Synthesis
A solution of sodium nitrite (20 g, 288 mmol) in water (40 mL) was added dropwise to a solution of 3-amino-2-nitropyridine (40 g, 288 ) in 34% fluoroboric acid (140 mL).
mmol) in 34% fluoboric acid (140 mL) in a stirred mixture. The temperature was maintained between -8 ??C and -2 ??C during the addition.
After 0.5 h, the suspension was filtered and the solid was washed with 34% fluoboric acid (35 mL), ether (80 mL), and dried at room temperature under high vacuum for 12 h to give 52
g of fluoroborate as an orange-brown solid salt. The dried solid is decomposed by heating to 120 ??C.
After decomposition, the remaining oil was treated with a 10% sodium bicarbonate (80 mL) solution and the mixture was extracted with dichloromethane.
The combined extracts were dried with sodium sulfate, filtered and the solvent removed under reduced pressure to give the title compound as a light yellow solid.
