33858-94-5Relevant academic research and scientific papers
Staudinger and retro-Staudinger reactions. The dichloro-β-lactam moiety as a useful handle for the synthesis of 4-aryl-2H-1,3-benzothiazine 1,1-dioxides
Fodor, Lajos,Csomós, Péter,Csámpai, Antal,Sohár, Pál
experimental part, p. 3205 - 3207 (2010/08/05)
The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-benzothiazine 1,1-dioxides were obtained efficiently.
Synthesis and Conformational Analysis of Dibenzodithiocin Derivatives
Sohar, P.,Koevesdi, I.,Szabo, J.,Katocs, A,Fodor, L.,et al.
, p. 760 - 766 (2007/10/02)
N-(3,4-Dialkoxyphenylthiomethyl)aroylamides (1a, b) reacted with phosphoryl chloride to give not only the expected 4H- and 2H-1,3-benzothiazine derivatives (4a, b and 5a, b), but also dibenzodithiocins of new (dibenzodithiocins 2a, b) and known (dibenzodithiocins 3a, b) types.The analogous reaction of the 4-methylaroylamide 8a furnished the 4H-1,3-benzothiazine 9a, the dibenzodithiocin derivative 10a and benzonitrile.In contrast, 8b (the chloro analogue of 8a) furnished only benzonitrile and bis(4-chlorophenylmercapto)methane (11).The structures of the new compounds were confirmed by IR, 1H and 13C NMR, and (in part) by mass spectrometry.Temperature-dependent 1H NMR studies were used for the conformational analysis of 2a and its disulphone 6a; the nature and free enthalpies of activation of the two different conformational motions occuring at higher temperatures were determined.KEY WORDS - Dibenzodithiocins Synthesis 1H and 13C NMR Conformation Structural isomerism
