反应详情

To a solution of (R)-N-((5-chloropyridin-2-yl)(3-fluoro-5-(trifluoromethyl)phenyl)methylene)-2-methylpropane-2-sulfinamide (1.09 g, 2.68 mmol) in anhydrous TBME (45 mL) at −78° C. under argon was added BF3Et2O (0.57 mL, 5.38 mmol). After 5 min, benzylmagnesium grignard (5.38 mL, 5.38 mmol, 1.0M in ether) was added dropwise with stirring. After 40 min, LCMS indicated that the reaction was complete and the cold solution was quenched with saturated NaCl (ca 20 mL), transferred to a separation funnel and the organic phase extracted with EtOAc (3×20 mL). The combined organic portions were dried, decanted, concentrated and purified by silica gel ISCO chromatography.2×120 g cartridge columns were used 0-60% EtOAc/hexanes over 20 min. A trace amount of minor diastereomer eluted first followed by the major diastereomer (R)-N-((S)-1-(5-chloropyridin-2-yl)-1-(3-fluoro-5-(trifluoromethyl)phenyl)-2-phenylethyl)-2-methylpropane-2-sulfinamide (0.97 g, 72% yield). Rf0.4 (Hexane:EtOAc 2:1) LCMS: 2.15 min [M+1] 499.1 (2 min gradient, MeOH/H2O 0.1% TFA); HPLC: 4.15 min (4 min gradient, MeOH/H2O 0.2% PPA); Purity 99%; NMR: 400 MHz 1H (CDCl3) 8.65 ppm, d, 1H, J=2.6 Hz; 7.62 ppm, dd, 1H, J=2.6 and J=8.8 Hz; 7.36 ppm, 4H, m; 7.29 ppm, 1H, m; 7.24 ppm, 1H, m; 7.14 ppm, 2H, m; 6.99 ppm, 1H, d, J=10.1 Hz; 6.81 ppm, 1H, d, J=6.6 Hz; 4.09 ppm, 1H, d, J=13.2 Hz; 3.69 ppm, 1H, d, J=13.2 Hz; 1.18 ppm, 9H, s.

1. additionwas added dropwise
2. waitAfter 40 min
3. customthe cold solution was quenched with saturated NaCl (ca 20 mL)
4. customtransferred to a separation funnel
5. extractionthe organic phase extracted with EtOAc (3×20 mL)
6. customThe combined organic portions were dried
7. customdecanted
8. concentrationconcentrated
9. custompurified by silica gel ISCO chromatography.2×120 g cartridge columns
10. customover 20 min
11. washA trace amount of minor diastereomer eluted first