New isomers of 4,1-benzothiazepines. The first evidence for the desmotropy of seven-membered heterocycles

Péter Csomós, Lajos Fodor, Jari Sinkkonen, Kalevi Pihlaja, Gábor Bernáth

Research output: Article

26 Citations (Scopus)


A novel procedure was developed for the preparation of 2,3-disubstituted 4,1-benzothiazepines, via the ring transformation of (2R*,2aS*)-2-chloro-2a-phenyl-2,2a-dih ydro-2H,4H-azeto[1,2-a][3,1]benzothiazin-1-one (1) with sodium ethoxide in ethanol. The tautomeric products (R*)-3-ethoxycarbonyl-2-phenyl-3,5-dihydro-4,1-benzothi azepine (4) and 3-ethoxycarbonyl-2-phenyl-1,5-dihydro-4,1-benzothiazepine (5) exhibit the rare phenomenon of desmotropy of the condensed seven-membered heterocycles. Surprisingly, these desmotropes could be separated by column chromatography. The products are unexpectedly stable in solution and their structures were proved by means of NMR and mass spectrometry.

Original languageEnglish
Pages (from-to)5665-5667
Number of pages3
JournalTetrahedron Letters
Issue number32
Publication statusPublished - aug. 7 2006


ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

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