Hydrochloric Acid → 2-Bromo-5-methoxypyrazine

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Cl.N[C:3]1[CH:8]=[N:7][C:6]([Br:9])=[CH:5][N:4]=1.N([O:12][CH2:13]CC(C)C)=O>CO>[Br:9][C:6]1[CH:5]=[N:4][C:3]([O:12][CH3:13])=[CH:8][N:7]=1

참가 물질

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온도: -10 °C

실험 절차

Methanolic hydrogen chloride (0.8 mL of a 10M methanolic solution) was added to a stirred solution of 2-amino-5-bromopyrazine (6.96 g, 0.04 mol) in anhydrous methanol (125 mL). To this cooled (-10° C.) solution was added isoamyl nitrite (16.1 mL, 0.12 mol) and the reaction mixture was stirred at -10° C. for 1.5 hours then at room temperature for 2 hours. The solvent was evaporated and the residue partitioned between aqueous saturated sodium carbonate (50 mL) and dichloromethane (4×50 mL). The combined organics were dried (sodium carbonate) and evaporated to give a brown oil which was purified by column chromatography on silica using 5% ethyl acetate in petroleum ether (60-80) to afford 2-bromo-5-methoxypyrazine as a pale yellow solid (6.45 g, 85%).