6-(ethoxycarbonyl)pyridine-2-carboxylic acid

Synthesis

Diethyl pyridine-2,6-dicarboxylate (4.70g, 21.1mmol) was dissolved into a mixture of ethanol (50mL) and 1,4-dioxane (100mL), then NaOH (0.86g, 21.0mmol) was added. The mixture was heated to reflux for 1.5 hours, and then 1M HCl aqueous solution (21mL) was added. After removal of the solvents, the residue was applied to column chromatography with CH2Cl2/ethanol (1:1) as eluents to afford 2 as white powder (2.97g, 15.2mmol, yield = 72%). 1 H-NMR (400MHz, CDCl3) δ ppm 8.41 (d, J = 7.74 Hz, 1H), 8.37 (d, J = 7.80 Hz, 1H), 8.13 (t, J = 7.77, 7.77 Hz, 1H), 4.50 (q, J = 7.13, 7.13, 7.13 Hz, 2H), 1.46 (t, J = 7.13, 7.13 Hz, 3H). ESI MS: m/z = 196.1 [M+H]+ , 218.1 [M+Na]+ .