Synthesis library of phthalazines by novel magnetized inorganic-monosaccharide nanohybrid (Ni_0.4Zn_0.6Fe₂O₄@SiO₂/galactose) under green conditions

A novel inorganic-monosaccharide nanohybrid synthesized through coating the nickel–zinc ferrite (NZF) core by silica and subsequent functionalization with galactose (Ni_0.4Zn_0.6Fe₂O₄@SiO₂/galactose) and characterized by FT-IR, FESEM, EDAX, XRD, XRF, BET, TGA, and VSM techniques. Its catalytic efficacy examined in some domino four-component reactions to obtain various classes of phthalazine derivatives at 90 °C under solvent-free conditions: (i) the reaction of phthalic anhydride (PA), hydrazine hydrate, dimedone, and different aldehydes to get 3,3-dimethyl-13-(aryl)-3,4-dihydro-1H-indazolo[1,2-b]phthalazine-1,6,11(2H,13H)-triones; (ii) the reaction of phthalic anhydride/phthalimide, hydrazine hydrate, malononitrile, and different aldehydes to obtain 3-amino-5,10-dioxo-1-(aryl)-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine-2-carbonitriles; and (iii) the reaction of succinic anhydride, hydrazine hydrate, dimedone, and different aldehydes to prepare 3,3-dimethyl-11-(aryl)-3,4,7,8-tetrahydro-1H-pyridazino[1,2-a]indazole-1,6,9(2H,11H)-triones. In addition, the recovery and reusability of the Ni_0.4Zn_0.6Fe₂O₄@SiO₂/galactose determined successfully, and the reused nanocomposite identified through FESEM and EDAX techniques.