A Mild and Efficient One-Pot Synthesis of 2-Aminated Benzoxazoles and Benzothiazoles

Previous syntheses of the biologically active 2-aminated benzoxazoles have relied on forcing thermal conditions to generate the products directly from the corresponding thiols. The resulting yields have ranged from moderate to poor. A mild and high-yielding alternative one-pot chlorination-amination procedure is described. Compounds with a variety of substitution patterns are reported and the methodology has been successfully extended to benzothiazoles. Palladium catalysis on suitably activated examples has been employed to generate the desired compounds of interest.