A THF solution of 6-fluoro-3,4-dihydroquinolin-2(1H)-one (6.0 g, 36.36 mmol) was slowly added to a THF (80 mL) suspension of LiAlH4 (2.76 g, 72.73 mmol) under stirring conditions. The reaction mixture was stirred at room temperature for 2 hours. Upon completion of the reaction, the reaction was quenched with saturated sodium chloride solution and ethyl acetate and filtered through diatomaceous earth. The filtrate was diluted with ethyl acetate and washed sequentially with water and saturated sodium chloride solution and the organic phase was dried with anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure to give 4.5 g (81% yield) of 6-fluoro-1,2,3,4-tetrahydroquinoline as a brown liquid.1H NMR (400 MHz, CDCl3): δ 6.65-6.78 (m, 2H), 6.37-6.40 (m, 1H), 3.26 (t, J=5.3 Hz, 2H), 2.73 (t, J=6.6 Hz, 2H), 1.88-1.94 (m, 2H).
