An irreversible, mechanism-based inhibitor of lysine-specific demethylase 1 (LSD1) with an IC50 value of 20.7 µM and a Ki value of 242.7 µM that effectively inhibits histone demethylation in vivo; irreversibly inhibits monoamine oxidases (MAO) A and MAO B with IC50 values of 2.3 and 0.95 µM and Ki values of 101.9 and 16 µM, respectively.