Phosphorus oxychloride → Methyl 6-bromo-5-chloro-2-pyrazinecarboxylate

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Reaction Steps

A mixture of 6-bromo-5-hydroxy-pyrazine-2-carboxylic acid methyl ester and 9.75 mL (10.7 mmol) POCl3 was refluxed for 3 h and subsequently quenched with 200 g ice. The mixture was extracted with DCM, the combined organic phases were dried with MgSO4 and evaporated to dryness the residue was purified by column chromatography on silica eluting with a gradient formed from ethyl acetate and heptane. The product fractions were combined and evaporated to dryness to yield 0.95 g (29%) of the title compound as light yellow solid. 300-MHz-1H-NMR (DMSO): δ=9.00 (s, 1H, 3-H), d=4.04 (s, 3H, OMe).

Provenance & Evidence