An Attempt to Achieve Hydrated Imidazoline Ring Expansion (HIRE) of Diarene-Fused [1,4]Diazepinones Delivers Selective Dopamine D2 Receptor Ligands

Abstract 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) did not result in ring expansion but, rather, led to 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.