693774-10-6

61676-62-8

693774-10-6

Example 2A Synthesis of 2,6-dimethyl-3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-pyridine: 3-bromo-2,6-dimethylpyridine (5.10 g, 27.4 mmol) was dissolved in anhydrous ethyl ether (160 mL) under nitrogen protection and cooled to -78°C. Dropwise n-butyllithium (4.1 mL, 10 M hexane solution) was added and stirred at -78 °C for 45 min. Subsequently, an ether solution (20 mL) of 2-isopropoxy-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (10.2 g, 54.8 mmol) was added slowly and dropwise at the same temperature and stirring was continued for 3 hours at -78 °C. Upon completion of the reaction, the reaction was quenched with isopropanol (10 mL) and slowly warmed to room temperature. Saturated aqueous sodium chloride solution (150 mL) was added, and the aqueous phase was separated and extracted with dichloromethane (100 mL x 6) several times. The organic phases were combined, dried and concentrated to give 2,6-dimethylpyridine-3-boronic acid pinacol ester as a light brown oil (6.29 g, 98.4% yield). The product was confirmed by 1H NMR (300 MHz, CDCl3): δ 7.92 (d, J = 7.46 Hz, 1H), 6.96 (d, J = 7.80 Hz, 1H), 2.73 (s, 3H), 2.53 (s, 3H), 1.34 (s, 12H). Mass spectral analysis showed (M + H)+ = 234.