2,2'-Dithiosalicylic acid (I) is activated as the bis-succinimidyl ester (II) upon treatment with N-hydroxysuccinimide and DIC. Coupling of the active ester (II) with 3-aminopropionamide (III) gives rise to the corresponding dithiosalicylamide (IV). Reductive cleavage of the disulfide bond of (IV) using tris(2-carboxyethyl)phosphine (TCEP) affords thiol (V). The desired thiolcarbamate is then obtained by condensation of (V) with tert-butyl isocyanate in DMF.