abstract |
2,5-di(p-methoxyanilino)terephthalic acid crystal types I and Il are made by controlling the pH during the recovery of the oxidized product of the condensation of dimethylsuccinyl succinate with p-methoxyaniline. The resulting 2,5-di(p- methoxyanilino)-terephthalic acid can be converted into 2,9-dimethoxyquinacridone or a solid solution thereof having controlled characteristics. |