2-Propynoic acid, 3-(4-fluorophenyl)-, methyl ester → HCID 21948679, compound

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Reaction Steps

To a stirred solution of methyl 3-(4-fluorophenyl)propiolate (3.47 g, 19.5 mmol) and 1-amino-2-methylpyridinium 2,4,6-trimethylbenzenesulfonate (6.0 g, 19.5 mmol) in dry acetonitrile (75 mL) was added, dropwise over 10 min a solution of 1,8-diazabicycloundec-7-ene (5.82 mL, 39 mmol) in dry acetonitrile (25 mL). The mixture was allowed to stir at room temperature for about 18 hours. The solvent was evaporated under reduced pressure and the residue was partitioned between water (500 mL) and ethyl acetate (250 mL) and the organic phase separated. The aqueous was extracted with ethyl acetate and the combined organic extracts are dried over anhydrous magnesium sulfate, and the solvent removed under vacuum. The residue was purified by chromatography on silica gel using 10:1 hexanes:ethyl acetate as eluent to give the title compound as a white solid, 4.65 g (86%). 1H NMR (CDCl3) δ 8.15 (d, 1H, J=8.8 Hz), 7.86 (m, 2H), 7.41 (t, 1H, J=8.9 Hz), 7.19 (t, 2H, J=17.6 Hz), 6.87 (d, 1H, J=7.0 Hz), 3.89 (s, 3H), 2.85 (s, 3H). MS (+ve ion electrospray) 285 (100), (MH+).

Provenance & Evidence