Reaction Steps
To a slurry of 9.18 g (18.9 mmol) of N-[2-chloro-1-[4'-[(difluoromethyl) -sulfonyl][1,1'-biphenyl]-4-yl]ethyl]-2,6-difluorobenzamide in 70 mL of isopropanol was added a solution of 1.8 g (22.5 mmol) of aqueous 50% NaOH at 25-30° C. The mixture was allowed to stir for 30 minutes at ambient temperature, diluted with 40 mL of water, and filtered. The solid product was washed with 20 mL of 50% aqueous isopropanol and suction-dried to afford 7.5 g (88%) of 4-[4'-[(difluoromethyl)sulfonyl][1,1'-biphenyl]-4-yl]-2-(2,6-difluorophenyl)-4,5-dihydrooxazole, m.p. 107-111° C. An analytical sample was prepared by recrystallization from isopropanol, m.p. 109-111° C. IR(KBr): 1669, 1622, 1593, 1485, 1469, 1395, 1345, 1300, 1285, 1240, 1168, 1161, 1114, 1081, 1053, 1041, 1012, 822, 793 cm-1. UV(CH2Cl2): λmax =279 nm (ε=25.9×103). 1H-NMR (benzene-d6): δ3.9 (t, 1H), 4.25 (dd, 1H), 5.15 (dd, 1H), (dq, 2H), 5.68 (m, 1H), 6.22 (t, 1H, J=53 Hz), 6.7 (br d, 1H), 7.0 (t, 2H, J=9 Hz), 7.41 (m, 1H), 7.53 (d, 2H), 7.65 (d, 2H), 7.83 (d, 2H), 8.05 (d, 2H). 13C-NMR (CDCl3): δ69.9, 74.6, 107.1 (dd, JCF =2, 23 Hz), 114.8, 127.6, 127.9, 128.1, 131.2, 132.2. 19F-NMR (CDCl3): δ-112.1 (t, JHF =7.3 Hz), -121.8 (d, JHF =53 Hz).
