Reaction Steps
A dry 5 mL, conical pressure vessel was charged with a 100 mg mL−1 slurry of Reike® zinc (0.0276 g, 0.422 mmol), a stir bar and 2-fluoro-3-iodo-5-((2-methoxyethoxy)methoxy)-6-(trifluoromethyl)pyridine (0.0834 g, 0.211 mmol). The vial was flushed with Ar and sealed. The vessel was sonicated for 5 minutes and stirred at room temperature for 8 h. The slurry was filtered through a 0.22 μm PTFE membrane into a second dry, conical vessel with a stirbar. The transfer was quantitated with 2 mL dry THF. The filtered zincate solution was treated with tetrakis(triphenylphosphine)palladium (0.0244 g, 0.0211 mmol), 6-iodo-2-methylbenzo[d]thiazole (0.0697 g, 0.253 mmol) and sealed. The reaction was stirred at room temperature for 72 h, and then treated with 2 mL of a 10% EDTA solution (pH adjusted to 6.1 with HCl). The biphasic mixture was stirred for 15 minutes, and partitioned between 40 mL DCM and 10 mL of the EDTA solution. The DCM layer was passed through an unbuffered, 10 mL Varian Chem elut CE 1005 (PN 12198007). The aqueous layer was extracted with DCM, and the resulting extract was passed through the Chem elut tube (3×10 mL). The combined extracts were concentrated in vacuo. The residue was purified in one injection using a YMC pack diol-120-NP column (PN DN12S05-2520 wt, 250×20 mm, spherical particle, 5 μm particle size, 120 Å pore size, flow=20 mL min−1: A=6% DCE in Hex, B=THF; 20% B isocratic). A fraction that eluted from 6.2 to 7.1 minutes was isolated. The solvent was removed in vacuo to afford 6-(2-fluoro-5-((2-methoxyethoxy)methoxy)-6-(trifluoromethyl)pyridin-3-yl)-2-methylbenzo[d]thiazole (0.0186 g, 21.2% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 2.89 (s, 3H) 3.35 (s, 3H) 3.56-3.60 (m, 2H) 3.89-3.93 (m, 2H) 5.41 (s, 2H)-7.66 (dt, J=8.49, 1.72 Hz, 1H) 8.01-8.10 (m, 3H). 19F NMR (376 MHz, chloroform-d) δ ppm −78.34 (d, J=6.50 Hz, 1 F) −66.21 (s, 3 F). 13C NMR (101 MHz, chloroform-d) δ ppm 20.36 (s, 1 C) 59.04 (s, 1 C) 68.31 (s, 1 C) 71.37 (s, 1 C) 94.46 (s, 1 C) 120.84 (qd, J=274.18, 1.52 Hz, 1 C) 122.08 (d, J=3.90 Hz, 1 C) 122.77 (s, 1 C) 126.86 (d, J=3.47 Hz, 1 C) 127.85 (dq, J=29.91, 0.87 Hz, 1 C) 129.10 (d, J=5.63 Hz, 1 C) 130.09 (d, J=4.33 Hz, 1 C) 132.39 (qd, J=35.55, 13.22 Hz, 1 C) 136.47 (s, 1 C) 150.18 (d, J=4.34 Hz, 1 C) 153.18 (qd, J=239.29, 0.87 Hz, 1 C) 153.92 (s, 1 C) 169.08 (s, 1 C). HPLC-MS: 2.52 min (86.3%@215 nm; 89.6% @254 nm; m/z=417.0, calculated for C18H16F4N2O3S+H+=417.1).
