Reaktion #465939

Reaktionsgleichung

2,3-dimethyl-4-nitropyridine-1-oxide

methyl ethyl ketone

2,2,3,3,3-pentafluoropropanol

potassium carbonate

→

2,3-dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine-1-oxide

Lösungsmittel

hexamethylphosphoric acid triamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThen, the insoluble matter was filtered off
2. 2
   Einengenthe filtrate was concentrated
3. 3
   workup.ADDITIONWater was added to the residue
4. 4
   Extraktionthe mixture was extracted with ethyl acetate
5. 5
   TrocknenThe extract layer was dried over magnesium sulfate
6. 6
   workup.DISTILLATIONthe solvent was distilled off
7. 7
   WaschenElution
8. 8
   Sonstigewith chloroform-methanol (10:1) and recrystallization from ethyl acetate-hexane

Vorschrift

A mixture of 2,3-dimethyl-4-nitropyridine-1-oxide (2.0 g), methyl ethyl ketone (30 ml), 2,2,3,3,3-pentafluoropropanol (3.05 ml), anhydrous potassium carbonate (3.29 g) and hexamethylphosphoric acid triamide (2.07 g) was heated at 70-80° C. with stirring for 4.5 days. Then, the insoluble matter was filtered off and the filtrate was concentrated. Water was added to the residue and the mixture was extracted with ethyl acetate. The extract layer was dried over magnesium sulfate, then the solvent was distilled off, and the residue was applied to a silica gel column (50 g). Elution with chloroform-methanol (10:1) and recrystallization from ethyl acetate-hexane gave 2.4 g of 2,3-dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine-1-oxide as colorless needles. Melting point 148-149° C.

Quelle