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Synthesis 2006(17): 2885-2890  
DOI: 10.1055/s-2006-942524
PAPER
© Georg Thieme Verlag Stuttgart · New York

Ring Strain and Weak Bonds: Δ2-1,2-Diazetines as Building Blocks for Pyridazines

J. Fleischhauera, R. Beckert*a, W. Günthera, H. Görlsb
a Institute of Organic and Macromolecular Chemistry, Friedrich Schiller University, Humboldtstraße 10, 07743 Jena, Germany
b Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University, Lessingstraße 8, 07743 Jena, Germany
Fax: +49(3641)6948212; e-Mail: Rainer.Beckert@uni-jena.de;
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Publication History

Received 28 April 2006
Publication Date:
25 July 2006 (online)

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Abstract

Deprotonated 1,2-diazetines react with various ketones containing an acidic CH to yield pyridazine derivatives. The reaction allows the synthesis of dihydropyridazines containing a cycloamidine substructure via a sequence of ring-opening and recyclization. In this case, the in situ generated anion of 1,2-diazetines acts as a base as well as a chelator. The structures of the novel synthesized derivatives were confirmed by X-ray structural analysis and multidimensional NMR experiments.

Key words

ring expansion - regioselectivity - heterocycles - imines - ketones

    References

  • 1 Beckert R. Fleischhauer J. Darsen A. Weston J. Schenk S. Batista A. Anders E. Görls H. Döring M. Pufky D. Walter O. Heterocycles  2005,  65:  1311 
    CrossrefSearch in Google Scholar
  • 2 Fleischhauer J. Beckert R. Weston J. Schmidt M. Flammersheim H.-J. Görls H. Synthesis  2006,  514 
    Thieme Connect
  • 3 Nakayama J. Konishi T. Ishi A. Hoshino M. Bull. Chem. Soc. Jpn.  1989,  62:  2608 
    CrossrefSearch in Google Scholar
  • 4a González-Gómez JC. Uriarte E. Synlett  2003,  2225 
  • 4b Özer G. Saraço¢glu N. Balci M. J. Org. Chem.  2003,  68:  7009 
    Search in Google Scholar
  • 4c Soenen DR. Zimpleman JM. Boger DL. J. Org. Chem.  2002,  68:  3593 
    Search in Google Scholar
  • 5 Zey RL. J. Heterocycl. Chem.  1988,  25:  847 
    CrossrefSearch in Google Scholar
  • 6 El-Zohry MF. Younes MI. Metwally SA. Synthesis  1984,  972 
    Thieme Connect
  • 7 Pufky D. Beckert R. Döring M. Walter O. Heterocycles  2002,  1257 
  • 9 COLLECT, Data Collection Software   Nonius B.V.; Netherlands: 1998. 
  • 10a See ‘Processing of X-ray Diffraction Data Collected in Oscillation Mode’: Otwinowski Z. Minor W. Methods Enzymol.  1997,  276:  307 
    PubMedSearch in Google Scholar
  • 10b Macromolecular Crystallography   Part A:  Carter CW. Sweet RM. Academic Press; New York: 1997.  p.307 
    PubMed
  • 11 Sheldrick GM. Acta Crystallogr., Sect. A  1990,  46:  467 
    CrossrefSearch in Google Scholar
  • 12 Sheldrick GM. SHELXL-97 (Release 97-2)   University of Göttingen; Germany: 1997. 
8

CCDC 605533 (3b), 605534 (3n), and 665535 (3p) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44(1223)336033; or deposit@ccdc.cam.ac.uk].