Investigations in the series of heterocycles. 55. Synthesis and some reactions of 2-aryl-4-halo-6-oxo-1,3-thiazines

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.For report 54 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1328–1334, October, 1984.