| 摘要 |
Dialkylamino-substituted 2-anilino-5'/6'-carboxyfluorans, esterified dialkylamino-substituted 2-anilino-5'/6'-carboxyfluorans and 3,3-(corresponding-substituted-diaryl)-5/6-carboxyphthalides useful as color formers, particularly in carbonless duplicating and thermal marking systems, are prepared by the interaction of 4/5-carboxy-2-(4-dialkylamino-substituted-2-hydroxybenzoyl)benzoic acids and substituted diphenylamines to produce the phthalides which are then subjected to ring closure to produce the carboxyfluorans which are esterified with alkyl halides or dialkyl sulfates. |
