title: 5-Amino-6-benzoyl-8-nitro-2,3-di-hydro-1H-spiro-[imidazo[1,2-a]pyridine-7,3'-indolin]-2'-one dimethyl sulfoxide monosolvate.
abstract: In the title compound C21H17N5O4·C2H6OS, the central six-membered ring derived from 1,4-di-hydro-pyridine 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 NH2 group forms an intra-molecular 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 mol-ecule which acts as both an acceptor and a donor..
authors.affiliation: Department of Physics, The Madura College, Madurai 625 011, India.
authors.forename: R A
authors.initials: RA
authors.lastname: Nagalakshmi
authors.affiliation: Department of Physics, The Madura College, Madurai 625 011, India.
authors.forename: J
authors.initials: J
authors.lastname: Suresh
authors.affiliation: Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: S
authors.initials: S
authors.lastname: Sivakumar
authors.affiliation: Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: R Ranjith
authors.initials: RR
authors.lastname: Kumar
authors.affiliation: Department of Food Science and Technology, University of Ruhuna, Mapalana, Kamburupitiya 81100, Sri Lanka.
authors.forename: P L Nilantha
authors.initials: PL
authors.lastname: Lakshman