Reaktion #4453

Reaktionsgleichung

methyl-3-methoxyisonicotinoate

methyl acetate

hydrochloric acid

sodium bicarbonate

Sodium

sodium

→

3-methoxy-4-acetylpyridine

Ausbeute 46.3%

Lösungsmittel

methanol

water

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas removed by distillation
2. 2
   TemperaturThe resulting sodium methoxide was cooled
3. 3
   workup.ADDITIONwas added dropwise
4. 4
   TemperaturThe mixture was refluxed for four hours
5. 5
   Temperaturto cool
6. 6
   TemperaturThe resulting mixture was heated
7. 7
   Temperaturto reflux for 2.5 hours
8. 8
   Temperaturcooled
9. 9
   ExtraktionThe mixture was extracted with chloroform (4×50 mL)
10. 10
    Trocknenthe combined extracts dried over sodium sulfate
11. 11
    Einengenconcentrated
12. 12
    Sonstigechromatographed through a short column of silica gel

Vorschrift

A dry 50 mL three neck flask fitted with a reflux condenser and internal thermometer was charged with dry methanol (20 mL). Sodium (516 mg, 0.022 mol) was added in portions and after all the sodium had dissolved the methanol was removed by distillation. The resulting sodium methoxide was cooled and a mixture of methyl-3-methoxyisonicotinoate (2.50 g, 0.015 mol) and methyl acetate (6.65 g, 0.090 mol) was added dropwise. The mixture was refluxed for four hours, allowed to cool and dissolved in water (9.0 mL) and concentrated hydrochloric acid (6.0 mL). The resulting mixture was heated to reflux for 2.5 hours, cooled, and basified with 5% sodium bicarbonate. The mixture was extracted with chloroform (4×50 mL) and the combined extracts dried over sodium sulfate, concentrated, and chromatographed through a short column of silica gel to afford 3-methoxy-4-acetylpyridine (1.05 g, 46%). mp. 36°-37° C.

Quelle