Synlett 2009(7): 1047-1050  
DOI: 10.1055/s-0028-1088107
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A New and Facile Synthesis of Thieno[2,3-b]indole Derivatives via Condensation of Isocyanide and Indolin-2-thiones

Firouz Matloubi Moghaddam*, Hamdollah Saeidian, Zohreh Mirjafary, Salman Taheri, Somayyeh Kheirjou
Laboratory of Organic Synthesis and Natural Product, Department of Chemistry, Sharif University of Technology, P. O. Box 11155-9516, Tehran, Iran
Fax: +98(21)66012983; e-Mail: matloubi@sharif.edu;
Further Information

Publication History

Received 25 November 2008
Publication Date:
26 March 2009 (online)

Abstract

A new one-pot synthesis of thieno[2,3-b]indole ring systems is described. Condensation of cyclohexyl isocyanide with indolin-2-thiones yielded 3-cyclohexyaminomethylene-indolin-2-thiones, which upon reaction with α-halocarbonyl compounds produced the title compounds.

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Representative Analytical Data
Compound 8b: ¹H NMR (500 MHz, CDCl3): δ = 12.08 (m, 1 H), 8.06 (d, J = 13.71 Hz, 1 H), 7.43 (d, J = 7.55 Hz, 1 H), 7.21 (t, J = 7.51 Hz, 1 H), 7.13-7.16 (m, 2 H), 3.77 (s, 3 H), 3.50-3.49 (m, 1 H), 2.11-2.07 (m, 2 H), 1.93-1.89 (m, 2 H), 1.69-1.59 (m, 3 H), 1.51-1.37 (m, 3 H) ppm. ¹³C NMR (125 MHz, CDCl3): δ = 175.69 (C=S), 148.33 (CH), 139.86 (C), 127.68 (C), 123.16 (CH), 122.01 (CH), 114.61 (CH), 109.21 (CH), 106.58 (C), 58.76 (CH), 34.15 (CH2), 29.75 (CH3), 25.60 (CH2), 24.62 (CH2) ppm.
Compound 11a: mp 285-287 ˚C. ¹H NMR (500 MHz, CDCl3/DMSO): δ = 11.33 (s, 1 H), 7.48 (s, 1 H), 7.35-7.30 (m, 3 H), 7.26 (d, J = 8.30 Hz, 2 H), 7.03 (d, J = 8.17 Hz, 1 H), 6.83 (t, J = 7.67 Hz, 1 H), 6.73 (t, J = 7.51 Hz, 1 H) ppm. ¹³C NMR (125 MHz, CDCl3/DMSO): δ = 187.19, 149.22, 143.10, 137.71, 135.26, 131.71, 130.50, 128.38, 126.04, 125.79, 123.71, 122.35, 120.55, 119.71, 112.16 ppm.
Compound 11b: mp 280-282 ˚C. ¹H NMR (500 MHz, CDCl3/DMSO): δ = 11.33 (s, 1 H), 7.49 (s, 1 H), 7.40 (d, J = 8.36 Hz, 2 H), 7.35 (d, J = 7.73 Hz, 1 H), 7.10 (d, J = 8.36 Hz, 2 H), 7.04 (d, J = 8.12 Hz, 1 H), 6.85 (t, J = 7.38 Hz, 1 H), 6.76 (t, J = 7.40 Hz, 1 H)ppm. ¹³C NMR (125 MHz, CDCl3/DMSO): δ = 187.11, 149.21, 143.11, 137.50, 137.29, 135.33, 130.35, 128.77, 128.33, 125.80, 123.72, 122.37, 120.55, 119.71, 112.17 ppm.
Compound 17: mp 145-147 ˚C. ¹H NMR (500 MHz, CDCl3): δ = 10.43 (s, 1 H), 8.38 (d, J = 7.95 Hz, 1 H), 7.48-7.47 (m, 2 H), 7.42-7.40 (m, 1 H), 4.07 (s, 3 H), 3.67 (s, 2 H) ppm. ¹³C NMR (125 MHz, CDCl3): δ = 186.02, 138.82, 136.22, 125.96, 125.84, 124.18, 122.13, 121.48, 115.69, 110.87, 31.17, 23.33 ppm.