Substituted thiophosphoric esters and insecticidal compositions containing them

The invention comprises compounds of the formula: where R1 and R2 are alkyl radicals, X is oxygen or sulphur, Y is a radical NR3R4 wherein R3 and R4 are hydrogen or alkyl or R3 and R4 together with the nitrogen make up a heterocyclic ring, and Z is a radical NR3R4 as defined or an alkoxy radical. These compounds are prepared by reacting a salt of an O, O - dialkylthiolphosphoric acid or O, O-dialkyldithiophosphoric acid with a compound ZCO.CHHal.COY; or by reacting a compound ZCO.CH(SH).COY or a salt thereof with an O,O-dialkylthionophosphoric acid chloride or O,O-dialkylphosphoric acid chloride. The compounds of the invention are insecticides (see Group VI).ALSO:The invention comprises insecticidal compositions containing a compound of formula where R1 and R2 are alkyl radicals, X is oxygen or sulphur, Y is a radical NR3R4 wherein R3 and R4 are hydrogen or alkyl or R3 and R4 together with the nitrogen make up a heterocyclic ring, and Z is a radical NR3R4 as defined or an alkoxy radical (see Group IV (b)). These compounds may be made up as dusts by adding solid extenders, as sprays by adding dispersing, wetting and/or sticking agents to solid or liquid preparations, or as solutions or emulsions. Fungicides and/or other insecticides may be incorporated in the compositions. Examples use aqueous emulsions.