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Some derivatives of phenothiazine and phenoxazine compounds were synthesized via Hiyama‐cross coupling reaction protocol. The intermediates were prepared by reacting 2‐aminothiophenol, 2‐aminopyridin‐3‐ol and 4,5‐diamino‐6‐hydroxylpyrimidin‐2‐thiol with 2,3‐dibromonaphthalene‐1,4‐dione in alkaline medium of anhydrous sodium carbonate. These intermediates were subjected to the fluoride‐free Hiyama cross‐coupling reaction with 2‐(dimethylsilyl)pyridine and dimethyl(2‐thienyl)silanol using magnetically separable Pd/Fe3O4 as the catalyst under aqueous conditions to yield the derivatives. Molecular descriptors of these compounds were evaluated for their drug‐likeness. Pharmacokinetic parameters were also evaluated. Molecular docking studies were performed. The synthesized compounds showed drug‐likeness. Pharmacokinetic evaluation reveals a strong plasma protein binding and potentials to cross blood‐brain barrier. 6‐(Thiophen‐2‐yl)‐5H‐11‐azabenzo[a]phenoxazin‐5‐one (8 b) and 11‐Amino‐9‐thio‐6‐(thiophen‐2‐yl)‐5H‐8,11‐diazabenzo[a]phenoxazin‐5‐one (9 b) showed highest binding energies of −5.74 and −7.25 kcal/mol with the protein targets glucosamine‐6‐phosphate synthase (2VF5) and lanosterol‐14α‐demethylase (3JUV) respectively. The phenoxazines synthesized were found to be potential inhibitors of glucosamine‐6‐phosphate synthase and lanosterol‐14α‐demethylase. [ABSTRACT FROM AUTHOR]

Two novel heterocyclic ligands, 2‐[(5‐fluoro‐1,3‐benzothiazol‐2‐yl)amino]naphthalene‐1,4‐dione (HL1) and 2‐[(5‐methyl‐1,3‐benzothiazol‐2‐yl)amino]naphthalene‐1,4‐dione (HL2), and their Pd(II), Ni(II) and Co(II) complexes were prepared and characterized using 1H NMR, 13C NMR, infrared and UV–visible spectroscopic techniques, elemental analysis, magnetic susceptibility, thermogravimetry and molar conductance measurements. The infrared spectral data showed that the chelation behaviours of the ligands towards the transition metal ions were through one of the carbonyl oxygen and deprotonated nitrogen atom of the secondary amine group. Molar conductance results confirmed that the complexes are non‐electrolytes in dimethylsulfoxide. The geometries of the complexes were deduced from magnetic susceptibility and UV–visible spectroscopic results. Second‐order perturbation analysis using density functional theory calculation revealed a stronger intermolecular charge transfer between ligand and metal ion in [NiL1(H2O)2(CH3COO‐)] and CoL1 compared to the other complexes. The in vitro antibacterial activity of the compounds against some clinically isolated bacteria strains showed varied activities. [NiL1(H2O)2(CH3COO‐)] exhibited the best antibacterial results with a minimum inhibitory concentration of 50 μg mL−1. The molecular interactions of the compounds with various drug targets of some bacterial organisms were established in a bid to predict the possible mode of antibacterial action of the compounds. The ferrous ion chelating ability of the ligands indicated that HL1 is a better Fe2+ ion chelator, with an IC50 of 29.79 μg mL−1, compared to HL2 which had an IC50 of 98.26 μg mL−1. [ABSTRACT FROM AUTHOR]