One-pot synthesis of various xanthene derivatives using ionic liquid1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient and reusable catalyst under solvent-free conditions

In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.

Synthesis and solvatochromism study of some new 4-(benzyloxy)-2-((4-aryl)diazenyl)phenols

A series of novel azo disperse dyes were synthesized by coupling reaction of 4-benzyloxyphenol with diazotized p-substituted aniline derivatives as diazo components. These compounds were characterized by spectroscopic techniques and elemental analysis. Ionization constants, pKa, for these dyes were determined using electronic spectroscopic method.