General method: 5-Nitroquinolin-2(1H)-one (9a) (1.0 eq.) or analog (9b) (1.0 eq.) was dissolved in 1,2-dichloroethane (1,2-DCE), phosphorus oxychloride (POCl3) (2.0 eq.) was added, and the reaction was stirred for 12 hr at 80 °C. Upon completion of the reaction, the solvent and unreacted reagents were removed by evaporation to give the product 2-chloro-5-nitroquinoline (14a) or the like (14b). SPECIFIC EXAMPLE: The reaction was carried out according to the general method described above using 5-nitroquinolin-2(1H)-one (9a) (100.0 mg, 0.50 mmol) and phosphorus oxychloride (POCl3) (0.09 mL, 1.0 mmol) to give 2-chloro-5-nitroquinoline (14a) (78.0 mg) in 75% yield.
