The asymmetric unit of the title compound, C(19)H(17)N(3)O(3), consists of two independent mol-ecules that are disposed about a pseudo-centre of inversion. The plane of the phenyl substituent is twisted by 38.1 (1)° [43.6 (1)° in the second mol-ecule] out of the plane of the quinoxaline ring system. The five-membered ring of the substituent at the 2-position adopts an envelope conformation; the 5-CH(2) atom representing the flap lies out of the plane defined by the other four atoms [deviation 0.264 (7) Å in the first mol-ecule and 0.291 (6) Å in the second]. The dihedral angle between the five-membered ring and the 4-phenyl ring is 84.9 (1)° while that between the five-membered ring and the 5-phenyl ring is 65.6 (1)°.