Process for the preparation of &agr;-diketones from ketols or ketals from ketols
    11.
    发明授权
    Process for the preparation of &agr;-diketones from ketols or ketals from ketols 失效
    从酮基酮或酮缩酮制备α-二酮的方法

    公开(公告)号:US06316676B1

    公开(公告)日:2001-11-13

    申请号:US09794075

    申请日:2001-02-28

    IPC分类号: C07C4529

    摘要: The process for the preparation of carbonyl compounds of the formula I where R1 and R2 are a hydrocarbon radical, or R1 and R2 together are an unsubstituted or substituted alkylene group, and X is ═O or two alkoxy groups, comprises oxidizing alcohols of the formula II  where R1 to R2 and X are as defined above, with oxygen in the gaseous phase a) at temperatures of from 270 to 600° C. on silver coated catalysts which comprise an abrasion-resistant coating of metallic silver on a core of inert support material, or b) at temperatures of from 450 to 750° C. on silver crystals and/or copper crystals having a particle size of from 0.1 to 2.5 mm for a residence time of at most 0.1 second. Also claimed is an advantageous overall process for the preparation of &agr;-diketones, preferably diacetal, from the corresponding ketone, in particular methyl ethyl ketone, via the carbonyl compounds of the formula I where X is two alkoxy groups.

    摘要翻译: 制备式I其中R 1和R 2的羰基化合物的方法是烃基,或者R 1和R 2一起是未取代或取代的亚烷基,并且X是= O或两个烷氧基,包括将式II的氧化醇,其中R 1 在含有惰性载体材料芯上的金属银的耐磨涂层的银涂覆的催化剂上,在温度为270-600℃的温度下,R2和X如上定义,在气相中为氧) 在450至750℃的温度下,在银晶体和/或具有0.1至2.5mm的粒度的铜晶体上,停留时间至多为0.1秒。还要求保护的是制备α 二酮,优选二缩醛,通过其中X是两个烷氧基的式I的羰基化合物从相应的酮,特别是甲基乙基酮中获得。