反应详情

A suspension of 3-aminopyridine-4-carboxylic acid (2.00 g, 14.5 mmol), prepared by the method of Crum and Fuchsman, J. Het. Chem. 3, 252 (1966), in ethanol (~4 g) was treated with 4.0 g of sulfuric acid and warmed on a steam bath for 4 hours. After cooling to ambient temperature, water (~40 mL) and solid sodium carbonate were added to basify the solution which was then extracted with chloroform (3×). The combined organic extracts were washed with brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue obtained was flash chromatographed on silica gel eluting with 2:1 hexane/ethyl acetate to afford the title compound. 1H NMR (CDCl3, 300 MHz) δ 1.41 (t, J=7 Hz, 3H), 4.37 (q, J=7 Hz, 2H), 7.60 (d, J=6 Hz, 1H), 7.93 (d, J=6 Hz, 1H), 8.19 (s, 1H). MS (DCI/NH3) m/e 167 (M+H)+, 184 (M+H+NH3)+.

1. customprepared by the method of Crum and Fuchsman, J
2. temperaturewarmed on a steam bath for 4 hours
3. extractionwas then extracted with chloroform (3×)
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue obtained
8. customchromatographed on silica gel eluting with 2:1 hexane/ethyl acetate