Copper dipyridine dichloride (CuPy2Cl2) has been found to be an efficient catalyst for the synthesis of N-arylanthranilic acids from ortho halobenzoic acids and aromatic amines under microwave irradiation. Some of the advantages of this method are high chemoselectivity, ease of operation, less reaction times and high yields. (61–98%).
For recent reviews of microwave-assisted organic synthesis (MAOS), see: (a) KappeC.O., and DallingerD., Nat. Rev. Drug. Discovery., 2006, 5, 55; (b) W.D. Shipe, S.E. Wolkenberg and C.W. Lindsley, Drug Discovery Today: Tech., 2005, 2, 155; (c) N.E. Leadbeater, Chem. Commun., 2005. 2881; (d) C.O. Kappe, Angew. Chem., Int. Ed., 2004, 43, 650; (e) P. Lindstrom, J. Tierney, B. Wathey and J. Westmen. Tetrahedron, 2001, 57, 9225; (f) L. Perreux and A. Loupy. Tetrahedron, 2001, 57, 9199, and references cited therein
2.
For recent applications of microwave technology in natural product synthesis, see; (a) BaxendaleI.R., LeyS.V., and PiuttiC., Angew. Chem., Int. Ed., 2002, 41, 2194; (b) Y. Rang, Y. Mei and Z. Jin, Org. Lett., 2003, 5, 4481; (c) R.S. Grainger and A. Patel, Chem. Commun., 2003, 1072; (d) I.T. Raheem, S.N. Goodman and E.N. Jacobsen, J. Am. Chem. Soc., 2004, 126, 706; (e) R. Lepine, Zhu, J. Org. Lett. 2005, 7, 2981.
3.
(a) LoupyA., Microwave in Organic Synthesis; Wiley-VCH: Weinheim, 2002; (b) H.M. Kingston and S.J. Haswell, Microwave Enhanced Chemistry; American Chemical Society Publications: Washington, 1997; (c) C.O. Kappe, and A. Stadler, Microwaves in organic and medicinal Chemistry; C.H.I.P.S Books: Weimar, 2005.
4.
(a) OzaV.B., PetrassiH.M., KellyH.E., and BioorgJ.W., Med. Chem. Lett., 1999, 9, 1; (b) N.S. Green, S.K. Palaninathan, J.C. Sacchettini and J.W. Kelly, J. Am. Chem. Soc. 2003, 125, 13404; (c) V.B. Oza, C. Smith, B. Raman, E.K. Koepf, H.A. Lashuel, H.M. Petrassi, K.P. Chiang, E.T. Powers, J. Sachettinni and J.W. Kelly, J. Med. Chem., 2002, 45, 321; (d) P.W. Baures, V.B. Oza, S.A. Peterson and J.W. Kelly, Bioorg. Med. Chem., 1999, 7, 1339; (e) T. Klabunde, H.M. Petrassi, V.B. Oza, P. Raman, J.W. Kelly and J.C. Saccettini, Nat Struct. Biol., 2000, 7, 312; (f) S. Girault, P. Grellier, A. Berecibar, L. Maes, E. Mouray, P. Lemiere, M.A. Debeu, E. Davioud-Charvet and C. Sergheraert, J. Med. Chem., 2000, 43, 2646; (g) M. Demeunynck, F. Charmantray and A. Martelli, Curr. Pharm. Des., 2001, 77, 1703; (h) M.F. Brana, Cacho, De Pascual-Teresa.; Ramos, A. Curr. Pharm. Des. 2001, 7, 1745; (i) P.M. Paglialunga, I. Torrini, G.Z. Pagani, G. Lucente, E. Gavuzzo, F. Mazza and G. Pochetti, Tetrahedron, 1995, 51, 2379; (j) H.T. Nagasawa, J.A. Elberling and F.N. Shirota, J. Med. Chem., 1973, 16, 823; (k) A. Breveglieri, R. Guerrini, S. Salvadori, C. Bianchi, S.D. Bryant, M. Attila and L.H. Lazarus, J. Med. Chem., 1996, 31, 773; (l) Y. Inai, Y. Kurokawa, A. Ida and T. Hirabayashi, Bull. Chem. Soc. Jpn., 1999, 72, 55; (m) K. Ramesh, P. Balaram, Bioorg. Med. Chem., 1999, 7, 105.
5.
(a) InaiY., OusakaN., and OkabeT., J. Am. Chem. Soc., 2003, 125, 8151; (b) Y. Inai, K. Tagawa, A. Takasu, T. Hirabayashi, T. Oshikawa and M. Yamashita, J. Am. Chem. Soc., 2000, 122, 11731.
(a) KwongF.Y., KlaparsA., and BuchwaldS.L., Org. Lett., 2002, 4, 581; (b) C. Wolf and X. Mei, J. Am. Chem. Soc., 2003, 125, 65; (c) M.L. Docampo Palacios and R.F.Pellon Comdom, Synth. Commun., 2003, 33, 1771; (d) X. Mei and C. Wolf, J. Org. Chem., 2005, 70, 2299; (e) X. Mei and C. Wolf, J. Am. Chem. Soc., 2004, 126, 14736; (f) X. Mei and C. Wolf, Chem. Commun., 2004, 2078.
8.
HuangX., AndersonK.W., ZimD., JiangL., KlaparsA., and BuchwaldS.L., J. Am. Chem. Soc., 2003, 125, 6653.
9.
KunzK., ScholzU., GanzerD., Synlett., 2003, 2428.
10.
(a) HayA.S., and BlanchardH.S., Can. J. Chem., 1965, 43, 1306; (b) Y. Sasson, G.D. Zappi and R. Neumann, J. Org. Chem., 1986, 51, 2880.
11.
ChenL.S., ChenG.J., and TamborskiC., J. Organomet. Chem., 1980, 193, 283.
(a) ChristianW., ShuanglongL., XuefengM., AdamT.A., and MichaelD.C., J. Org. Chem., 2006, 71, 3270; (b) M.M. Babu, M. Amaravathi, V.N. Kumar and G.V.P. Chandra J. Mol. Cat. A. Chemical., 2007, 266, 47; (c) M. Xuefeng, T.A. Adam and W. Christian J. Org. Chem., 2006, 71(1), 142.