| Vitamin K3 is a kind of quinone, known as 2-methyl-1,4-naphthoquinone,2-menadione or menadione; and received more and more attention at home and abroad. It is widely used as a feed suppliment of the animal nutrition and as blood coagulating agent, and is also a key intermediate in the preparation of the other vitamins of group K. Thus, it is very important to research the synthesis method of 2-menadione. Industrially,2-menadione is produced via stoichiometric oxidation of 2-methylnaphtalene with CrO3 in sulfuric acid now. This process makes huge waste water containing chromium and the final pruduct having small amounts of chromium which makes an bad effect on animals and humans. And, The controlled oxidation of organic molecules is still a challenging task. This requires a well directed selection of the oxidizing agents as well as a strict control of reaction conditions.In this paper, we make research using 2-naphthalene as a material in combination with hydrogen peroxide as the oxygen source in the solvent of acetic acid. The reaction has beening studied using heteropoly acid and the carrier, functionalized ionic liquid and polyphosphoric acid as catalyzers, which show that they are without any chromium in the final priduct and in the waste water. Also, these catalyzers have high activities on this reaction, and we make some significant achievements.Firstly, the heteropoly acid is well known that it has acidity and oxidation. In this section, we compared different heteropoly acids with their carriers to synthesize vitamin K3, with heteropoly acid as activities center. The phosphorus acid showed superior selectivity and volume yield of 2-menadione compared to other heteropoly acids and the carriers. Meanwhile, we studied the reaction mechanism and the transformation rules of the among of the products. In this process,we found that the pH have great influence on the reaction.Secondly, In viewing of the effect of the pH to the reaction, we used functionalized acidic ionic liquids to synthesize vitamin K3. A series of functionalized acidic ionic liquids have been synthesized and compared their effects to the reaction. Various different factors were considered such as the category of catalysts, reaction temperature, reaction time, raw-material mol ratio, which showed that this type ionic liquids had highly synthesized the vitamin K3. The yield of the vitamin K3 reached 62.8% under the optimum reaction conditions. The results showed that the yeild and the waste water without chromium were improved compared with the traditional industrial process.Finally, In the present work, we found that the water content had an effcet on the reaction. In viewing of the acidity and dehydration of the polyphosphoric acid, we used polyphosphoric acid as catalyst to the reaction. The different concentrations of the polyphosphoric acid were synthesized to composed the vitamin K3. Various different factors were considered such as the category of catalysts, reaction temperature, reaction time, raw-material mol ratio, which showed that the yield of the vitamin K3 have been increasing with the increasing of the concentration of polyphosphoric acid. The optimal reaction condtions and excellent results in catalyzed process of 114% polyphosphoric acid was given as followed: 2-MNL 0.005 mmol, catalyst is 0.1 g, HOAc 15 mL, H2O2(30%) 20 mL,80℃for 4 h. The conversion of 2-MNL and the selectivity to vitamin K3 were 96.3%and 69.5%, and the yield of the vitamin K3 reached 66.9% under the optimum reaction condition. The results showed that the yeild and the waste water without chromium were improved compared with the traditional industrial process.
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