Crystal structure of 4-methyl-N-{(E)-meth­yl[(3aR,8aS)-2-oxo-3,3a,8,8a-tetra­hydro-2H-indeno­[1,2-d][1,3]oxazol-3-yl]-λ(4)-sulfanyl­idene}benzene­sulfonamide

The formulation that the title compound, C(18)H(18)N(2)O(4)S(2), adopts is a zwitterionic core with the charge separated to the sulfilimine S and N atoms and is supported by the two different S—N bond distances about the sulfinimine N atom [1.594 (2) and 1.631 (2) Å, respectively] that are typical for such bonds. The notably unusual bond is S—N(oxazolidinone) [1.692 (2) Å] that is longer than a typical S—N bond [1.603 (18) Å, Mogul analysis; Macrae et al. (2008 ▸). J. Appl. Cryst. 41, 466–470]. The bond-angle sum about sulfilimine sulfur (308.35°) reflects the trigonal–pyramidal geometry of this atom. Two of the angles are less than 100°. Despite the pyramidalization of this sulfur, there are no significant inter­molecular inter­actions, beyond usual van der Waals contacts, in the crystal packing.