Reaction Steps
A solution of 1-chloro-3-iodobenzene (49 mg, 0.205 mmol) in anhydrous THF (0.5 mL) was treated with PdCl2(PPh3)2 (7 mg, 0.01 mmol). After stirring for 5 min at 25° C., Et3N (0.2 mL, 0.603 mmol) and CuI (10 mg, 0.053 mmol) were added. The suspension was stirred for 35 min and 1-oxo-1-[5-(2-pyridyl)oxazol-2-yl]-hept-6-yne (3b, 30 mg, 0.067 mmol) was added. After stirring for 14 h at 25° C., the reaction mixture was filtered through Celite and concentrated. PTLC (SiO2, 50% EtOAc-hexanes) afforded 1-oxo-1-[5-(2-pyridyl)oxazol-2-yl]-7-(3-chlorophenyl)hept-6-yne (4hh, 24 mg, 0.066 mmol, 56%) as a yellow solid: mp 50-51° C.; 1H NMR (CDCl3, 500 MHz) δ 8.68-8.66 (m, 1H), 7.89-7.86 (m, 2H), 7.82 (td, 1H, J=7.7, 1.8 Hz), 7.38 (m, 1H), 7.34-7.31 (m, 1H), 7.27-7.18 (m, 3H), 3.20 (t, 2H, J=7.4 Hz), 2.49 (t 2H, J=7.0 Hz), 2.00-1.95 (m, 2H), 1.77-1.71 (m, 2H); 13C NMR (CDCl3, 125 MHz) δ 187.9, 157.2, 153.3, 150.1, 146.2, 137.1, 133.9, 131.4, 129.6, 129.3, 127.8, 126.8, 125.5, 124.1, 120.3, 90.9, 79.8, 38.5, 27.8, 23.1, 19.1; IR (film) νmax 3061, 2932, 2865, 2230, 1703, 1592, 1575, 1558, 1505, 1471, 1426, 1385, 1283, 1243, 1152, 1081, 1065, 1023, 990, 962, 930, 880, 784, 740, 683 cm−1; ESI-TOF m/z 365.1058 (C21H17ClN2O4+H+ requires 365.1051).
