GB834814A - ª‡-substituted o, o-dialkyl-dithiophosphorylacetic esters and process for their preparation - Google Patents

Abstract

The invention comprises O,O-dialkyl-dithiophosphorylacetic esters of the general formula <FORM:0834814/IV (b)/1> (wherein R4, R5 and R6 are like or different, saturated or unsaturated, straight- or branchedchain alkyl radicals and R3 is a substituted or unsubstituted aryl radical). They are prepared by reacting a salt of an O,O-dialkyl-dithiophosphoric ester <FORM:0834814/IV (b)/2> (wherein Y is ammonium, alkali metal or alkaline-earth metal) with an a -halogeno-a -arylacetic ester <FORM:0834814/IV (b)/3> (wherein Z is Cl, Br or I) in the presence of a solvent for either or both reactants. The salt may be prepared in situ by neutralizing the free acid. Suitable solvents are water, alcohols, ketones, esters, dioxane or aromatic hydrocarbons. The reaction may be effected at room temperature or under reflux. The products have insecticidal activity. In examples, the following esters are prepared, the free dialkyl-di-thiophosphoric acid being first neutralized with anhydrous sodium carbonate in each case; (1) ethyl O,O-diethyl-dithiophosphoryl-phenylacetate from O,O-diethyl-dithiophosphoric acid and ethyl a -phenyl-a -bromoacetate in acetone solution; (2) ethyl O,O-diethyl - dithiophosphoryl - p - nitrophenylacetate from O,O-diethyl-dithiophosphoric acid and ethyl a - p - nitrophenyl - a - bromoacetate in acetone; (3) ethyl O,O-dimethyl-dithiophosphoryl - phenylacetate from O,O - dimethyldithiophosphoric acid and ethyl a -phenyl-a -bromoacetate in acetone; (4) ethyl O,O-diisopropyl - dithiophosphoryl - phenylacetate from O,O - diisopropyl - dithiophosphoric acid and ethyl a - phenyl - a - bromoacetate in acetone; (5) ethyl O,O - diethyl - dithiophosphoryl - p - chlorophenylacetate from O,O-diethyl-dithiophosphoric acid and ethyl p-chlorophenyl-a -chloroacetate in acetone; (6) ethyl O,O-diisopropyl-dithiophosphoryl-p-chlorophenylacetate from O,O - diisopropyl - dithiophosphoric acid and ethyl a -p-chlorophenyl-a -chloroacetate in acetone; (7) isopropyl O,O-diethyl-dithiophosphoryl-phenylacetate from O,O-diethyl-dithiophosphoric acid and isopropyl a -phenyl-a -bromoacetate in ethyl alcohol; (8) methyl O,O - dimethyl - dithiophosphoryl - phenylacetate from O,O-dimethyl-dithiophosphoric acid and methyl a -phenyl-a -bromoacetate in dioxane; (9) ethyl O,O-diisopropyl-dithiophosphoryl-naphthylacetate from O,O-diisopropyldithiophosphoric acid and ethyl a -naphthyl-a -chloroacetate in acetone. Reference has been directed by the Comptroller to Specification 803,441.ALSO:Pesticidal compositions comprise O,O-dialkyldithiophosphorylacetic esters of formula <FORM:0834814/VI/1> wherein R4, R5 and R6 are like or unlike, saturated or unsaturated, straight- or branched-chain alkyl radicals and R3 is a substituted or unsubstituted aryl radical. (For preparation see Group IV (b)). Other disinfecting compounds and/or plant nutrients and/or fertilizers may be present. Aqueous dispersions and acetone and benzene solutions are used in examples. Reference has been directed by the Comptroller to Specification 803,441.