Thionation of β-lactams to β-thiolactams by silica-supported P2S5

In this paper, an improved method for the thionation of β-lactams is described. Using a solid-supported P2S5 reagent and heating under reflux conditions, β-thiolactams were obtained in good to excellent yields. Also the reaction time reduced significantly compared with that achieved under the more conventional method using P2S5 alone. Furthermore, inexpensive and easily available starting materials simple reaction conditions and a simple purification process are some other advantages of this method.