Reaction Steps
A solution of 6-bromohexylbenzene (31 pt, 0.2 mmol) in THF (1 mL) was treated dropwise with 1.7 M t-BuLi (235 μL, 0.4 mmol) at −78° C. After stirring for 30 min, the resulting alkyllithium reagent was added to a cooled solution of methyl 5-(pyridin-2-yl)-1,3,4-thiadiazole-2-carboxylate (S43, 44 mg, 0.2 mmol) in THF (0.5 mL) at −78° C. The reaction mixture was stirred for 3 h at −78° C. before it was quenched with the addition of MeOH. The mixture was extracted with EtOAc, washed with water, saturated aqueous NaHCO3 and saturated aqueous NaCl, and dried over Na2SO4. Evaporation in vacuo yielded the crude product which was purified by flash chromatography (SiO2, 3×14 cm, 15% EtOAc-hexanes) to provide the title compound (5.1 mg, 7%) as white solid: 1H NMR (CDCl3, 600 MHz) δ 8.69 (m, 1H), 8.41 (dd, 1H, J=0.8, 7.9 Hz), 7.89 (m, 1H), 7.45 (m, 1H), 7.27 (m, 2H), 7.17 (m, 3H), 3.27 (t, 2H, J=7.4 Hz) 2.61 (t, 2H, J=7.7 Hz), 1.81 (m, 2H), 1.65 (m, 2H), 1.45 (m, 4H); 13C NMR (CDCl3, 150 MHz) δ 194.1, 174.9, 169.6, 150.3, 148.6, 142.8, 137.5, 128.5, 128.4, 126.3, 125.7, 121.7, 39.4, 36.0, 31.4, 29.9, 29.1, 24.0; IR (film) νmax 2927, 2854, 1734, 1685, 1647, 1584, 1406, 1009, 785, 742, 698 cm−1; HRMS-ESI-TOF m/z 352.1474 ([M+H]+, C20H21N3OS requires 352.1478).
