Reaction #465939

Reaction equation

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

Solvents

hexamethylphosphoric acid triamide

Conditions

Workup

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

Procedure

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.

Source