Correction: A general synthesis of substituted indoles from cyclic enol ethers and enol lactones (Organic Letters (2004) 6:1 (79-82) DOI: 10.1021/ol036113f);A General Synthesis of Substituted Indoles from Cyclic Enol Ethers and Enol Lactones

Organic Letters

Volumn 6, Issue 1, 2004, Pages 79-82

  Campos, Kevin R ^a   Woo, Jacqueline C S ^a   Lee, Sandra ^a   Tillyer, Richard D ^a  

^a MERCK RESEARCH LABORATORIES   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ANTIMIGRAINE AGENT; ETHER DERIVATIVE; HYDRAZINE DERIVATIVE; INDOLE DERIVATIVE; INDOLEACETIC ACID; INDOLEPROPIONIC ACID; INDOMETACIN; LACTONE; SUMATRIPTAN;

ARTICLE; DRUG SYNTHESIS;

EID: 0742286908     PISSN: 15237060     EISSN: 15237052     Source Type: Journal    
DOI: 10.1021/acs.orglett.8b01644     Document Type: Erratum

References (30)

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3. (c) Saxton, J. E. Indoles; Wiley-Interscience: New York, 1983.
4. For a review of recent developments in the synthesis of indoles, see: Gribble, G. W. J. Chem. Soc., Perkin Trans. 1. 2000, 1045-1075 and references therein.
5. (a) Gribble, G. W. Contemp. Org. Synth. 1994, 1, 1.
6. (b) Hughes, D. L. Org. Prep. Proc. Int. 1993, 25, 607-632.
7. (c) Robinson, B. The Fischer Indole Synthesis; Wiley-Interscience: New York, 1982.
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12. This method has been attempted, resulting in low yields as a two-step process, (a) White, J. D.; Yager, K. M.; Yakura, T. J. Am. Chem. Soc. 1994, 116, 1831-1838. (b) McKittrick, B.; Failli, A.; Steffan, R. J.; Soll, R. M.; Hughes, R.; Schmid, J.; Asselin, A. A.; Shaw, C. C.; Noureldin, R.; Gavin, G. J. Heterocycl. Chem. 1990, 27, 2151-2163.
13. This method has been attempted, resulting in low yields as a two-step process, (a) White, J. D.; Yager, K. M.; Yakura, T. J. Am. Chem. Soc. 1994, 116, 1831-1838. (b) McKittrick, B.; Failli, A.; Steffan, R. J.; Soll, R. M.; Hughes, R.; Schmid, J.; Asselin, A. A.; Shaw, C. C.; Noureldin, R.; Gavin, G. J. Heterocycl. Chem. 1990, 27, 2151-2163.
14. (a) Chen, C.-Y.; Senanyake, C. H.; Bill, T. J.; Larsen, R. D.; Verhoeven, T. R.; Reider, P. J. J. Org. Chem. 1994, 59, 3738-3741.
15. (b) Klaver, W. H.; Hiemstra, H.; Speckamp, W. N. J. Am. Chem. Soc. 1989, 111, 2588-2595.
16. Excess hydrazine (2 equiv) slightly reduced the amount of 1 (40%).
17. Importance of the cosolvent is due to the homogenization of the reaction mixture. In purely aqueous systems, the product and dihydrofuran are insoluble, creating a highly concentrated "organic layer" that leads to increased formation of 1.
18. Performing the reaction at 100°C was optimal. Lower temperatures gave significantly lower yields of 2a (50°C, 33% yield; 25°C, 18% yield). However, in the case of more electron-rich hydrazines such as p-methoxyphenylhydrazine, lower temperatures (55°C) were needed to prevent the formation of the methoxy-substituted analogue of 1.
19. 4 (aq) (10 mL) and DMAc (10 mL) at 100°C was added dihydrofuran (630 uL, 6.92 mmol) dropwise over 2 min. The reaction was aged for 2 h and then cooled to room temperature, extracted with isopropyl acetate, and washed with water three times. The crude material was purified by flash chromatography.
20. Highest yield obtained in a Fischer indole with 3 was 63%. (a) Albinson, F. D.; MacKinnon, J. W. M.; Crookes, D. L. U.S. Patent 5103020, 1992. (b) Brodfuehrer, P. R.; Chen, B.-C.; Sattelberg, T. R.; Smith, P. R.; Reddy, J. P.; Stark, D. R.; Quinlan, S. L.; Reid, J. G.; Thottathil, J. K.; Wang, S. J. Org. Chem. 1997, 62, 9192-9202. Much lower yields (20-30%) have been reported in most other cases. (c) Dowles, M. D.; Coates, I. H. U.S. Patent 4816470, 1989. (d) Oxford, A. W. U.S. Patent 5037845.
