METHOD OF HYDROXYETHYLIDENE PHOSPHONIC ACID SYNTHESIS Russian patent published in 1996 - IPC

FIELD: organophosphate compounds. SUBSTANCE: invention relates to method of synthesis of hydroxyethylidene phosphonic acid of the formula . In the process of synthesis fatty acid chloroanhydrides by interaction of synthetic C₃-C₁₈-fatty acids or their mixtures or vegetable oil acids with phosphorus trichloride phosphorous acid is formed as waste. The latter is polluted with reaction products and therefore high quality complexone at high yield can not be obtained. This waste is treated preliminary with methanol at weight ratio organic impurities and methanol = 1: (0.2-0.5), respectively, at 45-65 C, and prepared reaction mixture is kept for 20-30 min at 60-75 C to remove hydrogen chloride. Synthesized complexone, hydroxyethylidene phosphonic acid, is used in heat energetics, petroleum, perfume, textile industries, in domestic chemistry, medicine, for mineral fertilizers production. EFFECT: improved method of synthesis. 1 tbl