Dapsone is somewhat inconvenient to administer to patients because of its rather low water solubility.
In the search for more easily administered drugs, dapsone (1) was reacted with bromoacetic acid to give acediasulfone (2) which can be administered as a water-soluble salt.
References
^Jackson EL (February 1948). "Certain N-alkyl, N-carboxyalkyl and N-hydroxyalkyl derivatives of 4,4'-diaminodiphenyl sulfone". Journal of the American Chemical Society. 70 (2): 680–4. doi:10.1021/ja01182a074. PMID18907772.