Patent GB-872221-A (GB)
Title: Improvements in or relating to pesticidal compositions containing phosphorus esters
IPC: C07F9/165
Filed: 1957-07-15
Abstract: Compounds having the general formula <FORM:0872221/IV (b)/1> wherein X is oxygen or sulphur, R3 and R4 are the same or different radicals selected from hydrocarbon radicals such as alkyl, cycloalkyl, aryl, and substituted hydrocarbon radicals containing groups such as chloro, bromo, alkoxy, nitro, and R1 and R2 are hydrogen, halogen, nitro, or radicals selected from heterocyclic and saturated and unsaturated hydrocarbon radicals such as alkyl, aryl, cycloalkyl, aralkyl, and substituted derivatives thereof containing groups such as chloro, bromo, nitro, alkoxy, or hydroxy or are carboxy, carboxy ester, carbamy (including substituted carbamyl), carbanalido (i.e. N-aryl substituted amido), alkoxy, or S-(dialkoxyphosphinothioyl) mercapto groups, are obtained by reacting a methylene halide of the formula:- Y.C(R1)(R2)Z wherein Y and Z are chlorine or bromine with a thiophosphoric acid ester of the formula R3OP(X)(OR4)S-Metal.  In the preferred process two molar equivalents of the appropriate thiophosphoric acid are dissolved in a solvent such as ethanol or dioxane and a solution of the metal hydroxide e.g. a solution of potassium hydroxide in ethanol, is added until the pH is about 7; one molar equivalent of the methylene halide compound is then added and the mixture heated until reaction is complete.  When the product desired is one in which one of the substituents on the methylene carbon atom is a S-(dialkoxyphosphinothioyl)mercapto group three molar equivalents of the thiophosphate diester salt are reacted with the appropriate trihalomethane compound.  Suitable metal salts are the alkali metal, alkaline earth metal, ammonium and silver salts. Several examples are given, typical products being: bis(S-(dialkoxyphosphinothioyl) mercapto) methanes wherein the alkyl radicals have 1 to 6 carbon atoms and may be the same or different, bis(S - (diethoxyphosphinothioyl) mercapto) (phenyl) methane, and the invention includes these products 'per se'; tris(S-(diethoxyphosphinothioyl)mercapto)nitro-methane, and compounds in which R3 and R4 are ethyl, X is sulphur and either (1) R1 is Cl and R2 is NO2, (2) R1 is H and R2 is CONR5R6 wherein R5 and R6 are each allyl, ethyl or n-octyl or R1 and R2 taken together are pentamethylene or ethyleneoxyethylene, or (3) R1 is H and R2 is CONHR wherein R is hydrogen, allyl, 4-chlorophenyl, cyclohexyl, 4-nitrophenyl or carboxymethyl; and compounds in which R3 and R4 are ethyl, X is oxygen, R1 is hydrogen and R2 is hydrogen, phenyl, or 4-nitrophenyl.  The products have pesticidal properties (see Group VI).ALSO:A pesticidal composition comprises as active ingredient a compound having the general formula  <FORM:0872221/VI/1> wherein X is oxygen or sulphur, R3, R4, R5 and R6 are the same or different radicals selected from hydrocarbon radicals such as alkyl, cycloalkyl, aryl, and substituted hydrocarbon radicals containing groups such as chloro, bromo, alkoxy, or nitro, and R1 and R2 are hydrogen, halogen, nitro or radicals selected from heterocyclic and saturated and unsaturated hydrocarbon radicals such as alkyl, aryl, cycloalkyl, aralkyl and substituted derivatives thereof containing groups such as chloro, bromo, nitro, alkoxy or hydroxy or are carboxy, carboxyester, carbamyl (including substituted carbamyl), carbamalids (i.e. an N-aryl substituted amido group), alkoxy, or S - (dialkoxyphosphinothioyl) mercapto groups (see Group IV (b)).  The composition may be in the form of an aqueous emulsion, a dry or wettable powder or in the form of a solution or aerosol mixture and other toxicants or synergists may be present. A typical formulation comprises a wettable powder containing the pesticide, fuller's earth and an alkyl aryl polyether alcohol as wetting agent.  Preferred active ingredients are those in which X in the formula is sulphur and the R3 to R6 radicals are C1-C6 alkyl radicals.