Reaction Steps
Ex-634C) The 3-(4-fluorophenoxy)aniline (812 mg, 4 mmol) from EX-634B and 3-(1,1,2,2-tetrafluoroethoxy)benzaldehyde (888 mg, 2 mmol) were dissolved in dichloroethane (15 mL) and acetic acid (0.25 mL, 4.2 mmol), then solid NaBH(OAc)3 (1.01 g, 5 mmol) was added. The mixture was stirred at room temperature for 3 h, then acidified with 1 N HCl. After neutralizing to pH 7.5 with 2.5 N sodium hydroxide, the mixture was extracted with methylene chloride. The organic layer was washed with brine and water, then dried over anhydrous MgSO4, and evaporated to give 1.32 g (78%) of the desired of N-[3-(4-fluorophenoxy)phenyl][[3-(1,1,2,2-tetrafluoroethoxy)phenyl]methyl]amine product as a brown oil, which was greater than 90% pure by reverse phase HPLC analysis. MS m/z=410 [M+H]+. The N-[3-(4-fluorophenoxy)phenyl][[3-(1,1,2,2-tetrafluoroethoxy)phenyl]methyl]amine (612 mg, 1.5 mmol) product from EX-634C and 1,1,1-trifluoro-2,3-epoxypropane (268 mg, 2.4 mmol) were dissolved in 1.0 mL of acetonitrile. Ytterbium (III) trifluoromethanesulfonate (43 mg, 0.07 mmol) was added, and the stirred solution was warmed to 40° C. for 2.5 h under an atmosphere of nitrogen, at which time HPLC analysis indicated that no secondary amine starting material remained. The reaction was quenched with water and extracted with ether. The ether layer was washed with brine and water, then dried over anhydrous MgSO4. The ether was removed in vacuo, and the crude product was purified by flash column chromatography on silica gel eluting with ethyl acetate in hexane (1:11) to give 633 mg (81%) of the desired 3-[[3-(4-fluorophenoxy)phenyl][[3-(1,1,2,2-tetrafluoro-ethoxy)phenyl]methyl]amino]-1,1,1-trifluoro-2-propanol product as a yellow oil, 99% pure by HPLC analysis. 1H NMR (CDCl3) δ7.35 (t, 1H), 7.15 (m, 3H), 6.98 (m, 5H), 6.49 (dd, 1H), 6.38 (dd, 1H), 6.33 (m, 1H), 5.92 (tt, 1H), 4.67 (ABq, 2H), 4.37 (m, 1H), 3.91 (dd, 1H), 3.59 (dd, 1H), 2.48 (d, 1H). 19F NMR (CDCl3) δ−79.2 (d, 3F), −88.5 (m, 2F), −120.33 (m, 1F), −137.2 (dt, 2F). HRMS calcd. for C24H19F8NO3: 522.1315 [M+H]+, found: 522.1297.
