Synthesis of N-Acyl Triazolyl-Pyrazolines via Acylation Initiated by the Hydrazone Moiety with Carboxylic Acids

An efficient synthesis of N-acyl/N-substituted acyl pyrazolines and their triazole hybrids have been accomplished via acylation of pyrazolines and pyrazoline-triazole hybrids with carboxylic acids and/or substituted carboxylic acids in the absence of activating agents/catalysts. In the present study, a mechanism envisaging the in situ generation of a new transient acylating intermediate has been proposed to explain the acylation.     

Design,synthesis, and antibacterial studies of potent pyrazolinyltriazoles

Research on Chemical Intermediates - A library of pyrazolinyltriazole hybrids (3a–l, 4a–l) was synthesized via azide–alkyne dipolar (Huisgen) cycloaddition of azidoacetyl...     

Synthesis,structural, DFT investigations and antibacterial activity assessment of pyrazoline-thiocyanatoethanone derivatives as thymidylate kinase inhibitors

Two novel compounds 1-(5-[4-fluorophenyl]-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-2-thiocyanatoethanone (FSCN) and 1-(5-[4-chlorophenyl]-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-2-thiocyanatoethanone (ClSCN) were synthesized and characterized by SC-XRD, 1H NMR, 13C NMR, FTIR, and UV methods. The X-ray diffraction studies were utilized to prove the 3D crystal structures of FSCN and ClSCN. In both the compounds, the packing is mostly driven by C H⋯N, C H⋯O, and C H⋯π (benzene ring as an acceptor) interactions. In ClSCN, additionally, the π⋯π interaction is observed between the pyrazole ring of one molecule and the benzene ring of the other molecule. The experimental values were compared with the results of DFT/B3LYP/6-311G++(d,p) theoretical computations. The pharmacological screening for FSCN and ClSCN was performed using molinspiration and PreADMET web server. To analyze antibacterial inhibition of the synthesized ligands and Ciprofloxacin (control drug) were interacted with antibacterial protein Thymidylate Kinase (TMK) (PDB ID: 4QGG) with the help of AutoDock Vina tool. The ADMET and docking results of FSCN and ClSCN pointed out the better drug likeness nature and good inhibition behavior with TMK protein. The antibacterial in vitro studies suggested that FSCN compound inhibited well with antibacterial strains than that of ClSCN. The current investigation suggests that with further improvements, our compounds could be preferred as substitute medicine for bacterial diseases.     

Staudinger’s phosphazene as an efficient esterifying reagent

A new application of Staudinger’s phosphazene as an efficient esterifying reagent is reported. Staudinger’s phosphazene formed in situ by the reaction of organic mono-azide with triphenylphosphine, which is trapped by carboxylic acid, to afford amide exclusively. In contrast, interestingly the same phosphazene behaves in a different way as an efficient esterifying reagent, affording ester under a solvent-free microwave-assisted protocol wherein alcohol is added as the another component in addition to the other reactants. This discovery adds yet another new application of Staudinger’s phosphazene to synthetic chemistry.     

Sequential change in one-pot,three-component protocol: A stepping stone in heterocyclic synthesis

Two different heterocycles, thiazole-2-imines and imidazole-2-thiones, have been conveniently synthesized by just altering the sequential order (1 + 2 + 3 or 1 + 3 + 2) when combining the same components [aryl amine (1), aryl isothiocyanate (2), and phenacyl bromide (3)] in one-pot, three-component protocols. The third possible sequential order of combination (2 + 3 + 1) chemoselectively affords thiazole-2-imine. The finding is a stepping stone in the synthetic applicability of sequential one-pot, three-component protocols.     

An environmentally benign solvent/catalyst-free one-pot synthesis of N-substituted phthalimides via Aza-wittig reaction

For the first time an environmentally benign solvent/catalyst-free protocol for the synthesis of a variety of N-substituted phthalimides is submitted. It involves a one-pot coupling of nascent phosphazene generated in situ with phthalic anhydride. The protocol is novel in (1) avoiding toxic solvents, (2) no catalyst is employed and (3) no isophthalimide is formed as noted in the prevailing solution phase/catalysed methodology.