Three 5(6)-carboxyl fluoresceines were obtained from trimellitic anhydride and resorcinol derivatives using methylsulphonic acid as catalyst.And its isomer separation was studied.

• 以偏苯三酸酐和取代间苯二酚为原料,以甲基磺酸为催化剂缩合制备了三种5(6)-羧基荧光素,并对其进行了异构体分离研究。