An attempt at the hydrated imidazoline ring expansion (HIRE) of diarene-fused [1,4]diazepinones delivers selective dopamine D2 receptor ligands

Attempts to extend the hydrated imidazoline ring expansion (HIRE) strategy to a series of diarene-fused [1,4]diazepinones (earlier applied successfully to bis-pyrido substrate nevirapine) resulted in no ring expansion but rather 2-aminoethyl side chain expulsion. This seeming setback (setting the limitations to the HIRE methodology substrate scope) led to the discovery of selective dopamine D2 ligands with elements of structure-activity relationships.