2,1-BENZOTHIAZINE 2,2-DIOXIDES. 5. HYDROLYSIS OF ALKYL 1-R-4-HYDROXY-2,2-DIOXO-1<i>Н</i>-2λ⁶,1-BENZOTHIAZINE-3-CARBOXYLATES

Abstract

Hydrolysis of 1-R-4-hydroxy-2,2-dioxo-1Н-2λ⁶,1-benzothiazine-3-carboxylate esters in HCl–AcOH–H₂O mixture at 60°С was accompanied by decarboxylation and led to 1-R-4-oxo-3,4-dihydro-1H-2λ⁶,1-benzo-thiazine-2,2-diones. In the alkaline medium, regardless of the type of the substituent at position 1, analogous structural transformations occurred at first, but the thiazine ring was also destroyed along with the ester fragment when performing the reaction for a longer time.

How to Cite
Ukrainets, I. V.; Petrushova, L. A.; Dzyubenko, S. P.; Liu Yangyang Chem. Heterocycl. Compd. 2014, 50, 1047. [Khim. Geterotsikl. Soedin. 2014, 1135.]

For this article in the English edition see DOI 10.1007/s10593-014-1563-7