ZnBr2-SiO2 catalyzed green synthesis of tetrazoles: Molecular docking and antioxidant activity studies

A series of 5-substituted and 1,5-disubstituted tetrazoles were synthesized in high yields from various biologically active substituted nitriles with sodium azide under heterogeneous catalysed (ZnBr2-SiO2) [2+3] cycloaddition conditions. This reaction gave an excellent yield in the presence of catalytic amount of 0.2 g of ZnBr2-SiO2, glycerol solvent system under microwave irradiation conditions. All the prepared compounds were characterized by elemental analysis 1H NMR, 13C NMR, FT-IR, and mass spectral data. The newly synthesized compounds were investigated for their respective molecular target using molecular docking studies. The results reveal that compounds 5a, 5c, 5e and 3e have conferred with multi target property. The compounds 5a, 5c and 5e have shown the highest binding affinities of -10.1, -9.7 and -10.6 with reverse transcriptase, -8.5, -8.2 and -8.9 with Aurora B, respectively. The compounds 5a, 5e and 3e have shown -8.9, -8.5 and 8.4 with Aromatase, respectively. In addition, the antioxidant activity data reveals that all the compounds showed good antioxidant activity, particularly the compounds 3d, 5d, and 5e exhibited promising radical scavenging activity

Synthesis, isolation, identification and characterization of new process-related impurity in isoproterenol hydrochloride by HPLC, LC/ESI-MS and NMR

One unknown impurity (Imp-II) during the analysis of laboratory batches of isoproterenol hydrochloride was detected in the level ranging from 0.04% to 0.12% by high performance liquid chromatography with UV detection. The unknown impurity structure was proposed as 4-[2-(propan-2-ylamino)ethyl]benzene-1,2-diol (Imp-II) using the liquid chromatography--mass spectrophotometry (LC--MS) analysis. Imp-II was isolated by semi-preparative liquid chromatography from the impurity-enriched reaction crude sample. Its proposed structure was confirmed by nuclear magnetic spectroscopy such as 1H, 13C, DEPT (1D NMR), HSQC (2D NMR) and infrared spectroscopy (IR), and retention time and purity with HPLC followed by the chemical synthesis. Due to less removable nature of Imp-II during the purification, the synthetic process was optimized proficiently to control the formation of Imp-II below to the limit<0.12% in the course of reaction. The new chemical route was developed for the preparation of this impurity in required quantity with purity to use as reference standard. The most probable mechanism for the formation of Imp-II was discussed in details. Keywords: Isoproterenol hydrochloride, Impurities, HPLC, NM

Expeditious, Nano-BF₃ · SiO₂-Catalyzed Michaelis–Arbuzov Reaction in an Ionic Liquid: Synthesis of Privileged Aryl/Heterocyclic Phosphonates

<div><p></p><p>An expeditious, simple, and green method was developed for the synthesis of privileged aryl/heterocyclicphosphonates, <b>8(a–c)</b> to <b>13(a–c)</b> through Michaelis–Arbuzov reaction of aryl/heterocyclic halides (Br), <b>1–6</b>, and trialkylphosphites, <b>7(a–c)</b>, in room-temperature ionic liquid [bbim]Br using heterogeneous Lewis catalyst, nano-silica-supported boron trifluoride (BF₃-SiO₂). The advantages of this protocol are simplicity, good yield of the products, less reaction time (20–38 min), mild reaction conditions, easy workup, and reusability of the catalyst and ionic liquid. It is demonstrated that nano-BF₃-SiO₂ is a recoverable and easy accessible catalyst for the formation of C(sp²)-P bond in an ionic liquid.</p> </div

New substituted 2-aminomethyl-2-oxo-2λ⁵-perhydro-[1,3,2]oxazaphospholo [3,4-<i>a</i>]pyridine: Design, synthesis and antimicrobial activity

<p>The synthesis of a new series of P-heterocyclic compounds, substituted 2-aminomethyl-2-oxo-2λ⁵-perhydro-[1,3,2]oxazaphospholo[3,4-<i>a</i>]pyridine derivatives <b>8(a-j)</b>, was accomplished. A key intermediate, 2-(chloromethyl)-2-oxo-2λ⁵-perhydro-[1,3,2]oxazaphospholo[3,4-<i>a</i>]pyridine <b>(6)</b> was primarily synthesized by the condensation of (±)-2-piperidinemethanol <b>(4)</b> and chloromethylphosphonic dichloride <b>(5)</b>; subsequently, it was treated with various heterocyclic amines/benzylamines/aminoacid esters, <b>7(a-j)</b> to obtain the desired products. The structures of the newly synthesized compounds were elucidated by ¹H, ¹³C, and ³¹P NMR spectroscopy, mass spectra and elemental analyses. The biological potency of title products was investigated by screening <i>in vitro</i> antimicrobial activity. The bio-screening data revealed that most of the synthesized derivatives showed potent growth of inhibition against fungi while compared with bacteria. Particularly, compounds <b>8c</b> and <b>8i</b> against bacterial strains, and <b>8a</b> and <b>8f</b> against fungi exhibited promising activity.</p

CeCl₃.7H₂O-SiO₂ Catalyzed Ultrasonicated Solvent-Free Synthesis of Carbamoyl/Carbamothioyl Phosphonates and Antimicrobial Activity Evaluation

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<i>N</i>-Phosphorylated Derivatives of 5-Nitroindazole as Antimicrobial and Antioxidant Agents and Docking Study Against DNA Gyrasea

<div><p>GRAPHICAL ABSTRACT</p><p></p></div