General Steps:
Preparation of solution A: PdCl2(dppf)-CH2Cl2 (0.958 g, 1.174 mmol), KOAc (6.91 g, 70.4 mmol) and bis(pinacolato)diboron (7.15 g, 28.2 mmol) were added sequentially to a 250 mL flask followed by degassing.
Preparation of solution B: In another vial, 5-bromo-2-methoxynicotinonitrile (5 g, 23.47 mmol) was dissolved in 100 mL of anhydrous dioxane.
Solution B was slowly added to solution A. The mixed reaction solution was heated to 80 °C and maintained for 16 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with EtOAc and filtered to remove insoluble solids. The filtrate was concentrated under reduced pressure to give a black oily substance. Purification by rapid chromatography on silica gel (eluent: CH2Cl2/MeOH, 95/5) afforded the target product 2-methoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)nicotinonitrile (5.7 g, 89% yield) as a beige powder.
Product Characterization:
1H-NMR (400 MHz, DMSO-d6, 298 K): δ 1.31 (s, 12H), 4.03 (s, 3H), 8.31 (s, 1H), 8.62 (s, 1H).
MS: m/z 261.5 [M + 1]+, retention time (Method 2) = 1.47 min.
