Uses
A comparison of catalysts promotes imidazolide couplings including the identification of 2-hydroxy-5-nitropyridine as a new, safe, and effective catalyst.
Synthesis
General procedure for the synthesis of 2-hydroxy-5-nitropyridine from 2-amino-5-nitropyridine: 2-amino-5-nitropyridine (13.9 g, 0.1 mol) was dissolved in 55.6 g of 15% dilute hydrochloric acid, and 44.85 g of 20% aqueous sodium nitrite (NaNO2) was added slowly dropwise. After the dropwise addition, the reaction was continued for 6 hours. The reaction temperature was maintained at 40°C for 40 minutes. After completion of the reaction, the reaction mixture was concentrated under reduced pressure and a light yellow solid was precipitated after cooling. The solid was washed with ice water and dried to obtain 2-hydroxy-5-nitropyridine (12.61 g), which was analyzed by high performance liquid chromatography (HPLC) with a purity of 97.69% and a yield of 88.02%.
References
[1] Patent: CN105523995, 2016, A. Location in patent: Paragraph 0026; 0047; 0048
[2] Chemistry of Heterocyclic Compounds, 2002, vol. 38, # 7, p. 805 - 809
[3] Bulletin of the Chemical Society of Japan, 1987, vol. 60, # 10, p. 3597 - 3602
[4] Zhurnal Russkago Fiziko-Khimicheskago Obshchestva, 1914, vol. 46, p. 1240
[5] Chem. Zentralbl., 1915, vol. 86, # I, p. 1066
