A novel and convenient synthesis of 5-aryl-4-bromo-3-carboxyisoxazoles: useful intermediates for the solid-phase synthesis of 4,5-diarylisoxazoles

A novel synthesis of 5-aryl-4-bromo-3-carboxyisoxazoles employing a [3+2] cycloaddition of a nitrile N-oxide to 2-aryl-1-bromoalkynes is described, and the utility of these 5-aryl-4-bromo-3-carboxyisoxazoles for the solid-phase synthesis of 4,5-diarylisoxazoles is demonstrated.