A mixture of 2-(5-bromo-2-fluoro-phenyl)-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (0.76 g, 1.87 mmol), morpholine (1.63 g, 18.7 mmol), copper (I) iodide (0.21 g, 1.1 mmol), L-proline (0.11 g, 0.94 mmol) and potassium carbonate (0.78, 5.61 mmol) in DMSO (3 mL) was heated for 4 hours at 120° C. After cooling to room temperature, the mixture was treated with ethyl acetate (50 mL) and washed with water (20 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. Purification on flash silica gel chromatography (silica gel from QingDao, 200-300 mesh, glass column from Shanghai SD company)(20% ethyl acetate/hexanes) to afford 2-(2-fluoro-5-morpholin-4-yl-phenyl)-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (0.12 g, 16%) as a white solid: LC/MS m/e calcd for C24H29FN2O3 (M+H)+: 413.5, observed: 413.4.
