A five-step sequence allowing the preparation of ethyl 3-aminopropanedithioate from N-(Boc)-beta-alanine via the key intermediate N-(Boc)-beta-alaninethioacyl-N-phthalimide is described.
Josse, O., Labar, D., & Marchand-Brynaert, J. (1999). A convenient synthesis of ethyl 3-aminopropanedithioate (beta-alanine ethyl dithioester). Synthesis : journal of synthetic organic chemistry, 3, 404-406. https://doi.org/10.1055/s-1999-3417 (Original work published 1999)