Efficient Two-Step Syntheses of Sulfonylguanidines from Sulfonamides

Various sulfonylguanidines have been synthesized from a sulfonamide by two mild and efficient synthetic methods. In route A, the methylthio group of S-methylsulfonylisothiourea is displaced by a variety of amines while in route B the amines are reacted with sulfonylthiourea in the presence of mercury oxide HgO.