GB812369A - Esters of monothiophosphoric acid, process for preparation thereof and insecticidal compositions containing them - Google Patents

Abstract

The invention comprises esters of monothiophosphoric acid having the formula <FORM:0812369/IV (b)/1> wherein R1, R2 and R4 are lower aliphatic hydrocarbon radicals containing 1 to 3 carbon atoms, and R3 is an alkoxymethyl radical containing 2 to 4 carbon atoms. The preferred compounds are those in which R1, R2 and R4 are methyl or ethyl radicals and R3 is methoxymethyl or ethoxymethyl. The novel compounds may be prepared by reacting a compound of the formula <FORM:0812369/IV (b)/2> wherein R1 and R2 are as defined above and X is a halogen, e.g. chlorine, with a compound of the formula <FORM:0812369/IV (b)/3> wherein R3 and R4 are as defined above and M is hydrogen or an alkali metal, preferably in the presence of acid-binding agents such as sodium carbonate, acetate or cyanide, and solvents, such as toluene, xylene or acetone, and advantageously at temperatures of 50-150 DEG C. The products are stable in aqueous suspension and soluble in oils and inorganic solvents and may be used in insecticidal compositions (see Group VI). In examples: (1) sodium in boiling xylene is treated dropwise with ethyl (3-methoxy-2-hydroxypropyl) sulphide, dimethyl thiophosphonyl chloride is added and the mixture is stirred for 3 hours at 100-110 DEG C. to give a compound of formula (I) wherein R1 and R2 are methyl, R3 is methoxymethyl and R4 is ethyl; (2) the same acid chloride and sulphide treated at 30-40 DEG C. with pyridine give the same product as (1); (3) the product of (1) is produced in the presence of potash, copper powder and benzene; (4) ethyl-(3-ethoxy-2-hydroxy-propyl) sulphide and dimethyl thiophosphonic acid chloride are reacted as in (1) giving a product where R1 and R2 are methyl, R3 is ethoxymethyl and R4 is ethyl; (5) ethyl-(3 - methoxy - 2 - hydroxypropyl) sulphide and diethyl thiophosphoric acid chloride are reacted as in (1) giving a product where R1 and R2 are ethyl, R3 is methoxymethyl and R4 is ethyl; (6) ethyl - (3 - ethoxy - 2 - hydroxypropyl) sulphide and diethylphosphoric acid chloride reacted as in (1) give a product where R1 and R3 are ethyl, R3 is ethoxymethyl and R4 is ethyl. Specifications 697,120 and 767,950 are referred to.ALSO:An insecticidal composition comprises an ester of monthiophosphoric acid of the formula <FORM:0812369/VI/1> wherein R1, R2 and R4 are lower aliphatic hydrocarbon radicals containing 1 to 3 carbon atoms, and R3 is an alkoxymethyl radical containing 2 to 4 carbon atoms, and a diluent, e.g. an emulsifying agent, such as a polyglycol ether, or a finely divided, solid water-insoluble organic or inorganic p substance. Examples describe the following compositions: (7) a solution containing 0.02 per cent p-iso-octylphenyloctaglycolether and 0.02 per cent of an ester of the above formula wherein R1 and R2 are ethyl, R3 is methoxymethyl and R4 is ethyl; (8) a composition similar to (7) where the active substance is an ester of the above formula wherein R1 and R2 are methyl, R3 is methoxymethyl and R4 is ethyl; (9) an aqueous emulsion containing 0.01 per cent of a di-iso-octyl phenylheptaglycol ether and 0.01 per cent of an ester of the above formula wherein R1 and R2 are ethyl, R3 is methoxymethyl and R4 is ethyl; (10) an aqueous emulsion containing 0.01 per cent of a di-iso-octyl phenylheptaglycol ether and 0.01 per cent of an ester of the above formula wherein R1 and R2 are methyl, R3 is methoxymethyl and R4 is ethyl; (13) an ester of the above formula wherein R1 and R2 are methyl, R3 is ethoxymethyl and R4 is ethyl, is mixed with lauryl hexaglycol ether and toluene and a 0.1 per cent aqueous emulsion of this mixture is used as a spray; (14) an ester of the above formula wherein R1 and R2 are ethyl, R3 is methoxymethyl and R4 is ethyl is mixed with octylphenylpolyglycol ether and butyl-polyglycol, and a 0.05 per cent aqueous emulsion of the mixture is used to kill plant lice; (15) the ester used in (8) is mixed with talc and the mixture is ground in a ball-mill to give a powdered material which kills Periplaneta; (16) the ester used in (7) is mixed with an oleylpolyglycol ether with 20 ethenoxy groups and glycolmonoethyl ether and a 0.05 per cent aqueous solution of the mixture is active against plant lice; (17) an ester of the above formula wherein R1 and R2 are ethyl, R3 is ethoxymethyl and R4 is ethyl is mixed with octylphenylpolyglycol ether and butylpolyglycol and a 0.05 per cent aqueous emulsion is effective against plant lice; (18) the ester used in (7) is mixed with oleylpolyglycol ether, paraffin oil and octyl alcohol to give a clear solution and an aqueous 1 per cent emulsion of this material is used as a spray against plant lice and harvest ticks. (For preparation of the esters of monothiophosphoric acid see Group IV (b)). Specifications 697,120, [Group IV (b)], and 767,950 are referred to.