Reaction Steps
8-(2-Chlorophenyl)-8-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)-2,2-dimethyloctanoic acid ethyl ester (0.86 g, 1.92 mmol) was added to a solution of ethanol (32 mL) and sodium hydroxide (0.53 g, 13.4 mmol) in water (10.4 mL). The mixture was heated to reflux for 6.5 hours. The solution was concentrated under reduced pressure and water (43 mL) was added to the residue. Any starting material was extracted with ethyl acetate/heptane (1/10, 43 mL). The heptane extract was discarded. The remaining aqueous solution was adjusted with 10 N hydrochloric acid solution to pH=6. The product was extracted with CH2Cl2 (3×40 mL), dried over Na2SO4, concentrated and purified by column chromatography (silica gel, ethyl acetate/heptane=1/10 to 1/3) to provide 8-(2-chlorophenyl)-8-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)-2,2-dimethyloctanoic acid (Compound Im, 0.35 g, 43.8% yield, 99.6% purity by HPLC) as a yellow oil. 1H NMR (Field: 300 MHz, Solvent: CDCl3/TMS) δ (ppm): 10.43 (br, 1H), 7.52 (d, 1H, J=7.50 Hz), 7.39 (d, 1H, J=8.10 Hz), 7.28-7.15 (m, 2H), 7.03 (d, 1H, J=5.0 Hz), 6.69 (d, 1H, J=5.0 Hz), 4.24 dd, 1H, J=9.3, 4.2 Hz), 3.83 (d, 1H, J=14.40 Hz), 3.51 (d, 1H, J=14.40 Hz), 2.92-2.73 (m, 4H), 1.99-1.81 (m, 2H), 1.46-1.41 (m, 2H), 1.28-1.15 (m, 6H), 1.13 (s, 6H). (t, 3H, J=7.2 Hz), 1.15-1.08 (m, 2H), 1.07 (s, 6H). 13C NMR (Field: 75 MHz, Solvent: CDCl3/TMS) δ (ppm): 184.02, 138.85, 135.16, 133.87, 133.42, 129.60, 129.17, 128.17, 126.92, 125.52, 122.74, 63.53, 50.54, 47.90, 42.29, 40.70, 32.95, 30.52, 25.75, 25.64, 25.26, 24.96. HRMS (FIA-ESI): Calculated for C23H30ClNO2S (M+H)+: 420.1759. found 420.1779. CHN analysis: Calculated; 65.77; C, 7.20; H, 3.33; N. found; 60.77; C, 6.68; H, 3.11; N. Best fit for CHN: C23H30ClNO2S+HCl
