Organic Phosphorus Compounds 59. A new method for the synthesis of phosphonic dichlorides

摘要: Heating of thiophosphonic dichlorides, RP(S)Cl2, R CH3, C2H3, C2H5, with a molar equivalent SOCl2 under pressure at 150° for 5 to 8 h yields phosphonic dichlorides in quantitative yield. In addition sulfur and dichloride is formed according the equation: This method particularly useful preparation CH3P(O)Cl2 since it was observed that chlorination CH3P(O)(OCH3)2 PCl5 CH3OP(O)Cl2 as by-product which difficult separate from CH3P(O)Cl2. On other hand methylphosphonic acid also gives pure CH3P(O)Cl2 .