The Research On Efficient Aerobic Oxidation Of Tetralin In The Presence Of Metalloporphyrins And The Preparation Of α-Tetralone By A Two-step Route

α-Tetralone are very important intermediates of many medicine. The liquid-phase oxidation of tetralin with molecular oxygen is an important way to prepareα-tetralone. Usual products are either mixtures ofα-tetralone andα-tetralol, or mixtures of these products withα-tetralin hydroperoxide(THP). THP can be converted quantitatively intoα-tetralone andα-tetralol by means of catalytic amounts of transition metal. Theα-tetralone andα-tetralol have substantially similar boiling points and, therefore, cannot be separated from each other without diffictlties. In order to get high selectivity ofα-tetralone, most of these catalysts are novel chromium amine catalyst complexes, especially chromium acetate 2-methyl-5-ethylpyridine. Because this method needs lots of catalyst and cocatalyst which cann’t be recovered, and especially chromium is harmful to environment, a new catalytic system which is under mild conditions in the absence of an adiditive and a cocatalyst is suitable for the development orientation of green chemical.This paper mainly studies on the preparation and characterization of metalloporphyrins, and they were used as catalyst in the oxidation of tetralin with air under mild conditions in the absence of an adiditive and a cocatalyst. Metalloporphyrins were found to be effective catalysts for the oxidation of tetralin, and T(p-Cl)PPCo showed the highest activity among T(p-Cl)PPFeCl, T(p-Cl)PPFMnCl and T(p-Cl)PPCo. The oxidation products of tetralin are mainlyα-tetralin hydroperoxide(THP), little ofα-tetralone and trace ofα-tetralol. This method can be used to produce THP andα-tetralone high selectively. With the reaction parameters: tetrlain 50 ml, reaction temperature 90℃, reaction time 4h, the concentration of T(p-Cl)PPCo 3.84×10-5mol/L, the conversion of tetralin can be 25.02% and the selectivity of THP andα-tetralone can be 95.40%.There is provided a method for the production ofα-tetralone, which comprises subjectjing tetralin to oxidation in the presence of T(p-Cl)PPCo and at temprerature of 90℃so as to convert from 20%-30% by weight of the tetralin to THP, and then adding to the resultant tetralin solution containing the formed THP and at a temperature of from 0℃to 60℃at one inorganic metal salt selected from water-soluble inorganic ferrous salts and water-soluble inorganic cuprous salts. The selectivity of the decomposition of THP intoα-tetralone is more than 93%, and it provides a highly efficient environment-friendly method for the produce ofα-tetralone.THP can be converted quantitatively intoα-tetralone andαte-tralol during the oxidation of tetralin by metalloporphyrins. It can effect the yield and selectivity of the oxidation products and the impact of catalyst activity. So we have studied the effects of temperature, the concentration of T(p-Cl)PPCo on the decomposition of THP.In addition, we have studied the mechanism of the oxidation of tetralin catalyzed by T(p-Cl)PPCo with the help of UV-Vis and ESR.