Abstrakt: |
The reaction of 2-aryl-4-hydroxy-6-oxo-1,3-thiazines with Vilsmeier's reagent results in the formation of a mixture of 2-aryl-6-oxo-4-chloro-1,3-thiazines and their 5-formyl analogs. Reactions involving the nucleophilic replacement of the halogen and nucleophilic addition to an aldehydic group have been studied. The intramolecular cyclization of the oxime and phenylhydrazone of 6-oxo-2-phenyl-5-formyl-4-chloro-1,3-thiazine gives new heteroaromatic systems, viz., isoxazolo-[4,5-d]-1,3-thiazine and pyrazolo]4,5-d]-1,3-thiazine, respectively. |