55293-74-8Relevant academic research and scientific papers
The δ2,2′-bi(2H-1,4-benzothiazine) structural motif of red hair pigments revisited: Photochromism and acidichromism in a unique four-state system
Leone, Loredana,Crescenzi, Orlando,Napolitano, Alessandra,Barone, Vincenzo,D'Ischia, Marco
, p. 5136 - 5140 (2012)
Complete spectral and computational characterization of δ2,2′-bi(2H-1,4-benzothiazine) (BBTZ) demonstrated that the structures of the stable yellow form and the photogenerated red form were assigned incorrectly and should be revised to the cis (Z) and trans (E) isomers, respectively. A blue elusive dication generated upon further protonation of the violet cationic form was also identified by UV spectroscopy and DFT calculations. On the basis of these data, BBTZ can be appreciated as a robust four-state system for various applications. Copyright
Reversible Formation of Cyclic 1,4-Benzothiazine Oligomers
Chioccara, Francesco,Novellino, Ettore
, p. 1741 - 1744 (2007/10/02)
1,4-Benzothiazine 2, generated in situ by mild hydrolysis of aminoacetal 3, readily undergoes aldolization to give mainly two pairs of diastereoisomeric trimers and tetramers, having the gross structure 5 and 6 respectively.In strongly acidic media the oligomers are depolymerized to give monomeric 2H-1,4-benzothiazine (1H nmr evidence) which, at slighly acidic or neutral pH, is converted to a mixture of the same trimers and tetramers.These results provide an improvement background to look into the biosynthesis of phaeomelanins which are known to originate by polymerization of 1,4-benzothiazine intermediates.
