C([Li])(CC)C.[C:6]([OH:16])(=[O:15])[C:7]1[CH:12]=CC(OC)=C[CH:8]=1.CN(CCN(C)C)C.[F:25][C:26]1[CH:27]=[C:28]([CH:34]=[CH:35][CH:36]=1)[C:29]([O:31]CC)=O.[CH2:37]1[CH2:41][O:40][CH2:39][CH2:38]1>>[F:25][C:26]1[CH:27]=[C:28]([CH:34]=[CH:35][CH:36]=1)[C:29]([C:8]1[CH:38]=[CH:37][C:41]([O:40][CH3:39])=[CH:12][C:7]=1[C:6]([OH:16])=[O:15])=[O:31]s-Butyllithium (52 mL, 1.4 M in pentane, 72 mmol) was added at −78 C over 90 min. to a solution of p-Anisic acid (5 g, 33 mmol) and TMEDA (11 ml, 72 mmol) in THF (80 mL). After stirring for 15 min. ethyl 3-fluorobenzoate (5 mL, 40 mmol) was added in one portion. The reaction mixture was stirred for 15 min. then it was quenched with water (20 mL). The reaction mixture was then warmed to room temperature poured into water (1.5 L) 1N NaOH (30 ml) was added and the reaction mixture was then extracted with EtOAc. The extracts were discarded. The aqueous phase was then acidified with conc. HCl to pH 1 and extracted with EtOAc. Drying (Na2SO4) and concentration gave a residue which was recrystallized from hexanes/EtOAc to give the title compound as a white solid.
Wird geladen…
