A Study on Synthesis and Oxidation Mechanism of mono-alkyl Phosphate

Oxidation of white phosphorus by peroxides to produce mono-alkyl phosphate in the alcoholic solution has been studied under non-and catalytic conditions. In this paper, the mechanism of the oxidation process was analyzed. The content of mono-alkyl phosphate in the product is affected by different types of alcoholic solution and peroxide solvent. The result shows the availability of the following order for the activity of the peroxide solvent and alcoholic solutions-tert-butyl hydroperoxide＞ (di) benzoyl peroxide＞ hydroperoxide; methanol＞ n-butyl alcohol＞ phenol. Under optimized reaction conditions a (white phosphorus): n (tert-butyl hydroperoxide): n (methanol)=1:10:12, reaction temperature 80℃, reaction time 2.5h, products of 80.0% mono-alkyl phosphonates can be provided when white phosphorus undergoes oxidation by tert-butyl hydroperoxide in the methanol solutions. When Cu (Ⅰ), and Cu (Ⅱ) complexes are used as catalysts, it is possible to significantly enhance the oxidation of white phosphorus with the increase in the reaction rate. The order for activity of catalysts is Cu (acac)2＞Cu (CH3 COO)2 ＞Cu (C3 H7 COO)2 ＞CuI＞CuCl2. Noticeably, with Cu (acac)2 as catalyst, the selectivity for mono-alkyl phosphonates can reach 95% under adequate reaction conditions.