A. General procedure for the synthesis of tert-butyl 2-(6-bromo-2-oxo-3,4-dihydroquinolin-1(2H)-yl)acetate: to an anhydrous N,N-dimethylformamide (30 mL) suspension of 95% dry sodium hydride (834 mg, 33.0 mmol) under dry nitrogen protection was added slowly at room temperature an anhydrous N,N-dimethylformamide (30 mL) suspension of 6-bromo-3,4-dihydroquinolin-2(1H)-one (6.780 g, 30.00 mmol) to a solution of anhydrous N,N-dimethylformamide (10 mL) at room temperature. The reaction mixture was stirred at room temperature for 30 minutes before tert-butyl 2-bromoacetate (7.5 mL, 49.7 mmol) solution in anhydrous N,N-dimethylformamide (10 mL) was added dropwise. Stirring of the reaction mixture was continued until most of the feedstock was converted (monitored by LCMS). Upon completion of the reaction, the reaction was quenched with methanol (40 mL) and the reaction mixture was concentrated under reduced pressure and then diluted with ethyl acetate (150 mL). The organic phase was washed sequentially with water (100 mL), 30% ammonium chloride solution (100 mL) and saturated saline (100 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure. Add ether (20 mL) for ultrasonication, filtration, washed with ether (20 mL), dried to obtain white solid tert-butyl 2-(6-bromo-2-oxo-3,4-dihydroquinolin-1(2H)-yl)acetate (7.348 g, 21.6 mmol, yield 72%). lcms m/z: 285.9 (M-56+H), 363.9 (M+ Na). Na).HPLC purity >97%.1H NMR (400 MHz, CDCl3) δ: 7.30-7.40 (m, 2H), 7.50-6.70 (m, 1H), 4.54 (s, 2H), 2.92 (m, 2H), 2.69 (m, 2H), 1.44 (s, 9H).
