Synthesis of Novel N-Substituted Imidazolecarboxylic Acid Hydrazides as Monoamine Oxidase Inhibitors

Novel 2-alkylsulfanyl-1-benzyl-5-imidazolecarboxylic acid hydrazides (15a,b) were synthesized as analogues of isocarboxazide, which is a known nonselective irreversible monoamine oxidase inhibitor and tested for monoamine oxidase A and B inhibitory activity. Neither of the compounds showed any inhibition of MAO B activity up to a high concentration of 100 μM. An MAO A activity was only slowly inhibited at this high concentration after prolonged incubation with either compound. This suggests any observed inhibition is not very specific.