Preparation of new nitrogen-bridged heterocycles. XIV Further investigation of the desulfurization and the rearrangement of pyrido [1, 2-d]-1, 3, 4-thiadiazine …
The formation of pyrazolo [1, 5-a] pyridine derivatives via the desulfurization and the rearrangement of pyrido [1, 2-d]-1, 3, 4-thiadiazine intermediates having various substituents at the 2-and 4-positions was investigated, and the wide applicability of this approach to the syntheses of pyrazolo [1, 5-a] pyridines was established. The substituent effect in these reactions was also clarified. The possibility of the extension of this reaction to other ...