Phthalic Anhydride → 5-Cyanomethyl-6-ethyl-pyridin-3-yl-acetic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 6-ethyl-5-(2-oxo-ethyl)-pyridin-3-yl-acetic acid methyl ester (0.77 g, 3.46 mmol), hydroxylamine hydrochloride (0.26 g, 3.80 mmol) and triethylamine (0.53 mL, 3.80 mmol) in acetonitrile (9 mL, 0.4 M) is stirred under nitrogen at room temperature for 2 h. Phthalic anhydride (0.55 g, 3.71 mmol) is added and the mixture is warmed to 90° C. for 16 h. After cooling to room temperature, water (50 mL) is added and the mixture is extracted with ethyl acetate (50 mL). The organic layer is washed with saturated NaHCO3 (50 mL) and dried over Na2SO4. The product is purified by flash chromatography (20-50% ethyl acetate in n-heptane) to provide 5-cyanomethyl-6-ethyl-pyridin-3-yl-acetic acid methyl ester as a clear oil (0.60 g, 80%): Rf 0.31 (50% ethyl acetate in n-heptane), 1H NMR (CDCl3, 300 MHz) δ 8.44 (s, 1 H), 7.67 (s, 1 H), 3.74 (s, 2 H), 3.73 (s, 3 H), 3.65 (s, 2 H), 2.83 (q, J=7.5 Hz, 2 H), 1.33 (t, J=7.5 Hz, 3 H). ESI-LCMS m/z calcd for C12H14N2O2: 218.1; found 219.0 (M+1)+.

Provenance & Evidence