The treatment of di (2-amino-5-methylphenyl) methane with N-sulfinylmethanesulfonamide gives two materials, 3-(2-amino-5-methylphenyl)-5-methyl-2, 1-benzisothiazole and what appears to be its tautomer, a 2, 1-benzisothiazolo [2, 3-b]-2, 1-benzisothiazole derivative. Reaction of the former with methyl iodide gives mono-, di-, and trimethyl derivatives. The second of these also possesses the symmetrical 2, 1-benzisothiazolo [2, 3-b]-2, 1- ...