Reaction #1244250

Reaction equation

16

3-Methoxy-1,6-dimethyl-2-oxo-1,2-dihydropyridine-4-carboxylic acid ethyl ester

sodium hydroxide

→

5

Yield 98.1%

3-Methoxy-1,6-dimethyl-2-oxo-1,2-dihydropyridine-4-carboxylic acid

Yield 98.1%

Solvents

methanol

Conditions

Workup

1. 1
   TemperatureThe resulting solution was heated
2. 2
   Temperatureat reflux
3. 3
   Othermethanol was removed under reduced pressure
4. 4
   ExtractionThe solution was extracted with ethyl acetate
5. 5
   Dryingthe organic extracts were dried over sodium sulfate, and solvent
6. 6
   Otherwas removed under reduced pressure

Procedure

To a solution of 16 (7.51 g, 33.3 mmol) in methanol (350 mL) was added a 4 M sodium hydroxide solution (350 mL). The resulting solution was heated at reflux, and after 2 h, methanol was removed under reduced pressure. An aqueous 3 N HCl solution was used to adjust the resulting solution to pH 1. The solution was extracted with ethyl acetate; the organic extracts were dried over sodium sulfate, and solvent was removed under reduced pressure to yield 6.44 g (98%) of 5 as a tan solid. 1H NMR (300 MHz, CD3OD): δ=2.40 (s, 3H, C—CH3), 3.58 (s, 3H, N—CH3), 3.86 (s, 3H, O—CH3), 6.36 (s, 1H, CH); 13C NMR (75 MHz, CD3OD): δ=20.6 (C—CH3), 32.6 (N—CH3), 61.0 (O—CH3), 105.9 (CH), 132.8, 143.4, 146.6, 162.6, 168.2; ESI-MS calcd for C9H11NO4 [M−H]−: 196.0610. found 196.0615.

Source