Immobilization of organofunctionalized silica (SiMPTMS) with biphenyl-2,2′-dioic acid and investigation of its catalytic property for one-pot tandem synthesis of acridine-1,8-dione derivatives

Abstract

MPTMS-functionalized silica immobilized with biphenyl-2,2′-dioic acid, an efficient heterogeneous catalyst, was synthesized and characterized by various spectroscopic techniques such as FTIR, TGA, TEM and SEM. The catalytic activity of the synthesized catalyst has been demonstrated for the one-pot Knoevenagel/Michael condensation reaction of aromatic amines and 5,5-dimethyl-1,3-cyclohexanedione with various aldehydes. This method results in the synthesis of high-yielding acridine-1,8-dione derivatives and also provides simple and facile recyclability of the catalyst. The synthesized derivatives were characterized by IR, 1H-NMR, 13C-NMR and mass spectroscopy. Molecular structures of three acridine-1,8-dione derivatives were determined by single-crystal X-ray diffraction which determines that 3,3,6,6-tetramethyl-9,10-diphenyl-1,8-dioxodecahydroacridine crystallizes in the monoclinic with space group P2 1 /c, 3,3,6,6-tetramethyl-9-(4-chlorophenyl)-10-(4-methylphenyl)-1,8-dioxodecahydroacridine crystallizes in the monoclinic with space group P2 1 /n and 3,3,6,6-tetramethyl-9-(4-chlorophenyl)-10-(4-methoxyphenyl)-1,8-dioxodecahydroacridine crystallizes in the monoclinic with space group P2 1 /n. The one-pot tandem synthesis of acridine-1,8-dione derivatives was carried out successfully with good yields under the catalytic influence of MPTMS-modified silica immobilized with biphenyl-2,2′-dioic acid which has proved to be an efficient heterogeneous catalyst with good recyclable property.