Crystal structures of ethyl (2S*,2'R*)-1'-methyl-2'',3-dioxo-2,3-di-hydro-dispiro-[1-benzo-thio-phene-2,3'-pyrrolidine-2',3''-indoline]-4'-carboxyl-ate and ethyl (2S*,2'R*)-5''-chloro-1'-methyl-2'',3-dioxo-2,3-di-hydro-dispiro-[1-benzo-thio-phene-2,3'-pyrrolidine-2',3''-indoline]-4'-carboxyl-ate.

ABSTRACT: 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 benzo-thio-phene 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 eth-oxy-carbonyl group occupies an equatorial position with an extended conformation. The overall conformation of the two mol-ecules differs in the angle of inclination of the indole unit with respect to the benzo-thio-phene 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), mol-ecules are linked via pairs of N-H?O hydrogen bonds, forming inversion dimers enclosing R 2 (2)(14) loops. The dimers are linked via C-H?O and bifurcated C-H?O(O) hydrogen bonds, forming sheets lying parallel to (100). In the crystal of (II), mol-ecules are again linked via pairs of N-H?O hydrogen bonds, forming inversion dimers but enclosing smaller R 2 (2)(8) loops. Here, the dimers are linked by C-H?O hydrogen bonds, forming ribbons propagating along [010].

SUBMITTER: Savithri MP 

PROVIDER: S-EPMC4158536 | biostudies-other | 2014 Aug

REPOSITORIES: biostudies-other