Br[C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([C:12]2[CH:17]=[CH:16][C:15]([CH3:18])=[CH:14][N:13]=2)[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[CH2:19]([Sn](CCCC)(CCCC)C#C)[CH2:20]CC.[F-].[Cs+].ClCCl>O1CCOCC1.[Pd].C(P(C(C)(C)C)C(C)(C)C)(C)(C)C.C(P(C(C)(C)C)C(C)(C)C)(C)(C)C>[C:19]([C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([C:12]2[CH:17]=[CH:16][C:15]([CH3:18])=[CH:14][N:13]=2)[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6])#[CH:20]
To a degassed solution of methyl 3-bromo-5-(5-methylpyridin-2-yl)benzoate (200 mg, 0.653 mmol) in dioxane (3 mL) was added tributyl(ethynyl)tin (247 mg, 0.784 mmol), cesium fluoride (198 mg, 1.31 mmol) and bis(tri-t-butylphosphine) palladium (16.7 mg, 0.033 mmol) and the mixture heated to 70° C. After 2 h, the reaction was cooled to ambient temperature and dichloromethane (50 mL was added). The organic layer was washed with 30 mL of saturated aqueous sodium bicarbonate (2×), dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (100% dichloromethane→95% dichloromethane/methanol) to give the title compound (145 mg). MS 252.1 (M+1).
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