The synthesis of ¹⁴C‐labeled suicide inactivators of monoamine oxidase

N‐[3‐(2,4‐dichlorophenoxy)propyl]‐N‐methyl‐2‐propynylamine‐1‐¹⁴C (¹⁴C‐clorgyline, 1a) and L‐N, α‐dimethyl‐N‐2‐propynyl‐1‐¹⁴C‐phenethylamine (¹⁴C‐L deprenyl, 1b) were synthesized by the Mannich reaction of 2‐methyl‐3‐butyn‐2‐ol, ¹⁴C‐formaldehyde, and secondary amines 3‐(2,4‐dichlorophenoxy)‐N‐methylpropylamine (2a) or L‐N, α‐dimethylphenethylamine (2b) followed by KOH catalyzed elimination of acetone from the respective Mannich base 3a or 3b.