Process for the preparation of durene diisocyanate
    3.
    发明授权
    Process for the preparation of durene diisocyanate 失效
    杜烯二异氰酸酯的制备方法

    公开(公告)号:US06486346B1

    公开(公告)日:2002-11-26

    申请号:US09460953

    申请日:1999-12-14

    IPC分类号: C07C27300

    CPC分类号: C07C263/10 C07C265/14

    摘要: Durene diisocyanate is prepared by reacting durene with nitric acid in sulfuric acid, catalytic hydrogenation of the dinitrodurene that is formed, and phosgenation of the resultant durene diamine in a conventional manner. The intermediate products dinitrodurene and durene diamine do not have to be worked up in a complicated manner as solid products, but can be worked up in dissolved form. The intermediate products dinitrodurene and durene diamine do not have to be isolated and purified in a complicated manner. but can be processed directly after preparation. Another advantage of this process is that only a single organic solvent need be used for the overall preparation process. Separation and re-use of spent acid in the conversion of durene with nitric acid also renders the process of the present invention significantly less environmentally harmful than the known processes of the prior art.

    摘要翻译: 杜烯二异氰酸酯是通过使杜烯与硝酸在硫酸中反应制得的,所形成的二硝基还原剂的催化氢化和所得的杜烯二胺以常规方式进行光气化。 中间产物二硝基呋喃和杜烯二胺不需要以固体产物的复杂方式处理,而可以以溶解的形式进行处理。 中间产物二硝基杜烯和杜烯二胺不需要以复杂的方式分离和纯化。 但可以在准备后直接加工。 该方法的另一个优点是在整个制备过程中仅需要使用单一的有机溶剂。 在杜烯与硝酸的转化中,废酸的分离和再利用也使得本发明的方法比现有技术的已知方法显着降低了对环境的危害。