3-Chloro-4-hydroxy-5-nitropyridine

5435-54-1

31872-64-7

General procedure for the synthesis of 3-chloro-4-hydroxy-5-nitropyridine from 4-hydroxy-3-nitropyridine: 3-nitropyridin-4-ol (8-a, 20 g, 142.76 mmol, 1 eq.) was dissolved in 50% aqueous acetic acid (250 mL) and reacted with the passage of chlorine gas for 20 h at room temperature. After completion of the reaction, the precipitate was collected by filtration and washed with distilled water. Intermediate 9-b (24 g, 97% yield) was finally obtained.