[Br:1][C:2]1[CH:8]=[C:7]([N+:9]([O-:11])=[O:10])[C:5]([NH2:6])=[C:4]([F:12])[CH:3]=1.[H-].[Na+].Cl[C:16]([O:18][CH2:19][CH3:20])=[O:17]>C1COCC1>[CH2:19]([O:18][C:16]([N:6]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:5]1[C:7]([N+:9]([O-:11])=[O:10])=[CH:8][C:2]([Br:1])=[CH:3][C:4]=1[F:12])=[O:17])[CH3:20]To a stirred solution of 4-bromo-2-fluoro-6-nitroaniline (1) (0.500 g, 2.12 mmol, 1.00 equiv) in THF (20 mL) was added NaH (0.250 g, 6.40 mmol, 3.00 equiv) portion wise at 0° C. After being stirred for 1 h at RT, ethyl chloroformate (1.00 mL, 10.6 mmol, 5.00 equiv) was added drop wise to the reaction mixture at 0° C. The reaction mixture was heated under reflux temperature for 36 h. After consumption of the starting material (by TLC), the reaction was quenched with saturated NH4Cl solution and extracted with EtOAc (2×100 mL). The combined organic extracts were dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure to give crude; which was purified by silica gel column chromatography (EtOAc/Hexane 1:4) to furnish compound 2 (0.350 g, 43.0%) as yellow solid.
Wird geladen…