A phthalide compound represented by the formula (1) :
wherein R1, R2, R3, R4, R5 and R6 are individually an alkyl group, and R1 and R2, R3 and R4, and R5 and R6 can respectively bond each other to form a heterocyclic ring together with a nitrogen atom, may be prepared from a triphenylmethane compound represented by the formula (2) :
wherein R1, R2, R3, R4, R5 and R6 are the same as above, by oxidising it in the presence of activated carbon in an aqueous solvent using an oxidizing agent.
By the use of this method a phthalide compound used as a color former in color-developing recording materials may be formed efficiently by oxidation of a leuco compound.
一种由式(1)代表的
邻苯二甲酸酯化合物:
其中 R1、R2、R3、R4、R5 和 R6 分别为烷基,且 R1 和 R2、R3 和 R4 以及 R5 和 R6 可分别相互键合,与一个氮原子一起形成杂环,可由式 (2) 所代表的
三苯基甲烷化合物制备:
其中 R1、R2、R3、R4、R5 和 R6 与上式相同,在
活性炭存在下,在
水性溶剂中使用氧化剂将其氧化。
利用这种方法,可以通过氧化一种亮族化合物,有效地形成一种在显色记录材料中用作
显色剂的
邻苯二甲酸盐化合物。