Patent ID: 6034260
Filing Date: 2000-03-07
Classification: C07F

Abstract:
A process for preparing a symmetrically substituted phosphoric acid diester from a long-chain linear or branched alcohol having a chain length of from C.sub.4 to C.sub.22 and phosphorus oxychloride, the process comprising the steps of:a) reacting from 1 to 4 moles of the phosphorus oxychloride with 1 mole of methanol to form a reaction mixture comprising methyl dichlorophosphate, hydrogen chloride, and optionally, excess phosphorus oxychloride,b) removing the hydrogen chloride from the reaction mixture,c) optionally, removing the excess phosphorus oxychloride from the reaction mixture, and optionally, purifying the methyl dichlorophosphate in the reaction mixture,d) reacting the methyl dichlorophosphate in the reaction mixture with from 2 to 6 moles of the linear or branched alcohol having a chain length of from C.sub.4 to C.sub.22 to form a product mixture comprising the symmetrically substituted phosphoric acid diester, chloromethane, and a water-soluble volatile substance,e) removing the chloromethane from the product mixture,f) removing the water soluble volatile substance from the product mixture.