申请人:Hoechst Aktiengesellschaft
公开号:US05200556A1
公开(公告)日:1993-04-06
Process for the preparation of 3,4,6-tetrafluorophthalic acid of the formula (1) ##STR1## or the anhydride thereof in good yields and in an advantageous manner, by dehalogenating tetrafluorophthalic anhydride of the formula (2) ##STR2## or tetrafluorophthalic acid in aqueous-alkaline medium using zinc at temperatures of approximately 20.degree. C. to approximately 160.degree. C. and, if appropriate, converting the resulting 3,4,6-trifluorophthalic acid into the anhydride in a known manner by dehydrating it.
制备式(1)的3,4,6-四氟邻苯二甲酸或其酐的过程,包括通过在水碱性介质中使用锌,在约20°C到约160°C的温度下,脱卤四氟邻苯二甲酸酐式(2)##STR2##或四氟邻苯二甲酸,以良好的产率和有利的方式进行反应。如有必要,可以通过脱水将产生的3,4,6-三氟邻苯二甲酸转化为其酐,以已知的方法进行。