Synlett 2017; 28(06): 684-690
DOI: 10.1055/s-0036-1588398
letter
© Georg Thieme Verlag Stuttgart · New York

A Sulfonylation Reaction: Direct Synthesis of 2-Sulfonylindoles from Sulfonyl Hydrazides and Indoles

Rajjakfur Rahaman
Department of Chemistry, National Institute of Technology Silchar, Silchar-788010, India   eMail: barmanpranjit@yahoo.co.in
,
Pranjit Barman*
Department of Chemistry, National Institute of Technology Silchar, Silchar-788010, India   eMail: barmanpranjit@yahoo.co.in
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Publikationsverlauf

Received: 13. Oktober 2016

Accepted after revision: 29. Dezember 2016

Publikationsdatum:
24. Januar 2017 (online)


Abstract

A metal-free synthesis of 2-sulfonylindole derivatives has been developed through a novel TBHP/I2-mediated coupling of C3/unsubstituted indoles with sulfonyl hydrazides. The reaction utilizes readily available starting materials under mild reaction conditions, providing an alternative and attractive approach to 2-sulfonylindoles with high yields. The developed synthetic procedure is suitable for both N-protected or unprotected indoles.

Supporting Information

 
  • References and Notes

    • 3a Campbell JA, Bordunov V, Borka CA, Browner MF, Kress JM, Mirzadegan T, Ramesha C, Sanpablo BF, Stabler R, Takahara P, Villasenor A, Walker KA. M, Wang J.-H, Welch M, Weller P. Bioorg. Med. Chem. Lett. 2004; 14: 4741
    • 3b Holenz J, Pauwels PJ, Diaz JL, Mercèr R, Codony X, Buschmann H. Drug Discovery Today 2006; 11: 283
    • 3c Bentley JM, Bickerdike MJ, Hebeisen P, Kennett GA, Lightowler S, Mattei P, Mizrahi J, Morley TJ, Plancher J.-M, Richter H, Roever S, Taylor S, Vickers SP. WO 2002051844A1, Chem. Abstr. 2002, 137, 78856.
    • 3d Williams TM, Ciccarone TM, MacTough SC, Rooney CS, Balani SK, Condra JH, Emini EA, Goldman ME, Greenlee WJ, Kauffman LR, O’Brien JA, Sardana VV, Schleif WA, Theoharides AD, Anderson PS. J. Med. Chem. 1993; 36: 1291
    • 3e Tong L, Shankar BB, Chen L, Rizvi R, Kelly J, Gilbert E, Huang C, Yang D.-Y, Kozlowski JA, Shih N.-Y, Gonsiorek W, Hipkin RW, Malikzay A, Lunn CA, Lundell DJ. Bioorg. Med. Chem. Lett. 2010; 20: 6785
    • 3f Romey G, Lazdunski M. J. Pharmacol. Exp. Ther. 1994; 271: 1348
  • 15 General Procedure for the Synthesis of 2-Sulfonylindoles To a mixture of indole 1 (0.5 mmol) with sulfonyl hydrazide 2 (1 mmol), iodine (20 mol%), TBHP (70% in water, 1 mmol) in DCE (2 mL). The resulting reaction mixture was stirred at r.t. for 2 h. Upon completion, distilled deionized H2O (10 mL) and sat. Na2S2O3 (10 mL) were added, and the mixture was extracted with EtOAc (3 × 20 mL). The combined organic layer was washed with sat. brine (20 mL), dried over anhydrous Na2SO4, and concentrated in vacuum. The crude product was purified by column chromatography using EtOAc–hexanes (1:5) as eluent to afford the desired 2-sulfonylindole 3.
