957230-68-1

General procedure for the synthesis of 3,6-dibromopyrazine-2-carboxylic acid from methyl 3,6-dibromopyrazine-2-carboxylate: a solution of LiOH (121 mg, 5.07 mmol) in water (1 mL) was added slowly and dropwise at 0 °C to methyl 3,6-dibromopyrazine-2-carboxylate (500 mg, 1.67 mmol) dissolved in a 1:1 THF/water (8 mL) solution. The reaction mixture was stirred continuously at 0 °C for 45 min. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in a mixed system of dichloromethane (DCM) and 1N aqueous hydrochloric acid. The organic layer was separated and the aqueous phase was extracted twice with DCM. All organic extracts were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated to give 350 mg (74% yield) of a cream-colored solid product. Mass spectrometry (MS) analysis showed: m/z (ES) 282 (M + H)+.

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