Synthesis Of Four N-hydroxy-9,10-Anthraquinone-2,3-Dicarboximide

Oxidation of hydrocarbons plays an important role in chemical production. The research of novel catalysts has been a challenging subject.NHPI, as a small molecule catalyst, can catalyze the reaction of molecular oxygen with a series of hydrocarbons efficiently under the mild conditions, and become the focus for academic research teams. The study found that, catalyst activity can be greatly improved when the various co-catalyst added. Anthraquinone(AQ), as an ideal cocatalyst in the catalytic system of NHPI and nonmetal cocatalyst. But the recovery of the catalyst is still hard to overcome in this two-component system.In the present work, several molecules containing the structure of anthraquinone and NHPI, have been designed, synthesized and applied as one-component system in aerobic oxidation.In this paper, we designed and synthesized four catalysts including N-hydroxy-5,6,7,8-tetrachloro-9,10-anthraquinone-2,3-dicarboximide,(referred NHTCADI), Nhydroxy-5,8-dichloro-9,10-anthraquinone-2,3-dicarboximide,(referred NHDCADI), N-hydroxy-5-hydroxy-8-chloro-9,10-anthraquinone-2,3-dicarboximide,(referred NHHCADI) and N-hydroxy-5,8-dihydroxy-9,10-anthraquinone-2,3-dicarboximide, referred NHDHADI).These molecules were synthesized from 1,2,3,4-tetrachlorobenzene, p-dichlorobenzene, 4-chlorophenol and hydroquinone via multistep reaction sequences: Friedel-Crafts acylation, cyclization, chlorination and N-hydroxy. NMR determined its structure, and the total yield was 17%(NHTCADI), 16%(NHDCADI), 12%(NHHCADI), 2%( NHDHADI).We have studied the activity of three novel catalysts in ethylbenzene oxidation reaction. Substrate was reacted in the presence of catalyst(2 mol%) in acetonitrile under a dioxygen atmosphere(0.4 MPa) at 110 ℃ for 10 h. The conversion of ethylbenzene was 19%(NHTCADI), 22%(NHDCADI) and 20%(NHHCADI).