To a solution of 3-(methylthio)-2-phenylquinoline-4-carboxylic acid (150 mg, 0.51 mmol) and triethylamine (0.17 mL, 1.22 mmol) in EtOAc (2.5 mL) at 5° C. was added thionyl chloride (0.043 mL, 0.61 mmol). The cooling bath was removed and the suspension allowed to stir for 0.5 h, then (S)-(−)-1-phenylpropylamine (76 mg, 0.56 mmol) was added and reaction allowed to stir for another 0.5 h. Water (2 mL) and EtOAc (2 mL) were then added, the layers shaken together, then separated, the organics dried over Na2SO4, filtered, and concentrated under reduced pressure. The resulting material was purified by silica gel chromatography (0-20% EtOAc/CH2Cl2) to give the desired product (150 mg, 70% yield) as a solid. 1H NMR (300 MHz, CDCl3) δ 8.11 (d, J=8.4 Hz, 1H), 7.78-7.67 (m, 4H), 7.55-7.27 (m, 9H), 6.12 (d, J=8.5 Hz, 1H), 5.30 (q, J=7.6 Hz, 1H), 2.16-1.91 (m, 5H), 1.06 (t, J=7.4 Hz, 3H); HRMS m/z 413.1669, calcd 413.1688.
