1-(5￠-n-Butyl-2,2￠-bipyridin-5-yl)ethynyl-3-ethynylbicyclo[
1.1.1]pentane (21). A solution of 17 (600 mg, 2.06
mmol) in dry triethylamine (10 mL) under argon was transferred
to a two-neck flask. Freshly sublimed 9 (3.52 g, 0.030
mol) was washed into the flask with dry triethylamine (25 mL),
and the solution was degassed by three freeze-pump-thaw
cycles. Then, Pd(PPh3)4 (60 mg, 2.5 mol %) was added from a
tip tube. The reaction mixture was stirred at 70 °C for 12 h.
The triethylamine was evaporated under reduced pressure
directly from the reaction flask, and excess 9 was sublimed
out. The crude product mixture was washed thoroughly with
diethyl ether, and the solid residue was filtered off. The filtrate
was concentrated under reduced pressure, and the resulting
crude solid was chromatographed (alumina, hexanes-ethyl
acetate, 10:1) to obtain 21 as a white powder: 556 mg (82%);
mp 151 °C; 1H NMR (CDCl3, 500 MHz) ? 0.92 (t, J ) 7.3 Hz,
3 H), 1.34 (m, 2 H), 1.60 (m, 2 H), 2.09 (s, 1 H), 2.45 (s, 6 H),
2.65 (t, J ) 7.7 Hz, 2 H), 7.60 (dd, J ) 8.1 Hz, J ) 2.1 Hz, 1
H), 7.77 (dd, J ) 8.3 Hz, J ) 2.2 Hz, 1 H), 8.25 (d, J ) 8.1 Hz,
1 H), 8.25 (d, J ) 7.7 Hz, 1 H), 8.45 (d, J ) 2.1 Hz, 1 H), 8.65
(d, J ) 1.4 Hz, 1 H); 13C {1H} NMR (CDCl3, 124 MHz) ? 13.82,
22.16, 30.05, 30.50, 32.53, 33.14, 58.71, 68.32, 77.20, 82.30,
92.00, 119.47, 119.93, 120.95, 136.80, 138.55, 139.55, 149.36,
151.73, 153.05, 154.87; IR (KBr) 413, 457, 654, 686, 743, 791,
839, 1024, 1049, 1243, 1384, 1464, 1538, 1587, 2857, 2877,
2915, 2959, 2993, 3280 cm-1; MS (EI+) m/z (relative intensity)
326 ([M]+, 75), 325 ([M - H]+, 95), 283 ([M - C3H7]+, 100),
268 (5), 254 (12), 217 (13), 204 (6), 190 (11), 177 (5), 165 (5),
141 (7), 115 (4), 77 (4); HRMS calcd 326.1783, found 326.1778.
Anal. Calcd for C23H22N2: C, 84.63; H, 6.79; N, 8.58. Found:
C, 84.34; H, 7.08; N, 8.43.
|
