C[SH+](C)=O.[CH3:5][O:6][C:7](=[O:16])[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[C:11]([Br:15])[CH:10]=1.[SH:17][C:18]1[CH:23]=[CH:22][N:21]=[CH:20][CH:19]=1>ClC(Cl)C>[CH3:5][O:6][C:7](=[O:16])[CH:8]([C:9]1[CH:14]=[CH:13][CH:12]=[C:11]([Br:15])[CH:10]=1)[S:17][C:18]1[CH:23]=[CH:22][N:21]=[CH:20][CH:19]=1To a solution of dimethylsulfoxonium ylide and 3-bromophenylacetic acid methyl ester (example 530E, 3 g) in dichloroethane (50 mL) are added 4-mercaptopyridine (2 equivalents) and [Ir(COD)Cl]2 (20 mg). The reaction mixture is refluxed overnight then concentrated to dryness under reduced pressure. The residue is purified by chromatography on silica gel (heptane/ethyl acetate 1/1) to give (3-Bromophenyl)(pyridin-4-ylsulfanyl)acetic acid methyl ester. 1H NMR: 8.50-8.35 (m, 2H), 7.68 (s, 1H), 7.55-7.45 (m, 2H), 7.35-7.20 (m, 1H), 7.20-7.05 (m, 2H), 5.08 (s, 1H), 3.77 (s, 3H).
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