To a solution of 5-((3,5-dichloropyridin-4-yl)thio)-4-nitro-N-(pyrrolidin-3-yl)thiophene-2-carboxamide (0.20 g, 0.48 mmol), (2-cyclopropoxyethoxy)trimethylsilane (498 mg, 2.86 mmol) and acetic acid (286 mg, 4.77 mmol) in methanol (10 mL) under nitrogen, was added sodium borohydride cyanide powder (150 mg, 2.38 mmol) by small portion. The resulting reaction mixture was heated under reflux for 4 hours. After this time, the reaction mixture was passed through a celite cartridge and the organic solution was concentrated. The resulting residue was dissolved in ethyl acetate and was washed with sodium bicarbonate solution and brine. The organic layer was separated, dried (Na2SO4) and concentrated. The crude was purified by reverse phase HPLC to afford the titled product as a solid (12.0 mg, 5% yield) 1H NMR (400 MHz, d6-DMSO) δ: 8.99 (2H, m), 8.87 (1H, d), 8.54 (1H, s), 4.23 (1H, m), 2.83 (2H, m), 2.07 (1H, m), 1.63 (2H, m), 1.23 (2H, m), 0.48 (2H, m), 0.38 (2H, m). MS m/z: 459.08, 461.07 [M+H]+.
