Cobalt ferrite nanoparticles for annulation of C3-substituted nitroarenes and aryl isothiocyanates.

The synthesis of medicinally relevant -aryl-substituted 2-aminobenzothiazoles often uses 2-aminothiophenol derivatives, which are not commercially abundant, as starting materials. Herein, we report a method for the annulation of C3-substituted nitroarenes and aryl isothiocyanates towards the synthesis of 2-aminobenzothiazoles. Reactions proceeded in the presence of cobalt ferrite nanoparticles as a catalyst, DABCO as a base, and DMF as a promoter. The cobalt ferrite nanoparticles could be recovered after each run and reused up to 3 times while the product yield was not diminished. Our method appears to be the first example of the direct use of substituted nitroarenes for yielding 2-aminobenzothiazoles.