Palladium-catalyzed chemoselective monoarylation of hydrazides for the synthesis of [1,2,4]Triazolo[4,3-a]pyridines

Organic Letters

Volumn 12, Issue 4, 2010, Pages 792-795

  Reichelt, Andreas ^a   Falsey, James R ^a   Rzasa, Robert M ^a   Thiel, Oliver R ^a   Achmatowicz, Michal M ^a   Larsen, Robert D ^a   Zhang, Dawei ^a  

^a AMGEN INC   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

2 CHLOROPYRIDINE; 2-CHLOROPYRIDINE; ACETIC ACID; HYDRAZINE DERIVATIVE; PALLADIUM; PYRIDINE DERIVATIVE; TRIAZOLE DERIVATIVE;

ARTICLE; CATALYSIS; CHEMICAL STRUCTURE; CHEMISTRY; COMBINATORIAL CHEMISTRY; CYCLIZATION; MICROWAVE RADIATION; SYNTHESIS;

ACETIC ACID; CATALYSIS; COMBINATORIAL CHEMISTRY TECHNIQUES; CYCLIZATION; HYDRAZINES; MICROWAVES; MOLECULAR STRUCTURE; PALLADIUM; PYRIDINES; TRIAZOLES;

EID: 76849113796     PISSN: 15237060     EISSN: 15237052     Source Type: Journal    
DOI: 10.1021/ol902868q     Document Type: Article

References (26)

1. For example, see: (a) Yoshimura, Y.; Tomimatsu, K.; Nishimura, T.; Miyake, A.; Hashimoto, N. J. Antibiot. 1992, 45, 721.
2. (b) Sadana, A. K.; Mirza, Y.; Aneja, K. R.; Prakash, O. Eur. J. Chem. 2003, 38, 533.
3. (c) Lawson, E. C.; Hoekstra, W. J.; Addo, M. F.; Andrade-Gordon, P.; Damiano, B. P.; Kauffman, J. A.; Mitchell, J. A.; Maryanoff, B. E. Bioorg. Med. Chem. Lett. 2001, 11, 2619.
4. (d) Kalgutkar, A. S.; Hatch, H. L.; Kosea, F.; Nguyen, H. T.; Choo, E. F.; McClure, K. F.; Taylor, T. J.; Henne, K. R.; Kuperman, A. V.; Dombroski, M. A.; Letavic, M. A. Biopharm. Drug Dispos. 2006, 27, 371.
5. (e) Luethy, C.; Hall, R. G.; Edmunds, A.; Riley, S.; Diggelmann, M. PCT Int. Appl. WO08006540, 2008.
6. (f) Abel, U.; Deppe, H.; Feurer, A.; Grädler, U.; Ott, I.; Matassa, V. G. PCT Int. Appl. WO06058752, 2006.
7. (a) Sliskovic, D. R. Bicyclic 5-6 Systems with One Ring Junction Nitrogen Atom: Two Extra Heteroatoms 2: 0. In Comprehensive Heterocyclic Chemistry II: A Review of the Literature 1982-1995: The Structure, Reactions, Synthesis, and Uses of Heterocyclic Compounds; Katritzky, A. R., Rees, C. W., Scriven, E. F. V., Eds.; Pergamon: Oxford, New York, 1996; Vol.8, Chapter 13, pp 367-388.
8. (b) Jones, G. Adv. Heterocycl. Chem. 2002, 83, 1, and references cited therein.
9. Schlosser, M.; Bobbio, C.; Rausis, T. J. Org. Chem. 2005, 70, 2494.
10. Abad, A.; Agulló, C.; Cuñat, A. C.; Vilanova, C. Synthesis 2005, 915.
11. Palladium-catalyzed additions:(a) Wang, Z.; Skerlj, R. T.; Bridger, G. J. Tetrahedron Lett. 1999, 40, 3543.
12. (b) Arterburn, J. B.; Rao, K. V.; Ramdas, R.; Dible, B. R. Org. Lett. 2001, 3, 1351.
13. (c) Lim, Y.-K.; Jung, J.-W.; Lee, H.; Cho, C.-G. J. Org. Chem. 2004, 69, 5778.
14. Copper-catalyzed additions: (a) Klapars, A.; Antilla, J. C.; Huang, X.; Buchwald, S. L. J. Am. Chem. Soc. 2001, 123, 7727.
15. (b) Wolter, M.; Klapars, A.; Buchwald, S. L. Org. Lett. 2001, 3, 3803.
16. (c) Lavecchia, G.; Berteina-Raboin, S.; Guillaumet, G. Tetrahedron Lett. 2004, 45, 2389.
17. A selective monoarylation of the terminal nitrogen atom of hydrazides with organobismuth reagents was reported: Tšubrik, O.; Mäeorg, U.; Sillard, R.; Ragnarsson, U. Tetrahedron 2004, 60, 8363.
18. Exploration of copper-based catalyst systems was not within the scope of this investigation.
19. Table 1 only contains a selected array of the conditions screened. All ligands were investigated in the presence of potassium phosphate (toluene), cesium carbonate (toluene, DMF), and sodium tert-butoxide (toluene, DME).
20. The structure of 4a was confirmed by NMR and by conversion to the corresponding triazolopyridine 6a. Conversions were determined by HPLC (215 nm).
21. For a leading reference regarding use of 3 for palladium-catalyzed couplings: Shen, Q.; Shekhar, S.; Stambuli, J. P.; Hartwig, J. F. Angew. Chem. Int. Ed. 2005, 44, 1371.
22. This impurity was tentatively assigned as structure 8 based on LC/ MS data. The formation of this impurity is most likely caused by dimerization of-intermediate 7, wich can observed by LC/MS.
23. Hansen, K. B.; Balsells, J.; Dreher, S.; Hsiao, Y.; Kubryk, M.; Palucki, M.; Rivero, N.; Steinhuebel, D.; Armstrong, J. D., III; Askin, D.; Grabowski, E. J. Org. Process Res. Dev. 2005, 9, 634.
24. While this manuscript was in preparation, a method for the formation, of [1,2,4]triazolo[4,3-b]pyridazines featuring microwave-assisted dehydration in acidic medium was published: Aldrich, L. N.; Lebois, E. P.; Lewis, L. M.; Nalywajko, N. T.; Niswender, C. M.; Weaver, C. D.; Conn, P. J.; Lindsley, C. W. Tetrahedron Lett. 2009, 50, 212.
25. >3000 according to ACD.
26. 4) and concentrated under reduced pressure. The resulting black oil was purified by flash chromatography to deliver the desired product (see Supporting Information).