7384
C. S. Harris et al. / Tetrahedron Letters 46 (2005) 7381–7384
was added solid phenyl-N(bis) trifluoromethanesulfon-
References and notes
amide (1.01 equiv). The slurry was stirred at ambient
temperature for 4 h. The slurry was filtered through a bed
of Celite and concentrated on a rotary evaporator to
afford a thick viscous oil which was recrystallised from ice-
cold methanol (3 ml/g) to afford the triflate (88%) as an
off-white solid.
1. Woodburn, J. R. Pharmacol. Ther. 1999, 82, 241.
2. Woodburn, J. R.; Barker, A. J.; Gibson, K. H.; Ashton, S. E.;
Wakeling, A. E. Proc. Am. Assoc. Cancer Res. 1997, 38,
6333.
3. Laird, A. D.; Cherrington, J. M. Expert Opin. Invest.
Drugs 2003, 12, 51.
8. Gilday, J. P.; Moody, D. PCT Int. Appl. WO 2004024703,
2004.
9. For review articles see: (a) Wolfe, J. P.; Wagaw, S.;
Marcoux, J.-F.; Buchwald, S. L. Acc. Chem. Res. 1998, 31,
805–818; (b) Hartwig, J. F. Ang. Chem. Int., Ed. 1998, 32,
2046.
10. For a high-pressure preparative procedure see Kotsuki,
H.; Kobayashi, S.; Suegna, H.; Nishiwaza, N. Synthesis
1990, 1145.
11. (a) Ding, S.; Gray, N. S.; Wu, X.; Ding, O.; Schultz, P. G.
J. Am. Chem. Soc. 2002, 124, 1594; (b) Tobe, M.; Isobe,
Y.; Tomizawa, H.; Matsumoto, M.; Obara, F.; Nagasaki,
T.; Hayashi, H. Bioorg. Med. Chem. Lett. 2001, 11, 545.
12. Typically: the amine (5.00 equiv) in NMP (1 ml/g) is
heated to 135 °C. The 7-OTf (1.00 equiv) is added and the
reaction temperature maintained for a further 3–5 h. The
reaction mixture is loaded onto pre-packed silica gel
cartridges and purified eluting with DCM to NH3–
MeOH–DCM gradient.
13. When the triflate is added at 135 °C, attack at sulfur in the
first part of the equilibrium is to a degree by-passed and
the desired products can be isolated, in certain cases, in
yields as high as 20%.
14. Typically: the 7-fluoroquinazoline (1.00 equiv), K2CO3
(1.10 equiv) and amine (5.00 equiv) in NMP (1 ml/g) are
heated to 135 °C for 5 h. The reaction mixture is loaded
onto pre-packed silica gel cartridges and purified eluting
with DCM–NH3–MeOH–DCM gradient.
4. For recent articles see: (a) Broxterman, H. J.; Georgopa-
padakou, N. H. Drug Resist. Updates 2004, 7, 79–87; (b)
Paez, J. G.; Ja¨nne, P. A.; Lee, J. C.; Tracy, S.; Greulich,
H.; Gabriel, S.; Herman, P.; Kaye, F. J.; Lindeman, N.;
Boggon, T. J.; Naoki, K.; Sasaki, H.; Fujii, Y.; Eck, M. J.;
Sellers, W. R.; Johnson, B. E.; Meyerson, M. Science
2004, 304, 1497; (c) Lynch, T. J.; Bell, D. W.; Sordella, R.;
Gurubhagavatula, S.; Okimoto, R. A.; Brannigan, B. W.;
Harris, P. L.; Haserlat, S. M.; Supko, J. G.; Haluska, F.
G.; Louis, D. N.; Christiani, D. C.; Settleman, J.; Haber,
D. A. New Eng. J. Med. 2004, 350, 2129.
5. Starting from commercially-available vanillic acid, a
similar process was used to access 3 as described by
Pandey, A.; Volkots, D.; Sergooy, J. M.; Rose, J. W.; Yu,
J.-C.; Lambing, J. L.; Hutchaleelaha, A.; Hollenbach, S.
J.; Abe, K.; Giese, N. A.; Scarborough, R. M. J. Med.
Chem. 2002, 45, 3772.
6. Hendrickson, J. B.; Bergeron, R. Tetrahedron Lett. 1973,
14, 4607.
7. Classical conditions (Tf2O, pyridine, DCM) proved unre-
liable to form the 7-OTf. During the reaction, equilibrium
is quickly established where the 7-OTf, once formed, is
attacked at sulfur by pyridine to afford the 7-phenol. To
prevent an equilibrium forming, phenyl-N(bis) trifluoro-
methanesulfonamide was used with considerable success.
Typically: to a stirred slurry of the phenol (1.00 equiv) and
K2CO3 (Aldrich À325 mesh, 3.00 equiv) in THF (5 ml/g),