The design and synthesis of the novel 2, 3, 4, 5-tetrahydro-1H-[1, 4] diazepino [1, 7-a] indole 5 is described. This azepinoindole has excellent affinity for 5-HT2C (Ki 4.8 nM) and modest selectivity over 5-HT2A (∼ 4-fold). Several N-and C11-substituted analogues of 5 were prepared, as were a number of biaryl indoline derivatives. The anxiolytic potential for the azepinoindole template 5 is demonstrated by activity in a mouse shock–aggression assay.