PURPOSE: To obtain the titled high-purity compound particularly useful as a raw material for an organic phosphorus agricultural chemical safely and simply, by reacting an O,O-dialkyl dithiophosphate with an alkali compound in a specific solvent, and recovering the salt in the separated aqueous layer.
CONSTITUTION: An O,O-dialkyl dithiophosphate of the formula (R is 1W4C lower alkyl) is reacted with an alkali compound in a solvent consisting of a fractionated component of crude oil having a boiling point of 40W350°C, e.g. petroleum ether, petroleum benzine or gasoline, to form a water-soluble salt. The aqueous layer is separated from the solvent layer to recover the salt from the aqueous layer and give the titled compound. An alkali metal hydroxide, alkaline earth metal hydroxide, etc. may be preferred as the alkali compound. The solvent dissolves only impurities, and will not dissolve in the aqueous solution of the O,O-dialkyl dithiophosphate to separate the ester suitably.
EFFECT: The aqueous solution of suitable concentration can be prepared economically.
NABEKAWA SHIYUUKICHI
OOTSUBO ITARU
HASHIMOTO MICHINORI
Next Patent: PURIFICATION OF O,O-DIALKYL DITHIOPHOSPHATE