To a solution of ethyl 5-[2-(acetylamino)pyridin-4-yl]-3-(4-chlorobenzyl)-4-cyanothiophene-2-carboxylate (0.080 g, 0.18 mmol) in tetrahydrofuran (1.28 mL) and water (0.85 mL) was added lithium hydroxide (1.0M solution in water, 0.236 mL, 0.236 mmol). The reaction mixture was stirred at room temperature for 16 hours. The mixture was acidified to pH 6 using aqueous 1N HCl (0.300 mL). The mixture was extracted with ethyl acetate. The combined organic extracts were washed with brine, and then dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. Column chromatography was performed to yield the title compound (0.058 g, 78%). LCMS: (FA) ES+, 412. 1H NMR (400 MHz, d6-DMSO) δ: 10.72 (s, 1H), 8.46-8.41 (m, 2H), 7.42-7.39 (m, 1H), 7.36-7.32 (m, 4H) 4.53 (s, 2H), 2.11 (s, 3H).
