Sodium p-toluenesulfinate can be used as intermediate of pharmaceutical and dispersal dyes, and also can be used as curing agent of grouting material.
p-Toluenesulfinic acid sodium salt is used as an intermediate for the preparation of pharmaceuticals and dispersal dyes. It acts as a curing agent of grouting material. It is also used as a discharge medium of dyes and pigments. Further, it serves as a chemical intermediate in the production of fluorescent pigments and fabric adhesive. In addition to this, it is used as an electroplating brightening agent and curing agent.
Recrystallise the salt from water (to constant UV spectrum) and dry it under vacuum, or extract it with hot *benzene, then dissolve it in EtOH/H2O and heat with decolorising charcoal. The solution is filtered and cooled to give crystals of the dihydrate.[Beilstein 11 I 718.]