Sematilide is an antiarrhythmic agent. It is the same structure as for procainamide, differing only by the placement of a mesyl sulfonamide moiety to the anilino nitrogen.
Synthesis
Sematilide can be synthesized from benzocaine (1).12 Reaction with mesyl chloride, followed by saponification and removal of the water from the reaction mixture, gives sodium 4-[(methylsulfonyl)amino]benzoate (2). Chlorination with thionyl chloride gives 4-[(methylsulfonyl)amino]benzoyl chloride. Amide formation with N,N-diethylethylenediamine (3) then concludes the synthesis of sematilide (4).
References
Lumma, William C.; Wohl, Ronald A.; Davey, David D.; Argentieri, Thomas M.; Devita, Robert J.; Gomez, Robert P.; Jain, Vijay K.; Marisca, Anthony J.; Morgan, Thomas K.; Reiser, H. J. (1987). "Rational design of 4-[(methylsulfonyl)amino]benzamides as class III antiarrhythmic agents". Journal of Medicinal Chemistry. 30 (5): 755–758. doi:10.1021/jm00388a001. PMID 3572962. /wiki/Doi_(identifier) ↩
David D. Davey, William C. Lumma, Jr., Ronald A. Wohl, U.S. patent 4,544,654 (1985 to Schering A.G.) https://patents.google.com/patent/US4544654 ↩