A novel synthesis of 5-aryl-4-bromo-3-carboxyisoxazoles employing a [3+ 2] cycloaddition of a nitrile N-oxide with 2-aryl-1-bromoalkynes as the key step is described. The utility of these 5-aryl-4-bromo-3-carboxyisoxazoles in the solid-phase synthesis of 4, 5-diarylisoxazoles is demonstrated.
[Hansen, John F.; Kim, Yong In; McCrotty, Stephen E.; Strong, Scott A.; Zimmer, Douglas E. Journal of Heterocyclic Chemistry, 1980 , vol. 17, p. 475 - 479]