Synthesis of 14H-dibenzo xanthene derivatives using choline chloride/tin(II) chloride deep eutectic solvent and Fe3O4/ƛ-carrageenan/Zn(II)

In this study, various xanthene derivatives have prepared efficiently through a simple method using choline chloride/tin(II) chloride (ChCl·2SnCl2) deep eutectic solvent (DES), alone, or in the presence of Fe3O4/ƛ-carrageenan/Zn(II) magnetic bionanocatalyst. In the employed procedure, 2-naphthol derivatives have mixed with aromatic or aliphatic aldehydes and the reactions have been completed in the presence of DES at 90 °C in 1.5 h. In addition, using DES/Fe3O4/ƛ-carrageenan/Zn(II), the reaction time was reduced to 30 min. The employed DES has been recycled four times without important loss of its activity.