To a solution of compound 10 (1.0 mmol) in DMF (5 mL) was added (S) 3-chloro-4-fluoro phenyl glycinol (1.2 mmol), then stirred for 15 h. The solvent was concentrated under vacuum. To the residue (1.0 mmol) in THF (1 mL) was added tert-butyl bis(dimethylamino)-methane (1 mL, 5 mmol). The mixture was stirred for 15 h at 50 ° C. and then concentrated under vacuum. To the residue (1 mmol) was added C2H5OH (5 mL) and hydrazine hydrate (1 mL, 20 mmol). The mixture was refluxed for 3 h and cooled to room temperature. The solvents were removed under vacuum and the crude products were purified from preparatory HPLC. This afforded the product 11 as a white solid. 1HNMR (CD3OD) 7.6 (s, 1H), 7.4 (s, 1H), 7.2-7.4 (m, 3H), 7.1-7.2 (m, 1H), 7.0 (t, 1H), 6.8 (d, 2H), 4.9 (t, 1H), 4.1 (s, 2H), 3.6 (dd, 2H).
