Example 1 Synthesis of 3,5-dinitropyridin-4-ylamine (2). H2SO4 (20 mL) was cooled to 0°C in an ice bath. 4-Aminopyridine 1 (4.84 g, 51.5 mmol) was slowly added to the acid. Fuming nitric acid (2.7 mL) was added dropwise, ensuring that the reaction temperature was maintained below 10 °C. The mixture was slowly warmed to room temperature over a period of 1 hour. Subsequently, the mixture was heated to 85 °C and another portion of fuming nitric acid (2.7 mL) was slowly added. After 30 minutes of reaction, the mixture was cooled to room temperature. The acidic mixture was neutralized with Na2CO3 and extracted several times with ethyl acetate. The combined ethyl acetate extracts were dried with MgSO4 and subsequently concentrated on a rotary evaporator to give the title product 2 as an orange oil (7.1 g, 75% yield, 38.6 mmol).1H NMR (DMSO-d6): δ 9.21 (s, 2H), 8.73 (bs, 2H).MS (ESI-POS): [M + H]+ = 185.
[1] Patent: US2006/189616, 2006, A1. Location in patent: Page/Page column 13; 19
[2] Bioorganic and Medicinal Chemistry Letters, 2010, vol. 20, # 8, p. 2512 - 2515
[3] Synthesis, 2011, # 5, p. 794 - 806
[4] Chemische Berichte, 1924, vol. 57, p. 1183
[5] Journal of the American Chemical Society, 1957, vol. 79, p. 6421,6423,6424
