[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[F:8].C([Li])CCC.CCCCCC.[F:20][CH2:21][C:22](OCC)=[O:23]>C1COCC1>[F:1][C:2]1[C:3]([F:8])=[CH:4][CH:5]=[CH:6][C:7]=1[C:22](=[O:23])[CH2:21][F:20]To a cooled (−78° C.) solution of 1,2-difluorobenzene (8.81 mL, 89 mmol) in THF (175 mL) was added dropwise butyllithium solution, 1.6M in hexane (61.5 mL, 98 mmol). After stirred for 2 h, ethyl fluoroacetate (8.64 mL, 89 mmol) ethyl fluoroacetate was added dropwise. The reaction was stirred for 1 h, the reaction was quenched with saturated NH4Cl and then warmed to room temperature. The resulted mixture was extracted with EtOAc. The organic extracts were washed with brine, dried over Na2SO4 and filtered. The filtrate was concentrated and purified by silica gel column (0-30% EtOAc/hexane) to afford 6.3 g of desired product as colorless oil.
Wird geladen…