To a stirred solution of 2-(8-fluoro-6-nitro-3,4-dihydroquinolin-1(2H)-yl)-N,N-dimethylethanamine (500 mg, 1.871 mmol) in Dichloromethane (8 ml) at room temperature was added phenyl chloroformate (0.352 ml, 2.81 mmol) via a syringe dropwise, slowly. The resulting solution was stirred overnight at room temperature. The reaction mixture was then diluted with water and potassium carbonate (dilute) and extracted with dichloromethane (3×). The combined organics were dried, filtered and concentrated, then chromatographed in 0-50% ethyl acetate in hexanes, giving the desired phenyl 2-(8-fluoro-6-nitro-3,4-dihydroquinolin-1(2H)-yl)ethyl(methyl)carbamate (576 mg, 1.543 mmol, 82% yield). 1H NMR (DMSO-d6) δ 7.85-7.76 (m, 1H); 7.75-7.70 (m, 1H); 7.34 (t, J=7 Hz, 1H); 7.22-7.16 (m, 1H); 6.99-6.95 (m, 2H); 3.77-3.65 (m, 3H); 3.60-3.54 (m, 1H); 3.43 (t, J=5.5 Hz, 2H); 3.02, 2.93 (2s, 3H); 2.75 (t, J=5.8, 2H); 1.90-1.81 (m, 2H). ESI-MS (m/z, %): 374 (MH+, 100).
