Reaktion #77150

Reaktionsgleichung

Diphenylphosphoryl azide

2-hydroxy-6-methylpyridine-3-carboxylic acid

triethylamine

triethylamine

benzyl alcohol

→

title compound

Ausbeute 56.0%

3-Benzyloxycarbonylamino-6-methyl-2-pyridinone

Ausbeute 56.0%

Lösungsmittel

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe resulting solution was heated to reflux
2. 2
   Temperaturthe solution was refluxed for a further 24 h
3. 3
   EinengenThe reaction mixture was concentrated in vacuo
4. 4
   Sonstigethe residue was partitioned between methylene chloride (200 mL) and brine (100 mL)
5. 5
   WaschenThe organic layer was washed with saturated NaHCO3 (2×100 mL), brine (100 mL)
6. 6
   Trocknendried over Na2SO4
7. 7
   Filtrationfiltered
8. 8
   SonstigeAfter evaporating the solvent in vacuo, methanol (100 mL) and hexane (20 mL)
9. 9
   workup.ADDITIONwere added to the residue
10. 10
    Sonstigethe solid was collected
11. 11
    Waschenwashed with methanol (50 mL)
12. 12
    Sonstigedried

Vorschrift

Diphenylphosphoryl azide (11.9 mL, 55 mmol) was added to a solution of 2-hydroxy-6-methylpyridine-3-carboxylic acid (7.65 g, 50 mmol) and triethylamine (7.7 mL, 55 mmol) in dry dioxane (100 mL) and the resulting solution was heated to reflux. After 16 h more triethylamine (7.7 mL, 55 mmol) and benzyl alcohol (5.7 mL, 50 mmol) were added and the solution was refluxed for a further 24 h. The reaction mixture was concentrated in vacuo and the residue was partitioned between methylene chloride (200 mL) and brine (100 mL), acidified to pH 1 with 10% HCl. The organic layer was washed with saturated NaHCO3 (2×100 mL), brine (100 mL), dried over Na2SO4 and filtered. After evaporating the solvent in vacuo, methanol (100 mL) and hexane (20 mL) were added to the residue, the solid was collected, washed with methanol (50 mL) and dried to give the title compound as a white solid (7.2 g, 56%). 1H-NMR (300 MHz, CDCl3) δ12.82 (s, 1H), 8.06 (d, J=7.0 Hz, 1H), 7.69 (s, 1H), 7.42 (m, 5H), 6.09 (d, J=7.5 Hz, 1H), 5.22 (s, 2H), 2.32 (s, 3H).

Quelle