(3c) Synthesis of 4-amino-2-hydroxy-3-nitropyridine: 18.0 g (104 mmol) of 4-amino-2-chloro-3-nitropyridine was dissolved in a solvent mixture of 120 mL of dimethylsulfoxide and 30 mL of water, and the reaction was stirred for 4 hr at 130 °C. Upon completion of the reaction, the reaction solution was cooled to room temperature and allowed to stand overnight, during which time it was cooled in an ice bath. The precipitated crystalline product was collected by filtration, washed with a small amount of cold water and dried at 50 °C. The product yield was 69% of the theoretical value. The molecular formula of the product was C5H5N3O3 (molecular weight 155.11) and the mass spectrometry showed (M + H)+ = 156 and (M - H)- = 154.
