5-dibroMo-2-Methoxypyrazine synthesis

Yield:1207853-31-3 96.4%

Reaction Conditions:

with hydrogenchloride;isopentyl nitrite in methanol at 60; for 3 h;

Steps:

62.1

Step 1 : A solution of 3,5-dibromopyrazin-2-annine (40 g, 158.17 mmol), isopentyl nitrite (56 g, 474.51 mmol) and HCI/MeOH (8 mL, 1 M) in MeOH (400 mL) was stirred at 60°C for 3h. The solution was concentrated under vacuum. The residue was diluted with DCM (150 mL), washed with NaHCOs (aq.) until pH = 7, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography on silica gel (ethyl acetate/petroleums ether =0/1 -1/20) to give 3,5- dibromo-2-methoxypyrazine (46 g, Yield: 96.4%) as a yellow liquid

References:

WO2016/55618,2016,A1 Location in patent:Page/Page column 90