613-50-3

5332-25-2

613-50-3

GENERAL STEPS: 6-bromoquinoline (0.5 mmol), copper(II) trifluoromethanesulfonate (45 mg, 0.125 mmol), potassium nitrite (KNO2, 128 mg, 1.5 mmol), and anhydrous dimethylsulfoxide (DMSO, 0.6 mL) were sequentially added to a pre-dried oven-dried pressure tube under nitrogen protection. The pressure tube was sealed with a PTFE screw cap with a micro-valve and purged by nitrogen for 5 min to remove air. Subsequently, the reaction mixture was stirred at room temperature for 10 minutes and then gradually warmed up to 130°C and the reaction was continued at this temperature for 48 hours. Upon completion of the reaction, the mixture was cooled to room temperature, washed with excess ice water and extracted with ethyl acetate (3 x 10 mL). The organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by column chromatography on silica gel (for entries 1-18 in Table 2) or basic alumina (for entries 19-23 in Table 2), using a solvent mixture of ethyl acetate and hexane as eluent, and the target product, 6-nitroquinoline, was finally obtained in good yield.