Synthesis
A. Synthesis of 8-bromo-5-nitroquinoline (464A): 8-bromoquinoline (25.00 g, 120.2 mmol) was dissolved in concentrated sulfuric acid (82.5 mL) at room temperature, and the reaction system was subsequently cooled to 0°C. Fuming nitric acid (32.5 mL) was slowly added dropwise over 10 minutes. After the dropwise addition was completed, the reaction system was gradually warmed to room temperature, followed by further heating to 65 °C. After 48 hours of continuous reaction at 65 °C, the reaction mixture was cooled to room temperature and slowly poured into ice (500 g). The mixture was extracted with dichloromethane (5 x 200 mL). The organic layers were combined, washed once with saturated brine and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure to give the crude product 464A as a light yellow solid (28.6 g, 94% yield).HPLC analysis: purity 98%, retention time 2.717 min (YMC S5 ODS column, 4.6 × 50 mm, mobile phase 10-90% aqueous methanol containing 0.2% phosphoric acid, gradient elution 4 min, flow rate 4 mL/min, detection wavelength (220 nm).
References
[1] Patent: US2004/77605, 2004, A1
[2] Patent: US2005/119228, 2005, A1
[3] Organic and Biomolecular Chemistry, 2016, vol. 14, # 6, p. 1969 - 1981
[4] Recueil des Travaux Chimiques des Pays-Bas, 1929, vol. 48, p. 552
[5] Journal fuer Praktische Chemie (Leipzig), 1893, vol. <2> 48, p. 158