  • 16 See Supporting Information for detailed experimental procedures and characterization data. 2-(Phenylsulfonyl)-1H-indole (3a)8a White solid (118.4 mg, 92% yield); mp 159–161 °C. 1H NMR (500 MHz, CDCl3): δ = 8.81 (br s, 1 H), 8.04 (d, J = 7.0 Hz, 2 H), 7.66 (d, J = 9.0 Hz, 1 H), 7.50 (d, J = 2.5 Hz, 1 H), 7.48 (d, J = 8.0 Hz, 1 H), 7.31 (d, J = 6.0 Hz, 1 H), 7.21–7.17 (m, 3 H), 7.14 (t, J = 7.0 Hz, 1 H). 13C NMR (125 MHz, CDCl3): δ = 141, 136.3, 133.5, 130.5, 128.9, 128.5, 124.6, 122.9, 120.7, 119.5, 111.4, 108.9. Anal. Calcd (%) for C14H11NO2S: C, 65.35; H, 4.31; N, 5.44. Found: C, 65.37; H, 4.32; N, 5.45. 2-Tosyl-1H-indole (3b) 8a White solid (122.1 mg, 90% yield); mp 195–197 °C. 1H NMR (500 MHz, CDCl3): δ = 9.02 (br s, 1 H), 7.95 (d, J = 8.0 Hz, 2 H), 7.65 (d, J = 7.5 Hz, 1 H), 7.50 (d, J = 2.5 Hz, 1 H), 7.46 (d, J = 8.0 Hz, 1 H), 7.30–7.27 (m, 1 H), 7.20 (t, J = 7.5 Hz, 1 H), 7.20 (d, J = 8.0 Hz, 2 H), 2.33 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 143.7, 136.3, 135.3, 130.2, 139.3, 128.9, 126.1, 122.8, 120.7, 119.5, 111.3, 108.5, 20.7. Anal. Calcd (%) for C15H13NO2S: C, 66.40; H, 4.83; N, 5.16. Found: C, 66.43; H, 4.81; N, 5.15. 2-[(4-Chlorophenyl)sulfonyl]-1H-indole (3c) 8a White solid (128.4 mg, 88% yield); mp 146–148 °C. 1H NMR (500 MHz, CDCl3): δ = 8.82 (br s, 1 H), 7.83 (d, J = 9 Hz, 2 H), 7.75 (d, J = 8.5 Hz, 2 H), 7.59 (d, J = 8.0 Hz, 1 H), 7.49 (d, J = 2.5 Hz, 1 H), 7.46 (d, J = 8.0 Hz, 1 H), 7.30–7.26 (m, 1 H), 7.20–7.17 (m, 1 H). 13C NMR (125 MHz, CDCl3): δ = 140, 137.6, 136.3, 130.6, 130.4, 128.6, 126.9, 123.1, 120.9, 119.3, 111.5, 109.1. Anal. Calcd (%) for C14H10ClNO2S: C, 57.63; H, 3.45; N, 4.80. Found: C, 57.65; H, 3.47; N, 4.82. 2-[(4-Bromophenyl)sulfonyl]-1H-indole (3d) 8a White solid (142.9 mg, 85% yield); mp 191–193 °C. 1H NMR (500 MHz, CDCl3): δ = 8.87 (br s, 1 H), 7.71 (d, J = 8.5 Hz, 2 H), 7.50 (d, J = 7.5 Hz, 1 H), 7.42 (d, J = 2.5 Hz, 1 H), 7.39 (d, J = 7.5 Hz, 1 H), 7.19–7.18 (m, 3 H), 7.12–7.09 (m, 1 H). 13C NMR (125 MHz, CDCl3): δ = 140.5, 138.4, 136.3, 131.5, 130.6, 127.2, 123.1, 120.9, 119.3, 118.1, 111.5, 109. Anal. Calcd (%) for C14H10BrNO2S: C, 50.01; H, 3.00; N, 4.17. Found: C, 50.04; H, 3.01; N, 4.15. 