Expected and unexpected reactions of 1,3-benzothiazine derivatives, II. Formation of isomeric 5,6-dihydro-1,5-benzothiazocines

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4 Citations (Scopus)

Abstract

A method for the synthesis of medium-sized 1,5-benzothiazocines by ring enlargement of 1,3-benzothiazines has been developed. When N-alkyl-1,3- benzothiazines were reacted with dimethyl acetylenedicarboxylate in acetonitrile at room temperature, regioisomeric 5,6-dihydro-2H-1,5-benzothiazocines and 5,6-dihydro-4H-1,5-benzothiazocines were obtained as novel ring systems. Dimethyl acetylenedicarboxylate could attack either the nitrogen or the sulfur atom of the thiazines. NMR spectroscopic and X-ray crystallographic investigations confirmed the structures of the products.

Original languageEnglish
Pages (from-to)592-594
Number of pages3
JournalTetrahedron Letters
Volume52
Issue number5
DOIs
Publication statusPublished - febr. 2 2011

Fingerprint

Thiazines
Derivatives
Sulfur
Nitrogen
Nuclear magnetic resonance
X-Rays
X rays
Atoms
Temperature
acetylenedicarboxylic acid dimethyl ester
acetonitrile

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

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title = "Expected and unexpected reactions of 1,3-benzothiazine derivatives, II. Formation of isomeric 5,6-dihydro-1,5-benzothiazocines",
abstract = "A method for the synthesis of medium-sized 1,5-benzothiazocines by ring enlargement of 1,3-benzothiazines has been developed. When N-alkyl-1,3- benzothiazines were reacted with dimethyl acetylenedicarboxylate in acetonitrile at room temperature, regioisomeric 5,6-dihydro-2H-1,5-benzothiazocines and 5,6-dihydro-4H-1,5-benzothiazocines were obtained as novel ring systems. Dimethyl acetylenedicarboxylate could attack either the nitrogen or the sulfur atom of the thiazines. NMR spectroscopic and X-ray crystallographic investigations confirmed the structures of the products.",
keywords = "1,5-Benzothiazocines, DMAD, Medium-sized ring, NMR, Ring expansion, X-ray crystallography",
author = "L. Fodor and P. Csom{\'o}s and A. Cs{\'a}mpai and P. Soh{\'a}r and Tam{\'a}s Holczbauer and A. K{\'a}lm{\'a}n",
year = "2011",
month = "2",
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doi = "10.1016/j.tetlet.2010.11.136",
language = "English",
volume = "52",
pages = "592--594",
journal = "Tetrahedron Letters",
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TY - JOUR

T1 - Expected and unexpected reactions of 1,3-benzothiazine derivatives, II. Formation of isomeric 5,6-dihydro-1,5-benzothiazocines

AU - Fodor, L.

AU - Csomós, P.

AU - Csámpai, A.

AU - Sohár, P.

AU - Holczbauer, Tamás

AU - Kálmán, A.

PY - 2011/2/2

Y1 - 2011/2/2

N2 - A method for the synthesis of medium-sized 1,5-benzothiazocines by ring enlargement of 1,3-benzothiazines has been developed. When N-alkyl-1,3- benzothiazines were reacted with dimethyl acetylenedicarboxylate in acetonitrile at room temperature, regioisomeric 5,6-dihydro-2H-1,5-benzothiazocines and 5,6-dihydro-4H-1,5-benzothiazocines were obtained as novel ring systems. Dimethyl acetylenedicarboxylate could attack either the nitrogen or the sulfur atom of the thiazines. NMR spectroscopic and X-ray crystallographic investigations confirmed the structures of the products.

AB - A method for the synthesis of medium-sized 1,5-benzothiazocines by ring enlargement of 1,3-benzothiazines has been developed. When N-alkyl-1,3- benzothiazines were reacted with dimethyl acetylenedicarboxylate in acetonitrile at room temperature, regioisomeric 5,6-dihydro-2H-1,5-benzothiazocines and 5,6-dihydro-4H-1,5-benzothiazocines were obtained as novel ring systems. Dimethyl acetylenedicarboxylate could attack either the nitrogen or the sulfur atom of the thiazines. NMR spectroscopic and X-ray crystallographic investigations confirmed the structures of the products.

KW - 1,5-Benzothiazocines

KW - DMAD

KW - Medium-sized ring

KW - NMR

KW - Ring expansion

KW - X-ray crystallography

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U2 - 10.1016/j.tetlet.2010.11.136

DO - 10.1016/j.tetlet.2010.11.136

M3 - Article

AN - SCOPUS:78651102274

VL - 52

SP - 592

EP - 594

JO - Tetrahedron Letters

JF - Tetrahedron Letters

SN - 0040-4039

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