| 摘要 |
The invention comprises compounds of the formula <FORM:0888648/IV (b)/1> where Alk is an alkyl group, and their preparation by reacting a dihalophenyl dichloromethyl ketone with a trialkyl phosphite. Examples prepare 2-chloro-1-(21,41-, 21,51- and 21,61-dichlorophenyl) vinyl diethyl phosphate, and 2-chloro-1-(21-fluoro-51-bromophenyl) vinyl diethyl phosphate. The starting ketones may be prepared by chlorinating the dihalophenyl methyl ketone, preferably with irradiation by ultra-violet light. The compounds of the invention are used in insecticidal compositions (see Group VI).ALSO:The invention comprises insecticidal compositions containing a compound of formula <FORM:0888648/VI/1> where Alk is an alkyl group (see Group IV (b)), and a carrier therefor, which may be solid, liquid or gaseous. The compositions may be aqueous sprays or dust compositions. The usual carriers are specified, and wetting or emulsifying agents may be present. |
