反应详情

温度

85 °C

A mixture of l-bromo-3,5-difluoro-2-(trifluoromethyl)benzene (25, 0.200 g, 0.76 mmol) and tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (0.237 g, 0.76 mmol), Pd(dppf) (0.056 g, 0.077 mmol), and 2 N Na2CO3 (2 mL, 4 mmol) in DME (3 mL) was heated to 85° C. for 5 h. The mixture was diluted with H2O (50 mL) and extracted with CH2Cl2 (3×75 mL). The combined organics were dried over Na2SO4, concentrated under reduced pressure, and the resulting residue was chromatographed over silica gel (24 g Redisep column, 0-25% EtOAc in hexanes) to afford tert-butyl 4-(3,5-difluoro-2-(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate (26) as a light yellow oil (0.325 g, 90%). 1H NMR (300 MHz, CDCl3) δ 6.92-6.80 (m, 1H), 6.78-6.68 (m, 1H), 5.58 (s, 1H), 4.06-3.94 (m, 2H), 3.69-3.53 (m, 2H), 2.36-1.24 (m, 2H), 1.50 (s, 9H).

1. extractionextracted with CH2Cl2 (3×75 mL)
2. dry with materialThe combined organics were dried over Na2SO4
3. concentrationconcentrated under reduced pressure
4. customthe resulting residue was chromatographed over silica gel (24 g Redisep column, 0-25% EtOAc in hexanes)