Synthesis and Reactions of Some New Heterocyclic Compounds Containing Cycloalka[e]thieno[2,3‐b]pyridine Moiety

Hydrolysis of ethyl 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxylates ( 3a-d) gave the corresponding o-aminocarboxylic acids 4a-d . Heating the latter compounds ( 4a-d) with acetic anhydride furnished the oxazinone derivatives 5a-d which, in turn, underwent recyclization reaction to give the corresponding pyrimidinones 6a-d upon treatment with ammonium acetate in acetic acid. Reaction of 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides ( 3f,h ) with triethyl orthoformate gave pyrimidinone derivatives 7a,b . Reaction of 3-amino-4-phenyl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides 3e,h with aromatic aldehydes furnished tetrahydropyridothienopyrimidinones 8a-d . Chlorination of 7a,b and 6a-d by using phosphorous oxychloride produced 4-chlorocycloalka[5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine derivatives 9a-f which were used as key intermediates in the synthesis of several new cycloalkapyrido-thienopyrimidines 10a-f ˜ 14a-f . Moreover, some cycloalkapyridothienotriazinones 15a,b-17a,b were synthesized.     

Binder-less and free-standing Co–Fe metal nanoparticles-decorated PVdF-HFP nanofiber membrane as an electrochemical probe for enzyme-less glucose sensors

Co–Fe bimetallic nanoparticles-affixed polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofiber membrane is fabricated using the electrospinning and chemical reduction techniques. The semicrystalline polymeric backbone decorated with the highly crystalline Co–Fe bimetallic nanoparticles enunciates the mechanical integrity, while the incessant and swift electron mobility is articulated with the consistent dissemination of bimetallic nanoparticles on the intersected and multi-layered polymeric nanofibers. The diffusion and adsorption of glucose are expedited in the extended cavities and porosities of as-formulated polymeric nanofibers, maximizing the glucose utilization efficacy, while the uniformly implanted Co⁴⁺/Fe³⁺ active centers on PVdF-HFP nanofibers maximize the electrocatalytic activity toward glucose oxidation under alkaline regimes. Thus, the combinative sorts including nanofiber and nanocomposite strategies of PVdF-HFP/Co–Fe membrane assimilate the enzyme-less electrochemical glucose detection concerts of high sensitivity (375.01 μA mM^?1 cm^?2), low limit of detection (0.65 μm), and wide linear range (0.001 to 8 mM), outfitting the erstwhile enzyme-less glucose detection reports. Additionally, the endowments of high selectivity and real sample glucose-sensing analyses of PVdF-HFP/Co–Fe along with the binder-less and free-standing characteristics construct the state-of-the-art paradigm for the evolution of affordable enzyme-less electrochemical glucose sensors.

     

The DFT investigations of the electron injection in hydrazone-based sensitizers

A brief review of popular polarizable potentials for water, including both those parameterized to fit experimental properties, typically of the liquid, or electronic structure calculations on small clusters, is presented. The recently developed POLIR potential, which was parameterized to reproduce both ab initio calculations on clusters and the experimental liquid IR spectrum, is discussed, and some new results for both clusters and the liquid phase are shown, indicating its transferable nature.     

Reactive kinetics of carbon dioxide loaded aqueous blend of 2-amino-2-ethyl-1,3-propanediol and piperazine using a pressure drop method

In this study, a new pressure drop method has been used to investigate the kinetics of carbon dioxide reaction with aqueous blend of 2-amino-2-ethyl-1,3-propanediol (AEPD) with piperazine (PZ). The blending of a small amount of PZ with AEPD has a significant effect on the observed rate constant, k_obs. It was observed that k_obs values of the blend increased more than twice than the summation of k_obs values of individual alkanolamines. The reaction kinetics in this study were modeled by assuming a termolecular mechanism. The addition of 0.1 mol/L of PZ to 1 mol/L AEPD exhibited an observed rate constant, k_obs of 8824.1 s⁻¹, which is comparable to other alkanolamine mixtures. Hence, PZ/AEPD mixtures can be potentially used for rapid carbon dioxide capture.     

Red and yellow color aspects of compound 3-dicyclopropylmethylene-5-dicyanomethylene-4-diphenylmethylenetetrahydrofuran-2-one:Chromism effect

The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.     

Multifunctional Magnetic Nanomedicine Drug Delivery and Imaging-Based Diagnostic Systems

Magnetically guided drug transportation is a technique in which magnetic pharmaceutical transporters in organisms are controlled by applied magnetic forces to deliver drugs to the desired location. Different magnetic drug delivery systems (MDDSs) are developed to treat a variety of illnesses, particularly cancer and neurological disorders. However, a unique magnetic setup is required in each application for an effective magnetically guided drug aiming to direct the drug-carrying nanocarriers to the intended area. The current and future perspectives of MDDS are investigated in this study by considering their biological functions, deliverable efficiency, complexity, and the nature of the externally applied magnetic field. Despite the fact that MDDSs have low cytotoxicity, regulated magneto reactivity, extended circulation lifespan, and high surface stability, very few clinical studies have been conducted to date in order to achieve optimized therapeutic efficacy before entering the market. In recent studies, the development of novel magnetic medication transporting carriers is preferred over direct magnetic medication administration. Better functional magnetic targeting technologies are required for such breakthroughs to enter clinical trials. Because MDDSs are unlikely to work in all clinical situations, more focused research is needed to replace or improve the strategy for treating multiple illnesses.     

Chemistry of 2,3-Dichloroquinoxalines

This review describes the synthesis, reactivity, and the utility of 2,3-dichloroquinoxalines as synthetic intermediates for the synthesis of condensed heterocycles with pharmacological interest.     

Structural Study and Biological Evaluation of Some Novel 1,2,4-Triazole,Thiazole, and Bisthiazole Derivatives Bearing a Sulfonamide Moiety

The starting material 1,2,4-triazole derivative ( 3 ) was used to synthesize some novel condensed triazoles. Thus, treatment of compound ( 3 ) with phenyl isocyanate in refluxing pyridine furnished the novel [1,2,4]triazolo[4,3-b][1,2,4]triazole derivative ( 5 ). Also, cyclization of compound ( 3 ) with phenyl isothiocyanate afforded the [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivative ( 7 ). Hydrazone derivative ( 9d ) was allowed to react with some halogenated reagents such as chloroacetone, ethyl chloroacetate, and chloroacetonitrile to furnish thiazole derivatives ( 12 ), ( 13 ), and ( 15 ), respectively. In a similar manner, bishydrazone ( 17 ) was used to prepare the novel bisthiazoles ( 18 ) and ( 19 ). Some of the synthesized compounds were evaluated for their antibacterial activity.     

Cyanoacetanilides Intermediates in Heterocyclic Synthesis,Part 3: Novel Syntheses of Thiazolinone and Thiazolo[3,2-a]Pyridine Derivatives

Thiazolo[3,2-a]pyridines 6a–c , 10 , 13 , and 14 have been synthesized via simple methods from the readily accessible 2-[N-(4-ethoxyphenyl)-acetamide-2-yl]-4,5-dihydro-4-thiazolinone 2. The structure of the synthesized compounds was established by analytical and spectral data.