GB924821A - New thiophí¡í¡ esters - Google Patents

Abstract

The invention comprises thiophosphoric esters of the formula (CH3O)2P(X)SCH2CH2 SCH(CH3)CONHCH3 wherein X is an oxygen atom or a sulphur atom. They may be obtained (a) by reacting a halogeno phosphate of the formula (CH3O)2P(X1)Hal with a compound of the formula HX2.CH2.CH2.S.CH(CH3) CONHCH3 or with a salt thereof, where X1 and X2 are both sulphur atoms or one of X1 and X2 is an oxygen atom and the other is a sulphur atom and Hal is a halogen atom preferably chlorine, (b) by reacting a salt, e.g. an alkali metal or ammonium salt, of an O,O-dimethylthio (or dithio) phosphoric acid with a reactive ester of the formula Y.CH2. CH2.SCH(CH3)CONHCH3 where Y is the acid residue of a reactive ester, e.g. a halogen atom, or a sulphuric or sulphonic ester group, or (c) by reacting a reactive ester (e.g. a halide) of an O,O-dimethylthio(or dithio)phosphoryl-2-ethanol with the compound HS.CH(CH3) CONHCH3 or with a salt thereof. Method (a) is preferably carried out in a solvent medium at below 150 DEG C. in the presence of a basic condensing agent, e.g. an alkali metal or its hydroxide or carbonate. The reaction may be effected without the condensing agent when the second mentioned reactant is used in the form of an alkali metal salt. Suitable solvents are aliphatic alcohols and ketones and chlorinated hydrocarbons. Methods (b) and (c) are preferably carried out in water or an organic solvent, e.g. an aliphatic alcohol or nitrile, or a ketone, at between 15 and 150 DEG C., e.g. at the boiling point of the solvent used. Examples are given for the production of the O,O-dimethylthiolo(and dithio)phosphoryl compounds using method (a). The products have pesticidal properties (see Group VI).ALSO:A pesticidal composition comprises at least one phosphorus ester of the formula <FORM:0924821/VI/1> wherein X is an oxygen atom or a sulphur atom (see Group IV (b)) together with at least one diluent compatible therewith. Specified diluents include talc, calcined magnesia, kieselguhr, tricalcium phosphate, powdered cork, absorbent carbon black, kaolin, bentonite, aromatic hydrocarbons e.g. toluene or xylene, and mineral, animal or vegetable oils. The compositions may be in the form of aerosols, suspensions, emulsions, or solutions in organic or aqueous organic media and may contain wetting, dispersing or emulsifying agents of the ionic or non-ionic type such as sulphoricinoleates quaternary ammonium compounds, ethylene oxide condensates e.g. with octyl phenol or fatty acid esters of anhydrosorbitols condensed with ethylene oxide. Other pesticides may also be present.