反应详情

温度

40 °C

To a suspension of 2-chloro-6-methyl-isonicotinic acid (20.0 g, 117 mmol) in isopropanol (80 mL), H2SO4 (5 mL) is added dropwise. The mixture becomes warm (40° C.). The mixture is stirred for 24 h at rt, then at 90° C. for 28 h before the solvent is removed in vacuo. The residue is dissolved in ether (200 mL), washed with sat. aq. NaHCO3-solution (3×50 mL) followed by brine (3×50 mL), dried over Na2SO4, filtered and concentrated to give 2-chloro-6-methyl-isonicotinic acid isopropyl ester (21.0 g) as a colourless oil which slowly crystallises; LC-MS: tR=0.97 min, [M+1]+=214.05.

1. additionis added dropwise
2. customat 90° C. for 28 h before the solvent is removed in vacuo
3. dissolutionThe residue is dissolved in ether (200 mL)
4. washwashed with sat. aq. NaHCO3-solution (3×50 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated