1380331-29-2

1380331-28-1

1380331-29-2

c) Synthesis of methyl 2-amino-5-fluoroisonicotinate: methyl 2-((tert-butoxycarbonyl)amino)-5-fluoroisonicotinate (1.80 g, 6.66 mmol) was dissolved in ethyl ether (40 mL) and 6 N hydrochloric acid (40 mL, 240 mmol) was added. The reaction mixture was stirred at room temperature for 20 hours. After completion of the reaction, the solvent was removed by evaporation under reduced pressure to give a light brown slurry. The slurry was diluted with ethyl acetate, cooled in an ice bath to 0 °C and the pH was adjusted with saturated sodium bicarbonate solution to 8. The organic layer was separated, washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was removed by concentration under reduced pressure to give methyl 2-amino-5-fluoroisonicotinate (932 mg, 82.2% yield) as a brown waxy solid. Mass spectrum (MS): m/z = 171.0 ([M+H]+).