LETTER
Multi-functionalized 2,2 :6 ,2 -Terpyridines
753
Scheme 2
cules with Higher Structural Order, Vol. 812; Khan, I., Ed.;
(10) See, for example: (a) Schubert, U. S.; Eschbaumer, C.;
Hochwimmer, G. Tetrahedron Lett. 1998, 39, 8643.
(b) Schubert, U. S.; Eschbaumer, C.; Hochwimmer, G.
Synthesis 1999, 779.
(11) Dimethyl-2,2 :6 ,2 -terpyridines. Route 1: The methyl-2-
tributylstannylpyridine 2a–c (3 g, 7.85 mmol), 2,6-
ACS Symp. Ser.: Washington DC, 2001, 163. (c) Heller,
M.; Schubert, U. S. Macromol. Rapid Commun. 2001, 22,
1358. (d) Schubert, U. S.; Eschbaumer, C. Macromol. Symp.
2001, 163, 177. (e) Schubert, U. S.; Eschbaumer, C.; Hien,
O.; Andres, P. R. Tetrahedron Lett. 2001, 42, 4705.
(f) Schubert, U. S.; Heller, M. Chem.–Eur. J. 2001, 7, 5252.
(g) Schubert, U. S.; Eschbaumer, C. Angew. Chem. Int. Ed.
2002, in press.
dibromopyridine 1 (0.75 g, 3.17 mmol) and tetrakis-
(triphenylphosphine)-palladium(0) (0.29 g, 6.0 mol%) are
refluxed for 4 days in absolute toluene (50 mL). After
removal of the solvent, the black residue is treated with aq
HCl (6 M). The suspension is extracted with CH2Cl2 and the
organic phase is washed again with HCl (6 M). The aq
solution is added dropwise into cold aq ammonia (10%). The
precipitate is filtered off, dissolved in CH2Cl2, dried over
Na2SO4, the solvent is removed again and the residue is
crystallized from ethyl acetate. Route 2: 2,6-Bis(trimethyl-
stannyl)pyridine 6 (12.23 g, 7.66 mmol), the 2-bromo-
methylpyridine 7a–c (3.29 g, 19.15 mmol) and tetrakis-
(triphenylphosphine)-palladium(0) (0.6 g, 6 mol%) are
refluxed in dry toluene (70 mL) for 72 h at 110 °C. The
workup is identical to route 1. 3: White crystals. Mp 186 °C.
1H NMR (CDCl3): = 2.39 (s, 6 H, CH3), 7.17 (dd, J = 4.96
Hz, 0.77 Hz, 2 H, H5,5 ), 7.94 (t, J = 8.01 Hz, 1 H, H4 ), 8.41
(s, 2 H, H3,3 ), 8.42 (d, J = 8.01 Hz, 2 H, H3 ,5 ), 8.56 (d,
J = 4.95 Hz, 2 H, H6,6 ). C17H15N3 (261.32): Calcd C, 78.13;
H, 5.79; N, 16.08. Found: C, 78.04; H, 6.00; N, 15.92. 4:
White crystals (Lit.15 67%). Mp 173 °C (Lit.15 169–171 °C,
Lit.15 174–175 °C). 1H NMR (CDCl3): = 2.39 (s, 6 H,
CH3), 7.63 (dd, J = 8.01, 2.28 Hz, 2 H, H4,4 ), 7.91 (t,
J = 7.82 Hz, 1 H, H4 ), 8.38 (d, J = 7.62 Hz, 2 H, H3 ,5 ), 8.49
(d, J = 8.40 Hz, 2 H, H3,3 ), 8.50 (s, 2 H, H6,6 ). C17H15N3
(261.32): Calcd C, 78.13; H, 5.79; N, 16.08. Found: C,
(4) Schubert, U. S.; Weidl, C. H.; Moorefield, C. N.; Baker, G.
R.; Newkome, G. R. Polym. Prepr. (Am. Chem. Soc., Div.
Polym. Chem.) 1999, 40, 940.
(5) (a) Padilla-Tosta, M. E.; Lloris, J. M.; Martinez-Manez, R.;
Benito, A.; Soto, J.; Pardo, T.; Miranda, M. A.; Marcos, M.
D. Eur. J. Inorg. Chem. 2000, 741. (b) Potts, K. T.; Usifer,
D. A.; Guadalupe, A.; Abruna, H. D. J. Am. Chem. Soc.
1987, 109, 3961. (c) Fallahpour, R.-A.; Neuburger, M.;
Zehnder, M. New J. Chem. 1999, 53. (d) Fallahpour, R.-A.;
Neuburger, M.; Zehnder, M. Synthesis 1999, 6, 1051.
(6) (a) Larson, S. L.; Elliot, C. M.; Kelley, D. F. Inorg. Chem.
1996, 35, 2070. (b) Balzani, V.; Juris, A.; Venturi, M. Chem.
Rev. 1996, 96, 759. (c) Maestri, M.; Armali, N.; Balzani, V.;
Constable, E. C.; Cargill Thompson, A. M. V. Inorg. Chem.
1995, 34, 2759.
(7) (a) Kröhnke, F. Synthesis 1976, 1. (b) Kröhnke, F. Angew.
Chem. 1963, 75, 317. (c) Potts, K. T. J. Org. Chem. 1991,
56, 4812.
(8) (a) Stille, J. K. Angew. Chem., Int. Ed. Engl. 1986, 25, 508;
Angew. Chem. 1986, 98, 504. (b) Labadie, J. W.; Stille, J. K.
J. Am. Chem. Soc. 1983, 105, 6129.
(9) Schubert, U. S.; Eschbaumer, C.; Heller, M. Org. Lett. 2000,
2, 3373.
Synlett 2002, No. 5, 751–754 ISSN 0936-5214 © Thieme Stuttgart · New York