Synthesis
1) Add 50 ml of water to a 100 ml four-necked flask, then add 7.5 g (48 mmol) of 2,2'-bipyridine, 1.6 g (0.0048 mmol) of sodium tungstate and 2.2 g (0.0048 mmol) of trioctylmethyl ammonium bisulfate. Heat to 60 °C, and slowly add 18.75 ml (182.4 mmol) of 30% hydrogen peroxide. React for 5 h. HPLC monitoring shows no starting material. Filter, wash three times with water, and dry to obtain 7.2 g of 2,2'-bipyridine nitride, yield 80%, purity 99.4% (HPLC). ¹H-NMR (DMSO-d6) of 2,2'-bipyridine nitride: 8.31–8.33 (d, J = 6.3 Hz, 2H) 7.39–7.62 (m, 6H).
2) In a 250ml four-necked flask, add 35ml (657mmol) concentrated sulfuric acid and 40ml 30% fuming sulfuric acid. Add 25g (133mmol) of 2,2'-bipyridine nitrogen oxides in portions. Heat to 110℃ and add 80ml (1942mmol) of fuming nitric acid dropwise. After the addition is complete, react for 5 hours, monitored by HPLC. Pour the reaction solution into ice water, filter, recrystallize, and dry to obtain 18.5g of a yellow solid, yield 50.2%, purity 99.2%.
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