2-[(4-Methoxyphenyl)sulfonyl]-1H-indole (3e) 8a White solid (127.9 mg, 89% yield); mp 186–187 °C. 1H NMR (500 MHz, CDCl3): δ = 8.81 (br s, 1 H), 7.9 (d, J = 8.5 Hz, 2 H), 7.42 (d, = 2.5 Hz, 1 H), 7.31 (d, J = 8.5 Hz, 1 H), 7.09 (d, J = 7.5 Hz, 2 H), 7.06–7.03 (m, 2 H), 6.91 (d, J = 8.5 Hz, 1 H), 3.77 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 162.9, 136.4, 135, 131.2, 129.8, 128.5, 125.5, 124.5, 115, 113.4, 112.3, 108.6, 55.6. Anal. Calcd (%) for C15H13NO3S: C, 62.70; H, 4.56; N, 4.87. Found: C, 62.72; H, 4.55; N, 4.89. 2-[(4-Fluorophenyl)sulfonyl]-1H-indole (3f) 8a White solid (112.9 mg, 82% yield); mp 155–157 °C. 1H NMR (500 MHz, CDCl3): δ = 8.95 (br s, 1 H), 8.03 (d, J = 8.5 Hz, 2 H), 7.57–7.52 (m, 3 H), 7.36 (t, J = 7.0 Hz, 1 H), 7.24 (t, J = 7.5 Hz, 1 H), 7.16 (d, J = 9 Hz, 2 H). 13C NMR (125 MHz, CDCl3): δ = 166 (d, J = 251.6 Hz), 136.4 (d, J = 3 Hz), 135, 130 (d, J = 9.6 Hz), 128.3, 124.9, 123.4, 121.3, 119.1, 116.3 (d, J = 22.6 Hz), 111.8, 109. Anal. Calcd (%) for C14H10FNO2S: C, 61.08; H, 3.66; N, 5.09. Found: C, 61.05; H, 3.67; N, 5.06. 2-(Naphthalen-2-ylsulfonyl)-1H-indole (3h) 8a White solid (138.3 mg 90% yield); mp 156–158 °C. 1H NMR (500 MHz, CDCl3): δ = 9.05 (br s, 1 H), 8.46 (s, 1 H), 7.96–7.93 (m, 2 H), 7.72 (d, J = 8.0 Hz, 1 H), 7.65–7.61 (m, 2 H), 7.48–7.45 (m, 2 H), 7.38–7.33 (m, 2 H), 7.29–7.25 (m, 2 H), 7.16–7.13 (m, 2 H). 13C NMR (125 MHz, CDCl3): δ = 138.5, 136.4, 133.6, 131.2, 130.5, 128.9, 128.1, 127.5, 126.8, 126.2, 124.9, 124.6, 123.3, 122.9, 120.8, 119.5, 111.4, 108.6. Anal. Calcd (%) for C18H13NO2S: C, 70.34; H, 4.26; N, 4.56. Found: C, 70.31; H, 4.23; N, 4.57. 2-(Methylsulfonyl)-1H-indole (3i) 8a White solid (89.8 mg, 92% yield); mp 184–186 °C. 1H NMR (500 MHz, CDCl3): δ = 9.01 (br s, 1 H), 7.65 (d, J = 7.5 Hz, 1 H), 7.43 (d, J = 8.0 Hz, 1 H), 7.29–7.25 (m, 1 H), 7.22–7.16 (m, 2 H), 3.25 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 136.4, 133.3, 126.9, 126.2, 122.9, 121, 111.6, 108.2, 45.2. Anal. Calcd (%) for C9H9NO2S: C, 55.37; H, 4.65; N, 7.17. Found: C, 55.40; H, 4.63; N, 7.15. 5-Methoxy-2-(phenylsulfonyl)-1H-indole (3m) 8a White solid (137.9 mg, 96% yield); mp 135–137 °C. 1H NMR (400 MHz, CDCl3): δ = 9.01 (br s, 1 H), 8.02 (d, J = 8.0 Hz, 2 H), 7.57–7.51 (m, 3 H), 7.36 (d, J = 7.6 Hz, 1 H), 7.22 (s, 1 H), 7.16–7.12 (m, 2 H), 3.81 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 155, 140.9, 134.1, 133.5, 132.6, 129.8, 128.1, 127.7, 117.6, 112.3, 109, 102.3, 55.5. Anal. Calcd (%) for C15H13NO3S: C, 62.70; H, 4.56; N, 4.87. Found: C, 62.67; H, 4.57; N, 4.85. 