Triethylamine → 1h-Pyrrolo[2,3-c]pyridine-5-carboxylic acid,4-[(1e)-2-ethoxyethenyl]-1-[(4-fluorophenyl)methyl]-,ethyl ester

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Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 1-(4-fluorobenzyl)-4-{[(trifluoromethyl)sulfonyl]oxy}-1H-pyrrolo[2,3-c]pyridine-5-carboxylate (10.09, 22.4 mmol) and ethoxyvinyl tributyltin [prepared according to A. Leusik, H. A. Budding, J. W. Marsman, J. Organomet. Chem., 1967, 9, 285-294] (9.7 g, 26.9 mmol, mixture of E-1,2: Z-1,2:1:1, ratio=1:0.3:0.1) in DMF (30 mL) under a nitrogen atmosphere were added triethylamine (3.2 mL, 22.4 mmol) and dichlorobis(triphenylphosphine)palladium(II) (1.0 g, 1.4 mmol). The resulting mixture was heated to 140° C. for 10 minutes. It was quenched with aq NaHCO3 solution, and extracted with ethyl acetate. The organic layer was washed with brine (2×), dried over sodium sulfate, concentrated in vacuo and purified by Biotage flash chromatography. Elution with hexane:ethyl acetate (3:2) provided the title compound as a brown glue (2.1 g) pure E-isomer together with 5.6 g of a mixture of E-1,2 and Z-1,2 and 1,1 isomers). 1H NMR (DMSO-d6) δ; 8.69 (s, 1H), 7.85 (d, J=3.3 Hz, 1H), 7.33 (t, J=6.8 Hz, 2H), 7.13-7.20 (m, 3H), 6.86 (d, J=3.3 Hz, 1 H), 6.43 (d, J=13 Hz, 1H), 5.55 (s, 2H), 4.27 (q, J=7.2 Hz, 2 H), 3.98 (q, J=7.0 Hz, 2 H), 1.29 (t, J=7.1 Hz, 6 H). LCMS (APCl, M+H+): 369.1.

Provenance & Evidence