19195-35-8Relevant academic research and scientific papers
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.
