Reacción #4453

Ecuación de reacción

methyl-3-methoxyisonicotinoate

methyl acetate

hydrochloric acid

sodium bicarbonate

Sodium

sodium

→

3-methoxy-4-acetylpyridine

Rendimiento 46.3%

Disolventes

methanol

water

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrowas removed by distillation
2. 2
   TemperaturaThe resulting sodium methoxide was cooled
3. 3
   workup.ADDITIONwas added dropwise
4. 4
   TemperaturaThe mixture was refluxed for four hours
5. 5
   Temperaturato cool
6. 6
   TemperaturaThe resulting mixture was heated
7. 7
   Temperaturato reflux for 2.5 hours
8. 8
   Temperaturacooled
9. 9
   ExtracciónThe mixture was extracted with chloroform (4×50 mL)
10. 10
    Secadothe combined extracts dried over sodium sulfate
11. 11
    Concentraciónconcentrated
12. 12
    Otrochromatographed through a short column of silica gel

Procedimiento

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.

Fuente