Biological evaluation and synthesis of hexahydro-11H-benzo[a]xanthen and pyridine-3-carbonitrile derivatives ...

Abstract In the present study, a novel magnetic organosilica supported Pd-Schiff base complex (Fe₃O₄@SiO₂/Si(CH₂)₃NH/HMPO/Pd(OAc)₂) was prepared. The nanocatalyst were synthesized using Fe₃O₄@SiO₂ core–shell nanoparticles and functionalized with 3-chloropropyltrimethoxysilane (CPTMS) as Fe₃O₄@SiO₂@Cl. The Schiff base ligand was synthesized by reaction of 5-hydroxypicolinaldehyde with hydrazine to produce of (hydrazineylidenemethyl)pyridin-3-ol (HMPO), then palladium acetate was added to produce of Schiff-base-Pd(II) complex. The catalyst was characterized thoroughly by FT-IR, XRD, SEM, TEM, VSM, EDX, TGA, SEM image of elemental maps and ICP analyses. Its catalytic activity was assessed in the synthesis of 12-aryl- 8,9,10,12-tetrahydrobenzo[a]xanthene-11-one, 14-aryl-14H- hexahydro-11H-benzo[a]xanthen-11-one and chromeno[2,3-b]pyridine-3-carbonitrile derivatives through a one-pot condensation of dimedone or malononitrile, naphthols, and aryl aldehydes in EtOH/H₂O. The excellent yield of products, easy work-up, column-free, short reaction time, and facility of reusability by an external magnet are other important advantages of this methodology.