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A novel photoisomerzation of 1,2‐benzothiazine 1,1‐dioxides to 1,3‐benzothiazine 1,1‐dioxides
Author(s) -
Elghamry Ibrahim,
Döpp Dietrich,
Henkel Gerald
Publication year - 2007
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570440416
Subject(s) - benzothiazine , chemistry , acetonitrile , saccharin , methanol , irradiation , photochemistry , medicinal chemistry , organic chemistry , medicine , endocrinology , physics , nuclear physics
A novel facile photoconversion of 4‐hydroxy‐1,2‐bezothiazine 1,1‐dioxides ( 3a‐e ) into 4‐ oxo ‐1,3‐2 H ‐benzothiazine 1,1‐dioxides ( 4a‐e ) and 4‐hydroxy‐2‐methyl‐ N ‐(pyridin‐2‐yl)‐2 H ‐1,2‐benzothiazine‐3‐carboxamide 1,1‐dioxide (PRX) into N‐methyl saccharin ( 2 ) upon 254 nm irradiation in methanol or acetonitrile is reported. The structures of the products have been elucidated by spectroscopic methods and single crystal X‐ray structure determination for 4a and 4d .