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ChemicalBook CAS DataBase List 2-BROMO-5-METHOXYPYRAZINE
143250-10-6

2-BROMO-5-METHOXYPYRAZINE synthesis

1synthesis methods
-

Yield: 100%

Reaction Conditions:

in tetrahydrofuran at 0 - 20; for 37.3 h;

Steps:

Intermediate 4: Lithium (5-methoxypyrazin-2-yl)acetate
A solution of 2,5-dibromopyrazine (30.0 g, 126 mmol) in THF (252 mL) was cooled to 0° C. Sodium methoxide (25 wt % solution in methanol, 29.0 mL, 27.3 g, 126 mmol) was added dropwise over 18 minutes. The solution was allowed to warm to room temperature and stirred for 37 hours. The suspension was filtered, the flask and filter cake rinsed with a small amount of THF, and the filtrate concentrated under vacuum to give 2-bromo-5-methoxypyrazine (4a, 23.80 g, 100%) as a solid. 1H NMR (400 MHz, CHLOROFORM-d) δ=8.20 (d, J=1.2 Hz, 1H), 8.03 (d, J=1.2 Hz, 1H), 3.97 (s, 3H).

References:

Pfizer Inc.;Behenna, Douglas Carl;Freeman-Cook, Kevin Daniel;Hoffman, Robert Louis;Nagata, Asako;Ninkovic, Sacha;Sutton, Scott Channing US2020/247784, 2020, A1 Location in patent:Paragraph 0381; 0382

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