Browsing by Author "Deepika"

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    DABCO Mediated Sulfur Activation-Intramolecular De-Nitration Strategy for the Synthesis of Novel Dihydrothiochromeno[4,3-c]pyrazoles
    (John Wiley and Sons Inc, 2023-07-24T00:00:00) Deepika; Paul, Avijit K.; Malakar, Chandi C.; Bansal, Ajay; Singh, Virender
    A facile and highly efficient metal-free approach has been unfolded for the synthesis of novel dihydrothiochromeno[4,3-c]pyrazoles using elemental sulfur as a powerful sulfurating reagent. This method includes sp2 C?H functionalization followed by sp2 C?NO2 group displacement using elemental sulfur as an odourless sulfur source activated by DABCO in DMSO. Using the developed synthetic strategy, a library of 29 novel dihydrothiochromeno[4,3-c]pyrazoles, incorporating two pharmacologically important scaffolds has been synthesized in 52�76% yield with a broad substrate scope. A sensible mechanistic proposal has been projected based on control experiments. � 2023 Wiley-VCH GmbH.
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    An efficient metal-free and catalyst-free C�S/C�O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides
    (Beilstein-Institut Zur Forderung der Chemischen Wissenschaften, 2023-03-02T00:00:00) Sharma, Shubham; Singh, Dharmender; Kumar, Sunit; Vaishali; Jamra, Rahul; Banyal, Naveen; Deepika; Malakar, Chandi C.; Singh, Virender
    An operationally simple and metal-free approach is described for the synthesis of pyrazole-tethered thioamide and amide conjugates. The thioamides were generated by employing a three-component reaction of diverse pyrazole C-3/4/5 carbaldehydes, secondary amines, and elemental sulfur in a single synthetic operation. The advantages of this developed protocol refer to the broad substrate scope, metal-free and easy to perform reaction conditions. Moreover, the pyrazole C-3/5-linked amide conjugates were also synthesized via an oxidative amination of pyrazole carbaldehydes and 2-aminopyridines using hydrogen peroxide as an oxidant. � 2023 Sharma et al.
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    Iodine-Catalysed Synthesis of ?-Carboline Tethered ?-Amino Amidines Through Ugi-Type Multicomponent Reaction
    (John Wiley and Sons Inc, 2022-09-15T00:00:00) Singh, Manpreet; Vaishali; Jamra, Rahul; Deepika; Kumar, Sunit; Singh, Virender
    A simple and efficient iodine catalysed protocol has been unfolded for the synthesis of novel ?-carboline C1-linked ?-amino amidines via one-pot assembly of 1-formyl ?-carbolines (Kumujian C analogues), anilines and isocyanides. This domino strategy proceeds through the formation of three C?N bonds in a single operation. The advantageous features of the developed methodology include one-pot synthesis, operational simplicity, high atom economy, broad substrate scope, multicomponent character, easy purification procedure (no column chromatography) and applicability towards gram scale synthesis. The scope of strategy has been demonstrated with the construction of a library of 32 novel ?-carboline tethered ?-amino amidines having three points of diversity. � 2022 Wiley-VCH GmbH.
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    Performance of magnetic iron nanoparticle decorated electrodes single chambered MEC fed with combined leachate and dairy industry wastewater
    (Central University of Punjab, 2017) Deepika; Yogalakshmi, K.N.
    Increased human activity and consumption of natural energy resources have led to decline in the stock of fossil fuels. The current technologies used for energy generation are not environment friendly. Microbial electrolysis cell (MEC) represents a new approach for harnessing the energy contained in the organic matter of wastewater. It is a type of bioelectrochemical systems in which chemical energy stored in organic compounds are converted to biogas such as hydrogen through biocatalytic oxidation by microorganisms. But it still suffers from the lack of efficiency in terms of hydrogen production and current generation. Previous studies have demonstrated that the electrodes coated with nanoparticles such as Fe, Au, Pd, and Ni nanoparticles have the potential to enhance energy recovery in MEC. Hence, the present study aims to use single chambered membrane-less microbial electrolysis cell with magnetic iron nanoparticle coated electrodes for treating combined leachate and dairy industry wastewater. The performance of the MEC was assessed through COD removal, current and biogas generation at an applied voltage of 0.8 V and HRT of 48 hours. Results demonstrated that the maximum current density achieved by nanoparticles decorated electrodes was 3.86 times higher than iv generated by plain electrodes. The highest COD removal efficiency of 96.5% was achieved at OLR equal to 17.14 gCOD/L/d. The maximum coulombic efficiency of 155% represents the conversion of maximum chemical energy stored in the combined wastewater into electrical energy. The hydrogen production rate of 3.192 L/L/d was achieved in this study. The results shows that magnetic iron nanoparticle coated electrodes enhance the current generation and COD removal in single chambered MEC operated with combined leachate and dairy wastewater treatment.