[OH:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([OH:12])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].C(=O)([O-])[O-].[K+].[K+].Br[CH:20]1[CH2:24][CH2:23][N:22]([CH3:25])[C:21]1=[O:26]>CN(C=O)C>[OH:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([O:12][CH:20]2[CH2:24][CH2:23][N:22]([CH3:25])[C:21]2=[O:26])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6]To a stirred solution of Methyl 3,5-dihydroxybenzoate (20 g) [CAS No. 2150-44-9] in dry DMF was added potassium carbonate (48 g) and the suspension stirred at ambient temperature under nitrogen. To this 3-Bromo-1-methyl-pyrrolidin-2-one (40 g) (Intermediate 5) [J. Med. Chem., 1987, 30, 1995-98] was added in three equal portions in 4 h intervals at room temperature and stirred overnight at ambient temperature. It was then quenched with water. The aqueous suspension was extracted with DCM. The to combined extracts were washed with water, brine, dried over Na2SO4, and filtered, concentrated under reduced pressure to get the thick liquid residue. The crude product was purified by column chromatography using silica gel as stationary phase and ethyl acetate: petroleum ether as a mobile phase to yield the product as white solid (15 g).
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