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MgSO4 and concentrated under vacuum. After purification by flash chromatography (SiO2, PE/EtOAc,
5:1), alkyne 16 (1.12 g, 3.81 mmol, 87%) was isolated as a colorless solid, mp 117-118 °C. 1H NMR (500
MHz, CDCl3): δ = 3.91 (s, 6 H), 3.96 (s, 2 H), 6.85 (d, J = 8.2 Hz, 1 H), 7.02-7.07 (m, 2 H), 7.15 (dd, J = 1.8,
8.3 Hz, 1 H), 7.23 (dd, J = 2.4, 8.9 Hz, 1 H), 7.53 (dd, J = 5.6, 8.5 Hz, 1 H) ppm. 13C NMR (126 MHz,
DEPT, CDCl3): δ = 22.8 (CH2), 55.9 (CH3), 55.9 (CH3), 83.6 (C), 95.6 (C), 111.1 (CH), 114.1 (CH),
114.4 (C), 115.4 (CH, d, J = 22 Hz), 115.7 (CH, d, J = 24 Hz), 116.8 (C), 119.1 (C, d, J = 4 Hz), 125.0
(CH), 133.9 (C, d, J = 8 Hz), 134.0 (CH, d, J = 9 Hz), 148.8 (C), 150.0 (C), 162.3 (CF, d, J = 251 Hz). IR
(neat): υ̃ = 3106, 3014, 2997, 2940, 2915, 2839, 2247, 2211, 1608, 1579, 1516, 1492, 1468, 1457, 1439,
1426, 1411, 1335, 1279, 1251, 1232, 1203, 1151, 1130, 1081, 1023, 969, 939, 929, 883, 849, 819, 798,
764, 731 cm-1. MS (EI): m/z (%) = 295 (100) [M+], 280 (16), 252 (27), 225 (18), 222 (7), 209 (13), 208
(20), 182 (12), 158 (5). HRMS: calcd. (C18H14NO2F) 295.1009; found 295.1008. Anal. Calcd for
C18H14NO2F: C, 73.21; H, 4.78; N, 4.74. Found: C, 73.11; H, 4.82; N, 4.74.
[2-(3,4-Dimethoxyphenylethynyl)-4,5-difluorophenyl]acetonitrile (17): Pd(PPh3)2Cl2 (155 mg, 0.22
mmol, 4 mol%), CuI (84 mg, 0.44 mmol, 8 mol%), PPh3 (115 mg, 0.44 mmol, 8 mol%), i-Pr2NH (5.5
mL) and DMF (5.5 mL) were placed in a round-bottomed flask. After the addition of aryl bromide 13
(1.28 g, 5.52 mmol), the mixture was stirred at 25 °C for 1 h and alkyne 14 (900 mg, 5.55 mmol) was
then added. After the mixture had been stirred at 80 °C for additional 16 h, saturated aqueous NH4Cl
solution was added. The mixture was extracted with MTBE (3 × 50 mL). The combined organic layers
were dried with MgSO4 and concentrated under vacuum. After purification by flash chromatography
(SiO2, PE/EtOAc, 5:1), alkyne 17 (1.36 g, 4.34 mmol, 79%) was isolated as a colorless solid, mp
113-114 °C. 1H NMR (300 MHz, CDCl3): δ = 3.92 (s, 8 H), 6.86 (d, J = 8.5 Hz, 1 H), 7.03 (d, J = 1.9 Hz,
1 H), 7.15 (dd, J = 1.8, 8.2 Hz, 1 H), 7.33 (dd, J = 7.7, 10.5 Hz, 1 H), 7.37 (dd, J = 7.7, 10.6 Hz, 1 H)
13
ppm. C NMR (75 MHz, DEPT, CDCl3): δ = 22.3 (CH2), 55.9 (CH3), 56.0 (CH3), 82.7 (C), 96.6 (C),
111.1 (CH), 113.9 (C), 114.1 (CH), 116.7 (C), 117.6 (CH, d, J = 20 Hz), 119.9 (C, dd, J = 4, 8 Hz), 120.9
(CH, d, J = 19 Hz), 125.2 (CH), 128.6 (C, dd, J = 4, 6 Hz), 149.7 (CF, dd, J = 13, 251 Hz), 148.9 (C),
150.3 (C), 150.1 (CF, dd, J = 13, 254 Hz) ppm. IR (KBr): υ̃ = 3000, 2966, 2939, 2839, 2257, 2214, 1600,
1578, 1517, 1466, 1445, 1424, 1413, 1346, 1320, 1251, 1224, 1173, 1137, 1023, 882, 869, 815, 754 cm-1.
MS (EI): m/z (%) = 313 (100) [M+], 298 (10), 270 (10), 243 (12), 226 (12), 212 (5), 200 (5), 162 (11),
151 (10), 113 (6), 91 (6). HRMS: calcd. (C18H13NO2F2) 313.0914; found 313.0930. Anal. Calcd for
C18H13NO2F2: C, 69.01; H, 4.18; N, 4.47. Found: C, 68.79; H, 4.24; N, 4.41.
2-[2-(3,4-Dimethoxyphenylethynyl)-5-trifluoromethylphenyl]ethylamine (18): A solution of AlCl3
(339 mg, 3.00 mmol) in Et2O (4.5 mL) was rapidly added to a suspension of LiAlH4 (114 mg, 3.00 mmol)