Study On Preparation Of β-naphthoquinone By Oxidation Of β-methylnaphthalene With High Concentration Hydrogen Peroxide

β-methylnaphthoquinone is an important intermediate in the synthesis ofanti-bleeding drug of vitamin K. And it has been largely widely used as feed additives.With the improvement of the science and technology, it can be used to prepare moremedicine that have biological activity. In order to solve the problem that the chromiumoxidizing agents system contain the chromium waste water, two green synthetic routesare researched.Synthesis ofβ-methylnaphthoquinone with OP-10 as the emulsifier oxidation ofβ-methylnaphthalene with high concentration 50% mass fraction hydrogen peroxide isresearched. The effects of reaction temperature, reaction time, amount-of-substanceratio of P-methylnaphthalene to glacial acetic acid , amount-of-substance ratio ofβ-methylnaphthalene to hydrogen peroxide and molar ratio of OP-10 toβ-methylnaphthalene onβ-methylnaphthalene conversion andβ- methylnaphthoquinoneyield were investigated by way of orthogonal experiment and single-factor experiment.The best reaction conditions are obtained:The optimal reaction conditions were that reaction temperature was 100℃,reaction time 4h, amount-of-substance ratio ofβ-methylnaphthalene to acetic acid1:16 , amount-of-substance ratio ofβ-methylnaphthalene to Hydrogen peroxide 1:11and OP-10 0.05ml/g (β-MN), in the OP-10 system. In these conditions,β-methylnaphthalene conversion was 96%, the yield ofβ-methyl-naphthoquinone wasabove 52%.Synthesis ofβ-methylnaphthoquinone with tetrabutylammonium bromide asphasetransfercatalyst oxidation ofβ-methylnaphthalene with high concentration 50%mass fraction hydrogen peroxide is researched. The effects of reaction temperature,reaction time, amount-of-substance ratio ofβ-methylnaphthalene to glacial acetic acidand amount-of-substance ratio ofβ-methylnaphthalene to hydrogen peroxide molar ratioofβ-methylnaphthalene to tetrabutylammonium bromide onβ- methylnaphthoquinoneconversion and yield were investigated by way of orthogonal experiment andsingle-factor experiment. The best reaction conditions are obtained:The optimal reaction conditions were that reaction temperature was 90℃, reaction time 4h, amount-of-substance ratio ofβ-methylnaphthalene to acetic acid 1:20 ,amount-of-substance ratio ofβ-methylnaphthalene to Hydrogen peroxide 1:11 and themass ratio of tetrabutylammonium bromide toβ- MN1:22, in the tetrabutylammoniumbromide system. In these conditions,β-methylnaphthalene conversion was 93.3%, theyield ofβ-methyl-naphthoquinone was above 58.2%.The product was defined by way of IR spectrum and LC-MS qualitative tests.Compared to the two ways of synthesis ofβ-methylnaphthoquinone, the way ofSynthesis with tetrabutylammonium bromide as phasetransfercatalyst oxidation ofβ-methylnaphthalene with hydrogen peroxide is better.