Download PDF
Synthesis 2004(2): 249-254  
DOI: 10.1055/s-2003-44389
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Concise Route to 2-Amino-3-aryl-3H-benzofurans and their Use as Precursors to 3-Aryl-3H-benzofuran-2-one and 1H-Benzofuro[2,3-b]pyridin-2-one Derivatives

Michèle Gerster*, Reto Wicki
Ciba Specialty Chemicals Inc., 4002, Basel, Switzerland
Fax: +41(61)6362332; e-Mail: michele.gerster@cibasc.com;
Further Information

Publication History

Received 8 September 2003
Publication Date:
18 December 2003 (online)

    Permissions and Reprints All articles of this category

Abstract

A concise approach to 2-amino-3-aryl-3H-benzofurans based on the Michael addition of NaCN onto in situ generated substituted o-quinone methides has been developed. Straightforward access to 3-aryl-3H-benzofuran-2-ones was achieved upon acidic hydrolysis whereas N-Boc-protected 2-amino-3-aryl-3H-benzofurans underwent smooth intramolecular cyclisation to give 1H-benzofuro[2,3-b]pyridin-2-one derivatives.

Key words

furans - Michael additions - quinones - cyclisations - heterocycles

    References

  • 1a Hinsken H, Mayerhöfer H, Müller W, and Schneider H. inventors;  WO-A-80/01566.  ; Chem. Abstr. 1981, 94 , 16620
  • 1b Nesvadba P, Evans S, Kröhnke C, and Zingg J. inventors; DE-A-94/4432732  .  , ; Chem. Abstr. 1995, 123, 55685
  • 2 Bistrzycki A. Flatau J. Chem. Ber.  1895,  28:  989 
    CrossrefGoogle Scholar
  • 3 Hewgill RF. Howie GB. Aust. J. Chem.  1978,  31:  907 
    CrossrefGoogle Scholar
  • 4 Smith LI. Dale WJ. J. Org. Chem.  1950,  15:  832 
    CrossrefGoogle Scholar
  • 5 Nesvadba P. Bugnon L. Dubs P. Evans S. Synlett  1999,  S1:  863 
    Article in Thieme ConnectGoogle Scholar
  • 6 Tinkl M, Evans S, and Nesvadba P. inventors;  WO-A2-99/67232.  ; Chem. Abstr. 1999, 132, 64163
  • 7 For a review on quinone methides, see: Grünager P. Houben-Weyl, Methoden der organischen Chemie   Vol. VII/3b:  Thieme; Stuttgart: 1979.  p.395 
    Google Scholar
  • 8a For a review on Mannich bases, see: Tramontini S. Synthesis  1973,  703 
    CrossrefGoogle Scholar
  • 8b Van de Water RW. Pettus TRR. Tetrahedron  2002,  58:  5367 
    CrossrefGoogle Scholar
  • 9 Stafford JA. Brackeen MF. Karanewsky DS. Valvano NL. Tetrahedron Lett.  1993,  34:  7873 
    CrossrefGoogle Scholar