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

In the title mol­ecule, C(24)H(18)N(2)O(3)S, the 13-atom ring system comprising the quinoxaline and fused five-membered ring exhibits an r.m.s. deviation from coplanarity of 0.039 Å, with a maximum deviation of 0.0710 (10) Å for the PhCO-bearing C atom of the five-membered ring. The 10-membered C(8)N(2) quinoxaline ring system has an r.m.s. deviation from coplanarity of 0.022 Å, with a maximum deviation of 0.0403 (9) Å 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) Å 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) Å, unlike the difference of nearly 0.06 Å in quinoxaline.