摘要:
Alumina is used as a support for the CuCl2 catalyst and as a diluent in the oxychlorination of ethylene. When a low surface area alumina, e.g. high purity alpha-alumina, is used as diluent for the reaction, reduced oxidation and less chlorinated by-products are achieved. Alternatively, the alumina used as the catalyst support, e.g. a gamma-alumina which has a high surface area and higher amounts of impurities, can be used as diluent if it is impregnated with an alkali metal ion, e.g K+ ion, which is usually employed as a salt.
摘要:
2,3,5,6-Tetrachloropyridine, and 2,3-dichloro-5-(trichloromethyl)pyridine are prepared by selectively chlorinating polychlorinated .beta.-picolines in the vapor phase between about 250.degree. and 450.degree. C. in the presence of specific Lewis acid halide catalysts on an inorganic support. The gamma position on the pyridine ring is usually not chlorinated in the starting material or reaction products. These compounds are useful intermediates to produce insecticides and herbicides.