PROCESS FOR THE PREPARATION OF 3,4,6-TRIFLUOROPHTHALIC ACID AND THE ANHYDRIDE THEREOF

摘要

of the disclosure: HOE 91/F 155 Process for the preparation of 3,4,6-tetrafluorophthalic acid and the anhydride thereof Process for the preparation of 3,4,6-tetrafluorophthalic acid of the formula (1) ( 1 ) or the anhydride thereof in good yields and in an advantageous manner, by dehalogenating tetrafluorophthalic anhydride of the formula (2) (2) 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.