PROCESS FOR THE PREPARATION OF THE O,O-DIMETHYL-O-(2,2-DICHLOROVINYL) ESTER AND THE O,O-DIETHYL-O-(2,2-DICHLOROVINYL) ESTER OF THIONOPHOSPORIC ACID

摘要

1501786 Preparing unsaturated chlorinecontaining thiophosphate esters BAYER AG 19 March 1976 [20 March 1975] 11163/76 Heading C2P Thiophosphate esters of the formula (RO) 2 P(S)OCH=C.Cl 2 wherein each R is methyl or ethyl are obtained by reacting at - 20‹ to + 100‹ C. a thiophosphonic acid diester: (RO) 2 P(S).CH(OH)CCl 3 with (a) a solution of an equivalent amount of an alkali metal alcoholate in an inert organic solvent or (b) a solution in an alcohol of an alkali metal hydroxide or an alkali metal carbonate, if appropriate in the presence of water, and optionally in the presence of another inert organic solvent. The preferred solvents in variants (a) and (b) are methanol and ethanol but several other solvents which may be used in variant (a) or as additional solvents in variant (b) are specified. The products have insecticidal properties and may be used as active ingredients in conventional insecticidal compositions.