Polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of ferric hydrogensulphate under melt conditions. The reactions proceeded in short reaction times by using a catalytic amount of Fe(HSO4)3 and the corresponding fluorescein derivatives were obtained in high yields. The simplicity, scale-up, along with the use of an inexpensive, non-toxic, recyclable catalyst of an environmentally benign nature, are other remarkable features of the procedure. The absorption and emission properties of these fluorescein derivatives were studied.

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