21. Highest yield obtained in a Fischer indole with 3 was 63%. (a) Albinson, F. D.; MacKinnon, J. W. M.; Crookes, D. L. U.S. Patent 5103020, 1992. (b) Brodfuehrer, P. R.; Chen, B.-C.; Sattelberg, T. R.; Smith, P. R.; Reddy, J. P.; Stark, D. R.; Quinlan, S. L.; Reid, J. G.; Thottathil, J. K.; Wang, S. J. Org. Chem. 1997, 62, 9192-9202. Much lower yields (20-30%) have been reported in most other cases. (c) Dowles, M. D.; Coates, I. H. U.S. Patent 4816470, 1989. (d) Oxford, A. W. U.S. Patent 5037845.
22. Highest yield obtained in a Fischer indole with 3 was 63%. (a) Albinson, F. D.; MacKinnon, J. W. M.; Crookes, D. L. U.S. Patent 5103020, 1992. (b) Brodfuehrer, P. R.; Chen, B.-C.; Sattelberg, T. R.; Smith, P. R.; Reddy, J. P.; Stark, D. R.; Quinlan, S. L.; Reid, J. G.; Thottathil, J. K.; Wang, S. J. Org. Chem. 1997, 62, 9192-9202. Much lower yields (20-30%) have been reported in most other cases. (c) Dowles, M. D.; Coates, I. H. U.S. Patent 4816470, 1989. (d) Oxford, A. W. U.S. Patent 5037845.
23. Highest yield obtained in a Fischer indole with 3 was 63%. (a) Albinson, F. D.; MacKinnon, J. W. M.; Crookes, D. L. U.S. Patent 5103020, 1992. (b) Brodfuehrer, P. R.; Chen, B.-C.; Sattelberg, T. R.; Smith, P. R.; Reddy, J. P.; Stark, D. R.; Quinlan, S. L.; Reid, J. G.; Thottathil, J. K.; Wang, S. J. Org. Chem. 1997, 62, 9192-9202. Much lower yields (20-30%) have been reported in most other cases. (c) Dowles, M. D.; Coates, I. H. U.S. Patent 4816470, 1989. (d) Oxford, A. W. U.S. Patent 5037845.
24. Reported difficulty of achieving regioselective Fischer indole cyclizations on unsymmetrical ketones makes this result particularly noteworthy. Zhao, D.; Hughes, D. L.; Bender, D. R.; DeMarco, A. M.; Reider, P. J. J. Org. Chem. 1991, 56, 3001 and references therein.
25. Structures containing this nucleus have been reported to be human neurokinin-1 receptor antagonists and serve as potential therapeutic agents for emesis, anxiety, and depression. Copper, L. C.; Chicchi, G. G.; Dinnell, K.; Elliott, J. M.; Hollingworth, G. J.; Kurtz, M. M.; Locker, K. L.; Morrison, D.; Shaw, D. E.; Tsao, K.-L.; Watt, A. P.; Williams, A. R.; Swain, C. J. Bioorg. Med. Chem Lett. 2001, 1233-1236. Dinnell, K.; Chicchi, G. G.; Dhar, M. J.; Elliott, J. M.; Hollingworth, G. J.; Kurtz, M. M.; Ridgill, M. P.; Rycroft, W.; Tsao, K.-L.; Williams, A. R.; Swain, C. J. Bioorg. Med. Chem. Lett. 2001, 1237-1240.
26. Structures containing this nucleus have been reported to be human neurokinin-1 receptor antagonists and serve as potential therapeutic agents for emesis, anxiety, and depression. Copper, L. C.; Chicchi, G. G.; Dinnell, K.; Elliott, J. M.; Hollingworth, G. J.; Kurtz, M. M.; Locker, K. L.; Morrison, D.; Shaw, D. E.; Tsao, K.-L.; Watt, A. P.; Williams, A. R.; Swain, C. J. Bioorg. Med. Chem Lett. 2001, 1233-1236. Dinnell, K.; Chicchi, G. G.; Dhar, M. J.; Elliott, J. M.; Hollingworth, G. J.; Kurtz, M. M.; Ridgill, M. P.; Rycroft, W.; Tsao, K.-L.; Williams, A. R.; Swain, C. J. Bioorg. Med. Chem. Lett. 2001, 1237-1240.
27. This is a commonly observed intermediate when the N-acylhydrazone forms a six-membered heterocycle. Gouault, N.; Cupif, J. F.; Picard, S.; Lecat, A.; David, M. J. Pharm. Pharmacol. 2001, 53, 981-985.
28. Shen, T. Y.; et al. J. Am. Chem. Soc. 1963, 85, 8-489. Shen, T. Y. U.S. Patent 3161654.
29. Shen, T. Y.; et al. J. Am. Chem. Soc. 1963, 85, 8-489. Shen, T. Y. U.S. Patent 3161654.
30. This hydrazine could be made in one step according to literature precedent in 90% yield from commercially available starting materials. Karady, S.; Ly, M. G.; Pines, S. H.; Chemerda, J. M.; Sletzinger, M. Synthesis 1973, 50-51.