28217-95-0

62673-31-8

21948-70-9

28217-95-0

Example 41 Preparation of Compound 215 Step A - Synthesis of 2-benzylpyrazine: To a solution of 2-methylthiopyrazine (1.26 g, 10 mmol) dissolved in 15 mL of THF was added benzylzinc bromide (0.5 M in THF, 40 mL, 20 mmol) followed by tetrakis(triphenylphosphine)palladium (1.16 g, 1 mmol). The reaction mixture was heated to 60 °C and stirred at this temperature for 2 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with ethyl acetate and washed with saturated sodium bicarbonate solution. The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by fast column chromatography (eluent: hexane solution of 15% ethyl acetate) to give 2-benzylpyrazine (0.76 g, 45% yield).