209959-33-1

Step A: 2-Amino-5-bromopyrimidine (2.75 g, 15.8 mmol) and di-tert-butyl dicarbonate (7.58 g, 34.8 mmol) were dissolved in pyridine (30 mL) and the reaction was stirred at 70 °C overnight. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was extracted by partitioning with ethyl acetate (EtOAc) and 1N hydrochloric acid aqueous solution. The aqueous layer was extracted once more with ethyl acetate. The organic phases were combined, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure to give 2-[bis(tert-butoxycarbonyl)amino]-5-bromopyrimidine (5.5 g, 93% yield) as a white solid. Mass spectrometry (MS) analysis showed m/z 398.2 [M + Na]+.

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