Microwave-assisted solvent-free synthesis of 2-thiazolines

There are many strategies for the preparation of thiazolines.1, 2 In our previous work for the synthesis of bacillamida derivatives (1), we prepared thiazoles by a thiazoline oxidation strategy. Thiazoline were prepared by cyclocondensation of nitriles and cysteine in aqueous buffer.3 This methodology used was associated with racemization problems and poor yields. Here we present an improved methodology for the preparation of thiazolines using different nitriles, β-amino thiols and catalyst, under microwave heating without solvent. We explore the scope of the reaction and discuss the obtained yields.