Synthesis and antidepressant properties of novel 2-substituted 4,5-dihydro-1H-imidazole derivatives

A unique combination of alpha 2-adrenoreceptor antagonist and serotonin-selective reuptake inhibitory activities has been identified in a series of 2-substituted 4,5-dihydro-1H-imidazole derivatives. This combination of blocking activities has provided one of these derivatives, napamezole hydrochloride (2), with potential as an antidepressant. A discussion of the syntheses of these compounds includes a convenient method for the conversion of nitriles to imidazolines with ethylenediamine and trimethylaluminum.