Process for the preparation of dimethyl succinylosuccinate, the disodium salt thereof, dianilinodihydroterephthalic acids, the dimethyl esters and salts thereof, and dianilinoterephthalic acids, and the dimethyl esters and salts thereof

摘要

Process for the preparation of dimethyl succinylosuccinate, or the disodium salt thereof, by condensation of dimethyl succinate in a 35-45 percent by weight solution of sodium methylate in methanol, and a process for the preparation of dianilinodihydroterephthalic acids, the dimethyl esters and salts thereof, and of dianilinoterephthalic acids, and the dimethyl esters and salts thereof, starting from the disodium salt of dimethyl succinylosuccinate prepared according to the new process, without intermediate isolation.