摘要 |
This invention relates to 3-aryl or heteroaryl-3-alkoxy, phenoxy-, alkylthio- or phenylthiophthalides useful as color formers, particularly in carbonless duplicating and thermal marking systems, which are prepared by the interaction of 2-(disubstituted amino)phenylcarbonylbenzoic acids with an acid chloride or an anhydride of an alkanoic acid in the first step and a further reaction of the product of the first step with an alcohol, a thioalcohol, a phenol or a thiophenol in a second step.
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