Cyclic two-stage nitration process for preparing
4-chloro-3,5-dinitrobenzotrifluoride from 4-chlorobenzotrifluoride
    141.
    发明授权
    Cyclic two-stage nitration process for preparing 4-chloro-3,5-dinitrobenzotrifluoride from 4-chlorobenzotrifluoride 失效
    从4-氯三氟甲苯制备4-氯-3,5-二硝基三氟甲苯的循环两阶段硝化方法

    公开(公告)号:US4096195A

    公开(公告)日:1978-06-20

    申请号:US796519

    申请日:1977-05-13

    CPC classification number: C07C201/08 C07C201/14

    Abstract: In accordance with the present invention, there is provided herein a cyclic, two-stage process for dinitrating 4-chlorobenzotrifluoride to form 4-chloro-3,5-dinitrobenzotrifluoride in high yield. The process commences with a mononitration stage wherein 4-chlorobenzotrifluoride is substantially completely converted to 4-chloro-3-nitrobenzotrifluoride (the "monoitro" compound) in the presence of a nitric acid, sulfur trioxide and sulfuric acid mixture. The used acid mixture then is diluted with water to form an aqueous used acid layer in which the solubility of the mononitro compound is negligible and a mononitro layer. The aqueous used acid layer then is separated from the mononitro layer and discarded. The mononitro compound thereafter is further nitrated in a dinitration stage in the presence of a fresh nitric acid, sulfur trioxide and sulfuric acid mixture. The fresh acid mixture contains an excess of nitric acid sufficient to carry out both nitrations using the partially spent acid mixture of the dinitration stage as the acid mixture for the mononitration stage. The reaction product of the dinitration stage is the desired dinitro compound and a partially spent acid mixture, which contains some dinitro compound dissolved therein. The dinitro layer then is separated from the partially spent acid layer and recovered and the acid layer is recycled back to the mononitration stage.

    Abstract translation: 根据本发明,本文提供了一种用于将4-氯三氟甲苯二硝基化以环状二步法,以高产率形成4-氯-3,5-二硝基三氟甲苯。 该过程开始于硝酸,三氧化硫和硫酸混合物存在下,4-氯三氟甲苯基本上完全转化为4-氯-3-硝基三氟甲苯(“一硝基”化合物)的单硝化阶段。 然后将所使用的酸混合物用水稀释以形成其中单硝基化合物的溶解度可忽略的水性使用的酸层,和单硝酸层。 然后将水性使用的酸层与单硝基层分离并丢弃。 此后的单硝基化合物在新硝酸,三氧化硫和硫酸混合物的存在下,在二硝化阶段进一步硝化。 新鲜的酸性混合物含有足够多的硝酸,使用二硝化阶段的部分废酸混合物作为单硝化阶段的酸混合物进行硝化。 二硝化阶段的反应产物是所需的二硝基化合物和部分废酸混合物,其中含有一些溶解在其中的二硝基化合物。 然后将二硝基层与部分废酸层分离并回收,酸层再循环回到单硝化阶段。

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