This letter reports the solid-phase synthesis of 2-imidazolidinethiones via the N-cyclization of N-(2-hydroxyethyl) thioureas using the Mitsunobu reaction in good yield and purity. This process employed the reductive amination of an ArgoGel-MB-CHO resin to anchor the aminoalcohols, followed by a reaction with isothiocyanates to give the resin-attached N-(2- hydroxyethyl) thioureas. Cleavage of the 2-imidazolidinethiones was performed with ...