Synlett 2003(10): 1465-1466
DOI: 10.1055/s-2003-40837
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A New Way to 2-Methylbenzo- and Pyridoindoles

Anna Korda, Zbigniew Wróbel*
Institute of Organic Chemistry , Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
Fax: +48(22)6681; e-Mail: wrobel@icho.edu.pl;
Further Information

Publication History

Received 23 April 2003
Publication Date:
24 July 2003 (online)

Abstract

Allyltriphenylphosphonium chloride reacts with some 1-nitronaphthalene and 5-nitroquinoline derivatives in the presence of Ti(i-PrO)4 and DBU to give 1-hydroxyindoles, which can be reduced in situ to the corresponding indoles.

    References

  • 1 Sundberg RJ. Indoles   Academic Press; London: 1996. 
  • 2a Bartoli G. Palmieri G. Bosco M. Dalpozzo R. Tetrahedron Lett.  1989,  30:  2129 
  • 2b Bosco M. Dalpozzo R. Bartoli G. Palmieri G. Petrini M. J. Chem. Soc., Perkin Trans. 2  1991,  657 
  • 2c Dobson D. Todd A. Gilmore J. Synth. Commun.  1991,  21:  611 
  • 2d Dobbs A.
    J. Org. Chem.  2001,  66:  638 
  • 2e Zhang Z. Yang Z. Meanwell NA. Kadow JF. Wang T. J. Org. Chem.  2002,  67:  2345 
  • 3a Wróbel Z. Tetrahedron Lett.  1997,  38:  4913 
  • 3b Wróbel Z. Tetrahedron Lett.  2000,  41:  7365 
  • 3c Wróbel Z. Pol. J. Chem.  1998,  72:  2384 
  • 3d Wróbel Z. Tetrahedron  2003,  59:  101 
  • 4 Acheson RM. In Advances in Heterocyclic Chemistry   Vol. 51:  Katritzky AR. Academic Press; New York: 1990.  p.129 
  • 5 Somei M. Tsuchija M. Chem. Pharm. Bull.  1981,  29:  3145 
  • 7 Wróbel Z. Eur. J. Org. Chem.  2000,  521 
  • 8 Wróbel Z. Mkosza M. Tetrahedron  1997,  53:  5501 
  • 9 Smolii OB. Vydzhak RN. Drach BS. J. Gen. Chem. USSR (Engl. Trans.)  1991,  61:  2419 
6

