512
T. A. Cross and M. C. Davis
(25 mmol, 5 equiv), and 25 mL of THF. This mixture was refluxed under
anhydrous N2 for 30 min. After cooling to rt, the combined catalyst mixture
[52 mg of PPh3 (4 mol%), 20 mg of CuI (2 mol%), and 11 mg of Pd(OAc)2
(1 mol%)] was added in one portion. The mixture was refluxed for 3 h, during
which time a yellow solid precipitated. The mixture was cooled to rt and
filtered on a medium-porosity glass frit. The crude solid (2.02 g) was a
1
mixture of product and DIPA HBr by H NMR. The solid was stirred in
.
50 mL of H2O for 1 h. The solid was collected on a medium-porosity glass frit
and air dried on the frit to give 1.1 g of the title compound (56%) as a yellow
powder. The compound can be recrystallized from toluene. Mp 245–2488C
(darkens at temperatures more than 2008C). dH (CDCl3): 7.64 (AB quart,
J ¼ 14.8 and 8.6 Hz, 4H), 7.50 (s, 4H), 7.41 (d, J ¼ 9.0 Hz, 2H), 6.72
(d, J ¼ 9.0 Hz, 2H), 3.84 (q, J ¼ 5.8 Hz, 2H), 3.53 (t, J ¼ 6.1 Hz, 2H), 3.48
(q, J ¼ 7.2 Hz, 2H), 1.61 (t, J ¼ 5.8 Hz, OH), 1.20 (t, J ¼ 6.8 Hz, 3H); dH
(DMSO): 7.91 (d, J ¼ 8.1 Hz, 2H), 7.75 (d, J ¼ 8.5 Hz, 2H), 7.55 (AB quart,
J ¼ 23.1 and 8.5 Hz, 4H), 7.34 (d, J ¼ 8.9 Hz, 2H), 6.69 (d, J ¼ 9.3 Hz, 2H),
4.75 (bs, OH), 3.54 (t, J ¼ 6.1 Hz, 2H), 3.47–3.43 (m, 4H), 1.09
(t, J ¼ 6.9 Hz, 3H); dC (DMSO): 148.11, 132.77, 132.58, 132.11, 131.84,
131.06, 126.99, 124.45, 120.31, 118.37, 111.22, 111.02, 106.97, 94.02, 93.03,
89.46, 86.79, 58.23, 51.89, 44.61, 11.85. Elemental analysis calculated for
C27H22N2O: C, 83.05; H, 5.68; N, 7.17. Found: C, 82.89; H, 5.78; N, 7.27.
1-(4-[N-Ethyl-N-(2-hydroxyethyl)amino]phenylethynyl)-4-(4-
nitrophenylethynl)benzene (4)
A 200-mL, round-bottomed flask equipped with magnetic stirbar was charged
with 1.27 g of 18 (4.4 mmol), 1.4 g of 12 (5.5 mol, 1.25 equiv), 2.22 g of
DIPA (22 mmol, 5 equiv), and 25 mL of THF. This mixture was refluxed
under anhydrous N2 for 30 min. After cooling to rt, the combined catalyst
mixture [52 mg of PPh3 (4 mol%), 20 mg of CuI (2 mol%), and 10 mg of
Pd(OAc)2 (1 mol%)] was added in one portion. The mixture was refluxed
for 3 h, during which time a red solid precipitated. The mixture was cooled
to rt and filtered on a medium-porosity glass frit. The crude solid was a
1
mixture of product and DIPA HBr by H NMR. The solid was stirred in
.
50 mL of H2O for 1 h. The solid was collected on a medium-porosity glass
frit and air dried on the frit to give 770 mg of the title compound (43%) as
a brick-red powder. The solid can be recrystallized from CHCl3 to give the
title compound as copper-colored microcrystals. Mp 220–2238C. dH
(CDCl3): 8.23 (d, J ¼ 9.1 Hz, 2H), 7.67 (d, J ¼ 9.1 Hz, 2H), 7.50 (s, 4H),
7.39 (d, J ¼ 9.1 Hz, 2H), 6.71 (d, J ¼ 9.1 Hz, 2H), 3.83 (q, J ¼ 5.7 Hz,
2H), 3.52 (t, J ¼ 6.0 Hz, 2H), 3.47 (q, J ¼ 6.9 Hz, 2H), 1.60 (t, J ¼ 6.0 Hz,
OH), 1.19 (t, J ¼ 6.9 Hz, 3H); dH (DMSO): 8.28 (d, J ¼ 8.8 Hz, 2H), 7.83
(d, J ¼ 8.8 Hz, 2H), 7.63 (d, Jab ¼ 8.3 Hz, 2H), 7.53 (d, Jab ¼ 8.3 Hz, 2H),
7.34 (d, J ¼ 8.3 Hz, 2H), 6.69 (d, J ¼ 8.8 Hz, 2H), 4.76 (t, J ¼ 5.5 Hz,