[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][N:3]=1.C(=O)([O-])O.[Na+].[CH2:16](O)[CH3:17]>S(=O)(=O)(O)O>[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([O:8][CH2:16][CH3:17])=[O:7])=[CH:4][N:3]=1To a solution of 6-hydroxynicotinic acid (5.0 g, 35.9 mmol) in ethanol (180 mL), sulfuric acid (1.0 mL) was added. The resultant mixture was stirred at 60° C. for 20 minutes, then added with surfuric acid (33.0 mL), and stirred for 6.5 hours while heated to reflux. The reaction solution was then added with a saturated aqueous solution of sodium hydrogen carbonate under ice-cold conditions and ethanol was concentrated in vacuo. After extracted with ethyl acetate, the organic layer was washed with brine, dried over sodium sulfate, and concentrated in vacuo. Ethyl 6-hydroxynicotinate (5.33 g, yield 89%) was obtained as a white crystal.
Loading…