Abstract
For synthesis of 2, 5-dianilinoterephthalic acid (2) as an intermediate for synthesis of organic red pigment, a linear type quinacridone (1), synthesis of (2) through diketene (3) ?A-haloacetoacetic acid ester (4), diethyl succinylsu ccinate (5), and diethyl dianilinoterephthalate (6) has been investigated from industrial point of view. It was found that no solvent was necessary for synthesis of (4) from (3), and using of a small amount of hydrochloric acid and 10% excess of aniline than the theory for synthesis of (6) from (5) gave yield of (6) 95% of theory.
