[CH3:1][O:2][C:3](=[O:15])[C:4]1[C:5](=[C:10]([OH:14])[CH:11]=[CH:12][CH:13]=1)[C:6]([O:8][CH3:9])=[O:7].[F:16][C:17]1[C:25]2[CH:24]=[C:23]([CH2:26]O)[S:22][C:21]=2[CH:20]=[CH:19][CH:18]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OC(C)C)=O)=NC(OC(C)C)=O>C1COCC1>[CH3:1][O:2][C:3](=[O:15])[C:4]1[C:5](=[C:10]([O:14][CH2:26][C:23]2[S:22][C:21]3[CH:20]=[CH:19][CH:18]=[C:17]([F:16])[C:25]=3[CH:24]=2)[CH:11]=[CH:12][CH:13]=1)[C:6]([O:8][CH3:9])=[O:7]To a stirred suspension of 3-hydroxyphthalic acid dimethyl ester (1.1 g, 5.2 mmol), (4-fluoro-benzo[b]thiophen-2-yl)-methanol (0.96 g, 10.5 mmol), and polymer-supported triphenyl phosphine (3.0 g, 10.5 mmol) in THF (35 mL) in an ice-bath was slowly added diisopropyl azodicarboxylate (2.1 mL, 10.5 mmol) and stirred at r.t. overnight. The mixture was filtered and the solid was washed with ethyl acetate (10 mL). The filtrate was evaporated and the residue was purified by flash column chromatography (EtOAc/Hexane) to give 3-(4-fluoro-benzo[b]thiophen-2-ylmethoxy)-phthalic acid dimethyl ester (1.5 g, 76% yield). The product was used in the next step without further purification.
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