(Phenyl)(3-phenylsulfonyl-1,2-dihydropyrrolo[1,2-a]quinoxalin-1-yl)methanone

In the title molecule, C24H18N2O3S, the 13-atom ring system comprising the quinoxaline and fused five-membered ring exhibits an r.m.s. deviation from coplanarity of 0.039 angstrom, with a maximum deviation of 0.0710 (10) angstrom for the PhCO-bearing C atom of the five-membered ring. The 10-membered C8N2 quinoxaline ring system has an r.m.s. deviation from coplanarity of 0.022 angstrom, with a maximum deviation of 0.0403 (9) angstrom for the C atom involved in the C=C bond in the five-membered ring. The three atoms of the five-membered ring fused to the quinoxaline ring system show deviations of up to 0.118 (2) angstrom for the PhCO-bearing C atom. C-N bond distances in the quinoxaline ring system of the title molecule deviate from those in unsubstituted quinoxaline. In particular, the two C-N distances to the N atom involved in the five-membered ring are essentially equal, with values of 1.3786 (17) and 1.3773 (16) angstrom, unlike the difference of nearly 0.06 angstrom in quinoxaline.