| 摘要 |
<p>The invention comprises the compounds of the general formula <FORM:1078172/C2/1> in which X and X1 are the same or different and represent chlorine or fluorine atoms. These compounds (except where X is fluorine and X1 chlorine) may be prepared by reacting a compound of formula <FORM:1078172/C2/2> with sulphur trioxide in the presence of a boron compound or a pentavalent antimony halide as catalyst. The compound in which X is fluorine and X1 chlorine may be prepared by heating the compound of formula <FORM:1078172/C2/3> with hydrogen fluoride in the presence of a Cr2O3 catalyst. Suitable boron compounds for use as catalysts are, for example, trimethylboroxine, borax, sodium or potassium fluoborate, methyl borate or boric bromide, iodide, carbide, chloride, fluorine, hydride, nitride, silicide or sulphide.ALSO:Compounds of the general formula <FORM:1078172/A5-A6/1> in which X and X1 are the same or different and represent chlorine or fluorine atoms, are used in insecticidal compositions.</p> |
