6-Hydroxy-5-nitronicotinic acid is synthesised using 6-Hydroxynicotinic acid as a raw material by chemical reaction. The specific synthesis steps are as follows:
6-Hydroxynicotinic acid 2 (25.0 g, 180 mmol) was dissolved in HNO3 fuming (1.52) (95 mL) and stirred at 50 oC for 18 h. After the solution was cooled to room temperature, the mixture was concentrated, and then co-evaporated with water, followed by the addition of MeOH to afford a brown precipitate. The precipitate was filtered and washed with 50 mL of cold MeOH twice. After drying under reduced pressure, a brown color product 3 was obtained; yield: 9.67 g (29percent); 1H NMR (300 MHz, CD3OD) 8.44 (d, J = 2.6 Hz, 1H), 8.85 (d, J = 2.6 Hz, 1H) ; HRMS (ES+): m/z 185.0194 (M+H+) (calcd for C6H5N2O5: 185.0198).
