Ba(OH)2 as the Catalyst in Organic Reactions‐Part X‐Reaction of Chalcone with Hydroxylamine

The reaction of several chalcones with hydroxilamine has been studied. A systematic catalytic study of the synthetic process has been accomplished. The different experimental conditions have been studied. The process catalyzed in the homogeneous phase gives mixture of products. Nevertheless the process catalyzed by activated barium hydroxide catalyst, C-200., in heterogeneous phase, produces Δ2 -isoxazolines with high yields and selectivities. The - mechanism of the process in the heterogeneous phase is discussed. The poisoning effect on the C-200 active sites, produced by an excess of NH2OH is analyzed. Some reactions products are described by the first time.