5-Amino-6-benzoyl-8-nitro-2,3-di­hydro-1 H-spiro­[imidazo[1,2- a]pyridine-7,3′-indolin]-2′-one dimethyl sulfoxide monosolvate

Abstract

In the title compound C ₂₁H ₁₇N ₅O ₄·C ₂H ₆OS, the central six-membered ring derived from 1,4-di­hydro­pyridine adopts a distorted boat conformation with a small puckering amplitude of 0.127 (3) Å. The sums of bond angles around the pyridine N atom [358.7 (2)°] and the other imidazolidine N atom [60 (2)°] indicate that these atoms are in sp ² hybridization, leading to an essentially planar imidazolidine ring. The last heterocycle, an oxindole moiety, is also nearly planar with an r.m.s. deviation of 0.0185 (1) Å. The amine NH ₂ group forms an intra­molecular hydrogen bond with the benzoyl group, giving a S(6) motif. In the crystal, N—H⋯O hydrogen bonds lead to the formation of chains along the c-axis direction. Within the chains there are further N—H⋯O and C—H⋯O hydrogen bonds enclosing R ² ₂(14) ring motifs. The chains are linked via N—H⋯O and C—H⋯O hydrogen bonds involving the dimethyl sulfoxide solvent mol­ecule which acts as both an acceptor and a donor..