| 摘要 |
PROBLEM TO BE SOLVED: To economically obtain the subject compound capable of extremely rapidly reacting, not causing a waste water treatment problem after the reaction and useful as a coupler for color development type recording materials by performing the reaction in the presence of activated carbon. SOLUTION: This method for producing a phthalide compound of formula II (R<1> -R<6> are each an alkyl or the like) [e.g. 3,3-bis(4-dimethylaminophenyl)-6- dimethylaminophthalide] comprises oxidizing a triphenylmethane compound of formula I e.g. 2-[4,4'-bis(dimethylamino)benzhydryl]-5-dimethylaminobenzoic acid} with an oxidizing agent, preferably one kind of compound selected from air, oxygen, hydrogen peroxide and the mixtures of oxygen with inactive gases in the presence of activated carbon in an aqueous solvent. |
