In the title compounds, C22H20N2O4S, (I), and C22H19ClN2O4S, (II), the pyrrolidine rings have twist conformations on the spiro–spiro C—C bonds. In (I), the five-membered ring of the oxindole moiety has an envelope conformation with the spiro C atom as the flap, while in (II) this ring is flat (r.m.s. deviation = 0.042 Å). The mean planes of the pyrrolidine rings are inclined to the mean planes of the indole units [r.m.s deviations = 0.073 and 0.069 Å for (I) and (II), respectively] and the benzothiophene ring systems (r.m.s. deviations = 0.019 and 0.034 Å for (I) and (II), respectively) by 79.57 (8) and 88.61 (7)° for (I), and by 81.99 (10) and 88.79 (10)° for (II). In both compounds, the ethoxycarbonyl group occupies an equatorial position with an extended conformation. The overall conformation of the two molecules differs in the angle of inclination of the indole unit with respect to the benzothiophene ring system, with a dihedral angle between the planes of 71.59 (5) in (I) and 82.27 (7)° in (II). In the crystal of (I), molecules are linkedviapairs of N—H...O hydrogen bonds, forming inversion dimers enclosingR22(14) loops. The dimers are linkedviaC—H...O and bifurcated C—H...O(O) hydrogen bonds, forming sheets lying parallel to (100). In the crystal of (II), molecules are again linkedviapairs of N—H...O hydrogen bonds, forming inversion dimers but enclosing smallerR22(8) loops. Here, the dimers are linked by C—H...O hydrogen bonds, forming ribbons propagating along [010].
5-[(1,3-Dimethyl-5-oxo-2-sulfanylideneimidazolidin-4-ylidene)amino]-2-methylisoindoline-1,3-dione
