1,3-Diallyl-1H-anthra[1,2-d]imidazole-2,6,11(3H)-trione.

In the title compound, C(21)H(16)N(2)O(3), the fused-ring system (r.m.s. deviation = 0.067 Å) is slightly buckled at the carbonyl C atom of the anthracenyl ring system [deviation = 0.177 (1) Å] that is closer to an allyl substituent. The two allyl units lie on the same side of the fused-ring plane but are oriented in opposite directions, with N-C-C-C torsion angles of 126.9 (2) and 116.7 (2)°. In the crystal, the mol-ecules are linked into chains propagating along the b axis by C-H⋯O hydrogen bonds.