Abstract: In our research, two commercially available compounds, 3-amino-1,2,4-dithiazole-5-thione (1) and xanthane hydride (2), and their derivatives 3-6 are found to be potential sulfur-transfer reagents. The efficiency and optimization of these new sulfur-transfer reagents were investigated by solid-phase syntheses of dinudeotide and oligonucleotide phosphorothioates. The results show that both compounds 1 and 2 are highly efficient sulfurizing reagents, and better than 99% sulfur transfer efficiency can be achieved at each step. In contrast to Beaucage reagent, these novel sulfur-transfer reagents are very stable in various solvents, and are available in bulk quantities at low cost. Due to these advantages, compounds 1 and 2 can be considered alternatives to Beaucage reagent, especially in large-scale preparation of oligonucleotide phosphorothioates. Furthermore, compounds 1 and 2 were modified to enhance their solubility in acetonitrile.