反应详情

or dianilinodihydroterephthalic acids or the salts thereof, is characterised in that the suspension of the disodium salt of dimethyl succinylosuccinate, which suspension is obtained by condensation of dimethyl succinate in a 35-45 percent by weight solution of sodium methylate in methanol, is acidified, and the liberated dimethyl succinylosuccinate is condensed with at least 2 mols of a compound of the formula ##STR3## in which