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291.
Russian Journal of Bioorganic Chemistry - The regioselective synthesis of twelve new benzimidazole-1,2,3-triazole hybrids through the Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction between...  相似文献   
292.
Journal of Plant Growth Regulation - Compact clusters and small berry size are the major problems associated with the commercialization of table grapes. The application of gibberellic acid 3 (GA3)...  相似文献   
293.
1-Methyl-2,4,5-trinitro imidazole (MTNI) is a well-known melt cast explosive possessing good thermal stability and impact insensitivity. MTNI has been synthesized from multi-step nitration followed by methylation of imidazole exhibiting low yield. It is desirable to screen the process thermodynamically for evaluating feasibility of the process. In the present investigations, B3LYP method in combination with 3-21G** basis set has been chosen to evaluate the enthalpy of formation for reaction species by designing reasonable isodesmic reactions. Thermodynamic feasibility of the processes has been worked out assuming free energies of reactions as derived from standard enthalpy and entropy of the reaction species. All possible synthesis routes for the target molecule, MTNI has been conceptualized from different precursors/intermediates viz. imidazole, 2-nitroimidazole, 4-nitroimidazole, 1-methyl imidazole and 2,4,5-triiodoimidazole. Various nitrating agents have been employed and their effect studied for deciding the feasibility of the reaction. It has been found that reaction entropy and enthalpy are favorable on usage of NO2BF4 as nitrating agent. The charge on nitro group (?QNO2) has been used for better understanding of the reactivity of substrates/intermediates. Overall, the study helped in screening several possible routes for MTNI synthesis and identified the thermodynamically feasible process by using NO2BF4 as nitrating agent.  相似文献   
294.
A series of 3α-amino-5α-cholestane and 3α,7α-diamino-5α-cholestane derivatives containing imidazole and pyridine rings were synthesized by simple and effective reductive amination, and their in vitro activities against a range of Gram-positive and Gram-negative strains were evaluated. Most of the compound exhibited enhanced activity against MRSA pathogen. 3α,7α-Di(pyridylmethyl)amino-5α-cholestane 10 showed the highest potency in these series toward the Gram-positive bacteria, Staphylococcus epidermidis 887E, with the lowest MIC value of 1 μg/mL.  相似文献   
295.
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