反应详情

A solution of (E)-2-methyl-5-(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)vinyl)-pyridine (1.0 g, 4.08 mmol; Example 23B) in acetonitrile (10 mL) was treated with N-bromosuccinimide (0.346 mL, 4.08 mmol; Aldrich) and triethylamine (0.625 mL, 4.49 mmol; Aldrich) and stirred at room temperature for 16 hours. Water was added and the mixture was extracted several times with ethyl acetate. The combined organic extracts were concentrated, and the resulting material was purified by flash chromatography (silica gel, hexane/ethyl acetate, 3:1) to afford the title compound as a 1.2:1 Z/E mixture: 1H NMR (300 MHz, CDCl3) δ ppm 2.54 (s, 3H), 2.57 (s, 3.6H), 6.52 (d, J=14 Hz, 1.2H), 6.75-6.85 (d, J=14 Hz, 1H), 7.01-7.22 (m, 4.4H), 7.52 (dd, J=8, 2 Hz, 1H), 8.07 (dd, J=8, 2 Hz, 1.2H), 8.43 (d, J=2 Hz, 1H), 8.66 (d, J=2 Hz, 1.2H); MS (DCI/NH3) m/z 198/200 (M+H)+.

1. extractionthe mixture was extracted several times with ethyl acetate
2. concentrationThe combined organic extracts were concentrated
3. customthe resulting material was purified by flash chromatography (silica gel, hexane/ethyl acetate, 3:1)