Standard procedure: To the slurry of 1 (2.5 mmol) and 2 (1 g, 3 mmol) in dry HMPA (2.5 mL), Ti(i-PrO)4 (1.85 mL, 6.25 mmol) was added followed by the addition of DBU (1.9 mL, 12.5 mol). The slurry was stirred at room temperature for the time specified in the table until HPLC analysis showed complete conversion of the substrate. At this point MeOH (5 mL) was added followed by Et3N (1 mL) and then ethyl bromoacetate (330 µL, 3 mmol), and the mixture stirred further until HPLC analysis showed complete conversion. Then, the mixture was diluted with ethyl acetate and ca. 5 mL of sat aq NH4Cl solution was added. The mixture was stirred for 20 min, filtered through a Celite pad, diluted with water, extracted with ethyl acetate and chromatographed. Selected spectral data (1H NMR: 400 MHz, CDCl3; Ms: 70 eV): 3a: δH = 2.37 (s, 3 H), 6.01 (broad s, 1 H), 6.88-6.94 (m, 1 H), 7.17 (ddd, J = 8.0 Hz, 6.8 Hz, 1.1 Hz, 1 H), 7.26-7.30 (m, 1 H), 7.40 (d, J = 8.4 Hz, 1 H), 7.72 (d, J = 8.0 Hz, 1 H), 8.34 (d, J = 8.4 Hz, 1 H), 8.69 (broad s, 1 H); HRMS: 197.0847; calcd. for C13H11ON: 197.0841; (1H NMR: 500 MHz, CDCl3; MS: 70 eV): 4a:
δH = 2.50 (d, J = 0.9, 3 H), 6.34-6.37 (m, 1 H), 7.36 (ddd, J = 8.2 Hz, 6.9 Hz, 1.3 Hz, 1 H), 7.46 (d, J = 8.5 Hz, 1 H overlapped on ddd, J = 8.3 Hz, 7.0 Hz, 1.3 Hz, 1 H), 7.61 (dd, J = 8.5 Hz, 0.9 Hz, 1 H), 7.87-7.88 (m, 1 H), 7.89-7.90 (m, 1 H), 8.51 (broad s, 1 H); δC = 132.99, 130.11, 129.89, 128.87, 125.22, 124.85, 123.20, 121.34, 120.37, 120.22, 119.00, 102.18, 13.73; HRMS: 181.0895; calcd. for C13H11N: 181.0892; 4b: δH = 1.29 (s, 9 H), 2.53 (d, J = 0.8 Hz, 3 H), 6.35-6.36 (m, 1 H), 7.45 (ddd, J = 8.2 Hz, 6.8 Hz, 1.3 Hz, 1 H), 7.50 (ddd, J = 8.2 Hz, 6.8 Hz, 1.3 Hz, 1 H), 7.90-7.92 (m, 1 H), 8.00 (s, 1 H), 8.60 (br s, 1 H), 8.82-8.84 (m, 1 H); δC = 133.47, 132.58, 132.41, 131.31, 128.82, 125.37, 124.36, 123.56, 121.79, 121.44, 119.15, 47.03, 31.20, 13.71; HRMS: 269.1246; calcd. for C17H19NS: 269.1238; 4c: δH = 2.48 (d, J = 0.8 Hz, 3 H), 3.99 (s, 3 H), 6.26-6.27 (m, 1 H), 6.96 (s, 1 H), 7.37 (ddd, J = 8.2 Hz, 6.9 Hz, 1.2 Hz, 1 H), 7.48 (ddd, J = 8.2 Hz, 6.9 Hz, 1.2 Hz, 1 H), 7.80-7.81 (m, 1 H), 8.28-8.29 (m, 1 H), 8.36 (br s, 1 H);
δC = 150.18, 132.92, 125.92, 125.16, 124.11, 123.34, 122.88, 122.71, 121.85, 118.82, 102.04, 97.99, 55.82, 13.73; HRMS: 211.0998; calcd. for C14H13NO: 211.0997; 4d: δH = 2.55 (d, J = 0.8 Hz, 3 H), 6.37-6.39 (m, 1 H), 6.94 (part AA′, 2 H), 7.07 (part BB′, 2 H), 7.40 (ddd, J = 8.3 Hz, 6.9 Hz, 1.2 Hz, 1 H), 7.52 (ddd, J = 8.2 Hz, 6.9 Hz, 1.2 Hz, 1 H), 7.96-7.98 (m, 1 H), 8.39-8.41 (m, 1 H), 8.70 (broad s, 1 H); δC = 138.35, 133.86, 131.67, 130.84, 130.51, 130.14, 128.78, 127.55, 127.30, 125.95, 124.74, 124.52, 122.25, 119.57, 119.27, 102.45, 13.73; HRMS: 323.0535; calcd. for C19H14NS35Cl: 323.0536; 4e: δH = 2.56 (d, J = 0.8 Hz, 3 H), 6.40-6.41 (m, 1 H), 7.39 (dd, J = 8.3 Hz, 4.3 Hz, 1 H), 7.76 (dd, J = 8.8 Hz, 0.8 Hz, 1 H), 7.85 (d, J = 8.8 Hz, 1 H), 8.30 (ddd, J = 8.3 Hz, 1.7 Hz, 0.8 Hz, 1 H), 8.81 (dd, J = 4.3 Hz, 1.7 Hz, 1 H), 8.89 (br s, 1 H); δC = 146.99, 145.71, 134.40, 127.38, 125.12, 123.84, 121.66, 120.95, 119.96, 116.52, 102.43, 13.80; HRMS: 182.0841; calcd. for C12H10N2: 182.0844; 4f: δH = 2.46 (d, J = 0.8 Hz, 3 H), 4.00 (s, 3 H), 6.31-6.33 (m, 3 H), 7.32 (dd, J = 8.3 Hz, 4.3 Hz, 1 H), 8.77 (dd, J = 4.3 Hz, 1.7 Hz, 1 H), 9.75 (br s, 1 H); δC = 149.72, 145.62, 137.83, 134.75, 127.98, 124.17, 123.87, 120.65, 117.50, 55.88, 13.63; HRMS: 21.0946; calcd. for C13H12N2O: 212.0949.