Methanol → Methyl 6-bromo-3-methoxypyrazine-2-carboxylate

In 100 mL of concentrated sulfuric acid was dissolved 17.0 g of methyl 3-amino-6-bromo-2-pyrazinecarboxylate. At an ice-cooled temperature, 10.1 g of sodium nitrite was added and stirred for 30 minutes. The reaction mixture was poured into 920 mL of methanol and heated under reflux for 5 hours. After cooling the reaction mixture, the mixture was concentrated under reduced pressure, the residue thus obtained was added to a mixture of 500 mL of ice water and 600 mL of chloroform, and the mixture thus obtained was separated into layers. The organic layer was washed successively with a saturated aqueous solution of sodium hydrogen carbonate, water and saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Thus, 6.30 g of methyl 6-bromo-3-methoxy-2-pyrazinecarboxylate was obtained as a light yellow oily product.

1. additionwas added
2. temperatureheated
3. temperatureunder reflux for 5 hours
4. temperatureAfter cooling the reaction mixture
5. concentrationthe mixture was concentrated under reduced pressure
6. customthe residue thus obtained
7. customthe mixture thus obtained
8. customwas separated into layers
9. washThe organic layer was washed successively with a saturated aqueous solution of sodium hydrogen carbonate, water and saturated aqueous solution of sodium chloride
10. dry with materialdried on anhydrous magnesium sulfate
11. customthe solvent was removed under reduced pressure

ORD record

ord-84efbb9db5f848ffa122de7edde43949

Source dataset

uspto-grants-2004_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06800629B2