Utilization of 2-nitrophenols in annulations with aryl isothiocyanates towards the synthesis of 2-aminobenzoxazoles.

A method for the annulation of 2-nitrophenols with aryl isothiocyanates is reported. The reactions proceeded in the presence of an iron(iii) acetylacetonate catalyst, elemental sulfur, NaOH as a base, and DMSO as a solvent. Derivatives of 2-aminobenzoxazoles bearing nitro, cyano, acetyl, sulfone, secondary amine, and pyrrolyl groups were successfully isolated.