1,2-Ethanedisulfonic anhydride

Oxadithiolane 2,2,5,5-tetroxide, i.e. 1,2-ethanedisulfonic anhydride, as well as its benzo derivative, may be used to improve the dyeing characteristics of polyesters with basic dyes (71JAP7142631). 

In 1996, Mitsubishi Chemical Corporation discovered that chain sulfonic acid anhydrides, such as methanesulfonic anhydride (49), can be used as additives in small quantities [77]. Furthermore, in 2002, NEC Corporation found that the cyclic sulfonic anhydride 1,2-ethanedisulfonic anhydride (50) can be used as an additive in small quantities [78]. 

---