The convenient synthesis of 4-arylmethylidene-4,5- dihydro-3-phenylisoxazol-5-ones

4-Arylmethylidene-4,5-dihydro-3-phenylisoxazol-5-ones were synthesized by the convenient three-component reaction of ethyl benzoylacetate, hydroxylamine and aromatic aldehydes in the presence of pyridine. The target compounds were also obtained by the reaction between 3-phenylisoxazol-5-one and aromatic aldehydes at 105 °C under solvent free condition. Yields of products depended considerably on the aldehyde used.