Abstract:
The invention comprises thionophosphoric acid fluoroamides of formula where R and R1 are C1-6 aliphatic hydrocarbyl or cycloaliphatic hydrocarbyl and R2 is hydrogen or C1-6 aliphatic hydrocarbyl, or R1 and R2 together with the nitrogen may form a heterocyclic ring which may contain further hetero atoms. They are prepared by reacting a thionophosphonic acid difluoride with an amine R1R2NH in the presence of an acid binding agent which may be excess amine reactant. The products are insecticides. Methylthionophosphonic acid difluoride required as a starting material is prepared by adding methylthionophosphonic acid dichloride rapidly to a mixture of antiminous fluoride and sodium fluoride or by the dropwise addition of a chlorobenzene solution of the dichloride to a chlorobenzene/sodium fluoride mixture while heating. Other phosphonic acid difluorides are said to be prepared similarly.ALSO:Insecticidal compositions contain as active ingredient a thionophosphoric acid fluoroamide of formula where R and R1 are C1-6 aliphatic hydrocarbyl or cycloaliphatic hydrocarbyl and R2 is hydrogen or C1-6 aliphatic hydrocarbyl, or R1 and R2 together with the nitrogen may form a heterocyclic ring which may contain further hetero atoms, in admixture with a solid or liquid carrier.