved that the highly graphitized MPCs exhibited a higher affinity for aromatic hydrocarbons than their aliphatic analogues. By increasing the degree of graphitization in the carbon‐based pore walls, the MPCs showed both larger adsorption uptake and faster sensor response towards toxic benzene and toluene vapors.     

Synthesis and characterization of new quaternary ammonium surfactant [C18-Dabco][Br] and its catalytic application in the synthesis of spirocarbocycles under ultrasonic condition

Research on Chemical Intermediates - A novel DABCO-based cationic surfactant [C18-Dabco][Br] has been easily synthesized by the reaction of DABCO and octadecyl bromide in acetonitrile at room...     

Brönsted acid hydrotrope combined catalyst for environmentally benign synthesis of quinoxalines and pyrido[2,3-b]pyrazines in aqueous medium

A new Brönsted acid hydrotrope combined catalyst (BAHC) has been developed and applied in acid catalyzed synthesis of pyrido[2,3-b]pyrazines and quinoxalines in an aqueous medium at ambient temperature with excellent yields. Interestingly, the catalyst can be easily recovered after the reactions and reused. Furthermore, BAHC catalyst worked well and avoids the use of organic solvents. We have reported herein the synthetic pathway which has less disastrous effect in the atmosphere and human survival.