General procedure for the synthesis of 2-amino-5-formylpyridine from 2-amino-5-cyanopyridine: To a solution of 2-amino-5-cyanopyridine (10 g, 83.95 mmol, 1 eq.) in tetrahydrofuran (THF, 150 mL) was slowly added lithium aluminum hydride (LAH, 6.37 g, 167.90 mmol, 2 eq.) at 0 °C. The reaction mixture was stirred continuously at 0 °C for 1.5 hours. Upon completion of the reaction, the reaction was quenched by the addition of saturated sodium sulfate solution at 0 °C followed by the addition of water (100 mL). The reaction mixture was extracted with ethyl acetate (100 mL x 3). The organic layers were combined, washed with saturated brine (30 mL × 1), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to afford the target product 2-amino-5-formylpyridine (7.50 g, 61.42 mmol, 73.16% yield) as a yellow oil.LCMS (ESI) analysis: m/z [M + H]+ Theoretical value for C6H6N2O was 123; measured value 123; retention time (RT) = 0.099 min.