4-Methyl-2-(phenylsulfonyl)-1H-indole (3n) 8a White solid (124.8 mg, 92% yield); mp 166–169 °C. 1H NMR (400 MHz, CDCl3): δ = 9.01 (br s, 1 H), 7.96 (d, J = 8.4 Hz, 2 H), 7.50–7.45 (m, 3 H), 7.32–7.27 (m, 3 H), 6.96 (d, J = 7.2 Hz, 1 H), 2.51 (s, 3 H). Anal. Calcd (%) for C15H13NO2S: C, 66.40; H, 4.83; N, 5.16. Found: C, 66.38; H, 4.80; N, 5.17. 6-Chloro-2-(phenylsulfonyl)-1H-indole (3o) 8a White solid (116.7 mg, 80% yield); mp 181–183 °C. 1H NMR (500 MHz, CDCl3): δ = 9.01 (br s, 1 H), 8.01 (d, J = 8.5 Hz, 2 H), 7.55–7.49 (m, 4 H), 7.24 (d, J = 7.5 Hz, 1 H), 7.09–7.06 (m, 2 H). 13C NMR (125 MHz, CDCl3): δ = 141.9, 136.4, 133.9, 129.7, 128.2, 125.9, 124.8, 123.3, 121.2, 119, 111.7, 109. Anal. Calcd (%) for C14H10ClNO2S: C, 57.63; H, 3.45; N, 4.80. Found: C, 57.61; H, 3.47; N, 4.78. 7-Methyl-2-(phenylsulfonyl)-1H-indole (3p) 1 White solid (130.2 mg, 96% yield); mp 171–173 °C. 1H NMR (500 MHz, CDCl3): δ = 8.97 (br s, 1 H), 7.98 (d, J = 8.0 Hz, 2 H), 7.61–7.53 (m, 4 H), 7.20 (s, 1 H), 7.13–7.07 (m, 2 H), 2.50 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 141.1, 136.2, 134.2, 131.8, 130.2, 129.4, 129, 126.2, 122.9, 120.7, 119.6, 111, 19.7. Anal. Calcd (%) for C15H13NO2S: C, 66.40; H, 4.83; N, 5.16. Found: C, 66.37; H, 4.81; N, 5.15. 3-Methyl-2-(phenylsulfonyl)-1H-indole (3q) 8d White solid (120.7 mg 89% yield); mp 168–169 °C. 1H NMR (500 MHz, CDCl3): δ = 8.87 (br s, 1 H), 7.99 (d, J = 7.6 Hz, 2 H), 7.60–7.49 (m, 4 H), 7.43–7.40 (t, J = 7.6 Hz, 2 H), 7.18–7.15 (t, J = 7.6 Hz, 1 H), 2.53 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 141.5, 136.2, 133.5, 129.4, 128.2, 127, 126.1, 122.2, 120.5, 119.6, 112.1, 111.4, 8.8. Anal. Calcd (%) for C15H13NO2S: C, 66.40; H, 4.83; N, 5.16. Found: C, 66.42; H, 4.80; N, 5.13. 5-Bromo-2-[(4-chlorophenyl)sulfonyl]-1H-indole (3r) 8b Brown solid (127.8 mg, 69% yield); mp 183−186 °C. 1H NMR (500 MHz, CDCl3): δ = 8.85 (br s, 1 H), 8.02 (d, J = 7.0 Hz, 2 H), 7.81 (s, 1 H), 7.59 (d, J = 7.0 Hz, 2 H), 7.46 (d, J = 7.0 Hz, 1 H), 7.43 (d, J = 7.5, 1 H), 7.14 (d, J = 2.0 Hz, 1 H). 13C NMR (125 MHz, CDCl3): δ = 141.1, 140, 137.4, 136.3, 131, 130, 129.2, 129, 126.4, 115.8, 114.3, 108.5. Anal. Calcd (%) for C14H9BrClNO2S: C, 45.37; H, 2.45; N, 3.78. Found: C, 45.39; H, 2.44; N, 3.75. S-p-Tolyl-4-methylbenzenesulfonothioate (3aa) 9f White solid (194.9 mg 70% yield); mp 91–93 °C. 1H NMR (500 MHz, CDCl3): δ = 7.49 (d, J = 7.0 Hz, 2 H), 7.22–7.16 (m, 4 H), 7.14 (d, J = 7.0 Hz, 2 H), 2.36 (s, 3 H), 2.32 (s, 3 H). 1,2-Di-p-tolyldisulfane (3ab) 9f White solid (36.8, mg 15% yield); mp 45–48 °C. 1H NMR (400 MHz, CDCl3): δ = 7.42 (d, J = 8.0 Hz, 4 H), 7.12 (d, J = 8.0 Hz, 2 H), 2.35 (s, 6 H).