Reaction Steps
A flask was charged with perfluorophenyl 1-(4′-chloro-2-fluoro-5-methoxy-3′-methyl-[1,1′-biphenyl]-4-yl)-3-methoxy-2-oxo-1,2-dihydroquinoline-6-sulfonate (0.2262 g, 0.338 mmol) and isoxazol-3-amine (0.034 g, 0.405 mmol). A septum was attached and THF (3.4 ml) was added under N2 flow. The solution was cooled to 0° C. and LHMDS (0.709 ml, 0.709 mmol) was added to give a bright yellow solution. After 10 min, 5 mL of 1 N HCl was added and the mixture was partitioned between 1 N HCL (10 mL) and EtOAc (20 mL). The layers were separated and the aqueous layer was extracted with EtOAc (1×10 mL). The combined organic layers were dried (Na2SO4) and concentrated for purification by MPLC (Biotage Isolera). The crude residue was taken up in minimal DCM and absorbed onto a 5 g loading cartridge and passed through a Interchim 25 g spherical silical gel column using a gradient of 5% EtOH and 15% EtOAc in heptane to 25% EtOH in EtOAc with 10% DCM constant additive to afford 1-(4′-chloro-2-fluoro-5-methoxy-3′-methyl-[1,1′-biphenyl]-4-yl)-N-(isoxazol-3-yl)-3-methoxy-2-oxo-1,2-dihydroquinoline-6-sulfonamide (0.187 g, 0.328 mmol, 97% yield) as a colorless foam. The racemic product was subjected to chiral separation by SFC on a Chiralcel OJ column (45% MeOH/80% CO2) to give (M)-1-(4′-chloro-2-fluoro-5-methoxy-3′-methyl-[1,1′-biphenyl]-4-yl)-N-(isoxazol-3-yl)-3-methoxy-2-oxo-1,2-dihydroquinoline-6-sulfonamide as peak 1 and (P)-1-(4′-chloro-2-fluoro-5-methoxy-3′-methyl-[1,1′-biphenyl]-4-yl)-N-(isoxazol-3-yl)-3-methoxy-2-oxo-1,2-dihydroquinoline-6-sulfonamide as peak 2. Data for peak 1: 1H NMR (500 MHz, DMSO-d6) δ 11.59 (br.s, 1H), 8.66 (d, J=1.62 Hz, 1H), 8.20 (d, J=1.88 Hz, 1H), 7.60-7.70 (m, 2H), 7.40-7.58 (m, 4H), 7.25-7.38 (m, 1H), 6.74 (d, J=8.89 Hz, 1H), 6.38 (d, J=1.56 Hz, 1H), 3.84 (s, 3H), 3.67 (s, 3H), 2.37 (s, 3H). m/z (ESI) 568.2 (M+H)+. Data for peak 2: 1H NMR (500 MHz, DMSO-d6) δ 11.56 (br. s, 1H), 8.65 (d, J=1.56 Hz, 1H), 8.19 (d, J=1.95 Hz, 1H), 7.60-7.71 (m, 2H), 7.40-7.57 (m, 4H), 7.32 (d, J=6.88 Hz, 1H), 6.73 (d, J=8.89 Hz, 1H), 6.37 (d, J=1.62 Hz, 1H), 3.83 (s, 3H), 3.66 (s, 3H), 237 (s, 3H). m/z (ESI) 568.2 (M+H)+.
